
NASA Funded Scientists Claim Breakthrough in Propellantless Propulsion - n0pe_p0pe
https://www.wired.com/story/mach-effect-thrusters-interstellar-travel/
======
commonjcb
Not this shit again...

Look closely at the picture of the test chamber in the article. Do you see
Helmholtz coils surrounding the entire apparatus? Nope.

[https://en.wikipedia.org/wiki/Helmholtz_coil](https://en.wikipedia.org/wiki/Helmholtz_coil)

It's the same story as the EMdrive: they run something at high current,
without cancelling earth's magnetic field.

high current + earth magnetic field = force. This method is used to move
satellites:

[https://en.wikipedia.org/wiki/Magnetorquer](https://en.wikipedia.org/wiki/Magnetorquer)

~~~
imglorp
Wouldn't you want to run tests in multiple orientations to cancel Earth fields
anyway? Similar to how you would run a Michaelson-Morley interferometer
experiment.

~~~
commonjcb
The torsion balance introduces fixed biases, and can be operated only in XY
plane. So in theory you're right, in practice it's not possible.

Not canceling earth's magnetic field (an easy thing to do) when measuring
microNewtons at high currents is just very poor experimental practice.
Unprofessional. Amateur.

------
snowwrestler
> On a clear night in March 1967, Woodward was stargazing on the rooftop of
> Pensión Santa Cruz, a hotel in the heart of Seville, in Spain.... As
> Woodward gazed up from atop his Spanish hotel, he saw a speck of light
> arcing across the sky and mentally calculated its path. But as he watched
> the satellite, it began deviating from its expected trajectory—first by a
> little and then by a lot.

> Everything Woodward knew about satellites told him that what he was seeing
> should be impossible. It would take too much energy for a satellite to
> change its orbit like that, and most satellites weren’t able to shift more
> than a couple of degrees. And yet, he had just seen a satellite double back
> with his own eyes. He didn't conclude that engineers at NASA or in the
> Soviet Union must have secretly achieved a breakthrough in satellite
> propulsion. Instead, he believes he saw a spacecraft of extraterrestrial
> origin.

Seems more likely he spotted a reconnaissance aircraft at very high altitude.
I think the U2, A-12, and SR-71 were all operational in 1967.

~~~
sgt101
Or a bird. Less high up, nice white tummy, reflects the light.

~~~
nkoren
Do you honestly think that somebody trained in astronomy could mistake a bird
for satellite? Have you _seen_ how satellites move? They traverse the sky in a
perfectly straight and constant-motion fashion that is utterly unlike any
bird.

Even a high-altitude plane such as the U-2 would be fairly difficult to
misidentify as a satellite. For obvious reasons, U-2s and SR-71s and such
didn't employ lights while operating at altitude; therefore the only way to
see them would be via reflected light. It would need to be reasonably long
after sunset, or else the sky isn't dark enough to credibly see a satellite --
but not so long after sunset that the plane would be in the earth's shadow.
Satellites have a similar window of observability -- but it's much longer,
because they're much higher. A high-altitude plane would have a very small
window. Moreover, it would need to execute that turn without crossing the
terminator: as soon as any reflecting object crosses the terminator, that
reveals its altitude.

~~~
pmoriarty
That he made a mistake is much more plausible than that it was aliens.

That he was hallucinating is much more plausible than that it was aliens.

That he was lying or had a false memory is much more plausible than that it
was aliens.

Pretty much any mundane explanation is much more plausible than that it was
aliens.

Extraordinary claims require extraordinary evidence.

------
roywiggins
It's worth noting that if a propellentless drive works, it will probably
_generate free energy_. This may adjust your expectations on how likely this
idea is. How likely is a free energy device (ie, one that reliably gives you
more energy out than you put in)? Well, this thruster can't be any more
likely, because it would produce free energy.

[https://arxiv.org/abs/1506.00494](https://arxiv.org/abs/1506.00494)

> the kinetic energy of a mass with a constant force applied will increase
> with the square of time, while the electrical energy input only increases
> linearly with time. A mass with such a drive attached would eventually have
> a kinetic energy greater than the energy input.

...

> For example, an evacuated track 10km long and supplied with 1 GW of power
> that is fed via induction along the track to a 100 kg mass equipped with an
> EM drive would result in the mass experiencing an acceleration of 4000
> m/s2(i.e., 407 g’s) and having a velocity of 8.94 km/s at the end of the
> track, at which point the mass would have a kinetic energy of 4 GJ. The time
> to accelerate the mass is only 2.23 seconds,however, so the energy input
> required is only 2.23 GJ. At the end of the track, the mass could be
> decelerated via regenerative braking, generating more energy out (4 GJ) than
> was input (2.23 GJ), for a net gain of 1.76 GJ free energy.

