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The article is very sweeping. You're getting only the pro side, not any of the critical view. People are still heavily debating the experiments. It has not bee

The article is very sweeping. You're getting only the pro side, not any of the critical view. People are still heavily debating the experiments. It has not been empirically demonstrated to a standard sufficient to call the thrust real. That's why only a very small community is working on this. "NASA" in this context means EagleWorks is letting a couple people spend a bit of spare time and resources on it as a speculative project. Mike McCulloch's work is interesting, but it's quite far from any mainstream acceptance or testing, as he himself would admit. It's mostly independent of the EmDrive stuff, but the enthusiast community has latched onto it as a way to escape the unpleasant reality that established physics says the EmDrive is a perpetual motion machine. I'm glad EmDrive is giving his work a boost because I think it should be tested, but there should be much better ways of testing Modified inertia by a Hubble-scale Casimir effect than the EmDrive (he's got a couple blog posts about it if you're curious).

techdragon 11y ago
Its arguably a possibility that we are so unsure of the effect because we have scientists "cautiously creeping" so as to not hurt their future reputation. There was anomalous scaling in the observed effects in one Chinese research teams results, but it has not been repeated because full reproduction and pushing past their power levels would cost some decent money. Seems stupid the (possibly) most groundbreaking advance in propulsion ever made, can't get a million or two when we collectively gamble more than that each day at casinos lotteries and horses races. We could quickly eliminate the question of "is this anomalous results from bad experiment design" with a bigger experiment that would make such flaws more evident. Yet we waste time instead of money.
- marcus_holmes 11y ago
  I think you've nailed it there. A professional scientist can't take this seriously because the reputational risk is so high. Science needs to embrace failure more!
  - madaxe_again 11y ago
    Nobody is allowed to fail or make mistakes any more, not just scientists. Your past used to fade with time. You used to be able to move town, escape your failure, try again. Now, any failure is forever emblazoned in shrieking tones online, and the only escape is a new name, and starting over. It's not just science, it's everything.
- Retra 11y ago
  Somebody built this complicated device without already having any understanding of how it supposedly works, and you think it might work anyway? Talk about winning the lottery. What's stupid is betting on stupid.
  - chriswarbo 11y ago
    > What's stupid is betting on stupid. What's stupid is making investments which are known to have an expected return less than 1:1. Playing the lottery isn't stupid because we don't understand how it works; playing the lottery is stupid because we do understand how it works, we know what the expected return is, and we know that it's a worse investment than just stuffing cash under a matress. This is entirely uncontroversial, and lotteries are run by profit-making entities (either private firms or as a "tax on the ignorant" by governments) whose entire viability relies on this fact. In contrast, things like the EmDrive are high-risk high-return investments. Their expected return is more difficult to estimate than a lottery, since we'd need to estimate the probability of it working and the expected return if it did work. However, whilst an idea like the EmDrive may be controversial, the idea that spending a small proportion of investment on ideas like the EmDrive isn't controversial. There may be arguments over how much counts as "small", which ideas should be prioritised, etc. but this just goes back to the uncertainty of estimating the expected return. It's entirely uncontroversial to say that, if it works, the EmDrive would be an incredibly lucrative technology; it's also uncontroversial to say that it's unlikely to work. The tricky part is working out which term dominates the expectation: does the big thing (the potential return) multiplied by the small thing (the probability) result in a big thing or a small thing (the expected return)?
    - Retra 11y ago
