There is a difference here: cars are built by car mechanics; they know cars inside out --- cars are never designed to drive in reverse. Physicists, on the other hand, didn't invent physics, so they know their current understanding of physics could be wrong.
This idea that we are so sure of everything is pervasive. The kind of people who like science are often the kind of people who crave certainty. And so for them science becomes like a religion, it provides them with a sense of certainty. Consistency. So when they rally against stories like this what they are really doing is reaffirming their own faith in an orderly universe, reaffirming their own faith in their scientific religion. It serves an emotional need. Which is why, paradoxically, their arguments are not alterable through logic.
If you go read what the real experts in a field have to say about the state of knowledge, they are often incredibly humble. They state that there is so much that they do not know. That are so many things that could be wrong. That there are even bigger pictures just beyond their grasp.
Now these reactionless thruster concepts don't look to be doing too well. But I for one am not particularly convinced that mach 's principle is so stupid.
This sort of argument is routinely used to dismiss the laws of thermodynamics as merely 'theories' and to then move on to the most outrageous violations of known physical law.
We are pretty sure of what we are sure of and we are pretty sure of what we aren't sure of, impressions notwithstanding. Science is a method, not a set of facts, and it has a built in mechanism to allow greater insights to replace lesser ones. As long as we stick to science we'll one day find the limits of what is knowable.
I don't think you and GP are in disagreement. The scientific method to let greater insights replace lesser ones is precisely to try and fail at falsifying observations that violate known physical laws.
No physical law is holy for this purpose, although scientists will necessarily have heuristics for what presumed observations they consider good enough to examine closer. Evidently, the EmDrive observations made the threshold! And now we know for sure. Well, close enough, anyway.
"A theory is the more impressive the greater the simplicity of its premises, the more different kinds of things it relates, and the more extended its area of applicability. Therefore the deep impression that classical thermodynamics made upon me. It is the only physical theory of universal content which I am convinced will never be overthrown, within the framework of applicability of its basic concepts."
(Albert Einstein)
"The law that entropy always increases holds, I think, the supreme position among the laws of Nature. If someone points out to you that your pet theory of the universe is in disagreement with Maxwell's equations — then so much the worse for Maxwell's equations. If it is found to be contradicted by observation — well, these experimentalists do bungle things sometimes. But if your theory is found to be against the second law of thermodynamics I can give you no hope; there is nothing for it but to collapse in deepest humiliation."
As plato would say the wall is choosing to hold us up. We may not understand why but it continues this way. At any point this could change. It wasn't until the theory of gravitation that we were able to define our obvervation as a general law.
"Newton's law of universal gravitation is usually stated as that every particle attracts every other particle in the universe with a force that is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers"
This is still a law. We haven't proved this to be true even though it looks to be true.
Laws can get superseeded.
The phlogiston theory is a superseded scientific theory that postulated the existence of a fire-like element called phlogiston (/flɒˈdʒɪstən, floʊ-, -ɒn/)[1][2] contained within combustible bodies and released during combustion
Can’t say I agree with the idea, but it’s certainly interesting to consider and at the least should help strengthen or discard a few assumptions!
I think he’s conflating the process with all the other human factors involved. Sure, Galileo maybe did some shady stuff to convince people of his arguments. But that in no way makes a telescope stop working the way it does.
If you want to go down a rabbit hole, Nonlinear dynamics is another way to understand science. Many systems operate from a different paradigm of causality; it happens in biology, also common in fields like weather prediction where a large dataset is analyzed for patterns and then hypotheses are driven off the data in the opposite direction.
This has caused some controversy in the scientific community because researchers have been caught using the methodology to "reverse engineer" hypotheses without disclosure, effectively gaming the system.
Huh? I was more trying to imply that there are probably no limits to what is knowable. Or at least, if we stay scientific, we should never believe we’ve reached the limits.
> it has a built in mechanism to allow greater insights to replace lesser ones. As long as we stick to science
Well you're not sticking to science when you assume any non-explained phenomenon is "impossible" and dismiss it outright.
