News on propulsion at NASA


There has been a lot of rumor on measurements performed by Eagleworks labs at NASA this spring. After that, NASA imposed a veto on whatever information should coming out about the work of this group until peer-reviewed work should have appeared. Most of the problems come out from the question of the EmDrive. This is a presumed thruster obtained by pumping radio-frequency into a cavity shaped as a closed frustum. This device has been largely dismissed by the physicists’ community due to a blatant violation of conservation of momentum. Such an object should stand still aside from known physical effects as Lorentz force or thermal thrust arising from heating of the cavity in the air. The claimed effect is really tiny standing on measurements that has been done since now and so, mundane explanations remain the most credited. Notwithstanding this, people at NASA have kept on working. This is testified by the recent posts by Paul March at Nasaspaceflight forum. Paul march is a member of the NASA group working on new propulsion technologies and what he is claiming is really striking. I report this here

Paul March post 1where he claims that, notwithstanding all the precautions, they keep on seeing a 100 \mu N thrust. They know perfectly that, for Maxwell theory, no thrust should be observed as stated by the following post

Paul March post 2So, they see a thrust, after having removed all mundane effects, and the possible explanation for it is not classical electromagnetism as all said from the start. In particular, it is cited by the questioner the link to Greg Egan’s post explaining why there cannot be any thrust by known electromagnetism with this geometry (see Greg Egan’s post). I think that they will make their results known once the peer-review process will be concluded. I would like to remember that other NASA labs asked to concur to confirm their measurements.

This group also performed interference experiments on this cavity and observed an effect. If all this will be confirmed it will represent a breakthrough, not only from the technological side let me say, as a new physical effect will be proved at work with general relativity now to be experimentally managed on a tabletop device. Note that general relativity is always at work in this situation with a large density of electromagnetic energy as I also discussed here. It should be said that this has nothing to do with warp drive as conceived in Alcubierre metric and similar.

We hope to hear very soon from this group with more official channels. Surely, their results will provide a wealth of new avenues to pursue for research and technology.

Marco Frasca (2015). Einstein-Maxwell equations for asymmetric resonant cavities arXiv arXiv: 1505.06917v1

NASA and warp drive: An update

25/04/2015 There is some excitement in the net about some news of Harold White’s experiment at NASA. I have uncovered it by chance at a forum. This is a well-frequented site with people at NASA posting on it and regularly updating about the work that they are carrying out. You can also have noticed some activity in the Wikipedia’s pages about it (see here at the section on EmDrive and here). Wikipedia’s section on EmDrive explains in a few lines what is going on. Running a laser inside the RF cavity of the device they observed an unusual effect. They do not know yet if this could be better explained by more mundane reasons like air heating inside the cavity itself. They will repeat the measurements in a vacuum chamber to exclude such a possibility. I present here some of the slides used by White to recount about this NASA White ExperimentNASA White experimentNASA White experimentThis is the current take by Dr. White as reported by one of his colleagues too prone to leak on nasaspaceflight forum:

 …to be more careful in declaring we’ve observed the first lab based space-time warp signal and rather say we have observed another non-negative results in regards to the current still in-air WFI tests, even though they are the best signals we’ve seen to date. It appears that whenever we talk about warp-drives in our work in a positive way, the general populace and the press reads way too much into our technical disclosures and progress.

I would like to remember that White is not using exotic matter at all. Rather, he is working with strong RF fields to try to develop a warp bubble. This was stated here even if implicitly. Finally, an EmDrive device has been properly described here. Using strong external fields to modify locally a space-time has been described here. If this will be confirmed in the next few months, it will represent a major breakthrough in experimental general relativity since Eddington  confirmed the bending of light near the sun. Applications would follow if this idea will appear scalable but it will be a shocking result anyway. We look forward to hear from White very soon.

Marco Frasca (2005). Strong coupling expansion for general relativity Int.J.Mod.Phys.D15:1373-1386,2006 arXiv: hep-th/0508246v3

What is going on at NASA?


