Einstein's theory 'may be wrong'. Sweet

[JuicyCivNewbie]

If you travelled faster than light, you'd travel backwards in time. Tachyons (hypothetical FTL particles) would travel backwards in time. I think (from what I've heard), but I'm not sure, that they'd be undetectable.

Time stands still if you travel at light speed.

BTW it's easy to slow light down. Light travels slower in water, for example. Actually, it's possible to accelerate particles to faster than light in water speeds.

 

[Switch625]

There is nothing in Einstein's theory that forbids anything travelling faster than light. What is forbidden is travel at lightspeed. Common sense would seem to indictate that since travel at the speed of light is impossible, travel faster than light in not possible as well. In this case, common sense may well fail us.

Don't ask me how one would test such an idea, but there it is.

 

[marshal zhukov]

Let say that I manage to travel 63 times faster than light for a year.
I would then be 63 light years away from Earth.
IF I were to point an extremelly large telescope towards Earth would I then be able to see Hitler invading Poland " live "?
Because 2002 - 62 = 1939 , the light that reflected of or from the invading Panzers is currently 62 light years away form here.

Is that what you, JuicyCivNewbie, mean about traveling back in time?

 

[basta72]

If the speed of light isn´t a constant, then what is the max speed of light? And if light isn´t constant then is should be possible to make it go faster or slower.

If you have an encoder that could transform a human into specific pattern of fotons and then send it away, as light, at the speed of light. Then you could have a decoder or reciever at the destination point that reads the pattern and rebuild the poor human. It may work, atleast something similar works in Star Trek

But the human the got sent away as fotons isn´t the same as the one at the destination point, they are just identical.

I belive that some scientist at CERN (European Organization for Nuclear Research) managed to move one particle from one place to another without actually moving it. Couldn´t find an article/link, just remember that I read about it somewhere.

 

[IceBlaZe]

The speed of light is 300,000 km/s in nothing but in reality it is slower, depending on the environment/material it is travelling in.

 

[The Troquelet]

First of all, photons are a different kind of particle than the atoms and quarks that make up regular matter. Radiant energy is OK for transmitting electronic information, like radio or internet or TV, though.

Yes, the speed of light is constant, 3.00 x 10^8 m/s, or 300,000 km/s, or about 176,000 mi/s.

Refraction is the bending of light rays, like bouncing off a mirror: that explains the "straw in water" effect, the light is not moving in a straight line but deflected. It doesn't "slow light down".

Faster than light speed is impossible, because to get there you must accelerate first. Then again, once you are about to accelerate to FTL, you hit LS, or rather you don't because you can't go at LS. So, it's impossible to go PAST LS either

Besides, for most purposes lightspeed is useless. Let's see how long it would take you to accelerate to Lightspeed. Well, 1 G if I remember correctly is an acceleration of 1 meter per second. That's pretty comfortable for a human: it's normal gravity. But, to get to lightspeed at that acceleration, it would take 3.00x10^8 seconds, or about 228.31 years. Wait, that doesn't sound so bad! I must be messing up somewhere.... well, in any case, the fuel you would have to burn for more than 2 centuries, and at constant acceleration, would be pretty bad. What distance would you go?

Well, the 1st second would have you go 1 meter. The 2nd would have you go 2 meters, the 3rd 3.

So, it's reasonable to assume that the total distance is 3.00x10^8 meters plus all the numbers below that. That's quite a bit. Just in the last second you would travel a whole light second, which is enough to go around the world a few times, eight I think. Just moving 8 minutes at this speed, would take you to the Sun.

Then, if you were to slow down again, at the same reasonable 1 G, your total trip would be some 456 years, if you wanted to keep a safe grav force. And, the whole distance would have to be in a straight line.

 

[IceBlaZe]

Originally posted by The Troquelet

Yes, the speed of light is constant, 3.00 x 10^8 m/s, or 300,000 km/s, or about 176,000 mi/s.

Refraction is the bending of light rays, like bouncing off a mirror: that explains the "straw in water" effect, the light is not moving in a straight line but deflected. It doesn't "slow light down".

Speed of light is not constant.
When light goes from one material to another it changes speed and therfor bends.
Each material has it's refraction index, which is actually calculated by speed differences of materials, etc.

Here is a rather simple explanation: http://www.ps.missouri.edu/rickspage/refract/refraction.html

When we talk about the speed of light, we're usually talking about the speed of light in a vacuum, which is 3.00 x 108 m/s. When light travels through something else, such as glass, diamond, or plastic, it travels at a different speed. The speed of light in a given material is related to a quantity called the index of refraction, n, which is defined as the ratio of the speed of light in vacuum to the speed of light in the medium:

index of refraction : n = c / v

When light travels from one medium to another, the speed changes, as does the wavelength. The index of refraction can also be stated in terms of wavelength

Taken from: http://physics.bu.edu/~duffy/PY106/Reflection.html
Boston University

This is a nice topic really, I learnt it briefly 2 years ago.

P.S. If you do not know what you are talking about do not argue about it.

Faster than light speed is impossible, because to get there you must accelerate first. Then again, once you are about to accelerate to FTL, you hit LS, or rather you don't because you can't go at LS. So, it's impossible to go PAST LS either

Unless you use something we didn't discover yet, like dimensional jump.
Don't close your minds, FTL is not possible yet.
It has been proven that each time we discover something new it completely changes the way we looked at the same topic before.

