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Where does light come from?????????

Were you ever scared of the dark? It’s not surprising if you were, or if you still are today, because humans are creatures of the light, deeply programmed through millions of years of history to avoid the dark dangers of the night. Light is vitally important to us, but we don’t always take the trouble to understand it. Why does it make some things appear to be different colors from others? Does it travel as particles or as waves? Why does it move so quickly? Let’s take a closer look at some of these questions—let’s shed some light on light!
When we’re very young, we have a very simple idea about light: the world is either light or dark and we can change from one to the other just by flicking a switch on the wall. But we soon learn that light is more complex than this.

Light arrives on our planet after a speedy trip from the Sun, 149 million km (93 million miles away). Light travels at 186,000 miles (300,000 km) per second, so the light you’re seeing now was still tucked away in the Sun about eight minutes ago. Put it another way, light takes roughly twice as long to get from the Sun to Earth as it does to make a cup of coffee!

Light is a kind of energy

But why does light make this journey at all? As you probably know, the Sun is a nuclear fireball spewing energy in all directions. The light that we see it simply the one part of the energy that the Sun makes that our eyes can detect. When light travels between two places (from the Sun to the Earth or from a flashlight to the sidewalk in front of you on a dark night), energy makes a journey between those two points. The energy travels in the form of waves (similar to the waves on the sea but about 100 million times smaller)—a vibrating pattern of electricity and magnetism that we call electromagnetic energy. If our eyes could see electricity and magnetism, we might see each ray of light as a wave of electricity vibrating in one direction and a wave of magnetism vibrating at right angles to it. These two waves would travel in step and at the speed of light.
Is light a particle or a wave?

For hundreds of years, scientists have argued over whether light is really a wave at all. Back in the 17th century, the brilliant English scientist Sir Isaac Newton (1642–1727)—one of the first people to study the matter in detail—thought light was a stream of “corpuscles” or particles. But his great rival, a no-less-brilliant Dutchman named Christiaan Huygens (1629–1695), was quite adamant that light was made up of waves.
Thus began a controversy that still rumbles on today—and it’s easy to see why. In some ways, light behaves just like a wave: light reflects off a mirror, for example, in exactly the same way that waves crashing in from the sea “reflect” off sea walls and go back out again. In other ways, light behaves much more like a stream of particles—like bullets firing in rapid succession from a gun. During the 20th century, physicists came to believe that light could be both a particle and a wave at the same time. (This idea sounds quite simple, but goes by the rather complex name of wave-particle duality.)

The real answer to this problem is more a matter of philosophy and psychology than physics. Our understanding of the world is based on the way our eyes and brains interpret it. Sometimes it seems to us that light is behaving like a wave; sometimes it seems like light is a stream of particles. We have two mental pigeonholes and light doesn’t quite fit into either of them. It’s like the glass slipper that doesn’t fit either of the ugly sisters (particle or wave). We can pretend it nearly fits both of them, some of the time. But in truth, light is simply what it is—a form of energy that doesn’t neatly match our mental scheme of how things should be. One day, someone will come up with a better way of describing and explaining it that makes perfect sense in all situations.

How light behaves

Light waves (let’s assume they are indeed waves for now) behave in four particularly interesting and useful ways that we describe as reflection, refraction, diffraction, and interference.

Reflection

The most obvious thing about light is that it will reflect off things. The only reason we can see the things around us is that light, either from the Sun or from something like an electric lamp here on Earth, reflects off them into our eyes. Cut off the source of the light or stop it from reaching your eyes and those objects disappear. They don’t cease to exist, but you can no longer see them.
Reflection can happen in two quite different ways. If you have a smooth, highly polished surface and you shine a narrow beam of light at it, you get a narrow beam of light reflected back off it. This is called specular reflection and it’s what happens if you shine a flashlight or laser into a mirror: you get a well-defined beam of light bouncing back towards you. Most objects aren’t smooth and highly polished: they’re quite rough. So, when you shine light onto them, it’s scattered all over the place. This is called diffuse reflection and it’s how we see most objects around us as they scatter the light falling on them.

If you can see your face in something, it’s specular reflection; if you can’t see your face, it’s diffuse reflection. Polish up a teaspoon and you can see your face quite clearly. But if the spoon is dirty, all the bits of dirt and dust are scattering light in all directions and your face disappears.
Refraction

Light waves travel in straight lines through empty space (a vacuum), but more interesting things happen to them when they travel through other materials—especially when they move from one material to another. That’s not unusual: we do the same thing ourselves.

Have you noticed how your body slows down when you try to walk through water? You go racing down the beach at top speed but, as soon as you hit the sea, you slow right down. No matter how hard you try, you cannot run as quickly through water as through air. The dense liquid is harder to push out of the way, so it slows you down. Exactly the same thing happens to light if you shine it into water, glass, plastic or another more dense material: it slows down quite dramatically. This tends to make light waves bend—something we usually call refraction.
You’ve probably noticed that water can bend light. You can see this for yourself by putting a straw in a glass of water. Notice how the straw appears to kink at the point where the water meets the air above it. The bending happens not in the water itself but at the junction of the air and the water. You can see the same thing happening in this photo of laser light beams shining between two crystals. As the beams cross the junction, they bend quite noticeably.

Why does this happen? You may have learned that the speed of light is always the same, but that’s only true when light travels in a vacuum. In fact, light travels more slowly in some materials than others. It goes more slowly in water than in air. Or, to put it another way, light slows down when it moves from air to water and it speeds up when it moves from water to air. This is what causes the straw to look bent. Let’s look into this a bit more closely.

Imagine a light ray zooming along through the air at an angle to some water. Now imagine that the light ray is actually a line of people swimming along in formation, side-by-side, through the air. The swimmers on one side are going to enter the water more quickly than the swimmers on the other side and, as they do so, they are going to slow down—because people move more slowly in water than in air. That means the whole line is going to start slowing down, beginning with the swimmers at one side and ending with the swimmers on the other side some time later. That’s going to cause the entire line to bend at an angle. This is exactly how light behaves when it enters water—and why water makes a straw look bent.

Refraction is amazingly useful. If you wear eyeglasses, you probably know that the lenses they contain are curved-shape pieces of glass or plastic that bend (refract) the light from the things you’re looking at. Bending the light makes it seem to come from nearer or further away (depending on the type of lenses you have), which corrects the problem with your sight. To put it another way, your eyeglasses fix your vision by slowing down incoming light so it shifts direction slightly. Binoculars, telescopes, cameras, camcorders, night vision goggles, and many other things with lenses work in exactly the same way (collectively we call these things optical equipment).

Although light normally travels in straight lines, you can make it bend round corners by shooting it down thin glass or plastic pipes called fiber-optic cables. Reflection and refraction are at work inside these “light pipes” to make rays of light follow an unusual path they wouldn’t normally take.
We can hear sounds bending round doorways, but we can’t see round corners—why is that? Like light, sound travels in the form of waves (they’re very different kinds of waves, but the idea of energy traveling in a wave pattern is broadly the same). Sound waves tend to range in size from a few centimeters to a few meters, and they will spread out when they come to an opening that is roughly the same size as they are—something like a doorway, for example. If sound is rushing down a corridor in your general direction and there’s a doorway opening onto the room where you’re sitting, the sound waves will spread in through the doorway and travel to your ears. The same thing does not happen with light. But light will spread out in an identical way if you shine it on a tiny opening that’s of roughly similar size to its wavelength. You may have noticed this effect, which is called diffraction, if you screw your eyes up and look at a streetlight in the dark. As your eyes close, the light seems to spread out in strange stripes as it squeezes through the narrow gaps between your eyelids and eyelashes. The tighter you close your eyes, the more the light spreads (until it disappears when you close your eyes completely).

Interference

If you stand above a calm pond (or a bath full of water) and dip your finger in (or allow a single drop to drip down to the water surface from a height), you’ll see ripples of energy spreading outwards from the point of the impact. If you do this in two different places, the two sets of ripples will move toward one another, crash together, and form a new pattern of ripples called an interference pattern. Light behaves in exactly the same way. If two light sources produce waves of light that travel together and meet up, the waves will interfere with one another where they cross. In some places the crests of waves will reinforce and get bigger, but in other places the crest of one wave will meet the trough of another wave and the two will cancel out.
Interference causes effects like the swirling, colored spectrum patterns on the surface of soap bubbles and the similar rainbow effect you can see if you hold a compact disc up to the light. What happens is that two reflected light waves interfere. One light wave reflects from the outer layer of the soap film that wraps around the air bubble, while a second light wave carries on through the soap, only to reflect off its inner layer. The two light waves travel slightly different distances so they get out of step. When they meet up again on the way back out of the bubble, they interfere. This makes the color of the light change in a way that depends on the thickness of the soap bubble. As the soap gradually thins out, the amount of interference changes and the color of the reflected light changes too. Read more about this in our article on thin-film interference.

Interference is very colorful, but it has practical uses too. A technique called interferometry can use interfering laser beams to measure incredibly small distances.
If you’ve read our article on energy, you’ll know that energy is something that doesn’t just turn up out of the blue: it has to come from somewhere. There is a fixed amount of energy in the Universe and no process ever creates or destroys energy—it simply turns some of the existing energy into one or more other forms. This idea is a basic law of physics called the conservation of energy and it applies to light as much as anything else. So where then does light comes from? How exactly do you “make” light?

