"And then you have the EM/reactionless drive, which is less efficient than a Hall effect thruster, and also impossible."
I could sense this was coming, and I stopped reading here.
I could sense this was coming, and I stopped reading here.
Extraordinary claims require extraordinary evidence.
This is a pretty big problem with any evidence purporting that it does work because it requires a massive reinterpretation of our understanding of existing physical laws: i.e. it's mechanism of operation has to simplify to existing theory in such a way as to also explain why the effect is undetectable at the staggeringly high resolutions of measurements we've been making of other physical constants for decades now.
This is a big ask. This is a huge ask.
Both he and I are firm believers of the scientific method though, so if researchers can show it experimentally then that's where the fun really begins. To my knowledge, the experiments until now have been fairly poor, with barely significant results (on the edge of noise).
Edit:
The 1) demonstrate and 2) explain parts are critical and it's not science unless you have 1). Preferably 2) also. EM has neither to match the magnitude of the claims until they can push something across the solar system and back (such that loss of mass is ruled out and the propulsive effect is without a doubt not instrument error).
That is hyperbolic. Pushing something around in orbit is sufficient to move forward (pardon the pun).
EM drive remains pretty controversial, and does present significant problems with explanation, and as an extraordinary device requires extraordinary evidence. So it could be conceivable not to focus too deeply on a remark which isn't the main point of the article.
I'm not dismissing your interest and excitement in the topic either. I'd love for it to be functional, and for us to learn new information on the way our universe works. The bar for entry is set particularly high on this, that's all :)
https://blogs.scientificamerican.com/guest-blog/its-not-cold...
HN discussion: https://blogs.scientificamerican.com/guest-blog/its-not-cold...
> Perhaps most surprising is that, in the formative years of atomic science in the early 20th century, some scientists reported inexplicable experimental evidence of elemental transmutations. In the 1910s and 1920s, this research was reported in popular newspapers and magazines, and papers were published in the top scientific journals of the day, including Physical Review, Science and Nature. The experiments, using relatively simple, low-energy benchtop apparatus, did not use radioactive sources so the results defied prevailing theory. Several researchers independently detected the production of the gases helium-4, neon, argon, and an as-yet-unidentified element of mass-3, which we now identify as tritium. Two of these researchers were Nobel laureates.
To think that our current models adequately explain every phenomenon in the universe is truly the height of hubris. They can't even explain every phenomenon that has been observed on Planet Earth, let alone universally.
Of course extraordinary claims require extraordinary proof - but we do a tremendous disservice by disincentivizing scientists from ever reporting a novel finding that disagrees with the prevailing theories.
Gotta love starry-eyed futurology people.
Just blanket suggesting that it is in no way possible without any evidence is no better than blanket suggesting it is possible without any evidence (well, it's a little better, since the laws of physics are on your side, but...)
The orbital motion of Mercury "violates" Newtonian gravity. There are other examples but I'm not trying to make a history lesson. I just want to point out, that science moves forward by impartial investigation of EVERYTHING. It's misguided to assume we know all and that there cannot be some thing we don't understand.
I'm as sceptical as anyone else about the EM Drive, but I want to understand "what the heck is going on with this thing that appears to move" more than I want to dismiss it as "not possible and obviously flawed because $ABC"
There are plenty of possible ways the drive could operate, and if it does work, it has the potential to significantly advance several fields of physics in a way no less valuable than other large expensive "hope this works" experimental physics experiments that no one is complaining about.
Mercury's motion does violate Newtonian gravity. General Relativity however simplifies to Newtonian gravity for various low-dimension applications though (i.e. an Apple falling from a tree, the orbit of the moon for most astronomical guidance purposes over that distance etc.)
In much the same way we don't account for the curvature of the Earth when building a house's foundations.
That's my point though: when you violate a fundamental physical law, it can't just be wrong. You have to somehow also account for why it doesn't happen all the time elsewhere (i.e. the effect is small to within experimental error over common measurement cases) and by necessity the new theory to explain it has to encompass the predictions of the old i.e. the benefit of Newtonian gravity was that it easily recovers the behaviour of nested epicycles of orbital motion (and made new predictions successfully where epicycles could not).
I still don't see how this is possible. In GR gravity travels at the speed of light, in Newtonian mechanics it is instantaneous. I have been unable to find an acceptable explanation for how these two very different universes can be compatible.
NASA also does the same thing, so don't feel bad.