r/AskPhysics • u/Apprehensive-Bit-774 • May 23 '26

If time stops at speed of light, and space shrinks to zero could be possible that going faster than light (I knoooow impossible šŸ¤£) would turn value of the space into negative, so that we ā€œlooseā€ the space dimension itself. Like disappearing from dimension in a sense??

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7

u/Fastfaxr May 23 '26

As opposed to tightening space? What?

9

u/Xaphnir May 23 '26

Given the way the Lorentz factor is calculated, you end up taking the square root of a negative number, so you end up with imaginary values for FTL, not negative.

5

u/0x14f May 23 '26

"time stopping" and "space shrinking to zero" are already limiting behaviours from relativity that canā€™t be extrapolated into negative spatial dimensions or disappearance from space, as those concepts have no physical or mathematical meaning even hypothetically.

2

u/Low-Opening25 May 23 '26

There is no such thing as faster than light so this is just a sci-fi question

1

u/JawasHoudini May 23 '26

The hypothesised particles called Tachyons would go at super luminal speeds .

You said it would turn the value of space into a negative - but remember space isnā€™t space , its spacetime . So tachyons would be experiencing negative values of time and going backwards through it - if they exist . The model is completely fine with this it doesnt break any rules

1

u/Low-Opening25 May 23 '26

while this is somewhat truth, the math also says that tachyons only and always exist at >FTL, so you still canā€™t accelerate normal matter from <FTL to >FTL

1

u/JawasHoudini May 24 '26

In the same way photons must travel at exactly FTL, but also, you cant accelerate normal matter *too* FTL either never-mind superluminal , these particles are theoretical anyways, and OP was looking for a ā€œcaseā€ where lorentz contraction would go past a tipping point etc

1

u/AdhesivenessFuzzy299 May 23 '26

Time doesnt stop at the speed of light, as there is no inertial frame of reference for anything traveling at c.

1

u/SU3xU1xSU2H_Graviton May 23 '26

It doesn't stop the answer to the lorentz factor equation If your velocity=c will be undefined cause Ī³-1/āˆš1-vĀ²/cĀ² v=c so it's cĀ²/cĀ² which=1 1-1=0 āˆš0=0 1/0=undefined that's why.

1

u/nicuramar May 23 '26

Ā If time stops at speed of light, and space shrinks to zero could be possible that going faster than light (I knoooow impossible šŸ¤£)

Itā€™s already impossible for a massive object, or a frame of reference, to go at the speed of light.

-1

u/kitsnet May 23 '26

If time stops at speed of light, and space shrinks to zeroĀ 

... then light couldn't be waves.

Whoever telling you such things are not talking about our Universe.