EMdrive paper published, nearly identical to leaked draft.
post by morganism · 2016-11-19T21:30:54.440Z · LW · GW · Legacy · 10 commentsContents
10 comments
Paper first, article next
http://arc.aiaa.org/doi/10.2514/1.B36120
http://www.sciencealert.com/it-s-official-nasa-s-peer-reviewed-em-drive-paper-has-finally-been-published
TLDR,
Yup, thrust estimates the same 1.2 millinewtons per kw, in vac.
Hypothesized to be pushing off the quantum foam.
"[The] supporting physics model used to derive a force based on operating conditions in the test article can be categorised as a nonlocal hidden-variable theory, or pilot-wave theory for short."
Pilot-wave theory is a slightly controversial interpretation of quantum mechanics.
It's pretty complicated stuff, but basically the currently accepted Copenhagen interpretation of quantum mechanics states that particles do not have defined locations until they are observed.
Pilot-wave theory, on the other hand, suggests that particles do have precise positions at all times, but in order for this to be the case, the world must also be strange in other ways – which is why many physicists have dismissed the idea.
But in recent years, the pilot-wave theory has been increasing in popularity, and the NASA team suggests that it could help explain how the EM Drive produces thrust without appearing to propel anything in the other direction.
"If a medium is capable of supporting acoustic oscillations, this means that the internal constituents were capable of interacting and exchanging momentum," the team writes.
Pilot wave theory
https://www.quantamagazine.org/20160517-pilot-wave-theory-gains-experimental-support/
10 comments
Comments sorted by top scores.
comment by Plasmon · 2016-11-20T07:32:46.310Z · LW(p) · GW(p)
It remains extremely likely that the em drive will turn out to either not work or work only by known-but-improperly-accounted-for physics (see also: Pioneer anomaly).
comment by James_Miller · 2016-11-19T22:14:37.590Z · LW(p) · GW(p)
Very bad news Great Filter-wise because an EM Drive pushes forward the time when we can start to colonize other star systems going beyond the reach of any local disaster, and likely survive to the end of the universe and thus know we have passed the Great Filter.
Replies from: g_pepper↑ comment by g_pepper · 2016-11-20T00:01:41.196Z · LW(p) · GW(p)
If I understand you correctly, you are saying that verification that the EM drive works would tend to increase the likelihood that we are about to reach the great filter, right?
If so, couldn't it also be argued that verification that the EM drive works would tend to increase the likelihood that we have already passed the great filter?
Replies from: James_Miller↑ comment by James_Miller · 2016-11-20T15:05:17.682Z · LW(p) · GW(p)
Yes, both are true.
comment by morganism · 2017-07-04T06:30:55.716Z · LW(p) · GW(p)
Roger Shawyer, SPR Ltd, invented the EMdrive and recently gave an EMdrive presentation to the UK Defence Academy Shrivenham.
"In orbit testing of EmDrive has been reported by CAST, suggesting commercial use of EmDrive has now been authorised by China
Implies military applications of first generation technology are now operational. Western space assets vulnerable."
Replies from: Elo↑ comment by Elo · 2017-07-04T06:43:24.680Z · LW(p) · GW(p)
What? It's not like western space assets are really far away and need a very slow acceleration curve to be attacked. Western space assets were already vulnerable considering they just float around in space. And are no more vulnerable now due to EM drive
comment by morganism · 2016-11-22T00:06:55.788Z · LW(p) · GW(p)
optimizing the microwave reflector cavity.
https://www.eurekalert.org/pub_releases/2015-02/s-nhm021115.php
http://link.springer.com/article/10.1140/epjp/i2016-16171-x?no-access=true