As a physicist I have been always interested about experiments that can corroborate theoretical findings. Most of these often become important applications for everyday life or change forever the course of the history of mankind. With this in view, I am currently following with great interest the efforts by the NASA group headed by Harold White.Harold "Sonny" White This work has arisen uproar in the web and in the media as it was come to envision the possibility to realize a warp drive, in the way Alcubierre devised it, and the stars were in the reach shortly. As it is well-known, Alcubierre drive implies exotic matter something that does not appear at hand neither in small nor in large quantity. On the other side, it was indirectly observed in the Casimir effect, a beautiful application of quantum field theory to real life. So, it is rather normal to link warp drive with exotic matter. It should be emphasized that nobody on Earth ever managed it in some way and it is not available at your nearest grocery store. The experiment carried out by Harold White and his group is realized with an interference device using lasers on an optical table. The idea is to observe a modification of space-time, a minuscule one, that would modify the paths of the laser beams. This would be comparable to the realization of the Chicago pile by Enrico Fermi that was the starting point for the Manhattan project. I would like to emphasize that such a laboratory small-scale manipulation of space-time would be a huge breakthrough in physics and would open up the way to a new kind of engineering, that of space-time. So, our hopes for a warp drive would be totally fulfilled.

There is an eager desire to obtain any possible information about the progress of White’s work but, of course, there are a couple of hurdles. The first one is that a scientist needs to be certain before to claim a result and we know very well why from some blatant examples in the last years. Extraordinary claims require extraordinary evidence. Last but not least, Harold White is employed at NASA and some restrictions could be required by the organization he is working with. So, it is really interesting a video appeared quite recently where White claims that the effect is there but further work is needed for confirmation. If you have a hour of your spare time, this video is worthwhile to be seen.

This video is interesting per se because Harold White is talking to his colleagues at NASA. But in the question time happens the interesting fact. A White’s colleague asks him “where is the exotic matter?”:

and here something interesting happens. White seems to avoid the question and admits that they talked before in the office. What is more interesting is what the White’s colleague is saying then unveiling some of the machinery behind the experiment. The colleague says that the experiment could be carried out in some strong coupling regime that makes the magic happen without any exotic matter. White denies and disagrees. We know that he is using strong electromagnetic fields in the interference zone. Indeed, the matter of the behaviour of the space-time in a strong perturbation was studied for cosmological aims by Belinski, Kalathnikov and Lifshitz, the BKL trio. David GarfinkleThis scenario was confirmed by numerical studies by David Garfinkle (see here). I was able to derive it by analysing the behaviour of the Einstein equations under a strong perturbation (see here) in analytical way. So, the chance to study such effects in a laboratory would be really striking and would mean an incredible breakthrough for people working in general relativity and related fields. What the exchange between White and his colleague implies is that this could be already at hand and without exotic matter. All the growing concerns about the work at NASA are then not applicable and a different kind of analysis would be needed. Particularly, Alcubierre drive should be devised in a different way. As a physicist, I am eager to learn more about this and to know the real answer, from the horse’s mouth, to the question “where is the exotic matter?”.

Miguel Alcubierre (2000). The warp drive: hyper-fast travel within general relativity Class.Quant.Grav.11:L73-L77,1994 arXiv: gr-qc/0009013v1

David Garfinkle (2003). Numerical simulations of generic singuarities Phys.Rev.Lett. 93 (2004) 161101 arXiv: gr-qc/0312117v4

Marco Frasca (2005). Strong coupling expansion for general relativity Int.J.Mod.Phys.D15:1373-1386,2006 arXiv: hep-th/0508246v3

Curiosity finds organics but where do they come from?


NASA logoYesterday, at the meeting of the American Geophysical Union in San Francisco, NASA announced first results from soil analysis performed by Curiosity. Indeed, initially there was an eager expectation about this announcement as some rumors leaked out and somebody told about historical results. Then, all this was teased by NASA but what they announced yesterday was all but disappointing. I followed a real-time chronicle on twitter by Emily Lakdawalla (@elakdawalla and check her blog) that was there in San Francisco and it was really exciting. The main point is that Curiosity indeed has found organics but that people at NASA cannot be sure yet that carbon was not from Earth. Anyhow, the analysis of the soil displayed a rich content and this is indeed a riverbed. Some further analysis are required before to give definitive conclusions about the presence of organics. If you need a short summary you can read this article on The Guardian but Emily should provide a complete account shortly.