Science has a long list of "impossibles" that have been proven to be possible. Though of course that list was mostly of phenomenon we couldn't ignore.
Saying "EMdrive is impossible given our current knowledge therefore it is not worth measuring" is tautological!
Electricity and magnetism were seen as separate phenomenon as well and it seems a lot of people would be opposed to even try to put a compass next to a wire!
The only thing I know is that the skeptics don't get the Nobel Prizes.
Good, they measured, and as expected, no thrust. Cool.
What makes this article so refreshing and so compelling is that they replicated the NASA results, and then explained and eliminated them. Another "We don't see anything and it's impossible anyway so you guys are idiots or charlatans" would not be helpful. This is.
Just because nothing is 100% knowable ultimately, doesn't mean all unknowns are equal.
Everyone who doesn't want to invest 10000 human lives and a small countries total resources trying to find out if maybe oxidization isn't really exothermic but just somehow always looks that way (is fire hot?), isn't guilty of being incurious or religious.
Part of the problem is that it's much easier to come up with a new perpetual motion machine or reactionless drive concept than to prove that it doesn't work. After seeing them all fail, at a certain point people are going to stop paying them any attention. Oh, this time it uses X force in Y configuration? Go away until you have data, we could be more profitably spending time on just about anything else.
It's only difficult because typically it involves a claimed effect right at the limits of what's measurable. A real effect wouldn't have to be barely perceptible, would it?
The person who discovered nitroglycerine didn't somehow find the amount they could make to be right on the edge of detection.
> Part of the problem is that it's much easier to come up with a new perpetual motion machine or reactionless drive concept than to prove that it doesn't work.
The framing of "science becomes like a religion" is just projection, nothing else...
For many of us, we just accept that science is, what it is, and its the facts we know at this time. That doesn't mean unwavering absolute faith as implied by saying it's religious, it's just we don't feel the need to have knowledge be anything else other than knowledge that we continuously build upon.
Of course in general, lots of scientists know much more than other scientists and there is always bickering, people who have their identities married to it and so much more - but often times those very same people are often religious too so i question if the religiosity argument really exists or if its merely weaponized by people who fear the comfort of others who are ok with science without faith.
I'm an atheist. I also have a degree in comp sci a degree in Mathematics and a master's degree in mathematics. I read arxiv daily. I love science, I read constantly. Watching the cutting edge of science from afar is a passion of mine. I like to try to hold a holistic vision of it all in my head - an impossible task, but it keeps me busy.
So, I'm not an enemy of science, I just dislike people harping on about 'impossible' from behind their keyboards when they have little more than a rudimentary knowledge of the subject at hand and too high an opinion of authority.
I appreciate the nuance here. As a person of faith one of the things I love most about both science and religion is the sheer amount of mystery there is in all of it. If there were no mystery in either, science would be dead and faith would be unnecessary. Yet science and religion pretend to be opposed.
Throughout history the greatest clashes between faith and science have occurred when scientific understanding threatens the faith-based assumptions of the age. Imagine Abraham arguing with God over his request to sacrifice Isaac. Instead, he reasoned that God would find another way.
Sometimes our understanding of religion limits our thinking with regard to not just science, but our faith as well.
well everything is a people thing because we’re people. What science offers is proof and data that can be reproduced. So no two scientists bickering is not the same as two theologian.
> This idea that we are so sure of everything is pervasive
I think this is a common misconception made mostly by people who distrust science as a whole, but not really broadly held. I don't know anyone who understands an area of science at any depth who holds such a view.
The really broad problem is that in science there are things we have very high confidence in, and there are things we have very little confidence in but are the best working models currently - and everything in between. However, communication about where the confidence lies is often poorly done. Many observers who mostly hear about things through the lay press have no good tools to differentiate between "some person with a Ph.D said Y once" and "the vast majority of experts in this field are confident that X".
