Just Enough Light Science to Get You Interested
What is Light?
Light, in simple terms, is energy. There are 4 forces working in the universe; gravity, strong nuclear force, weak nuclear force and electromagnetism. Light is a part of electromagnetism specifically electromagnetic radiation, I know radiation is usually used in scary contexts like with radiation poisoning or nuclear fallout but radiation simply means that energy is moving, either as a wave or particle from one place to another.
Light Radiation Works on a Spectrum
So Why Can't You See ALL The Light
If you look at the image above you'll see that visible light only makes up a very small portion of the whole spectrum, the reason you can't see higher or lower is all to do with wavelengths. In our eyes we have little cones called 'fovea' that can pick up waves between around 400 to 700 nanometers because that's the limit of what our brains can interpret. An interesting thing to consider is when you put something in the microwave you're actually bombarding it with light that's just too big for you to see, I know it sounds weird but your eyes just can't pick up those larger wavelengths of light. The bigger wavelengths can actually carry a lot more heat which is why they use microwave radiation to cook food, where the smaller wavelengths are more reactant and the ultraviolet end of the spectrum are what cause you to tan and can result in sunburns or some forms of skin cancer after prolonged exposure.
Light is Unique
Light is a very odd thing, light is made of particles called photons and yet these photons behave as waves. As for the difference between those two imagine picking up a spherical rock and giving it a toss into a pond, you gave the rock energy and it travels and collides with the water and transfers the energy you gave it in a concentrated spot. However, with waves using the above example is when the rock hits the water's surface it creates a splash and that splash sends those little ripples across the surface. Particles will transfer energy narrowly while waves will spread the energy throughout its medium very broadly. Light can have this effect because photons have no mass so even though it's a stream of particles they behave like one fluid body and can be reflected, refracted and diffracted like any other wave can!
"It seems as though we must use sometimes the one theory and sometimes the other, while at times we may use either. We are faced with a new kind of difficulty. We have two contradictory pictures of reality; separately neither of them fully explains the phenomena of light, but together they do."— Albert Einstein, Leopold Infeld (1938). The Evolution of Physics
Light: Wave or Particle?
In the scientific community back in Isaac Newton's time all the way through Einstein it was a debate whether light was a wave or particle because both sides had phenomenon that they could explain but the other could not, such as light being able to be reflected and refracted just as a wave should be but also being able to make electrons eject when shining on metals which would only be able to happen if a particle with energy was being delivered to the electron to excite it enough to shoot off. Einstein was the first one to properly explain this and has been come to be known as wave-particle duality
The Sun is a Wonderous Body
What This Means to Me
Light is truly a fascinating subject in my opinion and was one of the first things I remember being passionate about...you know besides cartoons and video games when I was a toddler. Nothing captivated me quite like space and it blew my mind to see those stars knowing they were so far away, realizing that light traveled millions of miles in my direction just to be seen by a kid looking into the sky at the right time was instrumental in shaping who I am because it sparked a real desire to know about space and light and science and everything I could get into my head. I'm not an expert, I don't have a degree in astronomy or quantum physics but I've spent my life loving science and sharing what I've learned to others that might not have heard it before on the off chance I can spark that same desire in someone else is why I wrote this and why I hope to write more.