~~~
PaulAJ
> [..] while the electrical energy input only increases linearly with time.

This is the fallacy. In an electric motor the power required to exert a force
is proportional to the speed, so if you want to keep the acceleration constant
you need to increase the electrical power (i.e. rate of energy use) linearly
over time. Hence the total energy input increases with the square of the time,
just like the kinetic energy imparted. If the system is 100% efficient then
the total electrical energy used will be equal to the kinetic energy of the
mass.

~~~
roywiggins
> proportional to the speed

In what reference frame? It's not obvious to me how this works in a space
drive. How does it "know" how much speed it gets per unit energy?

I guess if it's a sort of Dean drive that swims through the gravitational
field of the visible universe, then that's the reference frame. It's still
weird!

------
0xUser
Wiki: (...) Woodward states there is no violation of momentum conservation in
Mach effects:

If we produce a fluctuating mass in an object, we can, at least in principle,
use it to produce a stationary force on the object, thereby producing a
propulsive force thereon without having to expel propellant from the object.
We simply push on the object when it is more massive, and pull back when it is
less massive. The reaction forces during the two parts of the cycle will not
be the same due to the mass fluctuation, so a time-averaged net force will be
produced. This may seem to be a violation of momentum conservation. But the
Lorentz invariance of the theory guarantees that no conservation law is
broken. Local momentum conservation is preserved by the flux of momentum in
the gravity field that is chiefly exchanged with the distant matter in the
universe.

~~~
icegreentea2
How does Lorentz invariance guarantees that no conservation law is broken?

~~~
mhh__
I can't remember what the conserved current of LI is but symmetry implies a
conservation law.

(Noether's theorem)

------
z92
Reminds me of the recent EmDrive hype, that didn't go anywhere.

~~~
S_A_P
I see what you did there...

------
mikeknoop
Here’s the paper:
[https://www.researchgate.net/publication/280134421_New_Theor...](https://www.researchgate.net/publication/280134421_New_Theoretical_Results_for_the_Mach_Effect_Thruster)

------
sebringj
Interesting caveat about traveling close to the speed of light...if you run
into hydrogen atoms, which is near 100% likely, your ship violently explodes
because at very high speeds, there is a huge reaction on tiny matter
collisions. I just learned this and it was like learning that sound doesn't
travel in space when I was young and ruined many a starwars movie effects. I
keep learning how ignorant and dumb I am the more I follow SpaceX and become
curious about space.

~~~
kaiju0
Interstellar ships will be shaped like pencils to deflect rather than impact
gasses. They will also have to have consumable nose cone sections with old
ones in the front being removed and new ones installed at that back. Like a
mechanical pencil.