It turns out that light is made inside atoms when they get “excited”. That’s not excited in the silly, giggling sense of the word, but in a more specialized scientific sense. Think of the electrons inside atoms as a bit like fireflies sitting on a ladder. When an atom absorbs energy, for one reason or another, the electrons get promoted to higher energy levels. Visualize one of the fireflies moving up to a higher rung on the ladder. Unfortunately, the ladder isn’t quite so stable with the firefly wobbling about up there, so the fly takes very little persuading to leap back down to where it was before. In so doing, it has to give back the energy it absorbed—and it does that by flashing its tail.

That’s pretty much what happens when an atom absorbs energy. An electron inside it jumps to a higher energy level, but makes the atom unstable. As the electron returns to its original level, it gives back the energy as a flash of light called a photon.
Atoms are the tiny particles from which all things are made. Simplified greatly, an atom looks a bit like our solar system, which has the Sun at its center and planets orbiting around it.

Most of the atom’s mass is concentrated in the nucleus at the center (red), made from protons and neutrons packed together.

Electrons (blue) are arranged around the nucleus in shells (sometimes called orbitals, or energy levels). The more energy an electron has, the farther it is from the nucleus.

Atoms make light in a three-step process:

They start off in their stable “ground state” with electrons in their normal places.
When they absorb energy, one or more electrons are kicked out farther from the nucleus into higher energy levels. We say the atom is now “excited.”
However, an excited atom is unstable and quickly tries to get back to its stable, ground state. So it gives off the excess energy it originally gained as a photon of energy (wiggly line): a packet of light.
How light really works

Once you understand how atoms take in and give out energy, the science of light makes sense in a very interesting new way. Think about mirrors, for example. When you look at a mirror and see your face reflected, what’s actually going on? Light (maybe from a window) is hitting your face and bouncing into the mirror. Inside the mirror, atoms of silver (or another very reflective metal) are catching the incoming light energy and becoming excited. That makes them unstable, so they throw out new photons of light that travel back out of the mirror towards you. In effect, the mirror is playing throw and catch with you using photons of light as the balls!

The same idea can help us explain things like photocopiers and solar panels (flat sheets of the chemical element silicon that turn sunlight into electricity). Have you ever wondered why solar panels look black even when they’re in full sunlight? That’s because they’re reflecting back little or none of the light that falls on them and absorbing all the energy instead. (Things that are black absorb light, and reflect little or none, while things that are white reflect virtually all the light that falls on them, and absorb little or none. That’s why it’s best to wear white clothes on a scorching hot day.) Where does the energy go in a solar panel if it’s not reflected? If you shine sunlight onto the solar cells in a solar panel, the atoms of silicon in the cells catch the energy from the sunlight. Then, instead of producing new photons, they produce a flow of electricity instead through what’s known as the photoelectric (or photovoltaic) effect. In other words, the incoming solar energy (from the Sun) is converted to outgoing electricity.

Hot light and cold light

What would make an atom absorb energy in the first place? You might give it some energy by heating it up. If you put an iron bar in a blazing fire, the bar would eventually heat up so much that it glowed red hot. What’s happening is that you’re supplying energy to the iron atoms inside the bar and getting them excited. Their electrons are being promoted to higher energy levels and making the atoms unstable. As the electrons return to lower levels, they’re giving off their energy as photons of red light—and that’s why the bar seems to glow red. The fire gives off light for exactly the same reason.

Old-style electric lamps work this way too. They make light by passing electricity through a very thin wire filament so it gets incredibly hot. Excited atoms inside the hot filament turn the electrical energy passing through them into light you can see by constantly giving off photons. When we make light by heating things, that’s called incandescence. So old-style lamps are sometimes called incandescent lamps.

You can also get atoms excited in other ways. Energy-saving light bulbs that use fluorescence are more energy efficient because they make atoms crash about and collide, making lots of light without making heat. In effect, they make cold light rather than the hot light produced by older-style, energy-wasting bulbs. Creatures like fireflies make their light through a chemical process using a substance called luciferin. The broad name for the various different ways of making light by exciting the atoms inside things is luminescence.

(Let’s note in passing that light has some other interesting effects when it gets involved in chemistry. That’s how photochromic sunglass lenses work.)
Color (spelled “colour” in the UK) is one of the strangest things about light. Here’s one obvious riddle: if we see things because sunlight is reflected off them, how come everything isn’t the same color? Why isn’t everything the color of sunlight? You probably know the answer to this already. Sunlight isn’t light of just one color—it’s what we call white light, made up of all the different colors mixed together. We know this because we can see rainbows, those colorful curves that appear in the sky when droplets of water split sunlight into its component colors by refracting (bending) different colors of light by different amounts.

Why does a tomato look red? When sunlight shines on a tomato, the red part of the sunlight is reflected back again off the tomato’s skin, while all the other colors of lights are absorbed (soaked into) the tomato, so you don’t see them. That’s just as true of a blue book, which reflects only the blue part of sunlight but absorbs light of other colors.

Why does a tomato appear red and not blue or green? Think back to how atoms make light. When sunlight falls on a tomato, the incoming light energy excites atoms in the tomato’s skin. Electrons are promoted to higher energy levels to capture the energy, but soon fall back down again. As they do so, they give off photons of new light—and that just happens to correspond to the kind of light that our eyes see as red. Tomatoes, in other words, are like precise optical machines programmed to produce photons of red light when sunlight falls on them.

If you shone light of other colors on tomatoes, what would happen? Let’s suppose you made some green light by passing sunlight through a piece of green plastic (something we call a filter). If you shone this on a red tomato, the tomato would appear black. That’s because tomatoes absorb green light. There is simply no red light for them to reflect.
It’s not how it is—it’s how you see it

Many of the things we think are true of the world turn out to be true only of ourselves. We think tomatoes are red, but in fact we only see them that way. If our eyes were built differently, we might see the light photons that tomatoes produce as light of a totally different color. And there’s no real way any of us can be sure that what we see as “red” is the same as what anyone else sees as red: there’s no way to prove that my red is the same as yours. Some of the most interesting aspects of the things we see come down to the psychology of perception (how our eyes see the world and how our brains make sense of that), not the physics of light. Color blindness and optical illusions are two examples of this.

Understanding light is a brilliant example of what being a scientist is all about. Science isn’t like other subjects. It’s not like history (a collection of facts about past events) or law (the rights and wrongs of how people behave). It’s an entirely different way of thinking about the world and making sense of it. When you understand the science of light, you feel you’ve turned part of the world inside out—you’re looking from the inside, seeing everything in a totally new way, and understanding for the first time why it all makes sense. Science can throw a completely different light on the world—it can even throw light on light itself!

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Where does light come from?????????

Were you ever scared of the dark? It’s not surprising if you were, or if you still are today, because humans are creatures of the light, deeply programmed through millions of years of history to avoid the dark dangers of the night. Light is vitally important to us, but we don’t always take the trouble to understand it. Why does it make some things appear to be different colors from others? Does it travel as particles or as waves? Why does it move so quickly? Let’s take a closer look at some of these questions—let’s shed some light on light!
When we’re very young, we have a very simple idea about light: the world is either light or dark and we can change from one to the other just by flicking a switch on the wall. But we soon learn that light is more complex than this.

Light arrives on our planet after a speedy trip from the Sun, 149 million km (93 million miles away). Light travels at 186,000 miles (300,000 km) per second, so the light you’re seeing now was still tucked away in the Sun about eight minutes ago. Put it another way, light takes roughly twice as long to get from the Sun to Earth as it does to make a cup of coffee!

Light is a kind of energy

But why does light make this journey at all? As you probably know, the Sun is a nuclear fireball spewing energy in all directions. The light that we see it simply the one part of the energy that the Sun makes that our eyes can detect. When light travels between two places (from the Sun to the Earth or from a flashlight to the sidewalk in front of you on a dark night), energy makes a journey between those two points. The energy travels in the form of waves (similar to the waves on the sea but about 100 million times smaller)—a vibrating pattern of electricity and magnetism that we call electromagnetic energy. If our eyes could see electricity and magnetism, we might see each ray of light as a wave of electricity vibrating in one direction and a wave of magnetism vibrating at right angles to it. These two waves would travel in step and at the speed of light.
Is light a particle or a wave?

For hundreds of years, scientists have argued over whether light is really a wave at all. Back in the 17th century, the brilliant English scientist Sir Isaac Newton (1642–1727)—one of the first people to study the matter in detail—thought light was a stream of “corpuscles” or particles. But his great rival, a no-less-brilliant Dutchman named Christiaan Huygens (1629–1695), was quite adamant that light was made up of waves.
Thus began a controversy that still rumbles on today—and it’s easy to see why. In some ways, light behaves just like a wave: light reflects off a mirror, for example, in exactly the same way that waves crashing in from the sea “reflect” off sea walls and go back out again. In other ways, light behaves much more like a stream of particles—like bullets firing in rapid succession from a gun. During the 20th century, physicists came to believe that light could be both a particle and a wave at the same time. (This idea sounds quite simple, but goes by the rather complex name of wave-particle duality.)

