Do you believe in the EM Drive, Veeky Forums? Does your Hard SF setting use them?

I've noticed that there are three broad categories of sci-fi settings:
- Soft sci-fi.
- 'No numbers' hard sci-fi. They take concepts from actual science and throw them in without understanding them. Usually by failing to do the math.
- Really hard sci-fi. The authors understand the science and did the math.

The EM Drive is a good example of the difference between the last two. The 'no numbers' hard sci-fi setting will be written by people who didn't understand anything beyond it not using fuel. They will then stick it on everything, often producing levels of thrust that will splatter the crew against the back of the ship.

A really hard sci-fi setting will take note of the EM Drive producing barely any thrust. So they will only use it on things that can take a long time to get anywhere. For anything in a hurry (for example, anything with a human crew), they will use a different engine on the ship. One with enough thrust.

This.

I don't much believe in the EM drive, but things basically stay in orbit on their own and doing anything anywhere near a non-negligible gravitational field is not the point.

I am a retard. I believe that you can start with a hollow cylinder, then reduce the surface area of one end so that the walls taper in, and fill it with particles. The area of one end of the cylinder is bigger than the area of the other end, so particles colliding with the walls of the cylinder impart it with a net momentum. For this reason I believe that coke bottles can fly: the surface area of the cap is smaller than the area of the bottom, so logically the particles inside the bottle exert a net force towards the bottom.

Coke bottles are closed system. The EM drive has a magnetron generating microwaves into the cavity. The re is no solid explanation for how or why it seems to work, but several different experimenters have recorded anomalous thrust, so it's looking positive, at least.

>take cap off
>put bottle in microwave
>turn microwave on
>???
>PROFIT!

No. We don't have perpetual machines, yet.

EM drive is, supposedly, a perpetual machine with very low thrust. It won't get you anywhere quickly, but you can go infinitely fast so long you have infinite time.

Yes its thrust is minuscule, but it still has its uses, if it works I mean. It would accelerate slowly but in space we have plenty of time to build up speed. If it works, traveling from Earth to Mars would immediately become way faster and cheaper. And that would be a huge jump forward.

The Chinese are pretty convinced that it works and are already investing heavily in the technology, so I'm hopeful.

People forget that science is about discovery and act like our understanding of physics is perfect and set in stone. Believing in science as if it was some kind of deity, using scientific theories and laws to limit the world around us, when in reality, those theories and laws are superficial at best and change whenever we discover new stuff.

A magnetron pushing microwaves into a cavity is an equally closed system. The most probable explanation for the measured thrust is experimental error, not a break in the conservation of momentum. When you use the kinds of extremely precise instruments needed to "measure the thrust" of the EM "drive", many effects that can normally be ignored need to accounted for in order for the measurement to be accurate.

People also forget that all kinds of bullshit artists used to succeed in, currently succeed in and in the future will continue to succeed in separating fools from their money. How many magic boxes that make a spaceship move do people need to buy before they realize its bullshit?

The EM drive as designed? No. Even if the tests are accurate, it produces so little thrust as to be almost worthless.

But I think the important takeaway is that the EM drive shouldn't do anything at all. If it works, even slightly, then that means there is a fundamentally new kind of space thruster possible that we haven't explored, a different technological branch that's not even on our radar.

I'm willing to believe that, IF the EM drive turns out not to be bunk, then once we figure out what the actual hell is going on we will be able to build a better version based on our increased understanding of the principals in play. The first chemical rockets ever built couldn't go very far either, it took time and engineering to turn those into the escape velocity powerhouses we know today.

>do you believe
No, the math doesn't make sense within the framework of conventional physics.

My (relatively) hard Sci Fi universe had newer and better data available that completely changed our understanding of how things are and invalidated a lot of current limits on space travel.

Because why limit ourselves to modern understanding?

There have been several fission powered spacecraft built already.

Usually what happens when you do this is that you create some technology that violates physical laws in very extreme ways, like allowing for perpetual motion or violating causality then make no attempt to either explain why those consequences are not the case, or carry through those consequences to their logical conclusions.

Which makes you a dumb faggot.

Tax money has been used for much sillier things, so I'm happy to wait and see what happens with it.

If it really works though, it's sort of a scary thought. What happens if you can build a relativistic kill vehicle for a billion dollars?