You are quite right that real experts have a healthy feel for what they don't know - and often humility - but those are often very different things from those that worry people outside the field. All of those same experts could happily give you a list of things they and their colleagues have very good confidence in. It's almost always the right thing to do to accept these and move on.
On the flip side any scientist will tell you there is small but real value at the margins for someone plugging away at a "crazy" theory. They are almost always wrong, but occasionally it turns up something really interesting. The trick is not to involve more people or too much resources, as these are long bets that will mostly fail.
I have always found that people that enjoy science are comfortable with uncertainty. I worked at Bell Labs for 16 years from the mid 1980s through 2000, and I found a lot of people still looking at things that "we all understand" and still wondering about how it really worked.
Science is never 'settled'. There is the current understanding of the art, but that current understanding is not always fulfilling. There are edges and holes in most domains in science where people are poking around wondering how it really works.
A lot of the things I implemented as an engineer (I am not a scientist, but I worked with scientists) were attempts to answer questions. Many of them having to do with "how do we measure this thing, without touching it?" Modeling information and making decisions based on observations against what you were expecting to observe.
Scientism. The deification of scientists and our current models.
Which is ironic as we know our models are wrong somehow as we can't mesh Quantum mechanics and general relativity. There is clearly some undiscovered idea or principal.
Science is about the process not about the body of knowledge we amassed. Science is about doing experiments to poke at the gaps of our knowledge. Not to like the Ancient Greeks debate our way to truth or worse declare something false based clearly on our flawed understanding.
Celebrity scientists aren't deified... in fact, they have a tough life because people assume they're all knowing. Look at our man Neil DeGrasse who called a Bull a Cow because where he lives in NYC everything is a cow and he got ripped by other scientists for being stupid.
There is no universality to people period... i'm not sure why you feel its important to label some as "scientism" when there is no such thing as "scientism" with any universality.
Feynman said something like true science is not believing anything you hear and something you have to experience. If you believe anything without doing the work then you’re cargo culting science which is deifying it.
Scientists aren't deified because people assume they're all knowing?
As for scientism, there's a lot of people in this thread who essentially said "We could have known it wouldn't work by basic application of conservation of momentum". Or some other principal held to the standard of absolute truth.
Our knowledge of the world is faulty and incomplete. All scientific knowledge is subject to tweaking or replacement based on experimental evidence. Not the other way around.
We have models and guesses of how the world works, we don't have its source code.
Actually the whole point why this EM drive is interesting actually is that the measurements contradicted conservation of momentum. Otherwise having a small effect not contradicting any established physics is basically worthless.
Sure, but if the contradiction bore out, then what's false (at least in some edge cases) is established physics not the experiment result.
The strength of the established physics just means that there is an extremely high chance that the EM drive is experimental error, especially with the small effect size, rather than something novel.
> The kind of people who like science are often the kind of people who crave certainty.
Just to clarify - are you implying scientists crave certainty, or non-scientists who enjoy reading about science crave certainty?
The life scientists I know are the people in my life who are the most comfortable with uncertainty, or at least can recognize how uncertain the world can be. Perhaps they crave quantifying the uncertainty? But they certainly understand, respect, and live with uncertainty.
I took it to mean the fans of science who pile into forums like HN with expressive enthusiastic skepticism, the kind of people who think experimental physics is like working on a car.
> If you go read what the real experts in a field have to say...
If you go to read what the real experts in the field have to say then you would learn that not a single one of them thought that the EM Drive had even the slightest chance of being true.
In fact all the publications and work on EM Drive strictly avoided the real experts (physicists). They were all engineering journals. A paper that claims experimental evidence that overturns all physical theories from Newton onwards that's very telling isn't it?
Thank you for more eloquently expressing a sentiment that I have harboured for some time. After quoting the relevant Cave Johnson quote from PORTAL 2 so many times... it clicked and I came to the realisation that there is only one way to “do science” you “throw it at the wall and see if it sticks”.
At a fundamental level, you must throw your results at the wall of publication and see if they stick, the only way science sticks is when it can be replicated by others. It remain on the wall!