The real answer to this problem is more a matter of philosophy and psychology than physics. Our understanding of the world is based on the way our eyes and brains interpret it. Sometimes it seems to us that light is behaving like a wave; sometimes it seems like light is a stream of particles. We have two mental pigeonholes and light doesn’t quite fit into either of them. It’s like the glass slipper that doesn’t fit either of the ugly sisters (particle or wave). We can pretend it nearly fits both of them, some of the time. But in truth, light is simply what it is—a form of energy that doesn’t neatly match our mental scheme of how things should be. One day, someone will come up with a better way of describing and explaining it that makes perfect sense in all situations.

How light behaves

Light waves (let’s assume they are indeed waves for now) behave in four particularly interesting and useful ways that we describe as reflection, refraction, diffraction, and interference.

Reflection

The most obvious thing about light is that it will reflect off things. The only reason we can see the things around us is that light, either from the Sun or from something like an electric lamp here on Earth, reflects off them into our eyes. Cut off the source of the light or stop it from reaching your eyes and those objects disappear. They don’t cease to exist, but you can no longer see them.
Reflection can happen in two quite different ways. If you have a smooth, highly polished surface and you shine a narrow beam of light at it, you get a narrow beam of light reflected back off it. This is called specular reflection and it’s what happens if you shine a flashlight or laser into a mirror: you get a well-defined beam of light bouncing back towards you. Most objects aren’t smooth and highly polished: they’re quite rough. So, when you shine light onto them, it’s scattered all over the place. This is called diffuse reflection and it’s how we see most objects around us as they scatter the light falling on them.

If you can see your face in something, it’s specular reflection; if you can’t see your face, it’s diffuse reflection. Polish up a teaspoon and you can see your face quite clearly. But if the spoon is dirty, all the bits of dirt and dust are scattering light in all directions and your face disappears.
Refraction

Light waves travel in straight lines through empty space (a vacuum), but more interesting things happen to them when they travel through other materials—especially when they move from one material to another. That’s not unusual: we do the same thing ourselves.

Have you noticed how your body slows down when you try to walk through water? You go racing down the beach at top speed but, as soon as you hit the sea, you slow right down. No matter how hard you try, you cannot run as quickly through water as through air. The dense liquid is harder to push out of the way, so it slows you down. Exactly the same thing happens to light if you shine it into water, glass, plastic or another more dense material: it slows down quite dramatically. This tends to make light waves bend—something we usually call refraction.
You’ve probably noticed that water can bend light. You can see this for yourself by putting a straw in a glass of water. Notice how the straw appears to kink at the point where the water meets the air above it. The bending happens not in the water itself but at the junction of the air and the water. You can see the same thing happening in this photo of laser light beams shining between two crystals. As the beams cross the junction, they bend quite noticeably.

Why does this happen? You may have learned that the speed of light is always the same, but that’s only true when light travels in a vacuum. In fact, light travels more slowly in some materials than others. It goes more slowly in water than in air. Or, to put it another way, light slows down when it moves from air to water and it speeds up when it moves from water to air. This is what causes the straw to look bent. Let’s look into this a bit more closely.

Imagine a light ray zooming along through the air at an angle to some water. Now imagine that the light ray is actually a line of people swimming along in formation, side-by-side, through the air. The swimmers on one side are going to enter the water more quickly than the swimmers on the other side and, as they do so, they are going to slow down—because people move more slowly in water than in air. That means the whole line is going to start slowing down, beginning with the swimmers at one side and ending with the swimmers on the other side some time later. That’s going to cause the entire line to bend at an angle. This is exactly how light behaves when it enters water—and why water makes a straw look bent.

Refraction is amazingly useful. If you wear eyeglasses, you probably know that the lenses they contain are curved-shape pieces of glass or plastic that bend (refract) the light from the things you’re looking at. Bending the light makes it seem to come from nearer or further away (depending on the type of lenses you have), which corrects the problem with your sight. To put it another way, your eyeglasses fix your vision by slowing down incoming light so it shifts direction slightly. Binoculars, telescopes, cameras, camcorders, night vision goggles, and many other things with lenses work in exactly the same way (collectively we call these things optical equipment).

Although light normally travels in straight lines, you can make it bend round corners by shooting it down thin glass or plastic pipes called fiber-optic cables. Reflection and refraction are at work inside these “light pipes” to make rays of light follow an unusual path they wouldn’t normally take.
We can hear sounds bending round doorways, but we can’t see round corners—why is that? Like light, sound travels in the form of waves (they’re very different kinds of waves, but the idea of energy traveling in a wave pattern is broadly the same). Sound waves tend to range in size from a few centimeters to a few meters, and they will spread out when they come to an opening that is roughly the same size as they are—something like a doorway, for example. If sound is rushing down a corridor in your general direction and there’s a doorway opening onto the room where you’re sitting, the sound waves will spread in through the doorway and travel to your ears. The same thing does not happen with light. But light will spread out in an identical way if you shine it on a tiny opening that’s of roughly similar size to its wavelength. You may have noticed this effect, which is called diffraction, if you screw your eyes up and look at a streetlight in the dark. As your eyes close, the light seems to spread out in strange stripes as it squeezes through the narrow gaps between your eyelids and eyelashes. The tighter you close your eyes, the more the light spreads (until it disappears when you close your eyes completely).

Interference

If you stand above a calm pond (or a bath full of water) and dip your finger in (or allow a single drop to drip down to the water surface from a height), you’ll see ripples of energy spreading outwards from the point of the impact. If you do this in two different places, the two sets of ripples will move toward one another, crash together, and form a new pattern of ripples called an interference pattern. Light behaves in exactly the same way. If two light sources produce waves of light that travel together and meet up, the waves will interfere with one another where they cross. In some places the crests of waves will reinforce and get bigger, but in other places the crest of one wave will meet the trough of another wave and the two will cancel out.
Interference causes effects like the swirling, colored spectrum patterns on the surface of soap bubbles and the similar rainbow effect you can see if you hold a compact disc up to the light. What happens is that two reflected light waves interfere. One light wave reflects from the outer layer of the soap film that wraps around the air bubble, while a second light wave carries on through the soap, only to reflect off its inner layer. The two light waves travel slightly different distances so they get out of step. When they meet up again on the way back out of the bubble, they interfere. This makes the color of the light change in a way that depends on the thickness of the soap bubble. As the soap gradually thins out, the amount of interference changes and the color of the reflected light changes too. Read more about this in our article on thin-film interference.

Interference is very colorful, but it has practical uses too. A technique called interferometry can use interfering laser beams to measure incredibly small distances.
If you’ve read our article on energy, you’ll know that energy is something that doesn’t just turn up out of the blue: it has to come from somewhere. There is a fixed amount of energy in the Universe and no process ever creates or destroys energy—it simply turns some of the existing energy into one or more other forms. This idea is a basic law of physics called the conservation of energy and it applies to light as much as anything else. So where then does light comes from? How exactly do you “make” light?

It turns out that light is made inside atoms when they get “excited”. That’s not excited in the silly, giggling sense of the word, but in a more specialized scientific sense. Think of the electrons inside atoms as a bit like fireflies sitting on a ladder. When an atom absorbs energy, for one reason or another, the electrons get promoted to higher energy levels. Visualize one of the fireflies moving up to a higher rung on the ladder. Unfortunately, the ladder isn’t quite so stable with the firefly wobbling about up there, so the fly takes very little persuading to leap back down to where it was before. In so doing, it has to give back the energy it absorbed—and it does that by flashing its tail.

That’s pretty much what happens when an atom absorbs energy. An electron inside it jumps to a higher energy level, but makes the atom unstable. As the electron returns to its original level, it gives back the energy as a flash of light called a photon.
Atoms are the tiny particles from which all things are made. Simplified greatly, an atom looks a bit like our solar system, which has the Sun at its center and planets orbiting around it.

Most of the atom’s mass is concentrated in the nucleus at the center (red), made from protons and neutrons packed together.

Electrons (blue) are arranged around the nucleus in shells (sometimes called orbitals, or energy levels). The more energy an electron has, the farther it is from the nucleus.

Atoms make light in a three-step process:

They start off in their stable “ground state” with electrons in their normal places.
When they absorb energy, one or more electrons are kicked out farther from the nucleus into higher energy levels. We say the atom is now “excited.”
However, an excited atom is unstable and quickly tries to get back to its stable, ground state. So it gives off the excess energy it originally gained as a photon of energy (wiggly line): a packet of light.
How light really works

Once you understand how atoms take in and give out energy, the science of light makes sense in a very interesting new way. Think about mirrors, for example. When you look at a mirror and see your face reflected, what’s actually going on? Light (maybe from a window) is hitting your face and bouncing into the mirror. Inside the mirror, atoms of silver (or another very reflective metal) are catching the incoming light energy and becoming excited. That makes them unstable, so they throw out new photons of light that travel back out of the mirror towards you. In effect, the mirror is playing throw and catch with you using photons of light as the balls!

The same idea can help us explain things like photocopiers and solar panels (flat sheets of the chemical element silicon that turn sunlight into electricity). Have you ever wondered why solar panels look black even when they’re in full sunlight? That’s because they’re reflecting back little or none of the light that falls on them and absorbing all the energy instead. (Things that are black absorb light, and reflect little or none, while things that are white reflect virtually all the light that falls on them, and absorb little or none. That’s why it’s best to wear white clothes on a scorching hot day.) Where does the energy go in a solar panel if it’s not reflected? If you shine sunlight onto the solar cells in a solar panel, the atoms of silicon in the cells catch the energy from the sunlight. Then, instead of producing new photons, they produce a flow of electricity instead through what’s known as the photoelectric (or photovoltaic) effect. In other words, the incoming solar energy (from the Sun) is converted to outgoing electricity.