We get to live in an ideal but bland universe, devoid of alien sentience.

>go infinitely fast

Except it's a magic box that is being studied by several universities, space agencies and aeroespacial industries around the world and instead of being proven as a hoax it's actually the contrary.

I'm sure it is a measurement error. People want to believe so bad they let their biases blind them. I also wish there was a magic box that makes dreams real but the universe doesn't work that way.

Even if it is an error, it's an error that's been reproduced by several labs working independently.

Finding what the error was could be a useful discovery regardless.
>inb4 it exploits a flaw in the simulation
>inb4 mods delete our universe because hax

Wasn't China claiming they had one in orbit recently?

>55552046▶
best fucking response

>For anything in a hurry (for example, anything with a human crew)
Depends on how big the crew is.

>For this reason I believe that coke bottles can fly
youtube.com/watch?v=2wfppG7Tt0k

>produces an anomalous thrust even when turned off

>mfw it forces us to reexamine our fundamental understanding of physics and opens up a slew of new possibilities and paradigms

This seems like the optimal scenario, honestly. Physics has been getting stagnant and could use another revolution.

>literally the most horrific method of propulsion ever devised by mankind
Fuck yeah
The universe is quite the reactionary, unfortunately.

>looks that shit up
>continually reaching critical mass in solution
>just kinda... directing the resulting thermonuclear explosion out
jesus christ

>Even if the ISS devoted all of its power production to the EM drive, it would still fall from orbit.
The ISS or the EM drive?
Either way you would be wrong, the ISS and the EM drive (Assuming it was on or near the ISS at the time) are already in orbit around the earth and an object in motion will remain in motion unless an equal or greater force acts upon it, if the EM drive was accelerating prograde even at a extremely low amount of thrust it would only climb in altitude.

That is assuming of course that the EM drive is capable of generating thrust at all which it isn't.

I believe it's probably an expression of the Woodward effect, and quite an inefficient one at that.

From what I understand (which I will admit is not a lot) about relativity is that a spacecraft could theoretically accelerate infinitely but as you approach the speed of light you suffer increasingly diminishing returns in increased speed for the amount of energy expended eventually needing to consume billions of stars worth of energy just to move a meter per second faster and only getting worse form there. and that you can never reach the speed of light only increasingly larger percentages of it and that while this is happening you are also experiencing increasing dilation of time eventually having billions of years passing in seconds from your relative perspective so that time itself would end before you ever actually caught up with the speed of light.
So in a sense you could go infinitely fast in the sense that you keep getting faster forever but there is still a limit you will never surpass.

The ISS is at a low orbit (since it costs less money to put things on a lower orbit) and is constantly, very slowly, getting slowed down by the very thin atmosphere it flies through. This makes the ISS a handy benchmark for a drive: if it can't keep the station in orbit your drive is not going to have enough oomph to get you anywhere either.

Please try to actually be familiar with the topic you're talking about before opening your mouth.

What part are you complaining about?

>Hard Scifi
>Not limited to solar system
>Not limiting population centres to Earth and Mars
>Not having only minor settlements being mining outposts, research stations, and out of the way settlements created by radical anarchists, libertarians, fascists, white supremacists, etc.

>Hard sci fi
>everyone is dead from antibiotic-resistant diseases

infact using the heat of the reactor to keepbthe electronics warm enough for optimal function has been done a few times.

see
and then blow it out your ass.

>Not being genetically modified to be immune to antibiotic-resistant diseases

Yup. And as a bonus, since this is special relativity you can understand the consequences (though not entirely how they're derived) with just high school math. Velocities in relativity do not just add up like they do in intuitive Galilean / Newtonian mechanics. The formula to add velocities v and u to get w is

w = (v + u) / (1 + vu/c^2)

If v and u are a very small fraction of c (as all the normal everyday motion we see is), then "vu/c^2" is nearly 0 so w = (v + u) / (1 + 0), so w = v + u. That is, Newton.

But as you get to bigger fractions... say a child is on a train going at 0.8c and throws a baseball going another 0.5c. How fast is the ball going from the perspective of someone in the station? It can't be 1.3c! That's the point. It's (0.8c + 0.5c) / (1 + .8c * .5c / c^2) = (1.3c) / (1.4) = 0.93c. Fun!

