Support NeoGAF

[Branduil]

Err, this seems to be unlikely to change anything soon.
The thrust to power ratio of EmDrive, at least in its current experimental setups, is awful. Ion thrusters apparently are better, and they're useless for anything bigger than space probes.

Obviously, if this scales up, it will be useful for some things (depending on how good it gets).

But it probably won't solve cheap space access, and thus probably won't have effect on space mining right away.

Isn't the main advantage the fact that if it works, you can just keep the engines on forever without worrying about fuel?

 

[Ether_Snake]

Posting on this page since it might interest people:

Most of this is over my head but it sounds pretty damn significant if something is really going on.

Do we know what the hell a wave of space time is in Bohmian physics? Like, wtf is a "wave" of space time? Does it have to do with gravity and mass and does this mean anything new for what "time" is?

I'm so confused.

I don't know, but I think it has to do with probabilities. Things that are close to one another would have a higher probability of having interactions with one another than things that are far away.

I think it relates to Zeno's paradox (or the similar Quantum Zeno effect).

So what might happen is that if you have two particles at 10 light years away from one another, if there is nothing else at all in the universe between or around them, the probabilities that would result from their interactions (as in, where will either be in the next "frame" as a result of an interaction with one another) would be the same than if they were at ANY distance. Distance is irrelevant in influencing the outcome in this context; close or far, distances being relative and space being infinitely dividable means that there is no notion of space to measure in this case: is it really 10 light years or 10cm? You can't form a distance notion when you have nothing but two bits with infinite space everywhere around them; zoom in or zoom out, who knows how far they are? So the probabilities in this scenario can't take the distance into account.

But if you add a third particle somewhere closer to either than the other, the probabilities that their interactions will define where they end up next is higher than the probabilities that would result from an interaction with the one that is farther away; it's never zero, but lower. Now at this point space has a measure, through probabilities, or probabilities are now measurable as a result of space, same thing. Closer just means more probable, father means less.

So from what I can imagine, the "wave" in space is probabilities; no matter how great the distances are between two particles there is a chance that one will influence the other, mathematically speaking. It's just extremely unlikely that something really far will influence something close in our every day life, but possible.

There might be some ways to significantly increase the probabilities that two things will interact with one another without doing the obvious which is to move things closer.

The probabilities could be altered WITHOUT altering their spatial relationship. To us it would look like they are still far from one another, but we would have altered the probabilities of interaction, since they are just that; probabilities, that were just increased. They would react as if closer to one another, even if not.

The wave would be this mutation of probabilities that spreads through space or another dimension, altering interaction probabilities, even if spatial relationships are unchanged or fairly unchanged. With entangled particles, maybe we change the spatial relationship without changing the interaction probabilities; we make a change in one dimension that doesn't translate into a change in the other dimension.

 

[Messofanego]

Reading through the paper (barely understand all the jargon lol) and then came across real quantum mechanics, made a gif.

 

[Dr.Acula]

For those that don't know reddit, the /r/science board (the first link) has much much stricter posting requirements, and omits the "It Works" editorialisation.

 

[Woorloog]

Isn't the main advantage the fact that if it works, you can just keep the engines on forever without worrying about fuel?

It isn't that simple. It still needs power (gonna assume it doesn't actually grant free energy and that our knowledge simply has a gap, because otherwise all bets are off, at least in the long term). Some power sources need fuel (eg nuclear power), others need sunlight (solar panels) and are thus limited to space near the sun. Can't run either one indefinitely.

And constant thrust in space isn't necessarily useful, if you're trying to do things cheap. Robotic probe? Just sent it via transfer orbits, doing small accelerations when needed. No need to strap a nuclear reactor to one to keep it flying. Sure, it takes years but not that much longer than it would with minuscule constant thrust while being a lot cheaper, probably. Obviously things depend a lot on various factors. It is a balancing act.

For human-spaceflight, constant thrust is far more useful since less travel time means less supplies needed which means less power, fuel and reaction mass needed. But again, it is a balancing act. (Plus, one must question why not just use robots as much as possible instead of humans.)
I don't recall ion thrusters being considered for human spaceflight really. And the EmDrive is far weaker in its current incarnation.