Hot light and cold light

What would make an atom absorb energy in the first place? You might give it some energy by heating it up. If you put an iron bar in a blazing fire, the bar would eventually heat up so much that it glowed red hot. What’s happening is that you’re supplying energy to the iron atoms inside the bar and getting them excited. Their electrons are being promoted to higher energy levels and making the atoms unstable. As the electrons return to lower levels, they’re giving off their energy as photons of red light—and that’s why the bar seems to glow red. The fire gives off light for exactly the same reason.

Old-style electric lamps work this way too. They make light by passing electricity through a very thin wire filament so it gets incredibly hot. Excited atoms inside the hot filament turn the electrical energy passing through them into light you can see by constantly giving off photons. When we make light by heating things, that’s called incandescence. So old-style lamps are sometimes called incandescent lamps.

You can also get atoms excited in other ways. Energy-saving light bulbs that use fluorescence are more energy efficient because they make atoms crash about and collide, making lots of light without making heat. In effect, they make cold light rather than the hot light produced by older-style, energy-wasting bulbs. Creatures like fireflies make their light through a chemical process using a substance called luciferin. The broad name for the various different ways of making light by exciting the atoms inside things is luminescence.

(Let’s note in passing that light has some other interesting effects when it gets involved in chemistry. That’s how photochromic sunglass lenses work.)
Color (spelled “colour” in the UK) is one of the strangest things about light. Here’s one obvious riddle: if we see things because sunlight is reflected off them, how come everything isn’t the same color? Why isn’t everything the color of sunlight? You probably know the answer to this already. Sunlight isn’t light of just one color—it’s what we call white light, made up of all the different colors mixed together. We know this because we can see rainbows, those colorful curves that appear in the sky when droplets of water split sunlight into its component colors by refracting (bending) different colors of light by different amounts.

Why does a tomato look red? When sunlight shines on a tomato, the red part of the sunlight is reflected back again off the tomato’s skin, while all the other colors of lights are absorbed (soaked into) the tomato, so you don’t see them. That’s just as true of a blue book, which reflects only the blue part of sunlight but absorbs light of other colors.

Why does a tomato appear red and not blue or green? Think back to how atoms make light. When sunlight falls on a tomato, the incoming light energy excites atoms in the tomato’s skin. Electrons are promoted to higher energy levels to capture the energy, but soon fall back down again. As they do so, they give off photons of new light—and that just happens to correspond to the kind of light that our eyes see as red. Tomatoes, in other words, are like precise optical machines programmed to produce photons of red light when sunlight falls on them.

If you shone light of other colors on tomatoes, what would happen? Let’s suppose you made some green light by passing sunlight through a piece of green plastic (something we call a filter). If you shone this on a red tomato, the tomato would appear black. That’s because tomatoes absorb green light. There is simply no red light for them to reflect.
It’s not how it is—it’s how you see it

Many of the things we think are true of the world turn out to be true only of ourselves. We think tomatoes are red, but in fact we only see them that way. If our eyes were built differently, we might see the light photons that tomatoes produce as light of a totally different color. And there’s no real way any of us can be sure that what we see as “red” is the same as what anyone else sees as red: there’s no way to prove that my red is the same as yours. Some of the most interesting aspects of the things we see come down to the psychology of perception (how our eyes see the world and how our brains make sense of that), not the physics of light. Color blindness and optical illusions are two examples of this.

Understanding light is a brilliant example of what being a scientist is all about. Science isn’t like other subjects. It’s not like history (a collection of facts about past events) or law (the rights and wrongs of how people behave). It’s an entirely different way of thinking about the world and making sense of it. When you understand the science of light, you feel you’ve turned part of the world inside out—you’re looking from the inside, seeing everything in a totally new way, and understanding for the first time why it all makes sense. Science can throw a completely different light on the world—it can even throw light on light itself!

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An illustration on how light wor

Once Maxwell introduced the concept of electromagnetic waves, everything clicked into place. Scientists now could develop a complete working model of light using terms and concepts, such as wavelength and frequency, based on the structure and function of waves. According to that model, light waves come in many sizes. The size of a wave is measured as its wavelength, which is the distance between any two corresponding points on successive waves, usually peak to peak or trough to trough. The wavelengths of the light we can see range from 400 to 700 nanometers (or billionths of a meter). But the full range of wavelengths included in the definition of electromagnetic radiation extends from 0.1 nanometers, as in gamma rays, to centimeters and meters, as in radio waves.

Light waves also come in many frequencies. The frequency is the number of waves that pass a point in space during any time interval, usually one second. We measure it in units of cycles (waves) per second, or hertz. The frequency of visible light is referred to as color, and ranges from 430 trillion hertz, seen as red, to 750 trillion hertz, seen as violet. Again, the full range of frequencies extends beyond the visible portion, from less than 3 billion hertz, as in radio waves, to greater than 3 billion billion hertz (3 x 1019), as in gamma rays.

The amount of energy in a light wave is proportionally related to its frequency: High frequency light has high energy; low frequency light has low energy. So, gamma rays have the most energy (part of what makes them so dangerous to humans), and radio waves have the least. Of visible light, violet has the most energy and red the least. The whole range of frequencies and energies, shown in the accompanying figure, is known as the electromagnetic spectrum. Note that the figure isn’t drawn to scale and that visible light occupies only one-thousandth of a percent of the spectrum.

This might be the end of the discussion, except that Albert Einstein couldn’t let speeding light waves lie. His work in the early 20th century resurrected the old idea that light, just maybe, was a particle after all.
Maxwell’s theoretical treatment of electromagnetic radiation, including its description of light waves, was so elegant and predictive that many physicists in the 1890s thought that there was nothing more to say about light and how it worked. Then, on Dec. 14, 1900, Max Planck came along and introduced a stunningly simple, yet strangely unsettling, concept: that light must carry energy in discrete quantities. Those quantities, he proposed, must be units of the basic energy increment, hf, where h is a universal constant now known as Planck’s constant and f is the frequency of the radiation.

Albert Einstein advanced Planck’s theory in 1905 when he studied the photoelectric effect. First, he began by shining ultraviolet light on the surface of a metal. When he did this, he was able to detect electrons being emitted from the surface. This was Einstein’s explanation: If the energy in light comes in bundles, then one can think of light as containing tiny lumps, or photons. When these photons strike a metal surface, they act like billiard balls, transferring their energy to electrons, which become dislodged from their “parent” atoms. Once freed, the electrons move along the metal or get ejected from the surface.

The particle theory of light had returned — with a vengeance. Next, Niels Bohr applied Planck’s ideas to refine the model of an atom. Earlier scientists had demonstrated that atoms consist of positively charged nuclei surrounded by electrons orbiting like planets, but they couldn’t explain why electrons didn’t simply spiral into the nucleus. In 1913, Bohr proposed that electrons exist in discrete orbits based on their energy. When an electron jumps from one orbit to a lower orbit, it gives off energy in the form of a photon.

The quantum theory of light — the idea that light exists as tiny packets, or particles, called photons — slowly began to emerge. Our understanding of the physical world would no longer be the same.
Wave-Particle Duality
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At first, physicists were reluctant to accept the dual nature of light. After all, many of us humans like to have one right answer. But Einstein paved the way in 1905 by embracing wave-particle duality. We’ve already discussed the photoelectric effect, which led Einstein to describe light as a photon. Later that year, however, he added a twist to the story in a paper introducing special relativity. In this paper, Einstein treated light as a continuous field of waves — an apparent contradiction to his description of light as a stream of particles. Yet that was part of his genius. He willingly accepted the strange nature of light and chose whichever attribute best addressed the problem he was trying to solve.

Today, physicists accept the dual nature of light. In this modern view, they define light as a collection of one or more photons propagating through space as electromagnetic waves. This definition, which combines light’s wave and particle nature, makes it possible to rethink Thomas Young’s double-slit experiment in this way: Light travels away from a source as an electromagnetic wave. When it encounters the slits, it passes through and divides into two wave fronts. These wave fronts overlap and approach the screen. At the moment of impact, however, the entire wave field disappears and a photon appears. Quantum physicists often describe this by saying the spread-out wave “collapses” into a small point.

Similarly, photons make it possible for us to see the world around us. In total darkness, our eyes are actually able to sense single photons, but generally what we see in our daily lives comes to us in the form of zillions of photons produced by light sources and reflected off objects. If you look around you right now, there is probably a light source in the room producing photons, and objects in the room that reflect those photons. Your eyes absorb some of the photons flowing through the room, and that’s how you see.

But wait. What makes a light source produce photons? We’ll get to that. Next.
There are many different ways to produce photons, but all of them use the same mechanism inside an atom to do it. This mechanism involves the energizing of electrons orbiting each atom’s nucleus. How Nuclear Radiation Works describes protons, neutrons and electrons in some detail. For example, hydrogen atoms have one electron orbiting the nucleus. Helium atoms have two electrons orbiting the nucleus. Aluminum atoms have 13 electrons circling the nucleus. Each atom has a preferred number of electrons zipping around its nucleus.

