Let there be light. Someone or other said that once and all things being equal, humans and other living things have benefited from having light. There wouldn’t be much life without it. And while the sun was our big provider for a long time before we mastered fire and then electricity, these are far from the only light sources out there. Science provides some brilliant ways to bring light to darkness.
10. You Can Crack an Ice Cube Tray in the Dark and Create Light
Triboluminescence is a mouthful of a word but get used to it, we’ll bring it up again later. This is the scientific name for light that comes from friction or compression and it can come about in a variety of very unexpected ways. The fun thing about it is that it’s very accessible for the average person. You don’t need fancy machines or dangerous chemicals or anything. But you’ll probably need patience.
If you have an ice cube tray in your freezer, you can use it to produce light. Twisting the tray to free ice cubes can, sometimes, produce light thanks to triboluminescence. When you break ice, it undergoes mechanical stress that can release electron energy. As the electrons relax and get a little more stable, that can produce light energy. In this case it’s going to be a quick flash that, if it happens at all, can be easily missed so trial and error goes a long way if you want to see for yourself.
You can also separate and reunite electrical charges or create a current that ionizes molecules. If you’re looking to see it yourself, you need a pitch black room and the ice needs to be as cold as you can get it, the colder the better. You need to let your eyes adjust fully to the dark, then get your ice, then give it a crack. The light can be blue or white and most will be ultraviolent but it may also be so dim you can barely see it. Plus, as mentioned, it may not happen at all.
9. Collapsing Bubbles Underwater Can Produce Light
Water can be used in the production of light if you have some bubbles handy. This process is called sonoluminescence and requires not just underwater bubbles but sound waves. You can’t just pop the bubble with your finger and hope for a fireworks display.
The scientific process for this one is still a mystery but what we do know still sounds very cool. You need an air bubble underwater and if you hit it with a sound wave. The bubble will collapse and in that instance you create a burst of light.
When the sound hits the bubble, the bubble expands and then collapses extremely quickly. We’re talking the barest fractions of a second. The prevailing theory is that, in that tiny picosecond period of time, the gas inside the collapsing bubble gets super heated to something hotter than the surface of the sun. You’re creating a super hot plasma that exists barely long enough to exist at all and then it’s snuffed out. But, for a moment, that creates a burst of light.
8. Phosphenes Can Create Closed Eye Hallucinations of Light
Here’s a question for you. If you close your eyes and see lights, are they actually lights? If your brain registers something, even a hallucination or a dream, are the lights you saw still technically lights if they’re not real? You saw them after all, right?
Most of us have had the experience of rubbing our eyes and registering what looks like flashes of light as a result. The pressure on your eyes causes flashes in your eyes.These lights are caused by phosphenes and they aren’t just your imagination. There are even efforts being made to restore vision to people blinded by retinal disease by using implants that electrically stimulate phosphenes in your retina.
7. Tribal Rawhide Rattles Filled With Quartz Produced Flashing Lights
Another example of triboluminescence was discovered long ago by Native American tribes in Colorado when they created ceremonial rattles. Like any rattle, these had a handle, a container on the end, and something inside that rattled and made noise when you shook it. But the Ute Indians discovered something unique in the way they constructed these rattles.
While the exterior and the bulb part were just rawhide, for the rattle itself they used quartz crystals. When shaken, thanks to triboluminescence, the quartz crystals rub together and produce a yellow flash. In rattle form, this would cause the crystals to rub together constantly, producing random but frequent light flashes. You can imagine how this would have looked to an ancient, pre-technological society.
The flashes would have lit up the translucent hide during any rituals performed in the dark. The Ute believed spirits were being called and, as such, the rattles had great significance in rituals.
6. You Can Crush Sugar Crystals and Produce Light
Triboluminescence is back again and this time in your sugar. In a fashion similar to cracking ice, you can crush sugar and create energy as light. This was likely first noticed back when sugar was shipped in massive bricks and workers had to chip off smaller chunks for sale or for use. Sugar crystals can be broken down into smaller crystals. In doing so, positive and negative charges are separated and boom, sugar lights.
The light produced by sugar is blue and it is, in a technical sense, lightning. The positive and negative charges build until a static electric charge is produced which ionizes the nitrogen in the air. The result is a brief flash of light and is most often associated with wintergreen lifesavers which used to advertise the fact that if you bit one in the dark you might see a flash of light.
5. Earthquakes Produce Atmospheric Light
When it comes to natural disasters, you expect a light show with something like a thunderstorm which can even include hurricanes. Likewise, a volcano is not going to just produce glowing, orange lava but some of the most dramatic and chaotic lightning you’ll ever see in your life. But those are not the only disasters which can set the sky alight. Earthquakes actually produce atmospheric light as well, but not always.
