What Can Frogs See That We Can't?
980,229
Published 2013-03-04
What would you see if you were drifting through space, looking back at the sun? Well its light intensity would decrease as the inverse square of distance from the sun. And you would imagine the intensity would decrease smoothly, asymptotically approaching zero.
But this is not what happens.
If you had sensitive enough eyes, like frogs' eyes, you would find that at some point the sun would start to flicker. You would see flashes of light separated by complete darkness. And as you drift further from the sun, what's strange is that these flashes do not decrease in brightness, but they do become less frequent. That's because light comes in lumps, called quanta or photons, which are indivisible. So if you try to spread light out very thinly, you reach a point where there are only single bits of light reaching an observer's eye at any given time.
I should acknowledge the book "The Fabric of Reality" by David Deutsch, which contains a similar story about a frog and a torch. It inspired me to make this film. Thanks also to MinutePhysics for reviewing earlier drafts and suggesting I make it more ridiculous.
All Comments (21)
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I love how all the intellegent youtube channels all link to each other so often
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sun quantum flashes is Morse code from illuminati
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So a frog can see a single photon hitting its eye. And yet it can't see me coming, catching it for the next dissection in class.
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Do we get to know why frogs see that?
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they are closer than you'd need to be to reach the single photon limit, I'm thinking roughly a million light-years
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Was this somewhat eerie to anyone else?
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This went a lot different than I expected
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a frogs rods out past pluto procuring fleeting flickers of distant sunlight leaves me quite content in my understanding of photon phenomenon.
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Man, that distance to detect single photons from the sun would be enormous! Does the first photon emitted by the sun already traveled that distance? And can frogs really sense a single photon?
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If you tested them with and without single photons, they would be statistically slightly more likely to say they saw one when they did, though there would be many false positives and negatives.
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Plate is a quantum of a dinner set. But a knife is always a quantum of the washing up.
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the fact that we have pictures of pluto nowadays is insane
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Man you even make stuff that i already knew sound and look interesting. That's a talent
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I'm glad you came back to Earth, Derek!
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it's great, but.. frogs? i'm waiting to hear that part
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"So as you continue past the pluto formerly known as a planet" - It's still a planet, a dwarf planet, but still a planet.
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Thought can be quantized into units called D'oh's.
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Could you make a video on how the frog's eyes are different from our eyes? That would be really interesting!
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Now i somewhat think hot pockets are too energy hungry
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then explain why I only go frogging at night and they don't even see me....just like a sitting duck.
