Slower than light warp drive

[Moontanman]

Is slower than light warp drive possible? Maybe we are passing up a possibility that would open up the solar system without the negative mass required to go faster than light?

I couldn't find much on the idea but Sabine Hossenfelder mentions it in this video at about 02:30.  

https://iopscience.iop.org/article/10.1088/1361-6382/abdf6e

 

Quote

Conceptually, we demonstrate that any warp drive, including the Alcubierre drive, is a shell of regular or exotic material moving inertially with a certain velocity. Therefore, any warp drive requires propulsion. We show that a class of subluminal, spherically symmetric warp drive spacetimes, at least in principle, can be constructed based on the physical principles known to humanity today

 

Edited April 27, 2021 by Moontanman

[beecee]

First I have heard of Sabine...I love the rather "thick" pronunciation of Einstein.

Interesting video.

[Moontanman]

8 hours ago, beecee said:

First I have heard of Sabine...I love the rather "thick" pronunciation of Einstein.

Interesting video.

I am rather fond of Sabine, she cuts through the gobbledygook and makes her field understandable. As a bonus she sings, often about science.  

[Moontanman]

I was going back through my posts and found this one, evidently I was distracted by "life and death" and forgot to follow up on it.  Anyone have any ideas about slower than light warp drive? 

[Moontanman]

Evidently no one is interested but I think it's a mistake to concentrate on FTL warp drives that need things like negative energy and mass to operate and ignore slower than light possibilities. A STL warp type drive would revolutionise travel within the solar system and allow for the system wide exploitation of resources, reasonable travel times within the solar system, and possible STL travel between the nearest stars in years instead of thousands of years. 

[swansont]

You have to show the feasibility of warp drive. You’ve skipped that part.

[Moontanman]

5 hours ago, swansont said:

You have to show the feasibility of warp drive. You’ve skipped that part.

In the OP I pointed out that Sabine mentioned it in the video posted with this thread. I have looked high and low for some info on this but so far only vague mentions about STL warp drive not needing the impossible things that FTL warp drives need. I am hoping that enough of our fellows here at SFN will help me in this endeavor to find out more about this STL drive. Everyone is fixated on FTL but we are not even close to having a reasonably fast way to travel within our own solar system. I am looking for more than just a dismissal... I am looking for help in investigating this idea of STL warp drive... I find it odd that it is mentioned by some scientists but the focus on FTL warp drives is so dominant that any info about STL warp drive, possibility or impossibility, is difficult to find. 

[zapatos]

From what I've read the Alcubierre drive seems at the moment to not violate the laws of physics (although a better understanding of quantum gravity may change that). That of course doesn't mean it can be built, but not being impossible is obviously a positive first step for such an exotic machine.

[Moontanman]

1 minute ago, zapatos said:

From what I've read the Alcubierre drive seems at the moment to not violate the laws of physics (although a better understanding of quantum gravity may change that). That of course doesn't mean it can be built, but not being impossible is obviously a positive first step for such an exotic machine.

Then again I am not talking about the Alcubierre FTL warp drive. I am seeking info on the possibility of a slower than light warp drive. 

 

[swansont]

9 hours ago, Moontanman said:

Then again I am not talking about the Alcubierre FTL warp drive. I am seeking info on the possibility of a slower than light warp drive. 

 

But if it’s based on warping spacetime, you still need to establish how you do this.

[Moontanman]

2 hours ago, swansont said:

But if it’s based on warping spacetime, you still need to establish how you do this.

Bingo! That is what I am trying to find out! I did send a question to Sabine but she has yet to answer. 

Edited October 21, 2022 by Moontanman

[swansont]

1 hour ago, Moontanman said:

Bingo! That is what I am trying to find out! I did send a question to Sabine but she has yet to answer. 

I doubt she has an answer to give you.

[Moontanman]

5 hours ago, swansont said:

I doubt she has an answer to give you.

https://arxiv.org/pdf/2102.06824.pdf

Quote

Class I: Mild subluminal warp drives: These spacetimes are defined by the vector field ξ being timelike everywhere. Consequently, three-velocities of such drives are subluminal, i.e. vs < c. Spacetimes of this class approach the flat Minkowski spacetime in the trivial limit, and observers Oin, Oout,co reduce to a pair of co-moving timelike Lorentz observers. Non-trivial members of this class contain spacetimes with region Dwarp sufficiently curved, so that tetrads of observers Oin and Oout,co differ significantly from each other, i.e. the observers read off different rates of clocks and lengths of rulers. At the same time, such spacetimes also contain weak-field solutions corresponding to classical shell-like objects moving with subluminal velocities and weakly modifying the state of the spacetime inside them. Such solutions are possible because the Dwarp region may be set arbitrarily close to being flat, rendering the whole spacetime arbitrarily close to Minkowski spacetime.

 

[swansont]

2 hours ago, Moontanman said:

https://arxiv.org/pdf/2102.06824.pdf

 

“While the mass requirements needed for such modifications are still enormous at present, our work suggests a method of constructing such objects based on fully understood laws of physics.”

 And they don’t really tell you how to do this.

[Moontanman]

14 hours ago, swansont said:

“While the mass requirements needed for such modifications are still enormous at present, our work suggests a method of constructing such objects based on fully understood laws of physics.”

 And they don’t really tell you how to do this.

No they do not, that is what I am trying to figure out... but in the spirit of full disclosure the paper doesn't say that STL warp drive do not use impossible things like negative mass or negative energy. In fact it specifically says STL warp drives do indeed need these things. So I am back to square one, Sabine Hossenfelder did indeed include this paper with her Video, she always does, I just didn't read far enough. So the hunt for the possible STL warp drive goes on.