What Is Faster Than Light?
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So we raise the Off-Topic question
What is faster than light?
[quote name=“zerodrama” post=“45327” timestamp=“1387256572”]
[quote author=Kevlar link=topic=6061.msg45246#msg45246 date=1387237237]
… that nothing could travel faster than the speed of light. Turns out I was wrong on both accounts.
[/quote]Come again?
That neutrino thing failed.
What is this faster than light you speak of?
[/quote][url=http://en.wikipedia.org/wiki/Faster-than-light#Tachyons]Wikipedia - Tachyons[/url]
[quote]"In special relativity, it is impossible to accelerate an object to the speed of light, or for a massive object to move at the speed of light. However, it might be possible for an object to exist which always moves faster than light. The hypothetical elementary particles with this property are called tachyonic particles. Attempts to quantize them failed to produce faster-than-light particles, and instead illustrated that their presence leads to an instability.Various theorists have suggested that the neutrino might have a tachyonic nature, while others have disputed the possibility."[/quote]
Other easily googled links.
[url=http://rt.com/usa/nasa-warp-engine-light-488/]http://rt.com/usa/nasa-warp-engine-light-488/[/url]
[img]http://img.rt.com/files/news/1f/db/80/00/kinopoisk.ru-star-trek-1295635.si.jpg[/img][url=http://www.livescience.com/27920-quantum-action-faster-than-light.html]http://www.livescience.com/27920-quantum-action-faster-than-light.html[/url]
[img]http://i.livescience.com/images/i/000/033/080/i02/entangled-photons.jpg?1352213401[/img]What do we all think?
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No, the answer is more mundane I’m afraid.
Special relativity is a funny thing. It states that the speed of light is a constant regardless of your frame of reference. This particular wrinkle gives rise to all kinds of seemingly strange phenomenon, such as the fact that the universe itself will can outpace the speed of light. Just how this will happen is a bit complicated, so let’s begin at the very beginning: the big bang. Around 14 billion years ago, all matter in the universe was thrown in every direction. That first explosion is still pushing galaxies outward. Scientists know this because of the Doppler effect, among other reasons. The wavelengths of light from other galaxies shift as they move away from us, just as the pitch of an ambulance siren changes as it moves past.
Take Hydra, a cluster of galaxies about three billion light years away. Astronomers have measured the distance from the Earth to Hydra by looking at the light coming from the cluster. Through a prism, Hydra’s hydrogen looks like four strips of red, blue-green, blue-violet and violet. But during the time it takes Hydra’s light to reach us, the bands of color have shifted down toward the red endâ€"the low-energy endâ€"of the spectrum. On their journey across the universe, the wavelengths of light have stretched. The farther the light travels, the more stretched it gets. The farther the bands shift toward the red end, the farther the light has traveled. The size of the shift is called the redshift, and it helps scientists figure out the movement of stars in space. Hydra isn’t the only distant cluster of galaxies that displays a redshift, though. Everything is shifting, because the universe is expanding. It’s just easier to see Hydra’s redshift because the farther a galaxy is from our own, the faster it is moving away.
There is no limit to how fast the universe can expand. Einstein’s theory that nothing can travel faster than the speed of light in a vacuum still holds true, because space itself is stretching, and space is nothing. Galaxies aren’t moving through space and away from each other but with spaceâ€"like raisins in a rising loaf of bread. Some galaxies are already so far away from us, and moving away so quickly, that their light will never reach Earth. Therefore, these galaxies are traveling faster than the speed of light relative to us.
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[quote name=“Kevlar” post=“45336” timestamp=“1387259916”]
It states that the speed of light is a constant regardless of your frame of reference…
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Some galaxies are already so far away from us, and moving away so quickly, that their light will never reach Earth. Therefore, these galaxies are traveling faster than the speed of light relative to us.
[/quote]I understand everything you’ve said with the exception of how the first and last thing seem to contradict.
So it’s a yes and a no at the same time?
Like… Technically yes but relatively no.
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[quote name=“Kevlar” post=“45336” timestamp=“1387259916”]
Around 14 billion years ago, all matter in the universe was thrown in every direction. That first explosion is still pushing galaxies outward.
[/quote]The explosion is not pushing galaxies. The space itself is inflating.
Which is kind of funny as my eye is part of space too, it should be also inflating…so how to see the inflation?
