Unless you’ve been living under a literal rock, you’ve probably heard of or seen light. Scientists will tell you that light is an electromagnetic form of radiation or that it’s a stream of photons. Light exists all around us and is the reason behind a lot of interesting phenomena.
We know that light is essential for life on earth but what else does it do? To help answer your questions, we’ve compiled some facts to help shine some light on the topic. Read on if you want to learn more about light through these 6 amazing facts!
#1. Colors are the reflection of light
Have you ever wondered why green apples are green? The light that we see as humans, is made of a spectrum of electromagnetic waves which all have different frequencies. This spectrum forms all the colors of the rainbow. As light travels, it falls on the surfaces of things where two things can happen. The light can be absorbed or can bounce off. Things appear colored because they absorb some part of the spectrum and not others. The part is not absorbed, bounces off the surface of the item and into our eyes and we see colors. So an apple is green because only the green part of the spectrum reflects off it, while the rest is absorbed.
#2. You can study light to learn about space
Scientists can study the moon, the stars, and other planets from the earth, without needing to go to space. They can do this by using spectroscopy. If you’ve ever asked yourself what is spectroscopy, now’s your chance to learn. The main source of light on our planet is from the sun. We can use sunlight to determine how far away or how big things are in the solar system. Scientists have used this to determine that the moon is moving about 3.78cm away from the earth every year. With spectroscopy, scientists can also tell what stars are made of. This is done by determining their elemental composition, density, and temperature.
#3. Humans see a very small part of the electromagnetic spectrum
Electromagnetic waves can range from low-energy radio waves to high-energy gamma rays. Humans can only see the visible light part of the spectrum with the naked eye. Some animals have better eyesight than humans. Goldfish, for example, may have a bad memory, but they can see both infrared and ultraviolet radiation, which we can’t. The reason for this is because some animals have different or more cone cells in their eyes. These cone cells enable us to register electromagnetic waves and see them, as we would see different colors.
#4. Light is faster than the speed of sound
Have you ever wondered why you sometimes see lightning first before you hear it? Or how you can see the airplane moving, but the sound seems to have a delay. This is because light travels much faster than anything else in existence. The speed of light is about 300,000 km/second which is miles ahead of the speed of sound at about 343 m/s. Light is so fast that it takes only 8 minutes to travel from the sun to earth, which is about 93 million miles away. The speed of light is why you can sometimes see explosions before you hear them.
#5. Bubbles can turn sound energy into light energy
Yep, you read that right. Sound energy can be transformed into light energy underwater by bubbles. Small bubbles can be formed by pulsing ultrasonic sound waves underwater. When these bubbles collapse they produce a beam of light. This phenomenon is called sonoluminescence and it was first discovered in 1934. It has been puzzling scientists ever since. There are many theories that scientists are considering to explain the phenomenon, but none have made a breakthrough yet. But when they do, a Nobel Prize is sure to be in order.
#6. Humans can be bioluminescent too
Bioluminescence is the emission of light from a living organism. You can see it in a wide variety of marine life that glows light blue at night. Because of this, bioluminescence is the largest source of light within the ocean seeing as about 90% of deep-sea creatures glow in the dark. Although not as brightly, humans can be bioluminescent as well. Humans can glow mostly around the cheeks and lips because of chemical reactions with free radicals. This glowing effect is highest during the afternoon. So next time someone tells you you’re glowing, you’ll know why.
So there you have it! We hope that these 6 facts have sparked an interest in you for light. Light can be a fascinating aspect of life. Light is responsible for color, studying the stars, and in some cases, sound. It’s always good to have a fun fact to blow your friends away at the next gathering.