EmDrive fails ?
Trust the Germans.
The "impossible" EmDrive may be just that, though don't count it out just yet. A group of German physicists at TU Dresden has tested two proposed means of propellantless propulsion – the EmDrive and Mach Effect Thrusters – and found the act of testing is what makes these arguably physics-flouting technologies appear to work. …
Given that this is in direct contradiction of NASA's own previous experiments and the Chinese experiments (IIRC Chinese are actually sending a prototype into space on a satellite for orbital testing), I would take these results with a pinch of salt. It is not at all evident that the experimental hygiene applied here is more stringent than at NASA.
One side of me says "why is the physics community even entertaining this idea - it was obviously B0110cks from the start" and the other says well, where would physics be if we all discounted out-of-hand any ideas which at first glance, appeared to be utter bollocks.
But on balance, my suspicion is, it's bollocks.
It's probably bollocks, but it is theoretically possible that it's real. There's no way to know without testing it out -- so I think the various researchers are doing the right thing.
At this point, I think that anybody who says anything definitive about the effect are talking nonsense. There isn't enough data on which to base a conclusion either way.
If you were to tell someone the quantum physics / general relativity stuff without much context - if someone had discovered the physical effect before we'd derived the equations that helped us find it - that would have been called bollocks too.
It's only because we went the other way "Well, that leads to this... which can't be right... can it? My word, there it is..." that quantum physics "feels" right, everything else about it is completely counter-intuitive and contrary to so much of "ordinary" physics.
That said, it always felt dubious not because of some unknown effect being in play, but because said effect was so tiny, in such a huge and powerful piece of equipment, that it basically feel into the error margin. Don't you have to apply KW of electricity to see this effect, as per the original experiments? That's a hard thing to account for down to the tiny amount of thrust seen - the thrust is outweighed by things like losses in the cable (generating those magnetic fields!), the AC-DC conversion, etc.
But at least we didn't go silly. If we'd got into space and found out this thing didn't actually work, there'd be hell to pay. It's kind of expected that a few organisations would try to replicate the results with various success and that would throw up enough questions that we have to look deeper and doubt ourselves. And that's where we are.
Unfortunately, for the vast majority of papers written, this kind of reproduction just doesn't occur. Wasn't there a study once and something like 50% of academic papers had results that literally could not be reproduced even by experts?
Funny you should say that.
Because that's just about what current Ion thrusters need to generate milliNewton thursts from a big tank of (expensive) Xenon.
Until they run out of course.
IIRC Most people thought Shaylers explanation of how the thruster worked was BS.
However several teams claim to have demonstrated thrust is being generated. And if you don't understand how something works how do you know what it's safe to ignore (or just leave out) in the design? "I left the power transformer out of the amplifier I built but it should work fine anyway." WTF?
The really attractive part of a propellantless thruster is not that it could drive a probe out to Pluto (with a fission power source of some kind).
It could then bring it back afterward.
if someone had discovered the physical effect before we'd derived the equations that helped us find it - that would have been called bollocks too.
Um, we did do exactly that. The photoelectric effect, for instance, was known in the 19th century, and it makes no real sense in classical physics: Einstein didn't write the paper explaining how it worked until 1905, and we didn't have a really proper mathematical theory until the late 1920s. All of the development of QM was driven by experimental results which seemed insane classically: that's why there was, for instance, the old quantum theory (which explained some things but clearly made no real theoretical sense) and then two new quantum theories (matrix mechanics and wave mechanics) which explained much more, and then later turned out to be the same theory. It's worth reading the history of this stuff -- in particular if you read the letters people wrote each other in the 20s and 30s they're just full of 'this result makes no sense, and the theory which explains it makes even less sense': no-one wanted QM to be right (many people still don't!).
There are numerous occurrences of this in physics: in fact the cases where theory precedes experiment are pretty rare.
GR is, perhaps, a partial (but only a partial) exception to this. Special relativity was inevitable following experimental results which made no sense without it -- the Michelson-Morley experiment for instance. There is some evidence that Einstein came up with SR without really paying much attention to experiment, but he was working in an environment where everyone knew something was needed as a result of MM & similar things, and also the mathematical form of SR was already pretty much there: he 'just' provided a conceptual framework for it ('just' meaning 'this was a huge step'). General relativity is more nuanced: once you have SR it's immediate that Newtonian gravity makes no sense, but I don't think there were any really good experiments which showed that as the differences are pretty small on scales we could measure in the early 20th century: the precession of the orbit of Mercury was known to be an anomaly I think, but perhaps that's it. GR kind of should not have existed until the second half of the 20th century, and in a sense it really didn't: almost nothing happened with the theory until the GR renaissance in the 50s-70s, and that was driven substantially by experimental results in cosmology.
