Physics Girl

what color do you think the Sun is the sun's way because it's a light source though so it would be all the color fire reddish orange orange yellow because of a teeth yellow cuz that's the way it looks up in the sky what above the atmosphere what color do you think the Sun would look probably not yellow anymore because there's an atmosphere that we're looking through so I'm going to give you the answer the color of the Sun is actually white it's a bit of a misleading question because you can't really take like one of the colors you know between red orange yellow green blue and say that the Sun is only that color because the Sun has all the colors knowing that this one is white which of the colors of rainbow do you think this Sun emits the most of look it's orange orange II like this yeah cuz it looks good oh yeah pretty are you okay yeah I would say just a clear white light if you want to know what color it emits most it's actually green really okay I don't know why it would be green last question why do you think that plants are green because the concentration of chlorophyll so fiber probably is clear and so you can just see that colors enjoyment well because if the Sun is emitting mostly green light and that would be absorbing the most light that's available from the Sun that's what I thought yes I set up the question so you'd think that the spectrum of the Sun was related to green plants you're welcome what I thought that they were my train of thought let something like this leaves are green because chlorophyll is green and chlorophyll is the molecule that takes light from the Sun and turns it into usable energy in the plants photosynthesis now if the Sun spectrum peaks in green and even the light that makes it all the way down through our atmosphere peaks in green then plants are green to absorb the most green light wait hold on if leaves are green that means they are reflecting green light they're shooing away the most common color of light from the Sun what why that doesn't work that I don't know it doesn't work but also I did ask a bit of a leading question telling you that the Sun emits the most green and then asking you about green plans it sort of be thinking about green you cheated I can see if Klaus wanted to absorb the most energy wouldn't they absorb all the colors wouldn't they be black the black pigmented plants exists but they're rare like helium so maybe this whole getting rid of green thing has its benefit I mean it's kind of a global thing right like all plants on earth are pretty much green if they were black then the earth would look like this so why are plants green seems like something scientists should know but the truth is they don't know why plants evolved to be green here's some super interesting theory though plants absorb sunlight to make food like every good farmer's daughter knows more sunlight equals more food but there's a point called saturation we're shining more light on a leaf does it lead to a higher output so full sunlight on say a spinach leaf is three to five times the saturation level it's like being served three to five hamburgers when you can really only fit one in your stomach so reflecting away some green light isn't necessarily bad if plants always got full sunlight but they don't [Music] one theory goes that chlorophyll being bad at absorbing green light means that plants can actually absorb more light overall what here's how that works chlorophyll does absorb and use some green lights but because not all green light gets absorbed at the surface of the leaf some of it can then penetrate deeper into the leaf like burrowing worms and even if the top of the leaf gets saturated and get this 90 percent of blue and red light is absorbed the upper one fifth of a spinach leaf so that means that chlorophyll deeper down is there to absorb the green light that made it through genius and as an added bonus this prevents your leaf from overheating it's like reheating your burger in an oven versus in a fire you don't want a frozen patty with a burnt bun plus lower leaves of the plant get some of the green light that is reflected and scattered which is good for them because you know if you ate all three to five hamburgers then your family would starve why chlorophyll b evolutionarily awesome maybe it's a molecule that's easier for evolution to come up with maybe it's more efficient at turning suddenly to energy than other potential photosynthesizing black or purple pigments that absorb green better but neither of these series is in the lead nor this next one early light guzzling life on earth included in archaea called halobacteria that absorbs green and reflects red and blue so it looks kind of purple it's what gives this lake its purple color covered in this stuff Earth might've looks like this except the plates would have been in different places three billion years ago but I digress now the theory goes like this if halobacteria we're absorbing all the green light then another say green algae that were layers deeper in the ocean we have to make do without green light it's like if someone else ate the hamburger patty and lettuce and threw you the bun you have to get good at surviving off of carbs which brings me to the last theory which is that maybe evolution is not a perfect engineering process maybe chlorophyll is just good enough I know I'm not super happy with that answer either but it's possible that chlorophyll was the accident we got during the complex process of evolution on earth maybe it was slightly different condition it would go differently if life on earth went through evolution again so what color is the Sun well I'd say white what kind of greenish and they said I'd say because color is kind of a perception thing more than a physics thing but that's a topic for a whole other video so if you have any questions about the world around you or really anything that could get me out of the studio and filming back outside let me know in the comments and hey happy physics thing [Music]