I thought I would share this video on warp drive by a German physicist. She nicely goes through the issues with the Alcubierre drive, and possible workarounds, and presents a new paper that has generalized the analysis originally done by Alcubierre. According to her (and she is generally skeptical of fancy things) warp drives are the most scientifically plausible of sci-fi technologies, and I agree.
Her main argument against the FTL Alcubierre is that it requires negative energy, which has never been observed. I agree that this is the leap that is needed. I am less concerned about the amount of energy needed, because all that is required to get sufficient energy (in addition to clever designs, of which there now are several) is to unify gravity with the other 4 forces. If such a unification is ever found there exists a way to transform electricity into gravity and vice versa. Electricity is in the order of 10^40 times stronger than gravity and as such could be complete game changers in warp drives.
Therefore, my key objection to FTL is that it requires either General Relativity to be wrong OR the existence of negative energy. Of these two, I believe GR is most likely to be the weak point. I am actually a trained physicist and I do know GR, although I am not an expert in doing calculations with it. I do, however, know it well enough to know that there is something seriously funky with it and that alternative explanations exist.
The German physicist Unzicker has pointed out that Einstein developed an alternative theory to GR which does not require curvature of spacetime but rather only refraction of light through change in time. Amazingly, for some reason that no-one yet understands, gravity behaves EXACTLY like an ether with some density that slows down light (and clocks), and just like with lenses made of glass of water this results in light bending.
Granted, this ether is very weird, because it also simultaneously obeys special relativity so if the ether exists, it is not an ordinary substance. The ether, contrary to popular belief, lives on in Quantum Field Theory as “vacuum energy” or “fields.” This gets even weirder because the vacuum energy is supposedly extremely dense with (virtual) energy, and it is by altering this density that the clock speeds (and thereby the speed of light) is altered. Presumably matter only changes the density in one direction, but there may exist a mechanism for changing it in the other direction too. If that is true, FTL is possible in a way that is far less fancy than negative energy.
If you’re confused by all this, the bottom line is that FTL warp drives are not around the corner any time soon, but if you give physicists and ingenious people another 2-300 years, they may very well find a way to do “the impossible.”
3 replies on “The New Worlds Part 9: Even more warp drives and general relativity”
I apologize for chiming in with something that is just silly, considering how fast Bad News moves, would not a Bad News Drive, with a backup Agita Drive get you from one end of the galaxy to the other almost instantaneously – albeit entirely unwelcome and unwanted?
I’ve been following Sabine for some time now and I’ve even corresponded with her a bit. As you say, she’s excellent. (She’s also just about the most German German I’ve ever seen. And check out her singing videos. 🙂 )
After I started following, I found out that she holds that perhaps the biggest problem in physics is the reification of math, which I have been saying for years. She’s even written a book about it, Lost in Math. I haven’t read it yet but it’s high on my reading list.
This new paper is very interesting for the reason you mention – no negative energy like the Alcubierre FTL drive requires. I’ll be looking at it more closely. I’m not a trained physicist but a very interested layman who keeps up with developments in the field.
For anyone interested in physics, I recommend Sabine very highly.
I completely agree with her (and your assessment) about the reification of math. One example of this is the socalled “magnetic field lines” and “magnetic reconnection.” The lines are not real. They are like topographical lines and only represent an energy level, not an actual physical line. However, it is often interpreted as such. Reification is perhaps the greatest philosophical issue in modern physics.