The most glaring exception is black holes: BHs were just clearly a bit of interesting maths which didn't correspond to anything in the real world until, much later, people started seeing things which only really made sense if BHs were actual physical objects. But BHs might be one of the very few exceptions.
Even things like neutrinos -- predicted in 1930 and not observed until 1956 -- come out of experimental results: Fermi predicted the neutrino because without it beta decay does not conserve energy.
Great comment on how science was, and should be, done. Unfortunately, it's rather outdated. Today, scientists put their assumptions into computer models that 'prove' that which is desired to be proved. When real data conflict with the models' output, they clearly must be wrong, and are adjusted until they conform properly to the models.
Don't expected significant scientific breakthroughs in several fields for a while.
> Today, scientists put their assumptions into computer models that 'prove' that which is desired to be proved.
There have always been bad scientists, and computers gave them another toy for doing bad science. Massaging data into shape or outright fake is possible without computers and has happened all the time when computers were not around.
I dare to say good and proper science still exists.
Would you like to give concrete examples rather than making vague accusations of malpractice?
I work somewhere where we run very large computer models of physical systems, and I can tell you that people spend a lot of time worrying about the agreement or otherwise between the models and the data.
I think there is definitely a problem with some theoretical physics because the experiments to test theories have become essentially impossible to do -- we have theories that work essentially perfectly in all the cases we can construct experiments to test even though we know those theories can't be completely correct. So we're kind of stuck -- I suspect the best hope is either that a theory will come along which is compellingly good at explaining various astronomical observations or that someone will think up experiments which can be done without spending absurd amounts of money, or that something completely unexpected will turn up in existing experiments. Any of these would clearly be really good. But that problem is not the same problem.
Science stops being science the moment a claim is dismissed purely on the basis that our current theories say it can't happen. Sure, there are definitely nuances concerning how much effort you might be inclined to invest in studying a specific claim, but ultimately the only thing that matters is multiple experiments confirming or disproving that claim, not what we think "ought to" happen.
I agree with this, in case it's not clear: I don't object at all to people testing these things, any more that I object to people doing experiments to see if antimatter experiences gravity backwards (which people are doing/have done). There must come a time where you stop, but it's not fir me to say when that is.
"I can tell you that people spend a lot of time worrying about the agreement or otherwise between the models and the data."
Most people. I work in a similar environment and we've caught people just inserting fudge factors to close the gap between observations and calculations instead of flagging it for further research.
Senior people were understandably furious when they found out as it meant that opportunities to improve the calculations were being lost.
On the other hand one of the more interesting discussions in the last few years was a result of 32 and 64 bit versions of the same software giving different answers. The original assumption was that one was "wrong", but the eventual answer was that they both were - the reason many generations of compounded rounding errors. Rewriting the software to not feed the results of the last orbital calculation as input to the next vastly improved accuracy and got both flavours of software giving vastly more stable solar system modelling.
Yes, I'm not arguing that some people don't fudge things: people have always fudged results, and one of the purposes of peer review & the rest of the scientific process is to find that (which it looks like you did!).
What I claim is that there is not a wholesale move to a state where people run models on computers and then adjust the experimental data to fit those models.
Indeed where I work we have a problem very like this: our models give results which are uncomfortable in various ways, and there is a lot of pressure to insert a fudge factor to make them more comfortable, which is being resisted: the models may be wrong (there is not good enough experimental data to know yet) but people want to understand why they're wrong in terms of the physics they're modelling ('oh, we've missed out this process, let's put that in and see if things are better') rather than just adjusting the results.
"
that's not how science is done in *my* field.
Yes, models exist, but the *models* are adjusted to match the data, not vice versa.
"
That's the difference between a scientist and an engineer. If asked what 2+2 equals, the scientist will reply "4" and the engineer would close the door and whisper, "What do you need it to equal?"
I recall reading an early paper claiming that the MM effect was caused by the earth dragging the ether along with it. So the experimenters did a series of experiments at various elevations and found that as you got higher the speed of light differed in different directions.
It is difficult to separate out the truth when there may be experimental error, experimenter bias etc. After the fact it seems so obvious.
Ether dragging was one possible explanation, of course, and as I said it;s not clear how much Einstein paid attention to the experiments (relativity was kind of an exception, which was my point really). I think if ether dragging was true you'd get some interesting results looking at light coming from other planets.
if someone had discovered the physical effect before we'd derived the equations that helped us find it - that would have been called bollocks too.
Actually try looking at the rotation of our galaxy, Vera Rubin did and what was measured didn't match what we thought we knew.
So we now have dark matter and dark energy as a book keeping exercise until we can actually work out what is going on.
