t' = factor of time dilation, t = time, v = how fast you're going, c = speed of light
In the reference frame of a photon, all distances parallel to the direction of propagation become zero due to Lorentz contraction. (Read the first link which explains space contraction.) Because space contracts infinitely, the distance a photon travels, from its perspective, is zero. The zero distance is covered in zero time. In the reference frame of the photon, every photon of light comes into being at a single point, then instantly vanishes at the same point.
In other words, a photon of light connects its emitter and its absorber instantaneously. However, from our perspective that photon is emitted at the speed of light and travels at that speed until it is absorbed, and the time interval from emission to absorption, from our perspective, could be near zero to the age of the universe.
Why did I ask that question? I was reading a book on Einstein (or by Einstein?) and it talked about the twin paradox. There's a set of twins, and one of the twins goes on a spaceship with a clock onboard while his twin stays on Earth. The spaceship then orbits around the Earth near the speed of light for 30 seconds, according to the clock on the spaceship. When the spaceship lands, the twin on the spaceship meets his twin, but his twin who stayed on Earth has aged and is an old man! This is to illustrate how time slows down, or dilates, the faster you move in the reference frame of a stationary observer. So I had a question: If the faster you go, the slower time moves, and the speed of light is the "speed limit" in the universe, does that mean time stands still for a photon of light?
Why did I ask that question? I was reading a book on Einstein (or by Einstein?) and it talked about the twin paradox. There's a set of twins, and one of the twins goes on a spaceship with a clock onboard while his twin stays on Earth. The spaceship then orbits around the Earth near the speed of light for 30 seconds, according to the clock on the spaceship. When the spaceship lands, the twin on the spaceship meets his twin, but his twin who stayed on Earth has aged and is an old man! This is to illustrate how time slows down, or dilates, the faster you move in the reference frame of a stationary observer. So I had a question: If the faster you go, the slower time moves, and the speed of light is the "speed limit" in the universe, does that mean time stands still for a photon of light?
Eintein's paper in 1905: http://www.fourmilab.ch/etexts/einstein/specrel/www/
The first half deals with time dilation and space contraction. Time expands from the viewpoint of the stationary observer, and space contracts from the viewpoint of the moving observer! We'll get to Lorentz contraction later. It doesn't directly answer the question.
Informative webpage on time and the speed of light: http://www.costellospaceart.com/html/time_and_the_speed_of_light.html
The first half deals with time dilation and space contraction. Time expands from the viewpoint of the stationary observer, and space contracts from the viewpoint of the moving observer! We'll get to Lorentz contraction later. It doesn't directly answer the question.
Informative webpage on time and the speed of light: http://www.costellospaceart.com/html/time_and_the_speed_of_light.html
27 scientific replies:
it doesn't matter whether it's coming out of your flashlight or the sun
That is a crazy thought that from in the photons reference frame it travels 0 distance for 0 time...but for us it might be travelling 100 million light years, taking 100 million years...hard to get my head around!
Hm, I have no idea, but is that molecular genetics? :D (dont understand it as a rebuke ;))
Hah, it says at the very top.. and physics! Molecular genetics is just genetics at the molecular level instead of like a multi-generational allele viewpoint.
Good point, though Neon. I'll add some molecular genetics stuff later. :)
okay, that was a really good explanation haha.
I fucking knew it! hahah keep posting
This is pretty heavy stuff. This is basically time travel in one direction yes? If we had the technology to do this we could have people act as ambassadors from the past. Living time capsules as it were.
The twin paradox? Sure, it can be like that. The thing is the speeds required for relativistic effects to take place aren't even remotely achievable right now. I think the amount of contraction of space is like .01 mm for 300 km if you're traveling on the fastest satellite we have right now, which is like thousands of meters per second.
Great explanation, made it much easier to understand.
Maybe time just doesn't exist for a photon, or it can't experience it... Idk I'm bad at abstract concepts ^_^
Great explanation man, it is sort of an abstract concept and people have argued about this for years and its been a popular subject of debate! I think we will just never know for sure! Though its great to speculate
This stuff goes way over my head. I still don't understand properly after reading twice. Gonna have to check out that original paper :P
Man i'm to tired to understad it now. Gotta get some sleep;)
I can almost wrap my mind around this concept. It seems a bit complicated, and adding math only further confuses me, but it's interesting nonetheless. Also, thanks for the feature! Hooray for wild shots in the dark, eh?
mind bending stuff, gets me thinking
Is the speed of light the speed limit only because it's something we can measure, if you turn off a light doesn't darkness happen just as quickly?
Awesome information. I learned something today!
i heard that they have theorized at least 11 dimentions, and there may be more. cool. +followed
hey wow I never would have thought of that. good post, keep em coming.
@NaturalOne I think you're correct. If a light stops working, the last photon will leave a "trail" of darkness at the speed of light.
Im a total noob regarding this kind of things, but i find it fascinating!
Damn dude. I took Physics 1 and kinda wish I could go deeper, but it's all too far for me personally.
My God, physics is so freaking amazing. Shame I gave up learning during schooldays... Fascinating blog, following!
Ok i can't give you an answer to that.. but time standing still for a cell doesn't sound possible to me.
It's a bit hard to understand but I like it. Physics is always interesting to me. I'll look into more and hopefully can get a simpler explanation. +1!
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got this on my exam today :D
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