Sometimes called earthquake lights, this phenomenon appears before quakes occur, sometimes days in advance. Even more mysterious is that there’s no specific way they work. They can appear in different colors and in different shapes. Sometimes they’re green or blue, sometimes pink. Some are globes, some are flashes, some look like flames.
Because the phenomenon is so inconsistent and unpredictable, little hard evidence about it exists beyond recordings of incidents. But reports date back hundreds of years and researchers have found 65 cases back to the year 1600.
Because of how difficult it is to pin down what earthquake lights are, not everyone even agrees they exist and aren’t just totally different light phenomena happening at the same time as an earthquake. For instance, sometimes, these effects have been attributed to power lines being down during the quake.
4. Cherenkov Radiation Causes a Blue Glow in Nuclear Reactor Pools
Possibly one of the coolest forms of light in the world comes from Cherenkov radiation. It’s that eerie glow sci-fi assures us comes from radioactive things and it works thanks to wild and weird physics.
If you’ve ever seen a nuclear reactor, you may have noticed there’s a lot of water used to keep things cool. Water makes Cherenkov radiation work. It happens when charged particles in the water move faster than the speed of light.
Normally you will not find particles moving faster than light but, in a medium light water, light travels at 75% speed and that means the charged particles can move faster. When they collide with each other it produces the strange, blue glow discovered by Pavel Cherenkov.
3. Motyxia Millipedes Glow Bright Green/Blue
We didn’t cover bioluminescence because most of us know about that already. Fireflies are no big surprise, nor are the many species of fish that can produce their own lights. But there are one or two oddballs of nature out there producing light that maybe you never heard of before and that’s why the motyxia millipede is on the list.
Found in Sequoia National Park and limited to a very narrow range in the Sierra Nevada mountains, motyxia millipedes glow bright blue in the dark. This is done to warn off predators by making the millipede hard to miss. In some creatures, like fireflies, light displays attract mates but motyxia are blind so they don’t benefit from their own shiny blue/green show. They are the only millipedes in the world known to do this.
The many-legged light shows are doing predators a favor because if one were to ignore the lights they’d have to deal with the millipede’s toxins which include hydrogen cyanide gas that it can release when attacked.
2. Will-O’-The-Wisps Are Caused by Burning Swamp Gases
If you haven’t ever been to a swamp, you may not be aware of the phenomenon called a Will-o’-the-wisp or swamp lights. These mysterious lights can sometimes be seen in swamps, floating above the water. They are bursts of flame, sometimes sustained ones, that flicker but remain stationary with an eerie, blue light.
The lights are sometimes called fool’s lanterns, swamp lights, and so on. The fool name, usually translated as the Latin ignis fatuus, comes from the fact it could make a fool of travelers at night. If you were wandering a road near a swamp, you might see one of these lights in the dark and mistake it for a lantern, long before electrical lights were a thing. Thinking you’d found a house or inn, you could stray from the path and wander right into the swamp.
Swamp lights are actually caused by gas. The bottom of any bog or swamp is likely going to be full of decaying biomatter. Because it’s rotting underwater, without oxygen, bacteria can eat away and produce an abundance of methane gas. When pockets of methane bubble to the surface and mix with phosphines which can spontaneously combust in oxygen, setting the methane aflame and creating the sustain, burning lantern effect hovering above the water for a short time.
1. The Human Body Produces Visible Light
Has anyone ever told you that you were glowing? Or have you heard someone say it to a pregnant woman, or someone who got over an illness, maybe? It generally means you’re looking good and healthy and vibrant. It’s a figure of speech. But, whether any of us realize it, it’s also a literal description. The human body does produce light; it’s just incredibly hard to see.
There’s no need to squint at yourself in the dark in front of the mirror because it won’t help. The light your body emits, the level of which rises and falls over the course of the day, is not visible to the naked eye. In fact, they’re about 1,000 times less intense than what you can see without help.
Chemical reactions in the bodies of pretty much all living things produce light as one kind of energy during that process. It’s just a small amount and, since it’s not the point of most of those reactions, that makes sense. The light is basically wasted energy.
In a human body, light and heat don’t line up, either. The warmest parts of you are not the brightest, so that light-producing reaction isn’t warming you up too much.
Ultra sensitive equipment has to be used to measure the lights produced by humans. Our lights cycle, producing the brightest light in the afternoon and the dimmest light at night. Your face produces the most light, especially your cheeks, forehead and neck area.