Besides, for most purposes lightspeed is useless. Let's see how long it would take you to accelerate to Lightspeed. Well, 1 G if I remember correctly is an acceleration of 1 meter per second. That's pretty comfortable for a human: it's normal gravity. But, to get to lightspeed at that acceleration, it would take 3.00x10^8 seconds, or about 228.31 years. Wait, that doesn't sound so bad! I must be messing up somewhere.... well, in any case, the fuel you would have to burn for more than 2 centuries, and at constant acceleration, would be pretty bad. What distance would you go?

Well, that's not really an issue here.
By the time we will reach those speeds we will probably find a way to Freeze and Hybernate human bodies during the travel, something that will make the G-Forces they experience during acceleration to be significant as much as they are significant to a peace of ice.

 

[newfangle]

Bah! Everyone is missing the point. The glorious General and Special Theories of Relativity are based on (get ready)...... Relativity!!!

Everything can only be based within relative terms to something else. Regardless of how fast light is travelling, ordinary matter will not be able surpass whatever speed light decides to travel, except when it is slowed down (by that Danish guy). But the slowed light is off-topic, as it has very little to do with Einstein's actual theory.

I usually like BBC news, but they definitely bastardized this story. I am very familiar with Davies work, and I have attended several of his lectures. His life goal is to explain Einstein, rather than prove him wrong. Which leads me to another issue- you can't prove a theory wrong. The editor for this story was an absolutely pretentious fool.

 

[newfangle]

As for the FTL travel, it will never been done conventionally. My best guess would be a wormhole with antigravity, but it is still very far fetched.

 

[marshal zhukov]

QUOTE]Originally posted by The Troquelet


Besides, for most purposes lightspeed is useless. Let's see how long it would take you to accelerate to Lightspeed. Well, 1 G if I remember correctly is an acceleration of 1 meter per second. That's pretty comfortable for a human: it's normal gravity. But, to get to lightspeed at that acceleration, it would take 3.00x10^8 seconds, or about 228.31 years. Wait, that doesn't sound so bad! I must be messing up somewhere.... well, in any case, the fuel you would have to burn for more than 2 centuries, and at constant acceleration, would be pretty bad. What distance would you go?[/QUOTE]

1G = 10 meters per second
We would have no problem taking an acceleration of 2Gs.

I will now try to summarize the conclusion made in this tread.
-The light speed changes.
-FTL is not possible
-Traveling back in time is not possible either.
-Time slows down the closer one gets to the speed of light.

Cool, eventhough I am disapointed about the FTL thing

 

[Baleog]

AH, newfangle just beat me.

What Einstein proved is that FTL can't be achieved through conventional methods. As Troqulet pointed out you have to reach LS, before you can exceed it.
But the whole worm whole idea has, so far, not been disproved.
I believe a few physicists proved, a few years back, that it was, theoretically, possible to tear the spacetime fabric. They only proved it theoretically because the amount of energy needed to do it is well beyond what we are currently capable of.
Then you have to be able to, in order to jump ahead of light, keep the tear open, and make sure it is open at the other end, etc.. which takes much more energy.
Then, if you want to have ships that can do this they have to have the ability to create that energy in each one.
100s and 100s of years away.
At least that's what I can remember of what I know.

 

[Baleog]

One more thing.
Newton's theory was considered definitive. But what was learned later on was that it was definitive simply for the technology, mathematical techniques and knowledge that was around at the time.
Same with Einstein's. I'm not saying it's wrong (because Newton wasn't wrong either) just not definitive. The theory on special relativity (light) and general relativity (gravity) are ingenious and one of the great achievements of the last century. But it is all that was possible from the knowledge and techniques of the early 20th century. Probably in another 200 years there will be another physicist who will create a famous theory that'll sum up large areas of the available knowledge.

 

[EdwardTking]

Is light going slower or is space getting bigger so it takes longer?

 

[Richard III]

I always knew he was wrong. Of course. The theory was always b.s..

 

[Akka]

Just nitpicking, but...

Well, 1 G if I remember correctly is an acceleration of 1 meter per second.

1G = 10 meters per second

A distance over an amount of time is speed. Acceleration is the variation of speed over an amount of time, so it's distance over an amount of time over an amount of time.
Hence it's m.s^-2 (distance/time²).
1G = 9,8 m.s^-2

 

[newfangle]

Originally posted by Richard III
I always knew he was wrong. Of course. The theory was always b.s..

And here ladies and gentlemen we have the words from a gifted physicist. Obviously, his brilliance far outshines that tripe that came out of Einstein. Sure he won a nobel prize, but its all a scam anyways.

 

[newfangle]

As for the stuff about scientific determinism. Newton's laws are stil applied in a multitude of situations today. The GToR by Einstein basically describes the basic fabric of the universe. It won't be replaced, just expanded.

 

[Pongui]

I'm not so sure that a theory of gravity (we have only an observation, note) can be expanded out of General Relativity. Einstein's theory may if fact obscure our understanding of gravity.

It's true, lightspeed is economy-class travel. We need to accelerate with gravity itself before we can travel in comfort.

 

[amadeus]

Wouldn't the effect of such immense pressure on the body of the human or vehicle just destroy the entire thing?

 

[Pongui]

The force of gravity works on your entire body equally. That's why nothing can harm you as you leap off the garage roof. It's the sudden breaking of the fall that sprains your ankles. Trust me on this. If a spacecraft (or jet, etc.) accelerates in any way relative to the occupants, they get shoved by the craft. Since our long-term shove tolerance is 1G, space travel must be excrutiatingly slow... unless we can use gravity as the accelerating force. Using gravity, you could theoretically accelerate to, say, just under light speed in a few seconds, yet feel nothing but weightlessness.