May people consider dark matter and dark energy to be bollocks but so far nothing else fits and we don't appear to have a better explanation.
The experimenal results before QM were much cleaner and gave multiple "signals" that Newtonian machanics had problems. You couldn't accout for the black body radiation curve. Once the nucleus-orbiting electron model replaced the current-bun model for the atom, it was a classically impossible system as the electrons would radiate and spiral in, etc.
Unfortunately, for the vast majority of papers written, this kind of reproduction just doesn't occur. Wasn't there a study once and something like 50% of academic papers had results that literally could not be reproduced even by experts?
I'm not sure that's correct. Unfortunately I can't find a study which reproduces this study.
@Lee D:
I'm inclined to agree with much of what you say, and not just because of Relativistic vs Quantum theoretics debates (Okay - they shouldn't be vs debates anymore, they should be how do we get them to mate in that tree over there debates), but -- well -- if we look *out* from where we are and decide that the universe can give us some hints, the big one is that, well, when it comes to *stuff*, we really really really haven't made that much progress, and there is a *lot* of dark (matter/energy) that we cannot yet explain. Like, WAY more that we can't explain that we CAN explain.
So, if there's even a tiny ledge of theory that the bollocks can stand on we have to keep pushing them till they fall off that ledge. Then we can braise them in red wine and add some fungi and fava beans and have a fine meal.
Twice the Nobel Prize was awarded to people who demonstrated that accepted thoughts on the matter were completely wrong. I remember the professor giving us a stern lecture about assumptions. Scientists (the kind not on amusing TV shows) are now rightfully sceptical when the word "obviously" is used. In fact ever since Quantum Physics was established nobody should assume too much about anything that may appear obvious.
Just off the top of my head.. how big and how heavy is the device(s)? If gravity is throwing a curve ball into the works, make a mini-sat, launch it out into the void and see what happens. Probably not really ready to do that yet as apparently there's "design" issues. On the other hand, it might be bullocks like perpetual motion machines.
" For that they were getting a thrust that would counterbalance a desicated flea."
As long as the thrust is higher than the resisting forces holding it at rest, then you'll get acceleration and it (eventually) adds up to significant velocities.
Ion drives chew plenty of power. Their disadvantage is that they eventually run out of fuel.
>>...the power supply is similar to that required to run a single family house hold...
thought experiment -- edison accidentally discovers a form of led light but it takes the energy needed to power new york city to light a closet. pronounced as useless and unscientific rubbish on the spot.
point is that nobody knows what's going on or how it works. not claiming that the final design will run on a phone battery but IF IT WORKS AT ALL then the understanding of it would result in vast improvement in efficiency.
Still plenty of gravity out there, plus all kinds of poorly quantified and changing effects (outgassing from satellite, solar wind, radiation pressures like the Pioneer Anomaly). The effect has been hard to study this effect in a well-equipped lab here on Earth, being in space will just add to the fun.
Though if I were one of the researchers I'd certainly argue for its necessity, along with the need to budget for some site visits...
Legend has it that, when Thomas Edison had invented the light bulb, someone said to him something like "so it took you (let's say) 1480 tries to make it work ?", to which Edison replied "No, I invented 1479 ways not to make a light bulb".
This is Science. We don't just need to know that it doesn't work, we need to know why it doesn't work, in a mathmatically quantified way. Because maybe, one day, somebody will be able to revisit the maths and find a way to make it work. Or maybe the maths will give him an idea for something completely different.
In any case, some bloke on YouTube is not a scientific reference.
Except Edison didn't invent it. He was looking for a better way to make carbon filaments. Tungsten was too difficult to work with. Nor did he invent Cinema despite his patents. He was an entrepreneur, not a scientist.
I agree the EM drive and Mach drive are worth investigating (Photon propulsion does work), though the expectations of the proponents for space travel are overblown. Though you don't need reaction mass, unlike Ion drive, solar power is only good well within the orbit of Jupiter. Nuclear power needs fuel and if you had a fusion drive you can use the helium etc produced in a linear accelerator / Ion drive. Electrons can be accelerated separately and mixed with the Helium ions.
the problem with photon propulsion is that the energy required is highly inefficient. the existing ion drive using a heavy element gas is much better, since thrust = delta momentum = delta velocity * mass of propellant.
To double thrust you either double delta-velocity or double mass. If you double delta-velocity, then delta-kinetic-energy is QUADRUPLED.
So shooting photons has nearly zero mass times "speed of light squared" energy, as compared to something considerably less relativistic speed-wise, and the mass of a heavy nucleus. It may consume fuel, but the ion drive wins every thrusting contest this way.
