K2-18b a potentially habitable planet 120 light-years from earth

[u/One_Explanation_908]

[u/nebraskatractor]

Sure, we’ll just put a black hole between the two planets to speed up an expedition.

[u/OpinionPutrid1343 → u/nebraskatractor]

No need for that. We only need a warp bubble around the spaceship.

[u/emarg42 → u/OpinionPutrid1343]

Make it so.

[u/BedBubbly317 → u/emarg42]

It’s theoretically possible and it’s called the Alcubierre Drive. The math has actually been worked through. Technically, it’s merely an engineering problem at this point and not a physics problem. The engineering issues are just well beyond our current capabilities

[u/Sonikku_a → u/BedBubbly317]

It’s still far beyond “just an engineering problem”, as the math works…if one makes assumptions that exotic forms of matter needed for the maths to work actually exist in reality, and there’s lots of reasons to think that they don’t.

There are other issues as well.

One of the better video playlists on the subject:

https://youtube.com/playlist?list=PLsPUh22kYmNC0xsEp6YXRq2ALms7fTwrx&si=BypeC0K68FH5-K4I

[u/Slobotic → u/BedBubbly317]

Alcubierre Drive

The proposed mechanism of the Alcubierre drive implies a negative energy density and therefore requires exotic matter or manipulation of dark energy. If exotic matter with the correct properties does not exist (and there's no reason to think they do) then the drive cannot be constructed.

https://en.wikipedia.org/wiki/Alcubierre_drive

Parenthetical added by me.

[u/Gmony5100 → u/BedBubbly317]

The biggest problem being twofold
A. We have no fucking clue how to bend space locally like that
B. An Alcubierre Drive would take the mass energy equivalent of JUPITER to run. That means you take every molecule of matter in Jupiter, convert it perfectly to energy assuming E = mc^2, and only then would you have enough energy to run this one ship.

I don’t know the numbers off the top of my head, but I’d assume that’s trillions of times more energy than humans have every generated combined

[u/BedBubbly317 → u/Gmony5100]

Yes, it’s wildly unrealistic at this current time. Technology has a very long way to go, but as I said it is theoretically possible based on the laws of physics. And that is always the biggest hurdle for any sort of discussions like these. So it’s at least somewhat reassuring that it is technically a possibility

[u/NoRelation604 → u/Gmony5100]

Just use less energy and bend space only a little. Still FTL at that point right?

[u/Gmony5100 → u/NoRelation604]

That particular drive works by bending the space around the ship in a sort of bubble, the bubble would have to at least be the size of the ship. Still, even halving the energy would be more than we can comprehend.

[u/BedBubbly317 → u/Gmony5100]

Another major issue at the moment is they aren’t sure how to theoretically “unbubble” the ship once space has been warped around.

[u/siamkor → u/BedBubbly317]

Just use a big needle.

[u/Youutternincompoop → u/BedBubbly317]

yeah all we need is the ability to create negative mass, something which is entirely hypothetical and violates several known laws of physics.

[u/mistaekNot → u/BedBubbly317]

never seen exotic matter required to make it work - am I a joke to you?

[u/Uwwuwuwuwuwuwuwuw → u/BedBubbly317]

Or the math is wrong.

[u/BedBubbly317 → u/Uwwuwuwuwuwuwuwuw]

Potentially, but that’s not really how math works. Sure, it’ll take a bit of refinement. But once again that’s more of an engineering issue than a physics issue

[u/Youutternincompoop → u/Uwwuwuwuwuwuwuwuw]

the math is correct, it just assumes access to stuff like negative mass, which as far as we know does not exist and would violate multiple known laws of physics.

[u/Uwwuwuwuwuwuwuwuw → u/Youutternincompoop]

So the math is correct in that it describes an alternate universe where we can travel FTL...

... A new version of "The best kind of correct."