In the long term, perhaps things will be different. But for now, it offers little advantage, and it isn't even fully verified and tested, nor are its limits explored.

 

[bachikarn]

This is still nondeterministic, just in a slightly different way.

A particle can still be influenced by "ripples" in the pilot wave that originate from sources so far away there is no way study them directly.

Like turbulence? Pretty sure turbulence is technically deterministic but there is no way to measure everything so all the models are statistical.

 

[orthodoxy1095]

For those that don't know reddit, the /r/science board (the first link) has much much stricter posting requirements, and omits the "It Works" editorialisation.

One thing they do right. Less editorialization please.

 

[Slayer-33]

Gawd daaamn, this is awesome news

 

[FantasticMrFoxdie]

Holy shit. Its about to get real

It's too bad Trump will shut down NASA in order to fund the wall.

fml

 

[Orbis Tabula]

I still don't believe it.

But, I guess if things like this keep happening, I'm just going to have to start! Exciting news!

 

[Neo C.]

Ok so if this ends up true space exploration and mining could actually become a thing. If that is the case how does our current laws handle the ownership of those resources. Man just imagine what we could do if we just had a boat load of the rare earth minerals we needed for so many good technologies.

If it works, it's most likely a candidate for research outside of the solar system.

 

[Noisy Ninj4]

Ok so if this ends up true space exploration and mining could actually become a thing. If that is the case how does our current laws handle the ownership of those resources. Man just imagine what we could do if we just had a boat load of the rare earth minerals we needed for so many good technologies.

Basically, if you mine something in space it's yours according to US law. Thanks Obama.

Assuming the em drive pans out, it'd make for a killer stationkeeping solution on top of the stuff like normal spaceflight.

 

[Octavia]

How does one peer review something in a leading field by leading scientists? Wouldn't anyone else peer reviewing it be 'lessors' in the field with less knowledge?

 

[habithipster]

I remain skeptical.

 

[Noisy Ninj4]

That's not really how peer review works. There are teams and individuals all around the globe that engage in experiments like this to falsify work by other scientists.

 

[Muppet of a Man]

So not only is it still possible the drive works, it might actually prove pilot wave theory? That would be pretty huge if true.

Unified theory of physics here we come!

 

[Kinitari]

If this sort of validates that recent thread about the idea of quantum mechanics actually being deterministic, that would be really amazing.

It would also make my free will arguments a lot easier

I called it!!!! I said it would be related to pilot-wave!

http://m.neogaf.com/showpost.php?p=215830395

That thread is exactly what I was thinking about, it was a real interesting read and as soon as I saw the OP I was like 'Ether_Snake vindicated'

 

[SenjutsuSage]

ETA till I can seduce a blue-skinned alien girl?

Been there, done that. It's called Mass Effect. Get with the times.

 

[Cat Party]

Believe it or not, while Trump will still probably unfortunately gut the Earth sciences portion of NASA, he is actually really high on renewing efforts for extraterrestrial exploration.

Duh, he wants to bang blue-skinned aliens, too.

 

[Rektash]

I remain skeptical.

Rightfully so. This was published in some impact factor 1 engineering journal. I am no physicist so I won't comment on the paper itself but in general when this is all you can manage there are probably severe problems with your paper.

 

[Chittagong]

So. If this thing cretes thrust continuously in space, then what prevents us from making a giant space bicycle circling earth, with a dynamo generating electricity, and the thrust overcoming the friction of said dynamo?

 

[Elfforkusu]

Still too early. Interesting that there (seems to be) a real effect, unclear if that effect will be productive for space travel. Also, we still seem to be at the margins of experimental error, which always seems to happen when the emdrive is concerned...

For all we know, this is a novel way to push off against the earth's magnetosphere. Or (still) measurement error.

 

[Muppet of a Man]

I called it!!!! I said it would be related to pilot-wave!

http://m.neogaf.com/showpost.php?p=215830395

That is an amazingly sussinct and easy to follow explanation you've provided. Thanks for that.

This would be amazing and make the universe so much more understandable and predictable.