When people’s refutation of things like the em-drive is simply “this can’t work” my response is “prove it” not because I believe, but because “can’t work” just isn’t science, science is done by proving that something “does not work”. That means for something like the em-Drive you prove it doesn’t do what it claims, you prove it by replication and better measurement... and you learn how to build things better, learn how to measure better and that’s the value of these efforts! Or you prove it by detailed non destructive analysis of the experiment apparatus and prove your work by detailed physical simulation, publishing your code to prove you didn’t make any mistakes yourself! You cannot just give the answer you must show your work if you expect to go around calling what you do “science”. Providing such proof is not a waste, or bad science, it is the very essence of science itself.
You are missing a very important part of how science is done: science starts with a hypothesis, the refutation or confirmation of that hypothesis is done by experiment. Plenty of science has been locked into the theoretical phase for decades before experimental verification could be obtained.
If all we did was experiments we'd surely find some interesting stuff but without theory to guide where to do the next set of experiments science would be very inefficient. It's the closing of the loop that powers this tremendous progress you see from the renaissance to today.
Without that we'd be stuck in alchemy, astrology and other pseudo sciences.
Science must find a balance between extremes in how experimental resources are invested:
Extreme “Exploitation” Bias: “For maximally economical progress, experimental physics must strictly stay within the hard boundaries established by theoretical frameworks.”
Extreme “Exploration” Bias: “For maximally fundamental progress, experimental physics must question all theoretical assumptions and boundaries with extreme suspicion.”
It makes sense to diversify the kind of experimental investments we make along this risk/reward or exploration/exploitation spectrum. There are unique dangers if we weight too heavily on either extreme.
I think there's one more step that goes a bit earlier in the process. Before an observation is made, there needs to be a choice on what experiments are done. Typically, those measurements will be done with one of two goals. The first is to measure a free parameter in the theory that isn't well-constrained by existing experiments. (e.g. "According to Maxwell's equations, the speed of light should be constant. Let's measure that constant value." [0]) The second is to find an unintuitive prediction from current models, then measure what happens in those circumstances. (e.g. "According to special relativity, passage of time should vary based on velocity. That's weird. Let's measure and see if it is the case." [1])
The purpose of these is to narrow down which experiments are being performed, trying to choose experiments that will try their hardest to break an existing theory.
[1] https://en.wikipedia.org/wiki/Hafele%E2%80%93Keating_experim... (This article currently has an incorrect edit made yesterday. It seems to be based on a mistaken assumption that the rotating earth is a stationary reference frame. The opening paragraph should read "were consistent" rather than "were not consistent".)
> they know their current understanding of physics could be wrong.
Sure, we do know!
And we know how to recognise when someone masters current literature (a.k.a. factual knowledge) and proposes a breaktrough in a yet uncovered field, and when someone is speaking out of his ... nothing!
If you prefer a non-car analogy: we all do know that a hundred consecutive heads is possible, still you are not going to bet your week pay on it, even if you were promised 2^100 weeks of pay in return.
There are plenty of cases where someone who doesn't understand the underlying theory has contributed due to the outsider effect or just pure luck. The hype, and the swindling are not ok, but when an organization like NASA thinks they maybe successfully reproduced an experiment that invalidates a law of nature you have to keep trying. Sure I'm hoping for new science, always, because that is more fun, but mostly you need to know for sure what the experimental error was so that you don't repeat it in an experiment whose result you aren't as skeptical of.
>There are plenty of cases where someone who doesn't understand the underlying theory has contributed due to the outsider effect or just pure luck.
There are far more such cases where the outsider was wrong, so many more of these, that using the extremely rare event to claim this may be one is simply terrible reasoning. It is far more likely that this is yet another crackpot pushing nonsense.
No outside has found a breakthrough that for decades (the length the EmDrive people have been making noise) was discarded. In fact, when an outsider finds something useful or novel, for a long time now the science community nearly immediately understands and embraces it.