There's a similar equation for putting in kinetic energy: basically you invest nearly infinite energy into accelerating a non-zero mass and it'll move at nearly but not quite c.

Wait, am I messing up something or was it explained that the thrust was actually caused by power cord?

I'm pretty sure the experiments were set up so the battery would move with the engine.

I can't find a source, but I remember reading that when the battery was actually contained in the engine it produced no thrust and it's all just Lorentz forces. But don't quote me on it, it's been a while and I can find the article in question.

The only experiments I've heard of resulted in pathetically negligible thrust, even plasma drives (which still take forever to get up to speed) will probably only be used for robots. If I were creating a hard SF setting, manned ships would use a nuclear thermal rocket or fusion torch drive, while probes and robot cargo ships would use high Delta-v plasma drives.

>implying torches are realistic

For my purposes I assume they are, because it will probably take more than a hundred years for any significant space industry to start up unless we have another spurt of exponential industrial and technological growth. I make the assumption by then that magnetic containment will be significantly approved or super-ceramics will exist that can deal with prolonged exposure to plasma.

Two out of the three independent teams working on this have already withdrawn their support after they found holes in their own experiments. The Eagleworks team hasn't, and while they're techically NASA, they're also they same handful of guys who are "working" on the warp drive.

As for the nonzero results, the can be explained by systematic experimental errors, such as thermal effects that are pretty much the only possible explanation for the cases where the observed force didn't immediately stop after power to the engine was turned off, but instead slowly dissipated exactly as if it was following the temperature curve of a cooling object.

The original author's math was riddled with elementary mistakes. He stopped trying to show his math on the internet because of the constant ridicule and now spends his time drawing pictures of flying machines, and imagines not just one generation of his miraculous engine, but second and a third generation, the last of which will finally enable his dream of antigrav hovercars. But don't worry guys, he's only done this for 20 years, he'll reveal the true theoretical basis any time now!

The cranks who actually believe in the engine and possess above-average math skills (the typical example is an engineer who posts on conspiracy theory forums, and believes in perpetual motion, free energy, and the electric universe) constantly trawl the net for any theory that would explain the EMdrive. The last time I checked they'd moved on from the Unruh effect to a dark matter halo around the Earth. Their preferred theory has changed every few months for a couple of years now; they hop on to a new bandwagon after physicists show their previous calculations' errors. They don't seem to be dismayed by the experiment where one engine was inverted and produced even more "thrust" - which to any reasonable mind would be solid evidence that it's all just snake oil - but instead babble about the oncoming Chinese space armada with reactionless drives.

*Improved, not approved, my bad.

>Chinese space armada with reactionless drives.
Going to put that in my next scifi game, if I ever run another one.

>using the EM drive for thrust
It's a reactionless drive, user, it's a planet-killer waiting to happen.

Hook the EM drive on a boom arm in space that turns a generator that feeds back into the EM drive.
The EM drive's energy consumption is linear, but the energy output due to acceleration is a power function.
This means, that at a certain acceleration, the EM drive begins to put out more energy than it takes in; it's literal troll physics made manifest, if it actually works.

However, this means that it takes a lot of starting energy to "spin up" before it breaks even, meaning you either need to start it spinning, or just pump in a whole lot of power.

The most mundane application of this is to use a single EM generator to power any number of EM drives to some arbitrary power output, meaning the only thing holding back how fast you can go is how much power you can feed to the drives.

This is why almost nobody seriously believes that it works, because if it does, you've literally broken all of modern physics with what amounts to clarketech made out of scrap metal and a microwave.

Could someone please explain to me in simple English the what, why, and how, of whatever this EM Drive is that this thread is talking about?
I have absolutely no fucking idea what ya'll are talking about and don't want to participate in a stance of ignorance.

Some guy claims to have invented a reactionless drive, meaning it turns energy into thrust without shooting anything out the back (hot gas, plasma, ions, photons, nothing).
Naturally, this severely breaks the law of conservation of momentum, and compounded on top is that the thrust produced by the drive at reasonable levels of power is within the margin of error.

If it works, it's a literal perpetual energy machine.

