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TedEd Light, Visible and Invisible video

Added Feb 19, 2018 •

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what if you could only see one color imagine for instance that you could only see things that were red and that everything this was completely invisible to you as it turns out that's how you live your life all the time because your eyes can only see a miniscule part of the full spectrum of light different kinds of light are all around you everyday but are invisible to the human eye turn the radio on your favorite songs to the x-rays doctors used to see inside of you to the microwaves that heat up your food in order to understand how this can all be light will need to know a thing or two about what light is light electromagnetic radiation that acts like both a wave and particle archives like waves on the ocean waves crashing on the shore one right after the other the only role in every so often the size of a wave is called its wavelength and how often it comes by is called its frequency imagine being a boat in the ocean waves go by have long wavelengths so often if the waves instead of short wavelengths they'll be close together and you'll be up and down much more often at a high frequency different kinds of light are always they just have different wavelengths and frequency if you know the wavelength or frequency of a wave of light you can also figure out its energy long wavelengths have low energies while short wavelengths have high energies it's easy to remember if you think about being in that both if you were up sailing on a day with short choppy waves pretty high-energy yourself running around to keep things from falling over but I'm a long ways lights relax low energy Tree of Life tells us how to interact with matter for example the cells of Our Lives when we see it's because we are always sensitive to light with a very small branch in it also be called that branch of light visible light inside are red. Are special receptors called rods and cones the rods measure brightness so we know how much like there is cones are in charge of what color of light we see does different phones are sensitive to different energies of light some cones are more excited by light that is long and low energy other cones are more excited by short wavelength high energy light when light hits RI the relative of energy each cone measures signals are brain to perceive colors we perceive is actually visible light in order of its energy and one side of the rainbow is low energy light we see us. The other side is high energy light blue it's light shines on us that has an energy are retina can't measure we won't be able to see it life is too short wavelengths or high energy gets absorbed by the eye surface before I can even get to the retina and Light is too long wavelength doesn't have enough energy to stimulate already at all the only thing that makes one kind of like different from another is its wavelength radio waves have long wavelengths will x-rays have short wavelengths and visible light you can actually see is somewhere in between even though our eyes can detect light outside of the visible range we can build Special detectors that are stimulated by these other wavelengths of light kind of like digitalize with these devices we can measure the light that is there even though we can't see it ourselves so take a step back and think about all of this for a moment even though they seem different the warmth you feel from a crackling fire is the same as the sun shining on you on a beautiful the same as ultraviolet light you put on sunscreen to protect yourself from the same thing as your TV your radio and your microwave now those examples are all things here on Earth things you experience in your everyday life I think even more amazing first gives off the full spectrum of light to when you think of the night sky to see the stars shine with your own eyes but that's just visible light which is only the full spectrum if we had to draw the universe and could only use visible light it'll be like having only one friend on pretty sad to see the universe and it's full spectrum we need to have the right eyes and that means using spell telescopes that can help us see beyond visible light you probably heard of the Hubble Space Telescope and seen its beautiful pictures taken in visible and ultraviolet light but you might not know that they're almost space telescopes in orbit missions that can eat part of the full spectrum of light with telescopes acting as our virtualize both in space and here on Earth we can see some amazing things and the coolest thing of all no matter or energy the light that we see out in universe is the same thing as the light that we can experience and study here on Earth so since we know the physics of how x-ray ultraviolet light or microwaves work here Justin star or Galaxy happening there too so I see your eyes can and can't see just a little bit about the natural world can help you perceive the full spectrum around you all the time

Uploaded by Debra Hood.

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TedEd Light, Visible and Invisible video

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