Yeah the dream is sticking out your solar panel and having an electric no-fuel thruster, but it would be SO inefficient...
photon propulsion is the most efficient use of reaction mass possible, and reaction mass is what limits spacecraft, not energy.
Indeed, if you want to move around in the neighbourhood of a star you can just use a big mirror and rely on the photons the star is spitting at you. You use no fuel at all and expend no energy at all. You need a big mirror to get much thrust, OK (pressure from sunlight at earth's orbit is ~ 10^-6 Pa).
It may consume fuel, but the ion drive wins every thrusting contest this way.
The problem isn't consuming "fuel" - a photon drive will also consume fuel, after all, if it's not powered entirely by something external such as solar panels or fusing interstellar hydrogen or unicorn magic.
The problem is consuming reaction mass, which may or may not be a waste product of consuming fuel. Based on the rest of your post I assume that's what you meant, but calling it "fuel" is inaccurate.
The article makes the same error.
People are excited about propellantless drives for the same reason they're excited about photon drives: no reaction mass to haul around and run out of (or have to replace from somewhere). A photon drive isn't propellantless, but its propellant has zero rest mass and can be whipped up from just energy inputs, solving the same problem.
Personally I would be extremely surprised to see a working propellantless drive; conservation of momentum has always been good to me, and I plan on sticking by it as long as I can.
" Nor did he invent Cinema despite his patents."
Whilst the light bulb was the result of a lot of actual work making Swan and Priestly's inventions viable, the cinema was flat-out intellectual property theft.
He even stole complete movies made by the Lumiere Brothers and claimed copyright on them.
In any case, some bloke on YouTube is not a scientific reference.
That bloke on YouTube happens to be Phil Mason, PhD. One of his series of YouTube experiments ended up overturning the traditional explanation of why sodium dropped into water ends up exploding. So he's not a typical YouTube knowall who wibbles on about stuff in advanced Dunning-Kruger mode.
You did watch the video before commenting, right? Just enough to tell if he knew what he was talking about, right? Just to see if he raised any points that might discredit EMDrive, right? Just to see if he used empirical evidence and mathematics (as you insist are required) to substantiate his claims, right? Nah, wrong, you just wanted to mouth off.
Oh, and let's not forget that the Germans just confirmed what Mason figured out nearly two years ago, so your dismissal of him without even looking at what he had to say is even less justifiable.
I'm thrilled to learn that someone who is competent in physics had a good YouTube video of why something could not actually work.
Unfortunately, if I'm not mistaken, YouTube is not a recognized, peer-reviewed, scientific news platform.
So please point me to his published paper on why the EMDrive couldn't work, because if there isn't any, I fail to see why Science should take that into account.
I'm thrilled to learn that someone who is competent in physics had a good YouTube video of why something could not actually work.
I'm glad you're thrilled. It costs you very little to watch youtube and we all like cheap thrills.
Unfortunately, if I'm not mistaken, YouTube is not a recognized, peer-reviewed, scientific news platform.
Indeed it isn't. But it can be informative, nonetheless. It can, for example, point you to where further experimentation may be worthwhile and then a peer-reviewed paper may result.
So please point me to his published paper on why the EMDrive couldn't work, because if there isn't any, I fail to see why Science should take that into account.
There is absolutely no reason for science to take his video as authoritative or definitive. In fact, every reason not to. However, if the Germans had watched his video when it came out then they might have done their own work on the drive 18 months sooner than they did. Which is why I said that they ought to watch more youtube. They were a little late to the party.
Pascal Monett fails to appreciate the 'Appeal to Authority' failure with this, "...not a recognized, peer-reviewed, scientific news platform."
Hey. Science is proudly 'Self-Correcting', and that includes plenty "recognized, peer-reviewed" nonsense. It's a useful skill to separate the wheat from the chaff based on one's own understanding and logic.
Those that worship the nonsense that is sometimes "recognized and peer-reviewed" and published in journals are doing themselves a disservice.
To be crystal clear, I'm all in favour of Science. It's what passes for some science these days that is annoying. E.g. Dietary and Heath advice.
There's no excuse for worshipping and faith in Science.
"That bloke on YouTube happens to be Phil Mason, PhD"
It doesn't matter one damn bit what kind of PhWhateverthehellyouwant he may or may not have - until he sits down in front of a vacuum chamber, cranks up the amps and observes the outcome, he has NOT "proven" or "debunked" anything; he merely offered his educated opinion on why it's not supposed to work. Which has precisely zero relevance to whether or not it actually does.
@DropBear
It doesn't matter one damn bit what kind of PhWhateverthehellyouwant he may or may not have - until he sits down in front of a vacuum chamber, cranks up the amps and observes the outcome, he has NOT "proven" or "debunked" anything; he merely offered his educated opinion on why it's not supposed to work. Which has precisely zero relevance to whether or not it actually does.
