Viewing a single comment thread. View all comments

WULTKB90 t1_j9rsz5u wrote

No, any local area of the universe isnt expanding faster than the speed of light, rather the collective growth of the entire universe results in the areas further away from you expanding more.

Thing of it as each cubic centimeter of the universe growing by a millimeter per second. The further out you go the more milimeters per second are added but each local area only grows by 1.


pzerr t1_j9rx8si wrote

Eventually the local area will grow by that rate. Or so the theory goes. At some point it will rip atoms apart.

But ya matter isn't faster than light. The expansion can exceed that but not matter. Is a big distinction and doesn't break casualty.


farox t1_j9rx9w8 wrote

t1: x x x x x x x x x x x x x x x x x x 

t2: x  x  x  x  x  x  x  x  x  x  x  x  x  x  x  x  x  x  x

Each x is only one space further apart and has only "moved" a small bit compared to the distance of the first and the last. It took me a while to wrap my head around it as well, but it's space itself that is expanding, very slowly... but everywhere.


datapicardgeordi t1_j9s0a25 wrote

This. The vacuum pressure of black holes on the fabric of spacetime has been slowly increasing the distance between the granules that make up spacetime, calabi yau manifolds.


PyrorifferSC t1_j9s6gfv wrote

That includes matter, correct? So relative distances don't change between bodies/stars/galaxies


WULTKB90 t1_j9s8uzm wrote

Relative distance does change, but the galaxies aren't being pushed apart, rather more space is appearing between them, like a balloon being inflated, if you put 2 dots on the balloon then blow it up the dots don't move, rather the space between them grows, so they aren't moving faster than the speed of light, it is only faster when observed relative to an observer with enough distance.

When it comes to distances far enough out that they are receding away from an observer faster than light can travel the information from them is lost to the observer, without FTL travel the observer could never reach those locations so no information is traveling faster than the speed of light.


ieatdirt44 t1_j9shupj wrote

"So no information is traveling faster than the speed of light"---this is the key distinction. I feel like we are on the verge of no longer saying the speed of light, but the speed of causality or information seems more relavant.


[deleted] t1_j9sbfoq wrote

I don’t know if this question makes sense, but if every cubic centimeter of the universe is expanding due to dark matter, why doesn’t that include earth? Like I’m sitting here and neither me nor my house is expanding, so is the expansion only in the vacuum of space? If so, why?


WULTKB90 t1_j9sbzdg wrote

I used the 1mm per cubic centimeter as an example the actual expantion is much smaller though im not sure of the exact values.

But the answer is you, your house, the planet are all expanding. As far as I am aware gravity and the strong nuclear force holds us together against that force. Though some hypothosize that eventually the expantion rate will be great enough to tear atoms apart, its called the big rip. Edit: spelling.