CuriosityI would like to spend a few words here to let my readers know what is at stake here. On 1975, NASA launched the Viking probes on Mars. One of the aims of this mission was to perform some experiments that should give evidence of life on Mars. A pair of these experiments turned out  to give favorable results giving such an evidence but the probes failed at finding any organic molecules and so these results were interpreted as due to some other chemical process at work. Indeed, the question is open yet. Should Curiosity find any evidence of organic molecular, the original findings of Viking probes would be vindicated but, more important, one should have a first evidence of life, even if bacterial, on another planet. This is for historical book indeed!

Warp drive at NASA


I am currently a twitter user. One of my followings is Jeri Ryan. She has been Seven of Nine in Star Trek Voyager saga. Yesterday, it comes out of the blue what I read in one of her twits: NASA is developing warp drive! Indeed, Jeri was pointing to  this link. This is a Gizmodo’s post that was describing an effort by NASA to develop warp drive and it seemed like something consistent was in hand. Indeed, this is all true. It is a lab at NASA, Eagleworks, headed by Harold White that is working on a technical realization of the most recent ideas from physics in the area of “spacetime engineering”. This is somewhat of a new term as, so far, no ways were at our disposal to modify spacetime even if, in principle, this is a possibility offered by general relativity. If one would be able to do so, we would have warp drive but also time machines, wormholes and all that. White’s group claims to have found some loopholes in all the hurdles encountered so far in this kind of researches. The most fundamental one is that one needs a huge quantity of exotic matter to get some of these devices work. Nothing that is manageable in practice. So, all this matter was always put in an area of research much theoretical oriented. In a quite recent paper, Stefano Finazzi, Stefano Liberati and Carlos Barceló (see here)  show that Alcubierre drive is unstable with respect to quantum effects: Indeed, if you go faster than light, Hawking radiation will kill you.

So, there are some important difficulties to overcome to change the situation from theoretical to a practical one. One of the Editors of Physical Review Letters, Robert Garisto, commented as follows on twitter:

NASA warp drive story: Not sure which is less plausible, that it’s allowed by physics or that we could implement it if it were.

White’s group claims that they are on the verge to realize an experiment comparable to the Chicago Fermi’s experiment on the nuclear pile. This would imply that they have overcome all the difficulties seen so far in this kind of studies and are able to provide a working realization of the effect. You can find a paper by White here and is worth reading. They can controvert any skepticism by a sound experimental proof.

My view is always the same: As a physicist I have a blind faith on experimental facts and I would like to see accomplished one of my lifetime dreams arisen with that small step by Armstrong on the Moon. NASA is never a disappointment.

Stefano Finazzi, Stefano Liberati, & Carlos Barceló (2009). Semiclassical instability of dynamical warp drives PHYSICAL REVIEW D 79, 124017 (2009) arXiv: 0904.0141v2

Miguel Alcubierre (2000). The warp drive: hyper-fast travel within general relativity Class.Quant.Grav.11:L73-L77,1994 arXiv: gr-qc/0009013v1

The man passed away, the legend will always survive


Neil Armstrong passed away yesterday (see here and here). He was the first man to put his feet on the Moon. He started all my dreams when I was just nine and that July’s night I was staring at his extraordinary enterprise together with Buzz Aldrin (see here) and Michael Collins on the Apollo 11. Now, I am moved to tears by this but my dreams are still there and his legend will always survive. Thank you very much, Neil!

Curiosity touched down successfully!


I was excited this morning while I was looking at the last minutes of flight of Curiosity there at JPL. This remembered when I was nine and, with my father, I looked at man on the moon.  This time I was with my sons and we shared happiness with all the people that worked hard for another great success.  Keep up this great job!


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