I have a perpetual motion machine you can buy. It's very cheap, considering you can get infinite power out of it.
I guarantee you that nobody has performed any experiments on it whatsoever. Not even me. Therefore, by your logic, it works. Don't listen to anybody who mutters about the laws of thermodynamics because they're just offering educated opinions which have precisely zero relevance as to whether or not it actually works.
Limited offer: buy within the next 24 hours and you get two for the price of one.
This stuff is fun to play with and I get to mess with a lot of cool expensive toys. Can't I have another year (and the $) to play some more? I'm sure I'll have some answer or at least another request for more time and money to produce one.
It's really sad how much of science reporting boils down to just the above. I'm a scientist myself and still it grosses me out.
It's a little bit unclear what you're asking here. Is this a question, or a rhetorical device intended to imply something?
If it's a question, even then it's not so clear. Still, I'll have a go at providing a rough estimate at an upper bound. In the UK, a pure theory grant will be probably be dominated by the costs of postdoctoral research staff, plus perhaps 10% of the PI staff costs. Costing for a fast computer and an annual international conference is small compared to this. Under FEC, the staff costs will be 2-3 times the headline salary of those staff (max UK postdoc salary is about £40k, plus a few k extra if in London). Thus "what it pays as a %" could be roughly 30% of the total grant ... at best; if you are also costing for expensive equipment, consumables, or whatever, it will be less. Three years of 40k theory postdoc and the usual other costs might come in at about 300k in the UK; but note that German cost calculations are probably structured differently, and this experiment need not have been run on an all research-grant funded model.
Anyway, in this case the reported result /is/ real work. The reported "experimental hygiene" required will no doubt be invaluable in other experimental setups, and if somehow - in outright defiance of theoretical expectation - they do find a result they've discovered new physics. So it's a win-win scenario. And undertaken solely on the basis of expected gains in "experimental hygiene", I'd expect.
The missing pieces are a heat sink that will allow increasing the power from 2 to 50 Watts and mu metal magnetic shielding. Mu metal must be shaped then heat treated in a hydrogen atmosphere and a magnetic field. As those ovens do not grow on trees it can take a while for custom mu metal parts to arrive.
EM-Drive is based on an earlier, very successful investment fraud. It has been improved by not providing a clear theory for how it is supposed to work. The earlier version 'proved' the existence of a net force by using scaler addition instead of vector for forces at different angles. Despite the very obvious flaw in the mathematics it received funding from the DTI. The first 'successful' test used a chemical balance that was designed to be convenient for chemists but not useful for weighing magnets. EM-Drive got some massively better tests at NASA which made use of the impressive equipment they had to hand. They did not have the time or budget to identify and eliminate all possible sources of error.
Mach effect is a theoretical consequence of general relativity. The predicted thrust is so close to zero that it is useless for moving space craft. I am impressed that the physicists at TU Dresden have come up with equipment that will be accurate enough to test general relativity via the Mach effect. Their magic trick is to adjust the drive frequency to match the resonant frequency which changes as the stack of piezoelectric crystals (or EM-Drive microwave resonant cavity) warm up so they will get the maximum possible force.
The money was provided to test unlikely methods of spacecraft propulsion. The really weird bit is enough money went to people actually qualified to do the job properly (and they published preliminary results before they spent it all). I think a proper test of the Mach effect is worth the money, and as a bonus EM-Drive should get a well deserved kicking (that will do little to prevent further funding).
An even better result would be Mach effect turning out to be zero and EM-Drive working. That would show there is new physics to investigate. Believe it or not, there are a few physicists who are not part of a giant international conspiracy to trash talk EM-Drive because we all revile the possibility of cheap space travel.
No, and that's not why NASA would really be interested. If we assume that some reactionless drive like the EMDrive works, it means you can use them in a satellite to do position-keeping, where you need only very small amounts of thrust and energy is relatively easy to come by (from solar panels or, in deep space and if you can avoid the hippies, RTGs). What you don't need is a supply of reaction mass. At the moment satellites need to have a store of reaction mass to do this, and in due course that store gets depleted and the satellite is then dead, even though nothing may actually be wrong with it. Many spacecraft end their lives this way: Cassini for instance ended this way as did MESSENGER (which even used up the helium used to pressurize the tanks as propellant at the end).
Just for clarity: I don't think these things work or can work and I think there are a bunch of cranks involved in them. But if they did work the above would be a big advantage.
No, the Big Bang did NOT break the laws of physics.
The laws we know of now were very, very different during the BB, and they changed as the Universe formed and began expanding.
If something doesn't match the laws of Physics as we know them, there's either a failure to observe, or our interpretation of those laws is flawed.