A low number of dollars spent to put to bed an idea that would have upended physics is a fairly cost effective play in the risk to reward game. That’s what it comes down too.
Negative results are good. Utter quackery is not good. But hard data from experiment is usually not quackery. Even if the whole thing stands outside the established paradigm. I’d argue we could stand a bit more of it, in this age of funding bandwagons and careerism.
That's the OP's point. The EmDrive is utter quackery. It cannot exist because it necessarily violates the laws of thermodynamics. Anything that disproves those will literally undermine the entire foundation of what we understand about the universe. It would be directly comparable to discovering that the earth is flat.
We already know the laws of thermodynamics has exceptions. In very small systems, the entropy of a system fluctuates randomly - up and down. A light ray traveling over extremely long distances will have its energy reduced through red shifting, and that energy doesn't "go" anywhere, it is destroyed. In both of these regimes, over extremely small scales and extremely large scales, there are exceptions carved out of the laws of thermodynamics.
We know for certain that our understanding of physics is incomplete. General relativity (as formulated) is certainly wrong, because it precludes the possibility of small things existing; and yet they do. Quantum mechanics (as formulated) is certainly wrong, because it precludes the possibility of curved spacetime, and yet we know spacetime is curved.
There is, of course, a minuscule possibility that the emdrive actually works. It almost certainly doesn't. Ballpark one in a thousand. But we can't exclude the possibility that it works, based on the principle that the the laws of thermodynamics, which already has two exceptions, cannot have a third exception.
There's big talk about humanity traveling to other stars, colonizing other star systems, colonizing the galaxy and so forth. For this to happen, we would have to be wrong about physics. There's simply not any way to do it by building on the foundation of what we understand about the universe. So investing in low probability speculative ideas like emdrive is still necessary, even though for any given idea, there are lots of nines that say it won't work.
No, they don't. The "laws" you learn in high school are large scale approximations to the actual rules, which is codified in stat mech.
It's like claiming solids are not solid because atoms... Of course physicists know all this.
>General relativity (as formulated) is certainly wrong, because it precludes the possibility of small things existing
Having worked on GR stuff for a long time, this is news. GR most certainly allows any size thing to exist - it's a continuous theory.
>Quantum mechanics (as formulated) is certainly wrong, because it precludes the possibility of curved spacetime
No, it does not. QM in curved spacetime is so old and well understood it has a Wikipedia page [1] - from which you can start digging back into the literature.
You should really google such claims when making them to be sure you understand what you're claiming.
What an exciting time we live in, where links between quantum mechanics, thermodynamics, and GR May finally be emerging in physics! What will the final ramifications be? Hopefully something new comes of it.
If there are cases where conservation laws break down, or physical principles constrain one another in unforeseen ways, and they can be accessed at human scale, what an exciting thing! I’d guess you mostly feel this way too if I have not yet imposed any quackery on you, and suppose where we diverge is I do not see the harm in exploration as far out as the experimenter can dream to go. —Even if there is no theory for it. I know, the horror!
Do I think it will work? Well heck no. But that does not mean I wish the attempt to be quashed like I’m the inquisition. On the contrary, I bid them good luck. And if they do have good luck, they better have some results that are easily duplicated. I hope they do overthrow the foundations of physics. Why not? The earth will still possess curvature, and all the extant physics will still be as approximately right, and beautiful, as it was yesterday.
The guy had an experiment, his explanation for the results were utter quackery. I don't think the people at NASA expected his explanation was the right one, but they didn't have one so they replicated. MIT had an explanation of the results that was not due to thermal effects, and wasn't the originator's explanation. It didn't upend thermodynamics. The problem wasn't people exploring a tricky experiment, it was people buying in to a specific explanation of the experiment prematurely.
> we all do know that a hundred consecutive heads is possible, still you are not going to bet your week pay on it, even if you were promised 2^100 weeks of pay in return
The expected reward is just one-week's pay --- you have to offer better than that with all the uncertainty ;)
What if the reward is potentially infinite amount of money? If the investigation proved our current understanding of physics wrong, that could lead to historic breakthroughs in natural science.