~~~
pluto9
What happens when the ship has to turn around to decelerate, with its engines
facing the front?

~~~
mleonhard
The turn-around takes place at the half-way point of the journey. This means
that for the entire second half of the journey, the engine is pointed at the
oncoming dust.

Engines used in such long journeys will likely emit a thin stream of particles
at extreme velocities. This stream is not wide enough or thick enough to stop
space dust from hitting the engine. An unshielded forward-facing engine will
get destroyed. So we must shield the engine.

Instead of having two shields and turning the ship around, just turn the
engine around. Make the engine emit streams forward from the sides of the
ship.

------
rweir
Could we all just wait until there's a (reviewed) paper in Nature or
something?

------
jp555
This sounds, like the EM drive, too much like trying to move your car by
sitting inside and pushing on the dashboard....

Still, a "vacuum propeller" would be a massive revolution (no pun intended) if
it is at all possible.

~~~
at_a_remove
It is because the payoffs would be so enormous that business like this and
"overunity motors" continue to gain attention. All of those other elixirs were
shams, but _this_ one will work! Finally, immortality! The enormity of the
reward causes the payout matrix to lead people astray.

Don't get me wrong, I see a vacuum chamber, which is light years ahead of most
of these enterprises, but I would not spend a dime on it until it has been
proven to work in a region of space relatively far from the Earth's magnetic
field.

~~~
roywiggins
It's a kind of Pascal's mugging, I think.

[https://en.m.wikipedia.org/wiki/Pascal%27s_mugging](https://en.m.wikipedia.org/wiki/Pascal%27s_mugging)

That said, Woodward does not seem to be an actual charlatan, so I don't have a
problem with funding him. At least he might turn up something fun and/or
interesting, even if I don't think it's going to usher in a new space age.

~~~
shadowgovt
I personally believe he rides that line of charlatanism where he's not
pursuing this theory in bad faith at all, but he of course recognizes that
tromping around on the edge of a theoretical branch that most physicists don't
think is worth exploring garners attention he wouldn't otherwise receive.

I strongly suspect that whether history remembers him as a charlatan will
depend heavily on whether one of the supports of his branch proves false and
it snaps off, or whether he's been right this whole time and we suddenly oops
ourselves a propellantless drive that operates by coupling to the
gravitational field and pushing distant objects around. ;)

------
njarboe
One should note that propellantless propulsion systems exist. They are called
lasers. It is just that the thrust to weight ratio of such an engine is very
low.

A quick google search does not bring back any designs or research papers of
such a system, as the results are swamped by the idea of using ground based
lasers to push spacecraft instead of the craft itself containing the laser.

------
motohagiography
So, I have to ask: If Elon Musk is working on propulsion tech to go to Mars,
and Bob Lazar claims to have worked on reverse engineering propellentless tech
and is one of the single digit number of living people to have encountered it
directly, _and_ NASA is slow rolling their own understanding of it, given the
limited available expertise in this area how can Musk afford to not hire
Lazar? From a due diligence perspective, Musk would need to know with a high
degree of certainty that Lazar is full of crap.

While this might sound insane, from a portfolio perspective, if a VC firm is
invested in SpaceX, Blue Origin, Virgin Galactic, or anyone else in the space,
it seems negligent to not have some exposure to a company with someone like
Lazar involved in it, unless you really knew for sure, as he and people like
him present an existential risk to rocket-based tech companies. That guy is
the ultimate hedge.

~~~
boxed
Your logic assumes only one such person. The problem is that there are tens of
thousands of similar people with, let's be super kind, unlikely ideas. If you
hire them all that's not a hedge that's a huge cost with an almost 0%
probability of payoff.

I'd bet the number of such people with unreasonable ideas will go drastically
up if you start hiring them too.

~~~
motohagiography
The analog I'm thinking of is that space propulsion could turn out to be as
much of a sandbox as cybersecurity and crytpo have been, where there was
always a ceiling above which everyone just agreed to not look. I'm being super
charitable about Lazar, but having been in the security field both pre- and
post- Snowden, Lazar is more like a Binnie or Drake figure, with the full
extent of the issue still further off in the future. What good technologists
suspected about crypto and saw little edges of, vs. what ultimately came out
implies companies like those mentioned above would need to have done some
deeper arguments and analysis beyond blowing him off as just a kook. Musk's
opinion on Lazar would be interesting for its own sake.

