swansont

At this point I’ve tuned Bob out, because I seriously doubt his sincerity.

That doesn't stop people from trying. Applies to Star Trek, too.

You've made an excellent argument in support of moderated exchanges, in which a third party has the authority to tell Bob that assertion isn't argument, things are not true simply because he says they are, and if he continues to argue in bad faith, he will be shown the door. Then there is no point in communication, so all of this is moot. From a practical standpoint, we must reject Bob's position, because if everything is the same no progress can be made. All trees are fish and all fish are trees, declared by fiat! Bob: My work is done, pay me! Bob's boss: You did no work at all. Bob: No work and all work are the same thing! Pay me! <later> <Bob carries sign: Will philosophize exceedingly badly for food> It's the "Where's Waldo" where Waldo is the only person in the frame.

I was referring to the motors themselves. All else being equal, going from even a 30% efficient ICE to a 75% efficient electric motor seems like a big win. And that's before you consider Ken F's point about CO2 reduction (which would be maximized if you got your electricity from a green source) At some point efficiency bumps up against the utility of the vehicle. If the aerodynamic shape means you can't carry the stuff you want to carry, your potential customer population shrinks. Ethanol seems very much in this category. Unclear on the benefits other than corporate welfare. Other efforts seem niche and it's not clear to me that they scale very well.

Well, it discussed physics.

Bob is wrong. He is not arguing, he is asserting. And he is asserting something which is not true. This makes any conclusion based on his premise invalid. This is a little like the Monty Python sketch about arguments, except in the MP sketch the bad faith is done to be funny, and it's not at all evident that you are attempting humor here. Are you contending that Bob's assertion is credible?

TBH, I would reply "F*ck you, Bob. Stop arguing in bad faith" "affirmation and negation are indeed not the same thing" The rest of this is logical error and fallacy. To assert yes=no, after one has affirmed that they are not equivalent, one is drawing an invalid conclusion and then using circular reasoning with anything that follows. IOW, Bob's an idiot. ! Moderator Note And, I would like to point out, that shilling for a book is a violation of our rules (advertising) and posting with an agenda (that this was a setup to shill for your book) is a violation of our rule on good faith arguments. Which is why this thread is now in the trash.

Vacuum energy isn't negative. It's infinite, and can't be accessed to do work (except in the minds of some crackpots) What's most important in physics is energy difference between two states, which can be negative. We often define potential energy so that it is negative in all but the trivial case, so negative energy is (in that regard) already a coherent concept. But studiot is right, a better definition is needed. A distinction between inertial and gravitational mass would be a decent start, because there are different implications (and possible contradictions) for it being one but not the other, or the alternate case, or both.

Is there something you wanted to actually discuss? I will point out that the power of a laser (power having a meaning in physics) is largely uncoupled from the wavelength. You can have a very powerful red laser and a not very powerful violet laser. Generally speaking, the shorter the wavelength is the harder it is to make the laser, and the harder it is to make a powerful laser.

Not probably. We already observe this to be true, especially at the red end of the spectrum.

Internal combustion is part of the problem - typically pretty low thermal efficiency of ~20-25%. Diesel is generally better. Getting away from the combustion format altogether is probably where the big improvement is. Electric motors are more like 75-80% efficient, and benefit directly from things like regenerative braking.

No, it is not (the other option was "yes, it is" but both can't be true, and they aren't the same)

! Moderator Note No, which makes perfectly reasonable to ask for clarification. What is far less reasonable is to hijack a thread to engage in personal attacks. Hence the relocation of these posts.

The Casimir effect is well-understood without invoking negative mass. That’s why you need the next step of looking at what kind of experiment or what evidence exists to support the hypothesis. How can this be tested?