Better yet, we don't know what the odd is. It might only need 32 consecutive heads.
Oh, it's just 1024^10, a bit more than 10^30, or 10 million moles.
A water molecule contains 18 nucleons, thus a mole of water weighs 18 grams. 10 million moles of water are 180 cubic metres: an Olympic pools contains an order of magnitude more moles than that! ;-)
Sure, I hope nobody is paid so poorly that 2^100 times its week salary exists!
> Physicists, on the other hand, didn't invent physics, so they know their current understanding of physics could be wrong.
They also know they have experimented extensively over the region this effect claims to exist, and have found nothing of the kind for well over a century, and that if the EmDrive did what some claimed, it would violate literally thousands to millions of experiments already conducted.
Claiming physicists don't know everything about possible physics does not imply they don't know a tremendous amount about the places they have extensive experimental and theoretical agreement. Those places are not likely to ever change.
This whole thing has been obviously dumb for a number of reasons not even related to physics. You could almost use it as a good litmus test for who should be running a company, or working at important positions in government.
> Physicists, on the other hand, didn't invent physics, so they know their current understanding of physics could be wrong.
Technically, yes. but not in the sense that the word "wrong" is generally used. Existing measurements confirm that the current theories are mostly correct to high degree of accuracy, and over a lot of measurements, in a wide range of circumstances.
Current understanding may be proven _incomplete_, but it won't be superseded by something completely different that contradicts those measurements. That would be a non-starter, but it's what people think of when they hear "x is wrong".
e.g. Newtonian mechanics is "wrong" or "incomplete", but it gives very good answers for everyday circumstances. Just not for very small or very fast.
The best essay on this subject is "The Relativity of Wrong", Asimov, 1989
I agree that on this point the analogy is weak. But it describes the ignorance of all those hyping it up well.
People are generally aware that if someone is presenting a perpetuum mobile they are wrong. Free energy doesn't exist. The fact that you can't have free momentum is just as strong (and has been known longer), yet less widely intuited.
Let me give you an analogy though:
Let's say someone proposes a water base perpetuum mobile like this:
It only works if you place the machine under a massive waterfall though. Now this would be very difficult to refute experimentally, because you have to account for all possible interactions in the waterfall.
That's what the EM Drive is. A perpetuual motion machine built in such a way that there's a lot of energy going around and it's hard to eliminate all spurious interactions.
It's tough to know absolutely everything about a complex dynamic system, even if it's built by humans. Take the economy, for instance. Invented by humans, made up of humans and human technologies and concepts, and yet people only have vague ideas about how to control it.
Or take computers for that matter. People designed and built them from scratch. Someone had to design and lay out the transistors on the CPU, and presumably they know everything about how to do that. And yet we are currently trying to figure whether there's an ordering to switching the transistors on and off that would imbue the CPU with human-level intelligence. There are plenty of people who know computers inside and out, yet there are still questions that need answers. We have a whole discipline called Computer Science that performs experiments on computers for the purpose of answering these questions.
I really don't think cars are designed by the same people who end up fixing them - ease of repair really doesn't seem to be a big factor in lots of designs.
Ease of repair has largely been replaced by lack of need of repair. Cars, especially IC engines, are so much more reliable today that repair is relatively rare. Engine rebuilds are almost unheard of on small cars. Transmissions regularly outlast the chasis. Even tires rarely get flats. People now expect to drive many tens or even a hundred thousand miles without engine failure, on no more maintenance than an occasional oil change.
Ease of repair is a factor, but there are other factors. Safety and Fuel Economy (Aerodynamics and mass) are more important than ease of repair so many things to make it easy to repair just get tossed out.
The design of a car is obviously limited by fundamental aspects of physics which are outside of the control of car manufacturers. For example, car manufacturers didn't invent combustion, aerodynamics, etc.