I know, I know, gravity interfere with this process somehow, thats why we are able to measure red shift right? Cos our telescopes are material toys on big ball from some other weighty material.Bottom line: it seems our knowledge of universe is very weak, at least I have this feeling…
+And what about Quasars! Oldest visible stuff, very far supermasive black holes? Wait? Oldest visible things are big-ass blackholes? Do they not need some time to develop?? (first stars, then blackholes…not?)
Edit: by oldest I mean oldest :) = closest to big bang = young. Got it? -
[quote name=“Calem” post=“45339” timestamp=“1387260494”]
[quote author=Kevlar link=topic=6113.msg45336#msg45336 date=1387259916]
It states that the speed of light is a constant regardless of your frame of reference…
…
Some galaxies are already so far away from us, and moving away so quickly, that their light will never reach Earth. Therefore, these galaxies are traveling faster than the speed of light relative to us.
[/quote]I understand everything you’ve said with the exception of how the first and last thing seem to contradict.
So it’s a yes and a no at the same time?
Like… Technically yes but relatively no.
[/quote]I know, it’s a bit mind bending at first.
It’s all about relativity.
The speed of light is 299,792,458 m/s. This is an absolute, no matter where in the universe you are. This idea is VERY counter-intuitive at first glance, because it means that if I were moving away from you at some fraction of that speed, and you shined a flashlight at me, I would measure your beam as moving at 299,972,458 m/s, and if I reflected that light back to you with a mirror, you would measure it at 299,972,458 m/s, EVEN THOUGH we’re moving away from each other. Our motion relative to each other changes nothing about the speed of light as measured relative to each other. Yet it still takes time to travel… specifically it takes 1/299,972,458th of a second to travel 1 meter.
That means that a galaxy, as measured relative to us, can be moving away from us at a speed faster than 299,972,458 m/s. Yet to it, when it measures the speed of light, it sees 299,972,458 m/s, because from it’s frame of reference it’s standing still, That’s because it’s space itself that moving away from us. It’s the universe that’s expanding, and it’s being carried along in space, like a raisin in a loaf of rising bread in an oven.
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what if universe is an Hologram.
[url=http://worldsciencefestival.com/videos/a_thin_sheet_of_reality_the_universe_as_a_hologram]http://worldsciencefestival.com/videos/a_thin_sheet_of_reality_the_universe_as_a_hologram[/url] -
[quote name=“Kevlar” post=“45362” timestamp=“1387266669”]
and it’s being carried along in space, like a raisin in a loaf of rising bread in an oven.
[/quote]Now seriously, what make raisins so special? So that space within objects act diferently than “empty space” (I dont think there is empty space, absolutely empty space in our universe…)??
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I think the big bang was actually some false starts until it 'sploded.
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[quote name=“Calem” post=“45330” timestamp=“1387257861”]
What is faster than light?
[/quote]
Bad News.
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[quote name=“Kevlar” post=“45362” timestamp=“1387266669”]
[quote author=Calem link=topic=6113.msg45339#msg45339 date=1387260494]
[quote author=Kevlar link=topic=6113.msg45336#msg45336 date=1387259916]
It states that the speed of light is a constant regardless of your frame of reference…
…
Some galaxies are already so far away from us, and moving away so quickly, that their light will never reach Earth. Therefore, these galaxies are traveling faster than the speed of light relative to us.
[/quote]I understand everything you’ve said with the exception of how the first and last thing seem to contradict.
So it’s a yes and a no at the same time?
Like… Technically yes but relatively no.
[/quote]I know, it’s a bit mind bending at first.
It’s all about relativity.
The speed of light is 299,792,458 m/s. This is an absolute, no matter where in the universe you are. This idea is VERY counter-intuitive at first glance, because it means that if I were moving away from you at some fraction of that speed, and you shined a flashlight at me, I would measure your beam as moving at 299,972,458 m/s, and if I reflected that light back to you with a mirror, you would measure it at 299,972,458 m/s, EVEN THOUGH we’re moving away from each other. Our motion relative to each other changes nothing about the speed of light as measured relative to each other. Yet it still takes time to travel… specifically it takes 1/299,972,458th of a second to travel 1 meter.