> The laws we know of now were very, very different during the BB, and they changed as the Universe formed and began expanding.
Not so much laws as general guidelines then! The great thing is we change them as required to make them accurate as at the time of writing. No laws broken, just edited to fit...
The real disappointment here is that it's looking like we won't be able to make spaceships with just paperclips and a couple of AA batteries*.
.
* not included, each sold separately contents may vary etc
Didn't the 'Big-Bang' itself, once break all the laws of physics.
Perhaps not. According to Lawrence Krauss, not even conservation of mass-energy. Total mass-energy of the quantum event that triggered it: zero; total mass-energy of the universe: zero.
Yes, that last is a bit counter-intuitive and surprising. And involves mathematics and concepts that go way over my head. And is deeply disputed by some physicists.
"Yes, that last is a bit counter-intuitive and surprising. And involves mathematics and concepts that go way over my head. And is deeply disputed by some physicists."
The idea that there is negative energy (and not in a Kelly's Heroes way) is not disputed: it's called gravitational energy. If I let go of something in a gravitational field, it speeds up, gaining energy. But conservation of energy says that this cannot happen on its own, so something must be losing energy, and that's the gravitational energy. But the closer two objects get the stronger the gravitational energy becomes, so we say that the gravitational energy is negative.
So total energy is zero is just the same as saying that total energy of the universe is equal to the total gravitational energy, it's just we use a minus sign on the one.
"Next on the chopping block (hopefully): spooky action at a distance."
It's not spooky, it's just a manifestation of the wave nature of matter. You presumably have no trouble believing your eyes when you see a diffraction pattern (get a laser pointer if your teacher never showed it to you). What you see is the transversal wave interference. Your spooky action is based on the longitudinal wave properties (along the propagation direction). No magic, just very long and regular particle waves doing their thing.
>>Cold fusion
Cold fusion "didn't work" because they announced too early, too enthusiastically and without the repeatability you need, the experiments couldn't be repeated within the detection levels that they said was possible, subsequent experiments, years later, using different types of detectors found an unexpected (minute but measurable) decay using the same type of platinum plates, but it was too late and nobody who cares about reputation or funding will go into the field as it's so poisoned now, which is a shame because while the measurable effect is absolutely minuscule it will now not be studied (it's unlikely to ever earn the title of "cold fusion" if it does).
You are right for all the wrong reasons: cold fusion was demonstrated in 2005 using the pyroelectric effect to accelerate deuterium atoms into a deuterium target (see: https://en.wikipedia.org/wiki/Pyroelectric_fusion). Unfortunately, this concept doesn't seem suited to generate meaningful amounts of fusion energy.
As for the rest of the cold fusion claims, they seem to have moved from the scientific fraud stage (delusional chemists having trouble with nuclear physics measurements) to the financial fraud stage (delusional chemists collecting M$ to build cold fusion power plants). Come back when one of those demonstrator power plants produces any meaningful quantity of power. Until then, I'll continue to laugh at your cold fusion.
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Weren't we were promised FLYING cars from Blade-Runner to Back-to-the-Future. Instead all we got this century is dark dystopian 1984 orgasm-killing data-collection. Please someone somewhere invent an Anti-Grav engine. Some of us really want to get off this Slurpy Ad-Slinging rock.
No they were totally made up by the 'discoverer' (either deliberate fraud or self-delusion) and everybody else saw them by the emperors-new-clothes effect. The experimental test was to surreptitiously steal the bit of kit that was steering them when the experimenter wasn't looking
Excellent idea and if they need extra thrust they can use one of those sun-powered lightbulb things with the twirly fan thing inside - just attach a propeller to the other end of the shaft and you have even more free power.
The only caveat is you have to make sure you get the fan and the propeller correctly aligned or it will just twirl and not go anywhere.
FFS they've completely failed to look at the obvious - that being the need to merely find some guy called Zefram Cochrane and give him a job. Maybe we can then get on and explore the universe.
Anyone here called Zefram Cochrane? The Register seems like a likely hang out for this dude so it must be someone here that's holding this up. Come on, fess up already!
I'll get my coat.
"Anyone here called Zefram Cochrane? The Register seems like a likely hang out for this dude so it must be someone here that's holding this up. Come on, fess up already!"
I'm rather surprised Faux Science Slayer isn't here to explain why this is all true and that' its a conspiracy to keep cheap energy from the peons.
(With the caveat that I am not a quantum expert, and am not asserting anything, merely reporting what I've heard elsewhere)
The most intriguing explanation for how a rig like this might work was a suggestion that the energy (microwaves ?) being pumped into the cavity is somehow very minutely distorting spacetime enough that the centre of gravity of the rig shifts relative to the rest of the universe. This shift between the centre of gravity and centre of mass might just be enough to create the appearance of thrust.
