Science 4: UV light
Today we're going to teach about an invisible form of light that's like...totally there. We're not trying to trick you or anything. You can't see air, can you? Well, UV light is just like that, except you can't breathe it.
|Elementary and Middle School||4th Grade|
UV radiation, also known as UV light, is a form of electromagnetic radiation with a frequency [Coop pointing at a blackboard]
that's slightly higher than good ol' visible light.
So maybe it's time we turn the spotlight on UV radiation. [Crowd cheering]
It's invisible, so a spotlight won't help us see it or anything, but…you get the idea. [Spotlight searching around an empty stage]
UV radiation is probably most famous for its association with the sun.
Along with lots of other kinds of radiation, the sun beams UV radiation at our planet, [Different types of radiation being emitted from the Sun]
which can be both a blessing and a curse. [UV rays hitting the Earth]
It's a blessing if you like getting a tan.
The UV rays darken the melanin in human skin, which gives the body protection. [UV rays hitting an arm]
But it's a curse if you try to tan for too long.
Exposure to too many UV rays for too long means you're in for a nasty sunburn, and that's
never a good look.
No matter how much red might be "your color." [Guy in a Santa costume on a beach]
UV light comes from more places than just the sun, though.
If you've ever played laser tag, you've probably been in contact with black lights…y'know,
those weird lights that make whites really bright and give your teeth a spooky glow.
Yup, black lights emit UV light, too. [Kid smiles and his teeth are glowing]
And even though UV light is beyond the range of human sight, that doesn't mean it's invisible [Dino pointing at a blackboard]
Insects, for instance, have no problem seeing UV light. [Insects flying around a UV light bulb]
And sure, it might be kind of embarrassing knowing that insects can do something that [Fly is swatted]
you can't, but look on the bright side!
Humans are still the only species capable of dancing on rollerblades. [Girl dancing while rollerblading]
For now, at least…clever insects… [Ant wearing rollerblades]
Insect's ability to see UV light isn't just a nifty party trick.
A lot of flowers have evolved nectar guides, which are patterns that help guide pollinators [Coop pointing at a blackboard]
to their sweet, sweet rewards.
Some of these patterns are visible to humans…
…but some of them are completely invisible to us unless we're using a black light. [A black light reveals patterns on a flower's petals]
However, those UV-fluent bugs can follow these flowers' signals without any trouble, or black [Bee flying to a flower]
Which is good, because it would take a lot hours at the gym for an insect to lug around [Group of bees carrying a black light bulb]
a black light.
Unfortunately for insects, their ability to see UV light can be used against them. [They drop the light bulb]
The bulbs inside bug zappers are special UV light bulbs. [Someone swats an insect on their arm]
The light attracts the bugs closer and closer… [Insect flying into a bug zapper]
No more bug.
…Yeah, we guess we're not actually that jealous of them anymore. [Guy rollerblading past the smashed light bulb]
We'll take pride in our sweet rollerdance moves. [Guy rollerblades into a group of insects and falls over]