      This isn't high risk though. It's low risk. However, just because something's low risk doesn't mean it's worth the investment. The problem here is that you could make this same argument about almost anything, a la Pascal's Wager.
      - chriswarbo 11y ago
- RachelF 11y ago
  Exactly, in order to have a long career in science, one needs to toe the line, and keep in the mainstream.
- xlm1717 11y ago
  >Seems stupid the (possibly) most groundbreaking advance in propulsion ever made, can't get a million or two when we collectively gamble more than that each day at casinos lotteries and horses races. Perhaps they need to set up a crowdfunding campaign to get those people betting on their experiment, gambling on a science experiment rather than a game of chance.
StanislavPetrov 11y ago
>only a very small community is working on this >established physics says Restricting research capacity and dismissing empirical evidence because it doesn't jive with "established science" is exactly the opposite of what science is all about.
- sanderjd 11y ago
  This seems like a misconception to me. Scientists have always tried to apply their energies toward the most promising lines of research. The supply of research capacity is finite.
  - lunchTime42 11y ago
    Can you provide links to alternate timelines that proof your heuristics effective? ;)
- zamalek 11y ago
  Exactly, instead of spending time dismissing the EMDrive as impossible; time should be spent devising experiments that prove it ineffective. Modern science seems to be rapidly encroaching on religious territory: observable evidence is less important than what historical figures have said.
  - astrodust 11y ago
    Science has always had devout, religious elements, don't think otherwise. Look at the backpack the Theory of Evolution received from respected scientists and how much hand-waving dismissal there was of Relativity. It has been argued that the only way science progresses is when the obstacles to science die of old age.
  - pilsetnieks 11y ago
    There have always been the recalcitrant "that's how it's always been done around here" types that often push back even when confronted with evidence. Take, for example, Ignaz Semmelweis[1] - he had the evidence that it works but he couldn't explain how washing hands could decrease mortality in hospitals. Few people took him seriously, he suffered a nervous breakdown and died. Afterwards it took Pasteur and Lister to get people to actually accept the theory. [1] https://en.wikipedia.org/wiki/Ignaz_Semmelweis https://en.wikipedia.org/wiki/Ignaz_Semmelweis
alkonaut 11y ago
> established physics says the EmDrive is a perpetual motion machine. In what sense is it a perpetual motion machine? As far as I understand it violates the conservation of momentum, not the conservation of energy. How would a theoretical perpetual motion machine based on this effect work?
- deleted 11y ago
  [deleted]
- adlpz 11y ago
  Constant thrust means constant acceleration, so speed goes up indefinitely with a constant supply of energy. But kinetic energy is proportional to the speed squared. So you get more energy than you put in.
  - LoSboccacc 11y ago
    I don't think they actually claim acceleration will be constant as the devices accelerates up.
  - deleted 11y ago
    [deleted]
- xlm1717 11y ago
  It only looks like conservation of momentum is violated. From the article: >The cone allows Unruh radiation of a certain size at the large end but only a smaller wavelength at the other end. So the inertia of photons inside the cavity must change as they bounce back and forth. And to conserve momentum, this must generate a thrust. The new idea introduced is the quantization of inertia at small accelerations. As far as I understand it, from one end of the cone to the other there isn't a smooth change of inertia. This depends on the idea of Unruh radiation, and the reason the article gives for quantization of inertia is that as accelerations get very small, Unruh radiation wavelength becomes larger than the observable universe, forcing unruh radiation to take whole-value wavelengths (quantization). Again as far as I understand it, the inertia of photons on one end of the cone takes a different quantized value of inertia than the photons on the other end. So the thrust isn't a violation of conservation of momentum. The thrust is necessary to not violate conservation of momentum.