That means that a galaxy, as measured relative to us, can be moving away from us at a speed faster than 299,972,458 m/s. Yet to it, when it measures the speed of light, it sees 299,972,458 m/s, because from it’s frame of reference it’s standing still, That’s because it’s space itself that moving away from us. It’s the universe that’s expanding, and it’s being carried along in space, like a raisin in a loaf of rising bread in an oven.
[/quote]It’s fascinating, I’ll agree, but the idea relies on the speed of light being a constant. Scientists have been able to speed up and slow down light in the laboratory: [url=http://scienceblog.com/light.html]http://scienceblog.com/light.html[/url] Who is to say that light behaves the way we believe it to behave everywhere in the universe? Also, who is to say that light has always behaved this way? I’m not saying that I disagree, but we have no empirical evidence of either of these assumptions. Still though, fascinating stuff. Go science!
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[quote name=“MTRisner” post=“45506” timestamp=“1387299166”]
It’s fascinating, I’ll agree, but the idea relies on the speed of light being a constant. Scientists have been able to speed up and slow down light in the laboratory: [url=http://scienceblog.com/light.html]http://scienceblog.com/light.html[/url] Who is to say that light behaves the way we believe it to behave everywhere in the universe? Also, who is to say that light has always behaved this way? I’m not saying that I disagree, but we have no empirical evidence of either of these assumptions. Still though, fascinating stuff. Go science!
[/quote]Light always goes at c = 299,7blah. When they slow light down, they are inducing a delay between receiving and re-emitting. It’s slowed down by being trapped in electron energies.
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[quote name=“zerodrama” post=“45509” timestamp=“1387300125”]
Light always goes at c = 299,7blah. When they slow light down, they are inducing a delay between receiving and re-emitting. It’s slowed down by being trapped in electron energies.
[/quote]Of course. I understand the concept, my point was more eluding to the possibility that maybe we don’t have the entire puzzle figured on and that scientific discovery has historically changed the way that we view many key discoveries from the past. I feel that, as a whole, we are quick to accept and not question what’s currently being accepted as fact. I would love to see something man made travel at the speed of light (or greater). It may be impossible now, but things have been impossible in the past that we see every day. Then again, maybe I read/watch too much sci-fi. :D
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:o
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Actually, time slows down close to a mass. This is Einsteins General theory of relativity and why gravity works.
Imagine a space craft passing Earth. Because of it’s huge mass, the Earth slows down time, that slow down is reduced with the normal square of the distance from the center of mass.
If Earth is on the left, as the space ship passes, time is slower on the left.
So a straight line in space results in a curve. The craft is attracted left towards the Earth. i.e. the left side travels less, because time is slower…
The same for a humans on the ground, time goes slightly slower at your feet than your head. When you move you fall forward and walking is the act of keeping you up…
Inside materials the same effect is visible. Light can be slowed down many times, it then emerges at full speed.
A very interesting subject, when do we get on to quantum theory?
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[quote name=“wrapper0feather” post=“45526” timestamp=“1387301934”]
Actually, time slows down close to a mass. This is Einsteins General theory of relativity and why gravity works.Imagine a space craft passing Earth. Because of it’s huge mass, the Earth slows down time, that slow down is reduced with the normal square of the distance from the center of mass.
If Earth is on the left, as the space ship passes, time is slower on the left.
So a straight line in space results in a curve. The craft is attracted left towards the Earth. i.e. the left side travels less, because time is slower…
The same for a humans on the ground, time goes slightly slower at your feet than your head. When you move you fall forward and walking is the act of keeping you up…
Inside materials the same effect is visible. Light can be slowed down many times, it then emerges at full speed.
A very interesting subject, when do we get on to quantum theory?
[/quote]Energy exchanges happen freely in near 0g. That’s how we push things. Energy exchanges lose energy to gravity which results in delayed reactions so you age slower. When you get a large mass it becomes a black hole called trollbox.
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[quote name=“zerodrama” post=“45586” timestamp=“1387311205”]
Energy exchanges happen freely in near 0g. That’s how we push things. Energy exchanges lose energy to gravity which results in delayed reactions so you age slower. When you get a large mass it becomes a black hole called trollbox.
[/quote]This is true.
-GMm/r=BTC-e(trollbox)
Where G is the gravitation constant, M is the mass of the attracting body, and r is the distance between their centers…