Okay, so, a while back some astrophysicist in the UK (?) proposed a kind of space thruster called the EM drive. It basically bounces a bunch of microwaves around in a cone shaped resonance chamber and somehow that equals forward motion. This is what is referred to as a 'propellentless drive', aka a thruster that doesn't shoot anything at all out the back to make it move. Which is a nonsense idea on par with saying 'maybe make some kind of gravity engine???'

Thing is, the EM Drive guy took his design to a university and got them to build a version, and while it didn't do anything they did detect a very slight amount of forward motion. So very small that it could be equipment error.

So he took it to another university. Same thing, slightly different numbers but they also detected soemthing that could have just been equipment error.

An astrophyics lab in germany: almost nothing, so small as to be possibly an equipment error.

China built one, same thing.

NASA built one: same thing.

None of their numbers agree exactly, but they all point to something very, very weak happening that could just be an equipment error. To which some people ask the question: how many times can it happen for different people before it stops being an error?

The thing is, the EM Drive results as detected are dramatically weaker than even an Ion Drive, which is pretty weak. But the fact of the matter is the EM Drive shouldn't work AT ALL. So if it does anything even remotely like forward motion, its worth finding out what the hell is going on because it SHOULD be as much a space thruster as your toaster. Less so, even, because your Toaster can at least eject toast.

>If it works, it's a literal perpetual energy machine.

Stop saying that, people. Thats never what the EM Drive has claimed.

All it would mean is that we can plug in electricity for a small amount of thrust. It never says that we don't spend more energy as electricity than we get as kinetic energy, and it certainly never says that we get more net energy out than we put in. The efficiency on the exchange looks to be really shitty. But it shouldn't work at all, so its interesting.

And who says we understand all there is to know about modern physics? Obviously we don't - we actually have a proven reactionless drive! So our model of the universe is clearly incorrect.

user, it's a reactionless drive, which means it breaks conversation of momentum. At some velocity, the energy added to the drive due to acceleration will be greater than the energy put into it.
> Thats never what the EM Drive has claimed.
Because the people who promote it are either:
A) Unimaginative and don't know physics
or
B) Don't want to call it a perpetual energy machine in waiting for fear of ruining any credibility it might have

youtube.com/watch?v=JGcvxg7jJTs

>And who says we understand all there is to know about modern physics?
Nobody, but our current models are extremely well tested.
It's important to keep an open mind, but not so open that your brain falls out.

>we actually have a proven reactionless drive! So our model of the universe is clearly incorrect.
We MIGHT have a reactionless drive, and probably not.

Reaction we cannot detect=/=reactionless drive.

Making it out to be even more of a magic box isn't helping your case, user.

> user, it's a reactionless drive, which means it breaks conversation of momentum.

Not necessarily. For example, during the Eagleworks tests of the EM Drive, they found that one of the anomalies that came up during testing was that when they fired a laser through the resonance chamber, it came out the other side faster than the speed of light.

Which is, of course, a nonsensical result. Light going faster than light is just stupid.

One of the theories that came up out of the Nasa 'Room full of guys' forum, where you can't even register an account unless you have your doctorate, was that the light wasn't going faster, it was crossing less distance than the test conditions specified. A very small compression of space, creating a sort of 'incline' acting at the drive. This would also explain its very small amount of forward action, it is essentially leaning forward.

There isn't any reason at all it should do that, and proving the existence of such a field would take an enormous amount of funding. But it does satisfy most of our checkboxes, physically speaking. Even if it does mean that the EM Drive would be A) worthless as thruster because you can't just tip yourself forward so much you fly and B) be a groundbreaking discovery because that means compressing space is way, WAY easier than anyone could have guessed. Bonus points: microwave resonance chambers could have been doing this literally the whole time, no one ever would have noticed because the effect is so small.

What I believe in is that the measured "thrust" really is just heat expansion

I didn't believe the hundreds of scientists who worked on the FTL neutrino experiment for months before announcing their wrong result and I sure as hell don't believe the three guys at EW either.

There is a difference between 'magic box' and 'undetectable emission'. The most prominent example is radiation, with exposure of photographic plates by previously undetectable emissions. To presume that we understand it all is the height of folly.

It is equally fallacious to presume that there is an entirely new universe of physics to discover.