techdragon 11y ago

Its arguably a possibility that we are so unsure of the effect because we have scientists "cautiously creeping" so as to not hurt their future reputation. There was anomalous scaling in the observed effects in one Chinese research teams results, but it has not been repeated because full reproduction and pushing past their power levels would cost some decent money. Seems stupid the (possibly) most groundbreaking advance in propulsion ever made, can't get a million or two when we collectively gamble more than that each day at casinos lotteries and horses races. We could quickly eliminate the question of "is this anomalous results from bad experiment design" with a bigger experiment that would make such flaws more evident. Yet we waste time instead of money.

marcus_holmes 11y ago
I think you've nailed it there. A professional scientist can't take this seriously because the reputational risk is so high. Science needs to embrace failure more!
- madaxe_again 11y ago
  Nobody is allowed to fail or make mistakes any more, not just scientists. Your past used to fade with time. You used to be able to move town, escape your failure, try again. Now, any failure is forever emblazoned in shrieking tones online, and the only escape is a new name, and starting over. It's not just science, it's everything.
Retra 11y ago
Somebody built this complicated device without already having any understanding of how it supposedly works, and you think it might work anyway? Talk about winning the lottery. What's stupid is betting on stupid.
- chriswarbo 11y ago
  > What's stupid is betting on stupid. What's stupid is making investments which are known to have an expected return less than 1:1. Playing the lottery isn't stupid because we don't understand how it works; playing the lottery is stupid because we do understand how it works, we know what the expected return is, and we know that it's a worse investment than just stuffing cash under a matress. This is entirely uncontroversial, and lotteries are run by profit-making entities (either private firms or as a "tax on the ignorant" by governments) whose entire viability relies on this fact. In contrast, things like the EmDrive are high-risk high-return investments. Their expected return is more difficult to estimate than a lottery, since we'd need to estimate the probability of it working and the expected return if it did work. However, whilst an idea like the EmDrive may be controversial, the idea that spending a small proportion of investment on ideas like the EmDrive isn't controversial. There may be arguments over how much counts as "small", which ideas should be prioritised, etc. but this just goes back to the uncertainty of estimating the expected return. It's entirely uncontroversial to say that, if it works, the EmDrive would be an incredibly lucrative technology; it's also uncontroversial to say that it's unlikely to work. The tricky part is working out which term dominates the expectation: does the big thing (the potential return) multiplied by the small thing (the probability) result in a big thing or a small thing (the expected return)?
  - Retra 11y ago
    This isn't high risk though. It's low risk. However, just because something's low risk doesn't mean it's worth the investment. The problem here is that you could make this same argument about almost anything, a la Pascal's Wager.
    - chriswarbo 11y ago
RachelF 11y ago
Exactly, in order to have a long career in science, one needs to toe the line, and keep in the mainstream.
xlm1717 11y ago
>Seems stupid the (possibly) most groundbreaking advance in propulsion ever made, can't get a million or two when we collectively gamble more than that each day at casinos lotteries and horses races. Perhaps they need to set up a crowdfunding campaign to get those people betting on their experiment, gambling on a science experiment rather than a game of chance.

StanislavPetrov 11y ago

>only a very small community is working on this >established physics says Restricting research capacity and dismissing empirical evidence because it doesn't jive with "established science" is exactly the opposite of what science is all about.

sanderjd 11y ago
This seems like a misconception to me. Scientists have always tried to apply their energies toward the most promising lines of research. The supply of research capacity is finite.
- lunchTime42 11y ago
  Can you provide links to alternate timelines that proof your heuristics effective? ;)
zamalek 11y ago
Exactly, instead of spending time dismissing the EMDrive as impossible; time should be spent devising experiments that prove it ineffective. Modern science seems to be rapidly encroaching on religious territory: observable evidence is less important than what historical figures have said.
- astrodust 11y ago
  Science has always had devout, religious elements, don't think otherwise. Look at the backpack the Theory of Evolution received from respected scientists and how much hand-waving dismissal there was of Relativity. It has been argued that the only way science progresses is when the obstacles to science die of old age.
- pilsetnieks 11y ago
  There have always been the recalcitrant "that's how it's always been done around here" types that often push back even when confronted with evidence. Take, for example, Ignaz Semmelweis[1] - he had the evidence that it works but he couldn't explain how washing hands could decrease mortality in hospitals. Few people took him seriously, he suffered a nervous breakdown and died. Afterwards it took Pasteur and Lister to get people to actually accept the theory. [1] https://en.wikipedia.org/wiki/Ignaz_Semmelweis https://en.wikipedia.org/wiki/Ignaz_Semmelweis

alkonaut 11y ago

> established physics says the EmDrive is a perpetual motion machine. In what sense is it a perpetual motion machine? As far as I understand it violates the conservation of momentum, not the conservation of energy. How would a theoretical perpetual motion machine based on this effect work?

deleted 11y ago
[deleted]
adlpz 11y ago
Constant thrust means constant acceleration, so speed goes up indefinitely with a constant supply of energy. But kinetic energy is proportional to the speed squared. So you get more energy than you put in.
- LoSboccacc 11y ago
  I don't think they actually claim acceleration will be constant as the devices accelerates up.
- deleted 11y ago
  [deleted]
xlm1717 11y ago
It only looks like conservation of momentum is violated. From the article: >The cone allows Unruh radiation of a certain size at the large end but only a smaller wavelength at the other end. So the inertia of photons inside the cavity must change as they bounce back and forth. And to conserve momentum, this must generate a thrust. The new idea introduced is the quantization of inertia at small accelerations. As far as I understand it, from one end of the cone to the other there isn't a smooth change of inertia. This depends on the idea of Unruh radiation, and the reason the article gives for quantization of inertia is that as accelerations get very small, Unruh radiation wavelength becomes larger than the observable universe, forcing unruh radiation to take whole-value wavelengths (quantization). Again as far as I understand it, the inertia of photons on one end of the cone takes a different quantized value of inertia than the photons on the other end. So the thrust isn't a violation of conservation of momentum. The thrust is necessary to not violate conservation of momentum.