

Mustafa's Space Drive: An Egyptian Student's Quantum Physics Invention - mikeleeorg
http://www.fastcompany.com/1837966/mustafas-space-drive-an-egyptian-students-quantum-physics-invention

======
sigmaxipi
This appears to be another reactionless drive [1] that sci-fi authors and
crackpots come up with every few years. There are many variants of these
designs [2] and a drive based on the Casimir effect is just one of them.
However, they all tend to violate a critical law of physics or depend on a
custom theory of physics [3]

BTW, the original article at [http://www.onislam.net/english/health-and-
science/science/45...](http://www.onislam.net/english/health-and-
science/science/457096-egyptian-student-invents-a-new-propulsion-method.html)
goes into slightly more detail about her invention and mentions that it's
related to a differential sail.

[1] <http://tvtropes.org/pmwiki/pmwiki.php/Main/ReactionlessDrive> [2]
[http://en.wikipedia.org/wiki/Breakthrough_Propulsion_Physics...](http://en.wikipedia.org/wiki/Breakthrough_Propulsion_Physics_Program#Differential_sail)
[3] <http://en.wikipedia.org/wiki/Inertialess_drive>

~~~
jerf
There's also some variants that do work, or at least could work in theory,
which turn out to simply be highly inefficient photon drives. For instance,
one recurring one that seems to get reinvented every few years is one where
you put two electromagnets some distance from each other, and use the speed of
light delay and some moderately clever polarity flipping to make it so the
magnets always attract or repel each other in one direction, providing thrust.
There's no reason why this won't work... except that also shoots huge amounts
of defocused radio waves out the back, which is where the equal & opposite
momentum is "coming from", and it's wildly less efficient in every conceivable
way than simply shooting a conventional laser in the opposite of the direction
you want to thrust. (And there's some other caveats too when you really get
down to the engineering task of trying to flip the polarity of really powerful
magnets at the necessary rate of speed. But it is conceivable that using real
physics, you might be able to build something with this principle that could
generate vanishing fractions of a Newton without necessarily blowing up....)

Based on the link you provide, and guessing what the QM equivalent of the
differential sail (this thing, I think: [1]) would be, it seems to me this
could fall into either class, something that simply won't work or something
that will turn out to be another variant of inefficient electromagnetic
radiation drive, once the full set of interactions is taken into account.
(It's pretty easy to miss some of the more subtle ways of creating
electromagnetic waves.)

[1]:
[http://www.daviddarling.info/encyclopedia/D/differential_sai...](http://www.daviddarling.info/encyclopedia/D/differential_sail.html)

------
psykotic
Conservation of momentum has been one of the most unshakeable laws of physics.
Reactionless drives violate conservation of momentum. The likelihood that this
is flawed is infinitely greater than the likelihood that conservation of
momentum has been overturned. End of story, as far as I'm concerned.

Anyone remember the EmDrive debacle? <http://en.wikipedia.org/wiki/EmDrive>

~~~
nilaykumar
I don't think conservation of momentum is under fire here - the vacuum
fluctuations (due to second quantization, quantization of electron, quark,
etc. fields) might pick up the difference... although I don't really know
enough QFT to be definite. Not that I believe any of this though, haha, seems
like complete bullshit. The original article, especially. None of the physics
seems to make any sense.

------
ww520
Does anyone find the reporting horrible? It's like reading a press release
with all the buzz words and jargon thrown in. "Dynamic Casimir effect" that
produces a net force? Yeah, the net force is the opposing forces squeezing the
two plates together from outside. It produces zero directional net force. I
don't see how it can move an object in space.

~~~
ktizo
As far as I am aware, dynamic casmir is achieved by moving a virtual mirror at
relativistic speeds to create photons, so I am assuming that if the photons
are preferentially directed, there would be a small net force in the opposite
direction.

~~~
starwed
And what is a virtual mirror, I ask?

~~~
ktizo
In the report I read they were using SQUIDs to make the effect of a mirror
that operated in the microwave range.

[edit] you could also use a real mirror, is just very hard to move it that
fast.

------
waterlesscloud
Sounds a lot like some of the ideas in this NASA-produced survey of possible
drives- <http://www.grc.nasa.gov/WWW/bpp/1997-J_AIAA_SpaceDr.pdf>

NASA does have some research folks working on pretty esoteric space drive
concepts.
[http://www.nasa.gov/centers/glenn/technology/warp/ideachev.h...](http://www.nasa.gov/centers/glenn/technology/warp/ideachev.html)

------
nohat
I predict with very high confidence that this does not work.

~~~
ww520
It is a patent. Who say a patent has to work? It just describes some methods
dreamed up by someone. The hardwork of finding out and getting it to work is
left to the engineers. And payment is due to the idea guy if it ever works.

------
surrealize
"Lisa, in this house, we _obey the laws of thermodynamics_!"

\--Homer Simpson

Plus, "space drives" violate the conservation of momentum.

------
Rhapso
Still waiting for the very excited paper on zero point energy that explains it
in non-leagalise. If she figured this out, why not use it to run a generator?
They again, who wants to get power off the heat death of the universe
-tanstaafl -3rd law of thermodynamics

------
WalterBright
The only space drive that actually can work is the transmission of
information, not of mass. But you'll need a receiver that is capable of acting
on that information. Hopefully, such receivers can be made very small and then
"seeded" through the galaxy.

------
SkyMarshal
TLDR: It's like a solar sail, but instead of being pushed by energy from a
star, it manipulates local quantum particles to create a small force that
propels the vessel.

Eg, not warp or hyperdrive, but still very clever.

~~~
KaoruAoiShiho
It's not like a solar sail. You don't need energy to use the sail, you need
energy here. This idea is not going to change space propulsion.

~~~
stcredzero
Huh? It's "only" a >reaction-less< drive. That's only a science-fiction
conceit to allow compact little spacecraft to zip all over a solar system with
mass fractions that are actually sane.

If the guy has invented a science fiction conceit in real life, I think he
deserves some praise.

~~~
gus_massa
You need energy to move the mirror that is used to create the photons.

In the report, it isn’t clear if the photons are released or not. If they are
release it is not a reaction-less drive, it only throws a photon jet instead
of an atomic jet. If the photons remain inside the cavity, the device violates
the physics laws, and after building it they will find that they forget to
include some little detail that makes the device not useful.

It is important to remember that quantum mechanics is strange and the Casimir
effect is very strange, but none of them violates the conservation of momentum
law. The problem with the conservation of momentum law is that to prove it,
you only have to suppose that the space is invariant under translations (if
you "move" the universe 1 foot to the "right", the physical laws don’t
change), so any sensible physical theory comply with it.

------
troystribling
This is the Quantum Ram Jet in Artur C. Clarks "Songs of a Distant Earth" from
1985 <http://en.wikipedia.org/wiki/The_Songs_of_Distant_Earth>. It is based on
the Dynamical Casimir Effect which is thought to have been observed,
<http://www.technologyreview.com/blog/arxiv/26813/>

------
prawn
One thing I like about Fast Company's article is that it's not revealed (name
aside, for those familiar with it) that the student in question is female
until the last paragraph or so.

You can just imagine a TV reporter, breathlessly:

"It's a new space invention, from a _student_. And a _female_ as well!"

------
raverbashing
Well, this is awkward

It's apparently relying on the 'dynamic Casmir effect' but what exactly is
doing is not clear

I assume photons created by accelerating a plate have zero angular momentum
(the sum of all them) unless maybe if you have a plate near it then it isn't?
(and by 'near' I mean 'Casmir near')