If claims were being made that the EmDrive was producing thrust with no energy being expended, I would happily side with folks that dismiss it out of hand. But that's not what's happening here - energy is going into the system.
I have to admit to being a little annoyed at the opprobrium this appears to attract - especially as even detractors are forced to admit that there is a possibility that it's our "current understanding" which is wrong - or certainly "incomplete".
The one thing we do know, is energy and mass are equivalent. The one thing we don't know is the full implications of that. In fact we haven't even touched the surface.
The problem isn't the energy input. The problem is the conservation of momentum, or the lack of it. Conservation laws are extremely fundamental: they correspond to symmetries in ways which are mathematically very well understood. So if momentum is not being conserved, well, either the thing is junk (which I think it is) or, well momentum is being conserved somehow. And it's that second option which leads to all the quantum-vacuum explanations (which, again in my opinion, make no sense either).
Yes, it does.
So if we have a single atom of uranium traveling through a vacuum it then fissions does the momentum of all the physical components add up to the same as the original single atom?
Does this mean that the mass converted into energy appears as an increase in the physical momentum of the resulting components?
Yes, that's right. And sort-of-yes to the second question. The mass converted to energy appears as gamma photons, which carry away both energy and momentum. if you count the photons (which you should!) then momentum is conserved, if you don't then the momentum of the remaining massive objects will change, as some has leaked away in the photons.
Something like this is how the neutrino was discovered: certain kinds of radioactive decay appeared not to conserve either energy or momentum, even when everything known about was taken into account. There were then two options: either energy & momentum was not conserved for these processes, or it was escaping in some very-hard-to-detect particle. Fermi chose the latter option, and called the resulting particle (which no-one had then observed) the neutrino ('little neutral thing'). It took the best part of 30 years before neutrinos were detected.
Yes, conservation of momentum applies at the quantum level. The only caveat is that you can't measure the input or output momentum of the system with absolute precision. (But nobody has come up with a quantum experiment where momentum is clearly not conserved.)
... but I'll jot it down here lest I forget this (probably daft, but I don't know) notion:
If the challenge is reducing how much reaction mass a vehicle must carry (thus accelerate that reaction mass in addition to itself and its payload) then could a possible solution be:
Use stationary linear accelerators at the vehicle's departure point to shoot pellets of reaction mass / fuel at the departing vehicle? The vehicle could then 'catch' the pellets and make use of them.
As i say, its just an idle thought that popped into my head when I read this article. Anyone here with an envelope and a biro care to give ideas as to why it wouldn't be work / be impractical?
Yes, this is an approach that has been suggested. A common approach is to use huge lasers: this is what the 'Breakthrough Starshot' project plans to do.
It may be that you're suggesting something slightly different: not hurling momentum at the spacecraft with a laser or linear accelerator but to arrange that chunks of reaction mass arrive pretty gently so it can catch them and then squirt them out in some direction convenient to it. That would also be possible I think, but the accuracy you'd need would be terrifying.
All of these ideas suffer from the problem that you probably don't want the laser underneath the atmosphere, and you definitely don't want the fierce linear accelerator underneath the atmosphere. So you probably have to get the things onto the Moon or something before you can start. In the laser case you also have to get the sharks up there so you can mount the lasers properly, of course.
All of these projects count as 'mad science' I think: this is at least better than the EmDrive, which is almost certainly 'crank non-science'.
Thanks @tfb
Yep, it was the laser concept (central to Buzz Aldrin's hard sci fi novel Encounter with Tiber) that inspired my pellet shooter idea - that and an Osbourne children's book that featured a linear accelerator (akin to that seen in Duncan Jones' film Moon) based on the moon.
The basic premise of my mad notion is that accelerating one big thing over a set distance is hard (and no good for payloads) but accelerating lots of small things is easier - and can be done over a longer period of time.
That's exactly right. and I think exactly how the Breakthrough Starshot thing is intended to work. The other advantage is that you don't have to fit the thing that fires the pellets or laser beams into a spacecraft and you thus make one which weighs thousands of tonnes if you want (I presume the idea, for a Lunar one, would be to mine the materials for it up there rather than lift them).
It seems to me that a more plausible thing (than Breakthrough Starshot) would be to use the same techniques to drive spacecraft within the Solar system.
Typically, the boffins make these tests effectively at DC. (Yes, yes, yes, calm down. I know about the RF. I'm referring to the magnitude of the RF's amplitude.) They're ignoring the vast benefits of making use of the frequency spectrum.