There are different elements and isotopes, each with a different electron energy structure, owing to the variation in the charges and charge distributions in the nucleus. The differences in the electrostatic interaction strength have a direct effect on the energy levels. (e.g. two protons have twice the force on an electron as compared to one proton, all else being the same)

philo2001 banned as a sockpuppet of altaylar2000

No, actually. Not in a physics context. There’s a concept in particle physics: that which is not forbidden is mandatory. One frequency is a narrow constraint would require some physical law to be in place, such as conservation laws, and there aren’t any. It would be one thing to see that there were such laws, and one might ask why - and we start down the rabbit hole in the Feynman video joigus posted. Ultimately you hit a wall where you can’t explain why. But contemplating why a physical law doesn’t exist is really a non-starter. You hit that wall immediately. You would need to explain why that law should exist. Basically, science ultimately does not explain why. It explains how nature behaves.

An excellent point. This shown up as Doppler broadening in spectroscopy. You broaden the resonance owing to the motion of e.g. a gas, so even though a particular transition might emit a narrow frequency band, the overall light for the sample covers a larger range, since various atoms have different Doppler shifts.

There's no reason to not have the various wavelengths, i.e. there's no physical law requiring this. Some sources of light are a continuum, like blackbody radiation. If you accelerate a charged particle you get radiation that's related to the acceleration, and a wide range of accelerations are possible. Quantized sources depend on the nature of the bound system's energy levels, and these are all different, with many of these systems technically having an infinite number of transitions available. Even if you started with one wavelength, scattering processes and conservation of energy and momentum would require different wavelengths, as recoil would "steal" some energy from a photon, requiring a different energy after the interaction.

That's a missing piece in many discussions about life in space. What resources are you expending to attain your goal? Here's a paper that concludes that anything bigger than 10 earth masses requires an unreasonably large rocket For a classical Apollo moon mission (45 t), the rocket would need to be considerably larger, ∼ 400,000t. This is of order the mass of the Pyramid of Cheops, and is probably a realistic limit for chemical rockets regarding cost constraints. (this is for Kepler-20b, at 9.7 earth masses) https://arxiv.org/pdf/1804.04727.pdf

I don’t think any humans live there, and mining on Jupiter and Saturn for use elsewhere would be moot since you couldn’t get a rocket out of their gravity well with our current technology. Rockets leaving earth are mostly fuel, with a little payload. Bump the escape velocity up a little, and it’s no-go.

No, there are data which point to their existence. Much like there were data that pointed to the existence of the neutrino, before we could actually detect a neutrino. AFAICT the problem here is you are not familiar enough with the reasons scientists think dark matter and dark energy exist. That's probably one reason your common sense says it's nonsense. Another is that some of science is just plain weird and outside of common experience, and therefore not intuitive. Which would make "common sense" moot. You're wielding a NERF sword in this battle

With prisons, but not only prisons. Shouldn't we make an effort to see who can be rehabilitated? Prison, especially when one would be co-mingled with hardened criminals, doesn't seem to be the best environment for that. There are differences between crimes that involve premeditation, ones that aren't, and ones that are accidental (and perhaps other categories) There are also cases where restitution might be sufficient for justice to be served, i.e. there might be no point in throwing someone in prison for a minor offense. Or, as someone mentioned earlier, cases like someone stealing food in order to survive. I think one of the major issues (aside from not everyone being equal before the law) is the quasi-one-size-fits-all approach. As Peterkin has suggested, the current system doesn't work. (and I think the US system is probably worse than the Canadian system. If I'm reading the stats correctly, the US incarcerates people at ~6x the Canadian rate)

One should note that thermal radiation will be a blackbody spectrum (or close to it), so you get the whole thing. You could, in principle, get amplitude modulation by heating and cooling your source. This would be extremely limited in therms of modulation, as it will take time to cool the source down. You could so some sort of frequency modulation, but then the blackbody radiation would tend to mask it as it would appear as noise. Neither approach has any real utility as far as I can see.

The criminal justice system as implemented in the US is quite racist in its implementation, so that's not really justice. People should be treated equally under the law.