However, this is also like saying you have to rule out every "free energy"
conspiracy before starting a battery company as well, so it's not really that
much of a forcing function at all.

------
beepy
From the article:

> Mike McDonald, an aerospace engineer at the Naval Research Laboratory in
> Maryland, will be among the first [attempt to replicate their results]. He
> leads an internal program for independently testing advanced propulsion
> systems, which has previously shot down promising results from the EmDrive.

~~~
leephillips
There might be such a place, although it’s more likely they’re trying to refer
to the U.S. Naval Research Laboratory in Washington, DC.

~~~
tssva
The U.S Naval Research Laboratory also has several facilities in MD. Including
at Patuxent River, Chesapeake Beach and Blossom Point. Given the nature of the
work I would guess it is referring to the facility at Blossom Point.

------
ForHackernews
Sounds really bollocks to me. Seems like shades of the Emdrive:
[https://www.popularmechanics.com/science/a15323/temdrive-
con...](https://www.popularmechanics.com/science/a15323/temdrive-controversy/)

------
mcswell
Nit: "as Newton put it, inertia is why an object at rest tends to stay at
rest." No, what Newton said is that an object in motion tends to continue in
motion at the same velocity (and an object at rest tends to remain at rest,
i.e. with velocity=0).

While this doesn't have a lot to do with the original article (hence my
"nit"), it was revolutionary at Newton's time. People had observed objects at
rest staying there; that's why you can sit on a chair. But they had also
observed that any object in motion (except for those in the sky) slowed down
and eventually stopped, unless you kept pushing them. Newton attributed this
to friction.

This theory--which contradicted what people could plainly observe with their
eyes--is what makes possible satellites (and keeps the moon in orbit), since
being outside the atmosphere, they experience very little friction. Of course
the other thing necessary for man-made satellites is a way to get them moving
fast enough, for which Newton's third law comes in handy (it's why rockets
accelerate, even outside the atmosphere).

------
PaulHoule
See

[https://en.wikipedia.org/wiki/Dean_drive](https://en.wikipedia.org/wiki/Dean_drive)

particularly this article

[http://www.rexresearch.com/dean/stine.htm](http://www.rexresearch.com/dean/stine.htm)

------
mnw21cam
So, [https://xkcd.com/955/](https://xkcd.com/955/) appears to be relevant. If
someone were to take it, I'd make a bet that this is not real. If it is not
real, then I win the bet, but if it is real, then I'd be too fascinated by the
result to care.

------
nojokes
I would like to see more pictures of his desk. I adore such setups.

~~~
qayxc
I'm more curious to learn why the image on the monitor shows a screenshot
instead of an actual desktop or open program(s).

------
gintoddic
It's really disappointing that a human can work on something for 30 years and
only get a tiny amount of thrust. Our science needs to go in different
directions it seems we are stuck living in the past.

------
0xUser
So much hate in the comments. Have some hope, people.

~~~
AnIdiotOnTheNet
People don't like to see quack science take funding from legitimate science. I
am not qualified to judge whether or not this is quack science, but it
certainly reeks of the same claims as previously documented quack science.

~~~
cwhiz
I believe a total of $620,000 over a span of several decades. I am personally
quite happy to fund one-off random projects like this. The amount of money is
a trivial rounding error. Funding 100,000 failures at this level would be
worth it if one, just one, worked.

I do understand that others might think differently. I like moonshots.

~~~
ForHackernews
Referenced elsewhere in these comments
[https://en.m.wikipedia.org/wiki/Pascal%27s_mugging](https://en.m.wikipedia.org/wiki/Pascal%27s_mugging)

~~~
cwhiz
We spend about $150 billion per year on science funding in the US. I don't
think we're being irrational by giving moonshots roughly 0.00003% of the
funding. That's a generous percentage, too, considering the funding for Jim
Woodward spans many decades.