Electrons circle the nucleus in fixed orbits — a simplified way to think about it is to imagine how satellites orbit the Earth. There’s a huge amount of theory around electron orbitals, but to understand light there is just one key fact to understand: An electron has a natural orbit that it occupies, but if you energize an atom, you can move its electrons to higher orbitals. A photon is produced whenever an electron in a higher-than-normal orbit falls back to its normal orbit. During the fall from high energy to normal energy, the electron emits a photon — a packet of energy — with very specific characteristics. The photon has a frequency, or color, that exactly matches the distance the electron falls.

You can see this phenomenon quite clearly in gas-discharge lamps. Fluorescent lamps, neon signs and sodium-vapor lamps are common examples of this kind of electric lighting, which passes an electric current through a gas to make the gas emit light. The colors of gas-discharge lamps vary widely depending on the identity of the gas and the construction of the lamp.

For example, along highways and in parking lots, you often see sodium vapor lights. You can tell a sodium vapor light because it’s really yellow when you look at it. A sodium vapor light energizes sodium atoms to generate photons. A sodium atom has 11 electrons, and because of the way they’re stacked in orbitals one of those electrons is most likely to accept and emit energy. The energy packets that this electron is most likely to emit fall right around a wavelength of 590 nanometers. This wavelength corresponds to yellow light. If you run sodium light through a prism, you don’t see a rainbow — you see a pair of yellow lines.
Another way to make photons, known as chemiluminescence, involves chemical reactions. When these reactions occur in living organisms such as bacteria, fireflies, squid and deep-sea fishes, the process is known as bioluminescence. At least two chemicals are required to make light. Chemists use the generic term luciferin to describe the one producing the light. They use the term luciferase to describe the enzyme that drives, or catalyzes, the reaction.

The basic reaction follows a straightforward sequence. First, the luciferase catalyzes the oxidation of luciferin. In other words, luciferin combines chemically with oxygen to produce oxyluciferin. The reaction also produces light, usually in the blue or green region of the spectrum. Sometimes, the luciferin binds with a catalyzing protein and oxygen in a large structure known as a photoprotein. When an ion — typically calcium — is added to the photoprotein, it oxidizes the luciferin, resulting in light and inactive oxyluciferin.

In marine organisms, the blue light produced by bioluminescence is most helpful because the wavelength of the light, around 470 nanometers, transmits much farther in water. Also, most organisms don’t have pigments in their visual organs that enable them to see longer (yellow, red) or shorter (indigo, ultraviolet) wavelengths. One exception can be found in the Malacosteid family of fishes, also known as loosejaws. These animals can both produce red light and detect it when other organisms can’t.

Want to know more about how and why living things make light? Check out How Bioluminescence Works for a deep dive.

We’ll heat things up next with incandescence.
Probably the most common way to energize atoms is with heat, and this is the basis of incandescence. If you heat up a horseshoe with a blowtorch, it will eventually get red-hot, and if you indulge your inner pyromaniac and heat it even more, it gets white hot. Red is the lowest-energy visible light, so in a red-hot object the atoms are just getting enough energy to begin emitting light that we can see. Once you apply enough heat to cause white light, you are energizing so many different electrons in so many different ways that all of the colors are being generated — they all mix together to look white.

Heat is the most common way we see light being generated — a normal 75-watt incandescent bulb is generating light by using electricity to create heat. Electricity runs through a tungsten filament housed inside a glass sphere. Because the filament is so thin, it offers a good bit of resistance to the electricity, and this resistance turns electrical energy into heat. The heat is enough to make the filament glow white-hot. Unfortunately, this isn’t very efficient. Most of the energy that goes into an incandescent bulb is lost as heat. In fact, a typical light bulb produces perhaps 15 lumens per watt of input power compared to a fluorescent bulb, which produces between 50 and 100 lumens per watt.

Combustion offers another way to produce photons. Combustion occurs when a substance — the fuel — combines rapidly with oxygen, producing heat and light. If you study a campfire or even a candle flame carefully, you will notice a small colorless gap between the wood or the wick and the flames. In this gap, gases are rising and getting heated. When they finally get hot enough, the gases combine with oxygen and are able to emit light. The flame, then, is nothing more than a mixture of reacting gases emitting visible, infrared and some ultraviolet light.

Next up we’ll shine a light on lasers.

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Gruesome But True – A Male Snake Caught On Camera Lovingly Embracing Corpse Of A Female Snake

Gruesome But True – A Male Snake Caught On Camera Lovingly Embracing Corpse Of A Female Snake
By erlymags ( @cely / @lovern )

Look at the picture in this blog; this is the picture of the two snakes embracing. You may not believe this, but it happens this day. A male snake has shown a tender feeling towards a female snake. We thought that animals do not have affection towards their opposite sex. It is proven this day when a man from northern Australia came across a horrifying sight two snakes embracing lovingly, but that male snake had embraced the newly found dead body of a female snake thought to be its mate. What is bitter to think about is the female snake dead and pregnant. Australia is noted to having many snakes and different kinds of animals. Children there are taught at their young age about nature and characteristics of animals.

This man who has seen this scene is a science teacher who brought with him his students early morning to teach them about reptiles only to get shocked when saw these two snakes in dept feeling of something except the female dead. As they get closer to the scene they realized the female snake was pregnant with that male snake and all her eggs scattered on the road. It was told that the female snake was hit by a car. What a terrible moment seeing animals like this. These snakes are non-venomous and the driver should have not killed the pregnant snake, so pitiful view. We are also affected with this happening. Everyone should realize that animals should not just be killed brutally for they also have life. They are part of nature and they in return protect nature from danger.

It also important to science teachers to inculcate onto the minds of the children to give value to lives of animals so they could also develop appreciation to animals lives like snakes. The children will also have interest to share their role in their community and to the society as a whole develop a safe and protection behavior to animals especially in dealing with snakes and other reptiles. Their young minds need to equip with the right values about love to animals. Further, the children can have awareness of their role to share to their peer and group mates these animals need protection and they are also entitled to safety. The snakes are mainly feed on amphibians and small lizards. They do not eat humans just bite, LOL. They can also eat cane toads which are poisonous to other animals for they safe. The snakes are also important to other animals.

Look at the picture as photo image, these are the two snakes that lovingly embracing each other. What a pity to them. They also have their instinct of love. The male snake showed its feeling this way gruesome, but true as backed by science. You may see a YouTube on this just search about two snakes in embracing mood yet the female died. My heart goes to the feeling of these two snakes.

Image shown here, the two snakes showing their affection

Source: World News

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The Incredible Healing Power Of A Horse

The Incredible Healing Power Of A Horse
By erlymags ( @cely / @lovern )

Many of you may not believe that a horse is very important to man not only to a sport he likes or to have horse to serve his family as carriage in the absence of wheel. It has been proven as best animal friendly despite alone in his house. Who could believe now that a horse could be a help to people that deal with physical, emotional, social, cognitive and behavioral problems? I think many of you would laugh at this, but this is backed by science. Almost all animals play great role to man not only providing him with its meat for is food, skin for clothing, carriage, fields plowing, but all of those mentioned above that related to man’s healing
need.

What do you notice to animals like horse? All animals know how to take care of themselves. They are all equipped with a ready-instinct to take care of them in nature. Even if they are exposed to sun they could still survive for many hours, though there are some animals that cannot survive under the extreme heat of the sun like a cow. What do you notice to a cow? To those farmers, they have a carabao with them as their partner in the field. A carabao has a strong endurance against the incredibly heat of the sun. It can also withstand under a circumstance in a pace exposed to sun. Carabao only requires daily dipping in mud, a cow not. It requires a daily bath in a river or plain water in spring, faucet or well.

Let us go back to horse and its healing power. At first I was amazed. I was not able to sleep right away at night thinking about how nice to own a horse. Yes, after knowing this, I have a great desire to own a horse. Scientists have made their research on different varieties of animals. Their purpose is to know how we humans can learn from their different health mechanisms. Other animals have been found to possess amazing healing powers that can treat human illness. Their healing powers could also help rehabilitate patients. This is so incredible especially on a horse. We thought a horse is nothing but an animal. I wonder why those horse owners and horse racers find life in calm and serene because the ability of the horse to have these have been acquired by the horse lovers.

A horse can stay calm despite alone in the lonely field. It can withstand abuses of man. A horse could also withstand against a ferocious storm and bad climate alone. Anyone who can inhibit these attitudes of a horse could have a strong will to willingly undergo any circumstances and outsmart life’s problems. A horse
Is important to people who have depressive attitude and killer minded – mind. The best is to always talk to a horse, touch its forehead many times to inhibit the inherent characteristics of a horse- the healing power of the mind to stop loneliness, worries and uncertainties of feeling and beliefs. If you want to be physically, emotionally and socially strong, see a horse or pet a horse. Life is indeed mysterious. All that we have on earth came from God for all His children on earth to inherit them, yet others never care and never understand. To have peace of mind is sometimes hard to do for those that lack power to survive and lack power to accept some realities, so you need a horse to pacify you and give you a serene life. Life chaotic and problematic gives anyone an unhappy life. You need a horse. Go find a horse to stabilize your entire needs: physical, social, emotional, spiritual and financial needs.

