Let’s say the sun goes out at Sundown on the hottest day of the year, 100 degrees. It cools of 25 degrees the first night, just like every night, so 12 hours later, it’s 75. Now, there’s no sun to warm you up again, so it’s just like sundown on a nice spring day, 12 hours later, you lose another 25 degrees (just like you would on that spring night) it’s now 50. 12 hours later, it’s 25, then 0, then -25, then -50, then -75 and -100. After 3 days, it’s pretty much the coldest recorded temperature in history at the hottest point on the globe.
In a week, every single outdoor plant is dead, you can’t even go outside without super cold temperature clothing, nobody can transport materials or do their jobs, everything would shut down, we’re all dead.
Yes, Jake got it on the nose… I’m sorry for the trick question, but I wanted to see how much cognitive dissonance would be generated (or to bait out the Perfect Master or SDSAB) from something like this. The trick is that most of our sunlight is old photons, not new.
I think humans wouldn’t detect it immediately (certainly not until after 8 minutes) and at first, we might notice global warming being reversed. After that, as the sun dims, scientists would catch on pretty quick, then we’d be working on the fastest way to get to the next star on a generational ship. Given a thousand year deadline, we might actually achieve it.
Here’s a link , but since it seems to be down at the moment, here it is cached .
“Trick” questions and “baiting” are things I’d prefer to leave out of General Questions(or any forum for that matter). It smacks too much of “trolling.” I know you weren’t doing that in the classic sense, but it’s not gonna advance your career around here.
the main part of the ‘trick’ involved the fact that the question as posed in the title and the question as posed in the message are not really equivalent.
This doesn’t really work as a trick question as stated in the OP, however. The photon that travels from the photosphere of the sun to strike your retina is exactly as ‘old’ as the travel time from the photosphere to your eye - about eight minutes. Whatever high-energy photon was originally emitted in the sun’s core 10,000 years ago was immediately absorbed. The ‘original’ photon is long gone. The photon emitted from the surface is a new photon, and if the sun stopped producing them,it would instantly tun black.
If a blue-light photon from the sun hit a plant leaf 30 million years ago and got absorbed by chlorophyll, resulting in the fixation of some carbon, which then got turned into coal that I burn in a fireplace and thereby release a red-light photon, I doubt that you would argue that the light from the fire was 30 million years old (plus or minus 10,000 years).
IIRC mean travel time of a photon from the core, where it is emitted by fusion reactions, to the surface, is on the order of a few hundred thousand years. Cos it keeps getting absorbed and re-emitted by plasma along the way.
Of course that’s ignoring the existential questions about whether or not it’s the same photon after being re-emitted as it was before it was absorbed. I was never very good on the whole ‘light-interacting-with-matter’ thing . It’s probably better, rather than talking about the photon taking ~100,000 yrs to get to the surface, to talk about the energy getting there.
Anyway, since the natural interpretation of ‘producing light’ is ‘photons escaping from the surface’, it seems 8min is a better time-frame to think about than 100,000 yrs. For the latter you’re better off talking about a hypothetical cessation of nuclear fusion.
Photons don’t really age anyway (in fact they don’t experience time at all), but no - if the process of nuclear fusion in the centre of the sun abruptly ceased, it would take a very long time for the effects (or lack thereof) to propagate to the surface.
What makes you think the scientists would have a thousand-year deadline, and where are they supposed to get food and the materials necessary for an interstellar ship?
Actually, it does, to the extent that photons can be said to bounce around. Photons get absorbed and then immediately re-emitted in a random direction, with the net effect being individual photons bouncing around until they can random-walk their way to the surface.
Even given this interpretation, though, we humans (or at least those of us interested in such things) would know immediately, contrary to the OP. The same reactions in the core which produce the original photons also produce neutrinos, which unlike the photons can generally zip straight out without bouncing. There are a number of neutrino detectors on Earth which continually pick them up, and if the neutrinos suddenly stopped, at all of the detectors at once, it’d be a big clue that something freaky was going on.
In the movies, funds would be mobilised to send a magic spaceship to the core of the sun to start it going again. In reality, it would be too far in the future to worry about, right up until it was too late to do anything about it.
Suppose you argue that a photon which is absorbed and then re-emitted at the same wavelength is the same photon before and after the absorption, rather than two different photons. There still remains the problem that the spectrum of radiation from the surface of the sun does not match the spectrum that would be emitted from the core if we could see it, because the core is so much hotter. Because the wavelengths don’t match, we can’t be seeing the original photons.
. It’s probably better, rather than talking about the photon taking ~100,000 yrs to get to the surface, to talk about the energy getting there.