If they would "simply" (Yes, yes, yes...) amplitude modulate (not 100%, maybe 25%) the RF power with a given "audio" frequency, then they could employ signal processing to extract the resultant effects ("thrust") out of the noise. It would be much easier than trying to tease an effect out of the DC with all the inherent offsets and such. The frequency spectrum provides a fairly easy method to separate signals. It provides a vast signal to noise advantage over picking DC fly poop out of the DC pepper flakes.
Plus, they could apply an external magnetic field at their bench, approximately several times stronger than the Earth's magnetic field, and amplitude modulate it with a different audio frequency. Then, if the resulting effect ("thrust") is modulated with that frequency, then they'd instantly know where it's coming from (i.e. external magnetic effects). These findings can be instantly crossed-checked by fiddling with the "audio" frequency. The audio tone becomes the fingerprint of the source.
The frequency spectrum is highly useful. It's madness to confine one's thinking to the DC. They're just making things difficult for themselves.
DropBear posed, "...both would experience the same modulation..."
Clever design would have the modulation only exist (at significant power levels) in close physical proximity to the horn. This is a trivial requirement to achieve. Then, if the modulation frequency signature shows up in the detected thrust, then you know that the thrust is probably originating from that circuitry (the high power circuitry carrying the tone) or the horn itself. It eliminates the high power DC circuits, as they don't carry the tone.
It makes the detection simpler, but (and you're correct on this point) it doesn't explain where it's coming from. Except it DOES help in narrowing it down to those parts which carry the tone at power. Eliminating the torque effects caused by the DC currents at the liquid joints * would be critical.
(* Ref: Google this -> liquid mercury motor)
The second suggestion about the applied magnetic field is what would be added to the experiment a few days later, to help track down the source. It would be a different frequency tone, identifying the thrust as having a magnetic field origin.
It merely a technique, to make use of the vast frequency spectrum to separate signals from the endless offsets of DC, and from each other. This should be second nature to experienced experimentalists. All they need to do is think about it, and then include it. It makes experiments better, faster and cheaper.
its a rubbish drive anyway and not worth a god damn thing
my em drive is alot better and can replace jet engines https://forums.theregister.co.uk/forum/containing/3245239
its as simple as https://youtu.be/6gszIwmpsO0?t=56s if you have a fixed ring, and find the correct distance for a fix ring to be at
the idea to propel ourselves across the universe with a em drive, not requiring fuel, little emissions continually plugging away building to a comfy velocity to get us there.
but we have some unknowns,
1] mystery force;
2] therefore why & where it works, Does it only work in a galaxy or solar system, where EMR or gravity is sufficient. Crossing voids may be problematic, forcing us to take a circuitous route to our destination;
3] what energy do we need when we get there i.e. jet packs for landing;
On the other end of the scale scientists reported that they have managed to get E-Coli to produce 33 elements and many molecules from them including metals, this could enable distance space travel as we can manufacture what we need as we go as we go. (er from E-coli).
all solved if you use mine, it only needs electric to power the magnets, and will work anywhere in the universe as long as the repelling force has more gauss then the gravity your craft is in, and the force travel's with you as you use the repelling magnetic force from a ring
if you have the power source to replace a jet engine, you can easily fly from heathrow to the outter reaches of the solar system in 16 hours if your hull can handle 256 million MPH and being accelerated to it within 0.2 seconds
The "impossible" drive clearly works. Now they need to hide it... because this is reversed engineering from alien tech that shouldn't have been made public in the first place. So the ones that control everything aliens related now need an "official" "scientific" way with the usual official scientists puppets to tell the world that it was just a joke and it doesn't exist for real. 99% of the human population doesn't think and just trusts the usual lies and so the tech will be hidden to the public again and that's it. They probably will kill some of the people that made this public too in the first place but no one will care. This is the worldwide dictatorship this planet is really all about.
i dont care for america or governments so i spam the world with mine and anyone can make one, you will just need a marine fishing boat generator for the upto 8000kW and a 1000 KM range, for space planes for uk's space plane ports in 10 years
the world is so spammed with the basic's nobody can put a patent on it
In the article the research team reported that the device moved but not by the means of the expected thrust vector. This has shown that thrust is possible from the magnetic field interactions. While this force would decrease the further the sources of the magnetic field where from each other. It could provide a valuable Delta-v boost and reduce fuel load in achieving a velocity, as well as providing a means to generate a protective magnetic shield for any crewed mission.
Therefore, it may be possible to create a field with a surface area large enough that it could act as a sail in the solar wind. This could therefore provide additional boost and increase the reduction in fuel load further. Enabling faster transit from earth to say mars.
The down side is the requirement to generate large amounts of electrical power that is required to create and maintain the field strength. but this is a problem that can be solved within our current technical capabilities and it does not require us to invent any new technologies to achieve.