This time many of us are restless .There are so many reasons why feel this way. I believe the primary factor that drives many of us to feel this way is money. Despite of the fact that money cannot buy happiness, many also oppose for in the absence of money, one can be in a total loss of everything, A life can be extended because a patient could be treated well in a hospital; a debt can be paid already having surcharges accumulated ; foods could always be available on dining table; there is always money for children’s tuition; there is always money to pay many bills; there is always money to buy important materials needed at home and more only money can do. All these can make life miserable without money. That is why we cannot despise those who are always feeling down and out of control. They might have lost their control not to spend much to avoid extravagance for this can lead life to live on LOSS.

We have to be thankful to the scientists for everyday they study and research some possibilities that could help the human beings. There are many landed six feet below the ground through ending their lives shortly for they cannot anymore suffice to live in too many complications. There are also many life’s gone astray just to survive in a wrong way. From the standpoint of the researchers, it seems that animals are better than humans for animals have their own ways to heal themselves. They have their own healing power despite they have minds only they understand. Look at dogs despite others cruel to them , but look at the way they are treated well by their masters, they are superb pet that could convert the mind of man in peace.

From now on, let us think like a horse so we can always heal all our weak body and mind. From now on, let us love animals. Let us not be cruel to them. They are family member so love is all they need. From them, love and healing power can be inhibited so we all can live in peace and satisfaction of what we have. Life is beautiful worth to live. Don’t waste life, rather love it to the fullest for we only have one life to live and enjoy. To God Be The Glory.

Image credit to Pixabay

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Do you know you can verify the science you read???

Verifying the science you read can be tricky. After reading a scientific publication, check the underlying assumptions and look for internal consistencies. Look up references and studies the publication was based on. Talk to a scientist in a relevant field for more verification and clarification. Save yourself a lot of time and energy by choosing only high-quality sources published by peer-reviewed journals, governments, and trustworthy nonprofits.

Method One of Three:
Checking the Sources
Edit

1
Take note of verifiable facts as you read. Whether the science you read is an article, book, or web page, read the text in its entirety. As you read, pay attention to details. Write down or make a mental note of things that are confusing or unclear. Use a highlighter or pen to underline, circle, or highlight facts that can be verified.[1]
Verifiable facts are those which are based in objective reality rather than on opinion, conjecture, or unfounded belief.

2
Consult referenced data. All verifiable science relies on the work of other scientists to establish its credibility and inspire further studies. One way to verify the science you read is to follow up on the information provided in the study’s footnotes. Check referenced sources to ensure that their conclusions and statistics match those presented in the science literature you’re attempting to verify.[2]
If you’re reading science in a popular publication, sources will be cited in the text rather than in footnotes or endnotes.
Non-specialized sources should describe specific studies but might not refer to published peer-reviewed article by name. They might also refer to certain scientists or authors, or to the titles of scientific journals where relevant publications appeared. Use this information to track down more information whenever possible.

3
Talk to a scientist. If you’re confused about the science you read, contact a relevant scientist to help you verify it. For instance, if you wish to verify an astronomical report you read, you could contact an astronomer. If you wish to verify a physics issue, contact a physics professor.[3]
When you’ve discovered someone to help you verify the science you read, contact them and pose your question. Always be polite and professional when communicating with professional scientists.
Preferably, you will contact more than one expert in the field of the science you read. This will give you a range of opinions regarding whether the science you read is accurate.
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No
Was this method helpful?
Checking the Sources
Yes
Method Two of Three:
Taking a Second, Careful Look
Edit

1
Look at declarative statements. If you read science that has lots of declarative statements (for instance, “It is large”) and is low on quantifiable (numbers-based) data, steer clear. Verifiable science will utilize specific numbers, measurements, and sizes when reporting results.[4]
Check the terms used. Look out for vague or imprecise language. Likewise, avoid science that uses common scientific terms in a novel way. Verifiable science will use terms that other scientists in the field would readily understand.[5]
For instance, if the science you read says, “The heart-consciousness will heal you when you are ready,” you can safely discount it, since there is no “heart-consciousness” known to heal the human body.

3
Beware of facts that are stated absolutely. Many scientific questions are settled and have been for many years. For instance, the science you read might contain clear and categorical explanations regarding why the stars shine or why trees grow. However, some scientific questions are still open to exploration, and the answers are less clear. If the science you read contains facts stated absolutely with little or no corroborating research behind them, you should consider that a red flag.[6]
For instance, the scientific understanding of why we dream remains imperfect. So if the science you read states, “This is why we dream,” instead of a more cautious statement like, “This may be why we dream” or “This could be why we dream,” be wary.

4
Look for internal inconsistencies. If the science you read has charts and statistics that do not jive with the conclusions drawn by the author, you can discount the publication as flawed. Likewise, if the science you read has two conclusions which are at odds, or two data points that contradict each other, the science should be considered untrustworthy.[7]
Choose trusted publications. High-quality science might come from trusted governments, universities, individuals, peer-reviewed journals, and some nonprofit organizations. When checking a book or article for quality, it should be written by someone with significant experience in their scientific field. If you’re reading a scientific article or textbook, the scientist who authored it should have a PhD and long experience at a university or research institution.[8]
Lay publications will, of course, likely be written by someone without a PhD. The author might even be a student. If the lay publication is trusted, you may consider it a reliable source.
Choosing high-quality sources means someone has already verified the science for you before you read it.

2
Only use sources which are free of apparent bias. Poor quality sources are those which have a vested interest in the scientific results or data they are verifying or refuting. For instance, if you read science produced by a fossil fuel company regarding the polluting impact of their products, the company is producing scientific research which could directly impact its fortunes. In such a situation, you should be skeptical of the data.[9]
Good sources will provide a high degree of transparency, and include disclaimers regarding funding sources. They will also name all participants in the scientific research.

3
Compare the science you read to other publications on the subject. One way to verify the science you read is to check it against other sources on the topic. After reading a scientific article or publication, look the topic up in an encyclopedia or another trusted text. This way, you will learn what the consensus view on the subject is.[10]
Comparing the science you read against many other publications will help you determine whether the science you read is consistent with mainstream scientific thought.

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How to cut your expenses of $550 a month

TAMPA, Fla. (WFLA) – When it comes to saving money, most of us want to do it, but the trouble is many of us simply can’t.

Some feel they’d have to make drastic changes in their lives, like downsize to a smaller house or buy a cheaper car
TAMPA, Fla. (WFLA) – When it comes to saving money, most of us want to do it, but the trouble is many of us simply can’t.

Some feel they’d have to make drastic changes in their lives, like downsize to a smaller house or buy a cheaper car
But that’s not necessarily so. You can actually save hundreds of dollars a month without making a huge sacrifice. Here’s how you can do it.

First, we stop at your local coffee shop.

At Buddy Brew in Tampa, a cup of joe can really set you back.

Anna Maddamma comes here four times a week.

“Coffee I need. so I just buy it,” Maddamma said. When asked if she kept track of her spending when it comes to coffee, her answer was, “No.”

That means passing on the coffee could save Maddamma about $100 a month.

How about eating out? Those lunches and dinners sure can add up, too.

“I just can’t believe what things cost sometimes,” said Janet Ricket, as she sat outside a restaurant on Davis Islands.

She eats lunch out once a week and dinner twice a month.

That might not sound like a lot to you, but with two kids, ages 10 and 11, she has more mouths to take into consideration.

“It’s just family expense, I suppose,” Ricket said.

By staying home, Ricket could say about $200.

As far as staying in shape, that, too, comes with a price. How about running for free on the Riverwalk in Tampa instead of paying a monthly gym membership?

Laurie Mintzer doesn’t need to shell out a penny. She runs on the Riverwalk and has a free membership to her gym at work.

Possible savings here? About $50.

We asked Mintzer if she thought she could be saving money. “No, I don’t,” she said. “I probably could but not interested.”

One option that’s harder to do but not impossible, is leaving the car at home and renting bikes.

When we reminded Michael Abjner and Mark Micklow of Tampa that that’s not the norm, Micklow told us, “Oh well!”

They bike to work and save on gas, maintenance, and every day wear and tear on their car.

Possible savings here? About $200.

But for some people, this has nothing at all to do with money. So we wanted to know, why some people are living beyond their means?

Doctor Scott Anderson, clinical director of Addiction Recovery in Tampa, says it’s all about peoples’ judgments about others, especially when it comes to material things.

“A lot of people, they’re judge is based upon what they have and how they look and what they have, Dr. Anderson said. “You know, everybody’s’ keeping up with the Joneses.”

Financial planners will tell you to make a budget and stick to it.
If they’re not tracking exactly where they’re spending their money, they really don’t know where it’s going,” said Kevin Arquette, a chief financial planner at Harwood Financial Group in Tampa.

That means all those little things could turn into one big chunk of change.

“They’re out-spending their income and they’ll end up in debt ultimately,” Arquette told News Channel 8.

So let’s add it all up-

Coffee: $100
Eating out: $200
Gym membership: $50
Transportation: $200
All of these simple changes add up to about $550 every month that you can save.

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Where you discover inner peace?

 There comes a time when you want not a wander in life, but you want inner peace. Where to discover your own? What to follow in life?

I learned to more thank The God, not to ask. And if sometimes I ask for something from the heaven, I ask that God would send me not what I want but what I need, because from there God can see better. We can see too narrow, not feel the core. And today, looking to the past, I see that all challenges I had were only the good. We just need to believe and trust. Not to mutter on fortune, but forgive. After all, even the prayer teach us to forgive in order to be worthy of forgiveness.