We essentially have a relatable mental model that everyone already understands to some degree: the dynamics of boats on the ocean's surface and how waves interact with them.

 

[Einchy]

I hope it works and they're finally able to use them cus then we will be full on sci-fi.

 

[All Possible Ways]

Keep in mind, this is the same experiment Eagleworks did all those months ago. There are still plenty of experiments left to do, and we're still months away from determining even if it works, not to mention why.

Luckily, if they can get the thrust high enough, Goddard said they'd take a look, which would be a good source of independent verification of their results. Lots of wierd shit is supposedly found that later turns out to be error, see tons of new particles that were thought to be discovered at 3 sigma significance, to later be a statistical anomoly and the FTL neutrinos that were caused by a wiring error.

As with anything in science, it has not been proven to work, only to not fail, and continued experiments will try again and again to show how the device actually doesn't work, and it's just some source of error unaccounted for. It's important to be sceptical, exciting news as this is, particularly when what is experimentally observed contradicts a fundamental cornerstone of physics. This will be a process that takes years and years and years, and every experiment will have to be exhausted before we can definitively say it probably works.

Edit: As someone else pointed out, there has already been a future test stating it may have been electromagnetic interaction with an outside source causing the thrust. Future tests will have to take that into account.

This. To me it is far more likely that this is a fluke, because a violation of the conservation of momentum is too much to swallow. This is not some technicality, momentum conservation is a fundamental principle that has survived the transition from classical to quantum mechanics, field theory and beyond, and is rooted in the fact that the laws of physics are homogeneous in space, i.e., that they are the same everywhere. Giving up on this would require rewriting everything from the bottom up. The same deal happened early with the faster than light neutrinos. It would have been a tremendous revolution, but in the end, it was literally a loose cable in the experimental setup.

As far as pilot wave theory, as far as I am aware it makes exactly the same predictions as orthodox QM, except it is less economical, postulating extra baggage in the form of a non-local wave in real space whose sole purpose is making people who dislike the non-realism of QM sleep well at night, at the cost of gross locality violation, which is not ok with special relativity.

From glancing the paper it is unclear to me what the exact relationship is between their model of thrust and pilot wave theory. It seem to be some ad-hoc extension of it, but any well defined proposal should be reinterpretable in terms of ordinary QM, at least in principle.

Rightfully so. This was published in some impact factor 1 engineering journal. I am no physicist so I won't comment on the paper itself but in general when this is all you can manage there are probably severe problems with your paper.

EDIT: Also, this. Peer review is not some magical process that guarantees correctness. How reputable the journal and the reviewers are also matters a lot. And even then in some cases bullshit goes through the filter, only to be refuted later.

 

[BocoDragon]

If you can't get with a human girl, what chance do you have with a more advanced species?

Ouch!

 

[User 73706]

So matter is like the npcs in GTA?

We really are in a simulation aren't we..

OnHit if hit_actor isValid
      false callFunction_heisenberguncertainty_BPi return bUncertain?
            false callFunction_resetstate
            true SpawnActorFromClass_hit_actor
      true hit_actor GetClass
            if class='sapient_life'
                  false GetAllActorsOfClass_'sapient_life'
                        callFunction_random_dejavu_BPi
                  true GetComponentByClass_'spoken_word'
                        if 'spoken_word' isValid
                              false GetSoundCue_animal_ohfuck.cue
                                    SpawnSoundAtLocation
                              true GetSoundCue_sapient_watchitasshole.cue
                                    SpawnSoundAttached

 

[Nafai1123]

Shit just got real.

 

[Vulcano's assistant]

So. If this thing cretes thrust continuously in space, then what prevents us from making a giant space bicycle circling earth, with a dynamo generating electricity, and the thrust overcoming the friction of said dynamo?

building and maintaining a giant something in pace.

 

[LookAtMeGo]

What are the waves that the particles are riding?

 

[cebri.one]

We still need more research however the real test will to put this thing in space and test it.

 

[Damerman]

Check the thread I linked to

http://m.neogaf.com/showthread.php?t=1271856

i'm trying to read through this, i feel like i need a masters in physics.

