It’s essentially Occam’s razor. Of course we could currently be wrong, but the entire point of the western scientific mindset in which this article is written is that we can be reasonably certain that in this case we’re not. If you want to dedicate your efforts to showing otherwise, have at it. No one will stop you. They probably won’t fund you though, and on the minuscule chance you end up being right unless it’s blindingly obvious it’ll take a while to convince people (we still haven’t convinced everyone that the standard model matches experimental data as well as it does, and that’s more or less been settled for how many decades now?)
Huh? Would you argue that it's "incredibly naïve" to think perpetual motion machines aren't possible purely based on "laws of physics"? Because I think it's incredibly naïve to think perpetual motion machines would be possible, precisely because they do violate the laws of physics.
"The law that entropy always increases—the Second Law of Thermodynamics—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."
But hey there's a lot we still don't know about the universe. I mean these unbreakable laws are only a few hundred years old for us.
By all means, our physics works (now) and its the best we've got so lets bet on it and drive our society that way, but to suggest some things will never be possible not only creates 0 value for society (perhaps even negative value), but is also the stance proven wrong so many times needlessly. The truth is, we really just don't know and can only make our best guesses.
There is ‘plausible imagining’ and then there is also ‘scammy bullshit’.
Energy conservation relies on time translation symmetry. In other words, that the laws of physics do not change over time. Well, perhaps they do change slowly.
A prime example of this is the expansion of spacetime, which can reduce the energy of a photon travelling through empty space - it's redshifted. This has been experimentally observed.
See https://www.preposterousuniverse.com/blog/2010/02/22/energy-... for more details.
E = (hc)/λ
where h is the planck constant, c is the speed of light, and λ is the wavelength.
As a redshift is the increase in wavelength it is an actual decrease in the energy of the photon. This makes more sense when you consider that a photon is mass-less, and so its total, energy is bound up in its momentum rather than momentum and mass.
What do people mean by 'perpetual'? 1 year, 100 years, 1 million, is it expected to outlast the universe?
And 'laws of physics' is such an anachronistic term, it carries such baggage with it, better to say 'what we think we know so far'.
And a 'perpetual energy machine' is trivial, punch a hole through to another universe and siphon their energy out. That's probably what black holes are, another universe has punched a hole through to ours and is sucking the energy out.
Is it perpetual? Well, it'll last a billion years or so. Does it violate our naive understanding of physics? Not at all.
I also sometimes smoke too much weed.
I've seen so many documentaries and articles pessimistically concluding we'll never go to another star much less another galaxy based on the speed of light. Once again, too many smart people conclude we've figured it all out as is the perennial tradition.
When pushed, all scientists will admit "based on current understanding".
This is what makes a "breakthrough" revision of understanding so exciting! It doesn't happen every day!
Yes? People in the 1200s could fathom gods and magic, why not phones? What kind of dullards do you think people were back then?
The futures people imagine are consistently crazier than what actually happens. People thought that by year 2000 we'd have Mars colonies, flying cars and sentient computers. Sure, they didn't really see the Internet coming, and sure, the Internet is nice, but it's not exactly up to par, is it?
Understanding time travel and its possibility is definitely purely based on the laws of physics. What else would it be based on?
Usually, when people rule out time travel as impossible, it's because it has the potential to introduce paradoxes that totally break any possible understandable notion of causality, i.e. the inventor of time travel going back and killing himself before he invents it.
Thankfully, the known physically possible forms of time travel don't introduce that specific issue as they would not permit traveling back to any point before the wormhole was created, which also goes far to explaining why, if time travel is ever going to be invented in the future, we have never seen anyone come here from the future.
I'm not aware of any actual observational evidence or even strong theoretical prediction that wormholes exist or that they are physically possible.
Some parameterizations of our models don't rule out their existence, but it's all hypothetical. Including the question whether they are traversable.
That applies to time travel into the past.
It's obvious, but it bears noting that the converse is a lot simpler. I say that because, IIUC (and that's a real question), quantum mechanics treats the time dimension as symmetrical, which contradicts observation, at least to this point.
Is that because QM is wrong on that point? Which seems unlikely, since it's one of the most precisely confirmed (by observation) theories we have.
Or is there something about the "macro" world that destroys that symmetry?
I don't have the answer, but it's clear that in a particular reference frame, we move forward in time at a rate of 1 sec/second.
Again, that's obvious, but based on my (limited) understanding, that seems to contradict QM.
As far as I'm aware, the weak force is known (and experimentally demonstrated) to break time-reversal symmetry.
It's only combined Charge-Parity-Time symmetry that QM maintains.
(This still does not explain how a macro arrow of time arises, though)
Specifically, saying that something is “impossible” outside of a well-defined formal system would more correctly be classed as hyperbole than a statement based on knowledge.
The universe may not make a lot of sense, but there is some sense in it.
Futility of discussion: I can certainly understand anyone feeling like that after the last two years. But don't give up hope!