I am glad that today I am not afraid not to know, not afraid to admit it. I relax, inner peace I find being with myself. Today, I am already able not to take stressful conditions into myself, it is hard to unsettle me. And I teach my children to manage emotions, inhale and exhale. I like meditation, I walk by the sea, bike, kite surfing, traveling, reading books, listening to music. Relaxation for me is also cooking with a love for my family.

I cannot say that I do not mind other people’s opinion, we are not living in the jungle. In addition, I like to be well dressed, perfumed delicious, I care not only about my soul but also about the body. And I am doing that with great pleasure! If I love my soul, I must love also the body. It is a gift, I have to take care of him. I care what about I eat. After all, most we are what we eat.

I am surrounded by a lot of bright people. I am rewarded with the people who love me, care for, protect, help, if I need help. Around me are a lot of like-minded, spiritual personalities. And they inspire me. If I go to a man with an open heart, not with anger or aggression, I find the key to him. It is not hard for me to help or advice if someone needs me. For me in the first place it is always humanity, human goodness of man. I always want to warm up people with my love, because only love heals. I believe that if you done something good to other person, he later will give this goodness to another person again. In such way the circuit of goodness will not discontinue.

 

Picture by Pixabay.com

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My Thoughts About Climate Change : Global Warming or Global Returning?

Sharing these wacky thoughts of mine. Hoping you don’t run away from me even though I speak my mind which is often … kind of weird, strange and Krazee with a capital “K”!

 

OK So! It’s the year 2017 and it’s spring time here in Austin, Texas, and I never know what kind of weather to expect each day. When we moved to this city in 1998, people use to describe the weather as “climatically perfect”. The weather was terrific!

 

My kids have grown accustomed to my standard excuse that I use to point the finger of blame at … everything!

 

If something happens, no matter what … I say:

 

  • “IDK!  I blame global warming. Whatever!

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♦ ♦ ♦

 

Most of you know I believe/read the Bible a lot and as a result, my rationale and reasoning or explanations may come across to others as somewhat “peculiar”. Like this particular thought.

 

THOUGHT: Suppose global warming is actually global returning?


Follow my thought process (if you can).

 

According to the Bible, when the earth was first created, Adam and Eve used to walk around in their birthday suits. Naked! The reason they were given clothes didn’t have anything to do with a change in the weather.  Also, Noah preaching about a coming flood was disregarded by the masses because … Why?  Because it had never rained before! Water had never come down from the sky! It would take faith to believe such a thing could happen.

 

So if, in the beginning, man and woman were able to walk around au naturel, that must mean that the weather was terrific! All the time! Everywhere on planet earth!!

 

Today it like 79 degrees in Austin, Texas but the day is over.  Earlier this morning it felt a little chilly. Yesterday the heat from the sun was beating me down!

 

  • Maybe global warming is not disastrous.
  • Maybe it’s a good thing.
  • Maybe … ? Our weather is just going back to the way it was in the beginning.
  • Maybe … global warming is actually global returning.  (O.o)

 

JAOOMPT! Just another one of my peculiar thoughts.

 


glitter-graphics.com

 

He’s Got the Whole World in His Hands

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CHEMISTRY WORLD (history,proposed law, scientist that propose and modify,particles’ )