 

[EdibleExplosives]

What are the waves that the particles are riding?

XTREME ones

 

[KonradLaw]

I guess we're really living inside simulation and this drive is bug exploit

 

[blu]

No, it doesn't work.

You shouldn't be cheering at their inability to debunk their own setup.

The fact that the thrust effect isn't linear and they're listing the measured thrust as mN/kW when they've only gone up to 80 W is ridiculous.

So what, it's still 0.08kW /sarcasm

I'm highly sceptical of the EmDrive myself /non-sarcasm

 

[Ether_Snake]

Why do people says it violates conservation of momentum?

If you input some energy, and get more, it doesn't mean you broke the laws of physics, it just mean you got more energy, somehow. Could well be that something somewhere else is providing its energy into the experiment. It might look like energy came out of nowhere, but for all we know it just comes from somewhere we didn't know existed, or something outside the experiment.

If it is possible to have two particles that are far away from one another behave as if they were next to each other, then it's possible that in a controlled experiment, you would only see the increased energy without seeing the decrease wherever else it's happening, somewhere. In a computer program, you could easily represent this by coding it so that two physical objects interact with one another as if they were as close to one another as possible, in the physics' calculation, even if in the rendering code you render both in much different positions. The idea that in our universe, our perception of space negates the ability of particles to interact with one another beyond their relative distance, is pretty limited I think, especially with things like entanglement.

 

[efyu_lemonardo]

Well yes, if you want to go ahead and throw away hundreds of years of physics and invent your own then it's not all that strange.

 

[Iksenpets]

If it not only works, but also works in a way that confirms pilot-wave, that seems kind of huge? So much of the probabilistic interpretation of quantum mechanics has leaked into our culture, and would have to be completely rewritten.

 

[Kraftwerk]

Well yes, if you want to go ahead and throw away hundreds of years of physics and invent your own then it's not all that strange.

Its not as if our model is absolute and 100%. We are learning and discovering new things everyday.

 

[orientalNoodle]

So how does this engine move forward? Is it pushing against the vacuum of space?

 

[DragonSworne]

Good to see that God does not throw dice.

Now let's build em drives and get off this planet.

 

[Woorloog]

So how does this engine move forward? Is it pushing against the vacuum of space?

You turn the power on and magic happens and it produces thrust.

And i'm not being facetious, the thing's more or less a black box apparently.
From Wikipedia article introduction: "A radio frequency (RF) resonant cavity thruster is a proposed type of electromagnetic thruster in which electromagnetic radiation is confined to a microwave cavity, and provides thrust to the cavity in a particular direction as the radiation reflects within the cavity."
https://en.wikipedia.org/wiki/RF_resonant_cavity_thruster#Mechanism_and_hypotheses

Conventional photon drive should require about 300MW for one newton of thrust. This thing is supposedly far more powerful, so something happens in the systems that transcends our current understanding. There are ideas but no explanations.

 

[Gotchaye]

Why do people says it violates conservation of momentum?

If you input some energy, and get more, it doesn't mean you broke the laws of physics, it just mean you got more energy, somehow. Could well be that something somewhere else is providing its energy into the experiment. It might look like energy came out of nowhere, but for all we know it just comes from somewhere we didn't know existed, or something outside the experiment.

If it is possible to have two particles that are far away from one another behave as if they were next to each other, then it's possible that in a controlled experiment, you would only see the increased energy without seeing the decrease wherever else it's happening, somewhere. In a computer program, you could easily represent this by coding it so that two physical objects interact with one another as if they were as close to one another as possible, in the physics' calculation, even if in the rendering code you render both in much different positions. The idea that in our universe, our perception of space negates the ability of particles to interact with one another beyond their relative distance, is pretty limited I think, especially with things like entanglement.

This is just a criticism of conservation laws in general. When I conjure up a rabbit and pull it out of a hat, I haven't violated any sort of conservation law! No, instead I've simply teleported the rabbit from a heretofore unknown rabbit planet that is too far away for us to observe or interact with in any other way.

Like, the usefulness of conservation laws is that we find that we can count on them. Almost every time that they appear to be being violated, actually there's a perfectly ordinary explanation for what's going on that doesn't involve totally new physics. The hat had a false bottom and the rabbit was there all along.

