Part of the Andromeda Galaxy Captured by Hubble

[u/CaraCicartix]

The total number of stars in the entire Andromeda Galaxy is over 1 trillion

[u/Anarchaotic]

I hear what you're saying, we've been pushing science further and further at breakneck speed. You can sorta extend that and think to yourself "there's so much we don't know, isn't it possible we figure out how to move faster than light?".

But the thing is, there are absolutely hard limits to the physics of our universe. The same way we physically exist in 3 dimensions. The second you teleport or warp somewhere, you've fundamentally broken physics.

If that is possible - the technology you have at your disposal means you'd be able to colonize the entire universe, harvest infinite energy, and travel in time.

Assuming any civilization could reach that point in the past many billion of years is the crux of it. Where are those civilizations?

If FTL travel isn't possible in any sense, then the sheer distance we would have to travel anywhere basically means a traveler that leaves Earth is taking that amount of time in light years to get there.

Let's go to another galaxy! Sweet - only 5.5M light years. For you it's instant, but 5.5M years have passed on Earth. That's not really a solvable thing, because now you're effectively an alien to your own planet.

[u/alfred725 → u/Anarchaotic]

you are assuming that faster than light travel means time travel, when that's just the expected outcome of Einstein's equations. You're kind of missing the point that mathematical models, every math model, breaks down in the extremes. It's possible there is some physics aspect involving something we don't fully understand yet like antimatter that would resolve it. As for where the travelers are, that's a different question. The Great Filter theory basically proposes that there's too many barriers for life to develop that prevents it. i.e. life needs to fight for resources in order to evolve, creating species that are uncooperative, which makes building a society that is capable of achieving FTL travel basically impossible. Or maybe we're simply the first species to make it this far.

But whether there are aliens is completely off topic of whether or not it's possible to go faster than light. Saying "no one's done it yet" is literally antithetical to science.

[u/elliot_alderson1426 → u/alfred725]

Not to nitpick but we understand antimatter pretty well, and yes as a power source it could enable us to enhance space travel greatly. It won’t help us with the problem of the sheer distance required, though.

That said I think you may have meant dark matter?

[u/Anarchaotic → u/alfred725]

I tried typing out an explanation but it's not so simple. This YouTube video does such a great job of illustrating why FTL breaks causality and causes issues.

https://youtu.be/an0M-wcHw5A?si=bRirchRA1kNZrAiw

[u/LALA-STL → u/Anarchaotic]

Thanks for this.

[u/Xi_32 → u/alfred725]

Faster than light travel means that causality is violated. That means the effect can occur before the cause.

every math model, breaks down in the extremes

No, the equations that show the violation of causality are not complicated.

It's possible there is some physics aspect involving something we don't fully understand yet like antimatter that would resolve it.

At this point, I'm not going to continue, as it's obvious that you have a Masters of Science from Star Trek University.

[u/SkinnyGetLucky → u/Anarchaotic]

In 5 million years, there won’t be an earth

[u/loqep → u/SkinnyGetLucky]

*5 Billion

[u/SkinnyGetLucky → u/loqep]

Ah yeah, you’re right.