Many people have asked me about the supposed bubble of curvature accidentally observed by a NASA engineer that would allow it to travel faster than light. Sorry, even if such a microbubble had been observed, it would never allow a Star Trek-type bending micromotor to be made. The famous Harold "Sonny" White, ex-NASA engineer, has managed to sneak an article in a scientific magazine; presents a simulation of the Casimir effect in the vacuum between a cylinder and two parallel plates. In your opinion, your result looks like the negative energy density of the warp metricde Alcubierre (if the cylinder was not present and if the parallel plates were cylindrical). According to White and his co-authors, their result portends future laboratory observation of a microbubble of curvature. To make matters worse, the article proposes a scheme of a future experiment to verify its mathematical solution that DARPA could finance. Nothing more and nothing less. White sells smoke and social media boils with trekky dreams .
First of all, making an Alcubierre warp bubble requires huge amounts of energy; a bubble a few meters in diameter (for a person to fit inside) would need a total negative energy equivalent to several solar masses. If this energy were to accumulate in a region of a few kilometers, it would end up forming a black hole. The second, the warp bubble only allows to reach superluminal speeds in its interior; to an outside observer the bubble moves at subluminal speeds. To travel to Pluto from Earth, you would have to use a bubble as large as Pluto's orbit. And the third, two very close metal plates attract each other with a small force due to the Casimir effect, which can be interpreted as a small negative energy associated with the quantum vacuum between said plates. A miniscule amount of energy that is impossible to amplify by putting more parallel plates or making them larger, and which is infinitesimal compared to that needed to make a warp bubble. Therefore, White's idea is a mere mental straw.
All this is known (almost) by everyone, as it seems that in the peer review of White's article it has been (intentionally) forgotten by the reviewers. The truth is, I do not understand how articles of this nature can be published in a scientific journal. The article is Harold White, Jerry Vera,…, Jonathan MacArthur, «Worldline numerics applied to custom Casimir geometry generates unanticipated intersection with Alcubierre warp metric,» The European Physical Journal C 81: 677 (31 Jul 2021), doi: https: / /doi.org/10.1140/epjc/s10052-021-09484-z; the first two authors, White and Vera, work at the Limitless Space Institute(whose scientific director is White); His goal is research into future interstellar travel, which is attracting a lot of media attention. In this blog I recommend you read "Harold White, his superluminal warp drive and NASA", LCMF, Jan 19, 2013 ; "EmDrive: A self-propelled cone-shaped microwave oven", LCMF, 05 May 2015.
The main contribution of the article by White and his colleagues is to use the numerical method of the world line ( wordline numerics) by Gies – Langfeld – Moyaerts (2003) to estimate the negative energy density due to the Casimir effect for a cylinder between two infinite planes. This algorithm estimates the vacuum energy using the path integrals method. The authors implement it for the two-dimensional (2D) case and apply it to a metal cylinder with 1 µm diameter in the center of two flat metal plates 4 µm apart. This figure, on the left, shows the result for the energy density in a vacuum between the circular section of the cylinder and the metal plates; the result is convincing, although the article is not rigorously validated (it could be compared with previous works by Gies – Langfeld – Moyaerts).
White and his colleagues consider this 2D solution of the Casimir effect to be representative of the 3D solution for the negative energy density of a metallic sphere inside a cylinder; for some strange reason the reviewers of the article have not noticed that there is no Casimir effect in such a case. You don't have to be a physicist to realize that there can't be an attractive force between the cylinder walls towards the central sphere (as with infinite parallel plates); therefore, there is no negative energy density in that case. But White and his colleagues do not realize their mistake, or do not want to realize it; the reviewers either.
In a pun worthy of the best scientific billiards players, White and his colleagues argue that the 2D solution (on the left side of the figure) resembles the 2D cross-section of the 3D negative energy associated with the Alcubierre metric for a warp bubble ( shown on the right side of the figure). Look at both figures; remember that the circle on the left is a cylinder and that the center of the warp bubble on the right is empty. Do they look identical to you? White and his colleagues claim that the two figures are so similar that they are actually identical; therefore, the cylinder between the metal plates behaves like a warp bubble in spacetime. Thus, inside the cylinder (if it were not magically there) superluminal motion would be observed (at speeds greater than the speed of light in vacuum).
At this point you may ask yourself, why do many media claim that a microscopic-sized warp bubble has been observed? Apparently White has said in an interview that his numerical simulation illustrates a microscopic-sized warp bubble; In some medium, with little rigor, it has been understood that illustrating the idea with a computer-generated figure is the same as illustrating the result of an experiment; For this reason, said media has affirmed that a warp microbubble has been accidentally observed (pure sensationalism); the rest of the media have copied them, decorating the news with new homegrown hyperbole. As I have just told you, something that you can verify yourself if you read the scientific article, the warp microbubble has not been observed, it has not even been simulated by computer; The numerical method used by White and his colleagues solves a problem that has nothing to do with a warp bubble. That two figures look alike from afar, very from afar, does not in any way mean that they correspond to two analogous physical systems, much less that their physics are exactly the same.
In 2016 Nature magazine commissioned a science fiction writer to write a piece on the impact of Star Trek on science (Sidney Perkowitz, "Science fiction: Boldly going for 50 years," Nature 537: 165-166 (07 Sep 2016 ), doi: https://doi.org/10.1038/537165a). He wanted to mention bend motors, so he asked White for a drawing of his proposal; Sonny contacted graphic illustrator Mark Rademaker to prepare this figure that illustrates Alcubierre's metric with a kind of engine formed by a ring of exotic matter that surrounds a cylinder similar to a Star Trek ship (Rademaker has created spectacular Star-inspired ships Trek, but outside of series canon). Since then, White has included this image in all his articles (citing the piece inNature , as if citing a scientific article, as if it gave cache). The new article also includes such an image and suggests that the Casimir effect figure for the cylinder between parallel plates is representative of what would occur inside the ring of the digital artist figure.
To end their article, White and his colleagues propose a design of what would be an experimental bending motor based on their idea. Five micrometric metallic cylinders arranged in a row, each with a submicrometric sphere inside, all facing a wall and with a central hole that runs through the entire scheme; I have repeated the figure because I think that if I did not do it you would not believe it. As you may have noticed, the idea is nonsense bullshit; There is no use putting five warp bubbles in single file to enhance the superluminal effect, since the superluminal movement only occurs inside each bubble. Furthermore, the idea of the hole in the spheres suggests that White has no idea what a warp bubble is and thinks that its holed spheres somehow emit negative energy backwards. as by jet propulsion. It looks like a joke figure, but having been published in a magazine articleThe European Physical Journal C , honestly, strikes me as a very bad joke.
In short, the idea of the Alcubierre – White curvature bubbles as a means of interstellar transport is laughable. That a numerical simulation of the Casimir effect is published in a scientific article stating that the result is analogous to a warp bubble is incomprehensible. That many media publish sensational news on this topic seems shameful to me. But what alarms me most is that many of these outlets decorate the story with rubbish, such as that "this investigation could become classified as confidential by the Pentagon" (because White led a project funded by DARPA). How low the media fall when they publish bullshit as news! And only because they can illustrate it with a Rademaker Star Trek-type ship and attract unsuspecting Trekkies .