"Maybe somehow momentum from distant particles is being transferred to this device" is not a serious hypothesis. Produce the particles. Even if the thing works and we can't locate any source for the momentum in or immediately around the device, which I very much doubt, the natural conclusion is just going to be that conservation of momentum is wrong and not that no it's still right and somewhere out there there are particles that are losing momentum as the device gains it.

 

[Kraftwerk]

Is this a good explanation for this? It was posted on a science thread;

The simplest explanation is this. movement requires you leave something behind. When you jump off the ground, energy goes in two directions. Into the earth, and up into the air. You leave soime energy going down to get it's mirror energy to go up. That's how movement works in the universe.

So, in the air, when there is no surface to put energy into in order to move, you make a surface. A jet engine takes molecules from the air, compresses them, then explodes them out the back. While it's exploding, the hot air is like a surface to bounce off of.

Now there's a problem when you get to space. It's a vacuum. No surfaces to bounce off of. Rockets try to fix that problem by bringing a surface with you when you leave the surface of the earth. But eventually, you run out of surfaces. And you're stuck, and die. oops.

What the EM drive seems to do is a vastly more efficient system. Because it turns out no vacuum is a true vacuum. At the really small scale, tiny anomalies show up. Nobody's really quite sure what they are. They might be the carrier energy molecules use to talk to each other. Like telling the atom next door that you're positive and they're negative, so let's get together and be neutral. Others speculate it's the stretchiness of space time. The universe is expanding, so all of space time is technically exerting a restoring force as it reaches equilibrium length.

Regardless, these sudden moments of energy come in and out of existence too fast to really do much with.

What the EM drive may do, is bounce a wave into a volume of space time, and bet on the probability of something coming in and out of existence while the wave goes out. If it hits anything, then that bounces back and the EM drive moves forward. It bounces off the very act of space time and matter communicating.

This could also cause some interesting consequences. For example, if you could get it to manipulate the Higgs Boson carrier of the Higgs field, then you could technically lie about your mass to the universe and cheat your way to more speed!

 

[HStallion]

Duh, he wants to bang blue-skinned aliens, too.

Grab them in the snoo snoo

 

[Cyanity]

As an engineering student; this is awesome. I wonder if any professors at my university are studying this.

 

[DragonSworne]

Space isn't a vacuum guys.

 

[Gotchaye]

Is this a good explanation for this? It was posted on a science thread;

The talk about "surfaces" is weird, but I guess basically true.

The discussion about pushing against the fabric of space-time is entirely speculative. It is not clear that this is possible. It is not clear that this device actually functions in any weird sort of way. But yes, if something that looks like a reaction-less drive is possible, the most plausible way for it to work seems like it'd be to push against virtual particles or space-time itself or whatever. But I wouldn't bet on one being possible.

 

[All Possible Ways]

Why do people says it violates conservation of momentum?

If you input some energy, and get more, it doesn't mean you broke the laws of physics, it just mean you got more energy, somehow. Could well be that something somewhere else is providing its energy into the experiment. It might look like energy came out of nowhere, but for all we know it just comes from somewhere we didn't know existed, or something outside the experiment.

If it is possible to have two particles that are far away from one another behave as if they were next to each other, then it's possible that in a controlled experiment, you would only see the increased energy without seeing the decrease wherever else it's happening, somewhere. In a computer program, you could easily represent this by coding it so that two physical objects interact with one another as if they were as close to one another as possible, in the physics' calculation, even if in the rendering code you render both in much different positions. The idea that in our universe, our perception of space negates the ability of particles to interact with one another beyond their relative distance, is pretty limited I think, especially with things like entanglement.

Conservation laws are local. This means that energy and momentum cannot go from one place to another without crossing the space in between. This is a very important point.

Entanglement does not change this. The correlation between the distant particles does not alow the transfer of energy or momentum, it only shows up in that measurements on the two particles are correlated. Otherwise one could use this mechanism to transmit a message faster than light, which is impossible.

 

[cyberheater]

So back engineered alien tech...