It doesn't have to be an entire new universe, just a few things missing or unknown. There are still many things we don't know and many more we haven't proven - einsteins equation was only prooven a decade ago we only provably detected gravity waves last year.

On the other hand you're not the idiot who claimed we know all there is to know about the universe....are you?

That's nowhere near the height of folly. More like a small hill of folly, suitable for comfortable promenades and picnics on top. Not a flat land but certainly no highland either. Trying to ignore decades of scientific evidence based on wonky experiments and wishful thinking, however, is something I'd put quite near the top of Mt. Folly, if not exactly at the summit. At such a great height of folly you really need oxygen cylinders to survive, and it's very cold and lonely.

And yet people on those airless summits are the ones who make the breakthroughs that we're still having trouble understanding today.

Funny how that works.

What's your opinion on N-rays then? They were a previously undetected emission, as you mentioned, and discovered 8 years after Wilhelm Rontgen discovered X-rays. While more sceptical researchers criticized the results and suggested they were caused by experimenter bias, about 120 scientists, most of them patriotic Frenchmen and annoyed that a German had discovered X-rays, proudly asserted they had observed the new type of radiation. Were the skeptics right to defend the academic consensus because Blondlot's experiments were shitty and there was no plausible theory of N-rays?

en.wikipedia.org/wiki/N_ray

>hard sci-fi

>Hard sci fi
>everyone is dead from antibiotic-resistant diseases

Constant revolution leads only to anarchy, user.

>thrust
nigga.
please.

Human GMOing is easily a near future development.

You could genetically modify humans right now if you really wanted to. It would just be a really questionable process and you'd have no idea what the outcome would be.

It is effectively a Tesla Ramjet. I can see that nobody in this thread cared to see into it, because they call it a reactionless drive. It is ->NOT

...

>unironically believing in Tesla's tinfoilery

Tesla-y shit like quantum plasma is nothing new. The only thing that crazy serb got wrong was the small but important detail of extracting "free" energy ain't gonna be free.

...

It's about as realistic as the Phone Microwave from Steins;Gate.

>instead of being proven as a hoax it's actually the contrary.
can you show me a recent paper? Because the last time they measured the thrust it was barely within the error of the measuring device
then they turned it perpendicular to the measuring device and got the same thrust

Here is the relevant wiki entry:
>en.wikipedia.org/wiki/Vacuum_energy
AFAIK the EM Drive harnesses this one.

>What happens if you can build a relativistic kill vehicle for a billion dollars?

Well for one thing you stop sending out "hay aliens where are you I'm here on earth where is everyone???" messages

> How many times can an experiment have a miniscule error just on the remote bounds of measurability?
Um, all of them, usually.

But user, it IS the phone microwave. Hitlerally.

I seem to remember seeing a story the other week about a few experiments on genemodding embryos. Terminated after a few days, but as far as they could tell it worked...
Here. bbc.co.uk/news/health-40802147
>Human embryos edited to stop disease.

Noice.

>walk into thread about science thing
>mention a science thing that's taught in grade school
>doesn't actually know how it applies in real life and why he's wrong

The ISS is in LEO and encounters not-insignificant drag. It needs to get boosted back up with the Zvezda module which is why some of the cargo manifests include fuel.

The amount of drag on the ISS cannot be negated by applying all the 120 kilowatts it generates to an EM drive.

A Voyager-mass with a 100W power source hooked into an EM Drive would take 3500 years to match Voyager velocity. The Voyager RTGs only generated 160W at creation, and RTGs do eventually run out.

If you want to read the actual paper that establishes a thrust for the EM drive, see arc.aiaa.org/doi/pdfplus/10.2514/1.B36120 but if you want to check my calculations it's measured at 1.2 +- 0.1 mN / kW.

That's if it is working at all. We aren't really sure it's generating thrust.
If it's working at all, it's a first device and we don't even understand the principles it's functioning on. We can't usefully extrapolate how it might function in the future, other then an awareness that it's likely knowing why it works would help us make it work better.

It's like the first rocket, a open tube of crude serpentine powder being pushed forward with no nozzle, poor confinement and no understanding of what makes a rocket work. It's quite possible that the EM drive could see several orders of magnitudes improvement.

We can't definitively prove whether or not the EM Drive actually provides thrust, but I am pretty confident it's NOT a perpetual motion machine.