Van Helmont: 1648
A book is published in Amsterdam in 1648 which
can be seen as a definitive turning point between
alchemy and chemistry. Entitled Ortus Medicinae
(Origin of Medicine), it is the collected papers of
Jan Baptista van Helmont, an aristocrat who has
lived quietly on his estate near Brussels
conducting scientific experiments.
Van Helmont is inclined to mysticism. He
believes in alchemy and in the philosopher’s
stone which, if found, could turn base metals into
gold. But he also conducts experiments on
entirely scientific principles. Some, like his
famous five-year project with a willow tree, lead
him to the wrong conclusion. But the method is
valid.
Van Helmont weighs out 200 lbs of dried earth,
places it in an earthenware container and plants
a willow tree weighing 5 lbs. For five years he
waters the plant daily. At the end of the
experiment the willow tree weighs 169lbs and
the earth, when dried, not much less than 200
lbs. Van Helmont concludes, reasonably that the
wood, bark and leaves of the tree must be
composed of water, which he therefore considers
to be the chief constituent of all matter.
He is half right – any willow tree is about 50%
water. What van Helmont is unaware of is that
the tree has also absorbed carbon and oxygen,
as carbon dioxide or CO2, from the air.
Ironically, Van Helmont himself becomes the first
scientist to postulate the existence of carbon
dioxide. He burns 62 lbs of charcoal and finds
that he is left with only 1 lb of ash. What has
happened to the rest? Van Helmont is convinced,
ahead of his time, of the indestructibility of
matter. Indeed he is able to demonstrate that
metal dissolved in acid can be recovered without
loss of weight.
So he now reasons that the missing 61 lbs have
escaped in the form of an airy substance to
which he gives the name gas sylvestre (wood
gas).
The identity of this wood gas is not discovered
until a century later (by Joseph Black ), but van
Helmont is the first to have suggested the
existence of gaseous substances other than air.
It is he who coins the word ‘gas’ – deriving it
from Chaos (sounding similar in Flemish), which
is used in Greek mythology to mean the original
emptiness before creation.
The principles of experiment enter chemistry in
the work of van Helmont, and are developed by
another aristocrat fascinated by the puzzles of
science – Robert Boyle.
Robert Boyle: 1661-1666
The experimental methods of modern science
are considerably advanced by the work of Robert
Boyle during the 1660s. He is skilful at devising
experiments to test theories, though an early
success is merely a matter of using von
Guericke ‘s air pump to create a vacuum in which
he can observe the behaviour of falling bodies.
He is able to demonstrate the truth of Galileo ‘s
proposition that all objects will fall at the same
speed in a vacuum.
But Boyle also uses the air pump to make
significant discoveries of his own – most notably
that reduction in pressure reduces the boiling
temperature of a liquid (water boils at 100° at
normal air pressure, but at only 46°C if the
pressure is reduced to one tenth).
Boyle’s best-known experiment involves a U-
shaped glass tube open at one end. Air is
trapped in the closed end by a column of
mercury. Boyle can show that if the weight of
mercury is doubled, the volume of air is halved.
The conclusion is the principle known still in
Britain and the USA as Boyle’s Law – that
pressure and volume are inversely proportional
for a fixed mass of gas at a constant
temperature.
Boyle’s most famous work has a title perfectly
expressing a correct scientific attitude. The
Sceptical Chymist appears in 1661. Boyle is
properly sceptical about contemporary theories
on the nature of matter, which still derive mainly
from the Greek theory of four elements .
His own notions are much closer to the truth.
Indeed it is he who introduces the concept of the
element in its modern sense, suggesting that
such entities are ‘primitive and simple, or
perfectly unmingled bodies’. Elements, as he
imagines them, are ‘corpuscles’ of different sorts
and sizes which arrange themselves into
compounds – the chemical substances familiar to
our senses. Compounds, he argues, can be
broken down into their constituent elements.
Boyle’s ideas in this field are further developed
in his Origin of Forms and Qualities (1666).
Chemistry is Boyle’s prime interest, but he also
makes intelligent contributions in the field of pure
physics.
In an important work of 1663, Experiments and
Considerations Touching Colours, Boyle argues
that colours have no intrinsic identity but are
modifications in light reflected from different
surfaces. (This is demonstrated within a few
years by Newton in his work on the spectrum.)
As a man of his time, Boyle is as much
interested in theology as science. It comes as a
shock to read his requirements for the annual
Boyle lecture which he founds in his will. Instead
of discussing science, the lecturers are to prove
the truth of Christianity against ‘notorious
infidels, viz., atheists, theists, pagans, Jews and
Mahommedans’. The rules specifically forbid any
mention of disagreement among Christian sects.
The phlogiston theory: 18th century
Two natural processes, burning and rusting,
particularly intrigue the chemists of the 17th and
18th centuries. A concept is put forward in 1667
in Germany in a book by Johann Joachim
Becher. explaining such changes as the release
of a particular substance, present in all materials
which are capable of changes of this kind. The
theory was developed by George Ernst Stahl,
who in a 1702 edition of Becher’s work gave the
mystery substance the name phlogiston – from
the Greek phlogizein, to set alight.
Stahl is correct in his link between burning and
rusting, for each depends on oxidization (a
chemical reaction with oxygen). But experimental
evidence immediately provides a stumbling block
for the phlogiston theory.
If phlogiston is a substance released both in
burning and rusting, then the resulting ash and
rust should weigh either the same as or less than
the weight lost by the original object (there is
much debate as to the weight or weightlessness
of phlogiston). But experiments reveal that
oxygen-rich rust is heavier than unrusted iron,
while ash is much lighter than the burnt organic
material. Yet this difficulty is not enough to
prevent most scientists believing in the existence
of phlogiston, until Lavoisier and the discovery of
oxygen finally disprove the case.
Demons in the ore: 1742-1751
From the mid-18th century there is rapid
acceleration in the discovery of new elements,
as chemists improve their analytical methods in
the laboratory. These substances are not at first
recognized as elements (a concept only firmly
established in the 19th century), but in each case
it is evident that a previously unidentified
material has been isolated.
Two of the earliest in this series of discoveries
take place in Sweden. Both involve the analysis
of familiar metallic ores, and both acquire their
lasting names from the superstitions of German
miners.
Miners in the Harz mountains have often been
frustrated by a substance which appears to be
copper ore but which, when heated, yields none
of the expected metal. Even worse, it emits
noxious fumes. The miners blame this on the
influence of a spirit, the mischievous kobold, and
the name becomes attached to this kind of ore.
The only use found for the residue of such ore
after roasting is in the making of glass, to which
it adds a beautiful blue colour. In about 1735
Georg Brandt is able to show in his Swedish
laboratory that the blue derives from a previously
unknown metal. The mischievous spirit has been
identified, and Brandt gives its name to the new
substance – as cobalt.
A similar demon is blamed by miners in Saxony
for another ore which yields a brittle substance
instead of copper. In German a Nickel is a
dwarfish troublemaker, and the miners call the
disappointing ore Kupfernickel (copper scamp).
The impurity in ore of this type is analyzed in
Sweden in 1751 by Axel Cronstedt. He identifies
its components as arsenic and a previously
unknown hard white metal, quite distinct from
copper. Following the example of Brandt, he
honours the offending demon in the naming of
the new substance and calls it nickel.
Several other new metallic elements are isolated
in the following decades. But the main focus of
research moves now to the gases.
Joseph Black and fixed air: 1754-1756
Joseph Black presents his doctoral thesis to the
university of Edinburgh in 1754 and publishes it in
expanded form two years later as Experiments
upon Magnesia Alba, Quicklime, and Some Other
Alcaline Substances . The experiments which he
describes are a classically complete series of
compound transformations of calcium, carbon
and oxygen – though it is not as yet possible to
express his results in these terms.
Black has observed that if he heats chalk
(calcium carbonate), he gets quicklime (calcium
oxide) and a gas, the presence of which he can
identify by its weight. Unwilling as yet to
speculate on its identity, he calls it fixed air –
because it exists in solid form until released.
As a next stage, Black demonstrates that he can
reverse the process. Mixing water with the
quicklime, he gets a substance (slaked lime)
whch will take up the fixed air again – leaving
him with his original amount of chalk and the
water.
In other experiments Black is able to show that
this same unknown gas, his fixed air, is
produced as a result of burning charcoal, of
fermentation and of breathing. He demonstrates
this last point to his students by breathing
through a tube into a jar of limewater (a clear
solution of slaked lime). The liquid turns cloudy
as grains of chalk form in it.
Black’s fixed air is the gas sylvestre of which
the existence has been postulated by van
Helmont a century earlier. Its composition as
carbon dioxide is not discovered until the 1780s,
when Lavoisier achieves it by burning carbon in
oxygen.
Black’s proof that such a gas exists prompts an
energetic search for others. Hydrogen is
identified by Cavendish in 1766, and oxygen
almost simultaneously by Scheele and Priestley
in the 1770s. Meanwhile Black has observed
another important scientific principle, latent heat.
Cavendish and hydrogen:1766
In 1766 Henry Cavendish presents his first paper
to the Royal Society. Under the title Factitious
Airs he describes his experiments with two
gases. One is the ‘fixed air’ identified by Joseph
Black . The other is a gas which Cavendish calls
‘inflammable air’, soon to be given the name
hydrogen by Lavoisier .
Hydrogen has been observed as a phenomenon
for at least two centuries. The 16th-century
alchemist and charlatan Paracelsus finds that
the dissolving of a metal in acid releases a form
of air which will burn. But Cavendish is the first to
identify it as specific substance. He believes that
he has found the inflammable essence,
phlogiston.
The study of gases in the laboratory is by now a
standard chemical process thanks to the
pneumatic trough developed in the early part of
the 18th century by Stephen Hales. An upturned
vessel, full of water, stands in a shallow trough of
water. Gas is collected in the top of the vessel,
displacing water and being sealed in by it. With
this device Cavendish is able to calculate the
specific gravity of hydrogen.
He finds that it is one fourteenth that of common
air (it is the lightest substance known). Within
less than two decades of his observation, a
dramatic use is found for this very light new gas
– in ballooning .
Priestley and oxygen: 1774
Joseph Priestley, a nonconformist minister, is
employed as librarian from about 1773 in an
English nobleman’s house, Bowood in Wiltshire.
He is provided with a laboratory to carry out his
chemical researches. And he has recently
acquired a large 12-inch lens, with which he can
focus intense heat on chemical substances.
In August 1774 he directs his lens at some
mercury oxide. He discovers that it gives off a
colourless gas in which a candle burns with an
unusually brilliant light. Experimenting further
with this gas, he records a few months later that
‘two mice and myself have had the privilege of
breathing it’. The mice were presumably offered
the privilege first.
Priestley has isolated oxygen. He foresees a
medical use for it (‘it may be peculiarly salutary
for the lungs in certain cases’), but he does not
fully appreciate its chemical significance –
largely because he believes in the phlogiston
theory. He calls the new gas ‘dephlogisticated
air’, on the assumption that the phlogiston has
been removed from it.
In October 1774, visiting Paris with his noble
patron, he describes his discovery to a gathering
of French scientists. Among them is Lavoisier ,
who develops Priestley’s experiments in his own
laboratory and realizes that he has the evidence
to disprove the phlogiston theory.
Priestley meanwhile isolates a great many other
gases. Though he is the first to publish his
discovery of oxygen, he has in fact been
preceded in the identification of both oxygen and
nitrogen by the Swedish chemist Carl Wilhelm
Scheele.
Scheele separates air in 1773 into two gases
which he calls ‘fire air’ (oxygen) and ‘foul air
(nitrogen). His findings only become known with
the publication of his book Air and Fire in 1777,
but it is established that the experiments date
from four years earlier. Like Priestley, Scheele is
handicapped by his belief in the phlogiston
theory. When isolating hydrogen, he concludes –
as has Cavendish – that it is pure phlogiston.
Cavendish and water: 1784
During the last three decades of the 18th
century, with more and more chemical
substances becoming identified, there is great
interest in which of them may be elements – in
Boyle ‘s sense of being pure substances unmixed
with anything else. Of the four ancient Greek
elements , earth is clearly no longer a candidate.
Air is separated in 1773 by Scheele into oxygen
and nitrogen. Water receives its dismissal from
the club at Cavendish’s hands in a paper entitled
Experiments in Air (1784).
Cavendish mixes hydrogen and oxygen, in the
proportion 2:1, in a glass globe through which he
passes an electric spark. The resulting chemical
reaction leaves him with water, which stands
revealed as a compound (H2O).
Lavoisier: 1777-1794
Although Antoine Laurent Lavoisier has no single
glamorous discovery to add lustre to his name
(such as postulating the first gas , or identifying
oxygen), he is regarded as the father of modern
chemistry. The reason is that during the last two
decades of the 18th century he interprets the
findings of his colleagues with more scientific
clarity than they have mustered, and creates the
rational framework within which chemistry can
develop.
He gives evidence of this in his response to
Priestley’s discovery of ‘dephlogisticated air’. He
undertakes a series of experiments which reveal
the involvement of this new gas in the processes
where phlogiston has been assumed to play a
key role.
He is able to show that Priestley’s gas is
involved in chemical reactions in the processes
of burning and rusting, and that it is transformed
in both burning and breathing into the ‘fixed air ‘
discovered by Joseph Black. His researches
with phosphorus and sulphur cause him to
believe that the new gas is invariably a
component of acids. He therefore gives it in 1777
the name oxygen (from the Greek for ‘acid
maker’). On a similar principle Lavoisier coins
the word hydrogen (‘water maker’) for the very
light gas isolated by Cavendish.
With these two names chemistry takes a clear
and decisive step into the modern era. It is an
advance which Lavoisier soon consolidates.
With three other French colleagues Lavoisier
publishes in 1787 Méthode de nomenclature
chimique (Method of Chemical Nomenclature).
Their scheme, soon universally accepted,
sweeps away the muddled naming of substances
which has descended from alchemy and
replaces it with a logical system of classification.
This is an achievement of French rationalism
comparable to the metric system, in the planning
of which Lavoisier is also involved.
In 1789 Lavoisier follows this book on chemical
methodology with the related fruits of his own
researches – Traité élémentaire de chimie
(Elementary Treatise of Chemistry). In this he
attempts a list of the known elements.
Lavoisier names more than thirty elements,
which he defines – in the tradition begun by Boyle
a century earlier – as substances which can be
broken down no further by any known method of
analysis. The majority are metals, but there are
by now three gases which Lavoisier identifies as
elements – oxygen, hydrogen and nitrogen
(which he calls azote, ‘without life’).
Lavoisier is immensely active in public affairs, in
addition to his scientific work. Unfortunately his
tasks have included, under the ancien régime ,
membership of the ferme générale or tax
authority.
By the time of the Terror, in 1794, it makes little
difference that Lavoisier has been on the liberal
and reformist side on contemporary issues. An
order is given for the arrest of all the former
members of the ferme générale . In May 1794, in
a trial lasting only part of a day, twenty-eight of
them including Lavoisier appear before a
revolutionary tribunal. Condemned to death, they
are guillotined that same afternoon.
A colleague of Lavoisier, who has worked with
him on the commission to introduce the metric
system, comments: ‘It took only a moment to cut
off that head; a century may not be enough to
produce another like it.’
Stay tune. Am yet to coplete it

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