swansont

Yes, as I mentioned; Doppler broadening and collisional broadening are two of the prominent ones. Energy is conserved, and if you have a polyatomic molecule or your gas has collisions, there's a ready reservoir for both energy and momentum conservation. I don't know if anyone has looked at a single neutral atom absorbing and emitting photons in an isolated situation, trying to see if e.g. a red-detuned photon was absorbed and resulted in a red-detuned emission, because how would you do that?

! Moderator Note One thread per topic, please

Surely you mean absorption here. Photons can’t be at rest, and so can’t be adsorbed. Transition energies themselves do not have an arbitrarily small precision. They have a natural linewidth, which can be broadened by various mechanisms. The D2 transition in Rb-87, for example, has a ~6MHz linewidth, owing to the ~25 ns lifetime of the excited state. The transition probability decreases exponentially as you move off resonance. There is no mismatch in energy, as such. The atom absorbs all of the photon energy.

The above seems explicit to me. From your view, what issue isn’t being addressed? Momentum is conserved in interactions. The notion in QM that light slows down in a medium but takes a straight path is because the virtual excitations take time but don’t result in a real absorption because momentum has to be conserved - there’s nothing there to recoil. Only the straight path is permitted.

exchemist didn’t say it was. They said the average perturbation was zero. I thought Genady addressed this.

Vacuum fluctuations are not an example of variations about zero energy, though. The energy of the vacuum - zero-point energy - is not zero.

I didn’t see it here, I saw it in pieces discussing this.

What’s an example of a fluctuation about zero?

The linewidth of a de-excitation transition is related to the lifetime, owing to the uncertainty relation. The nominal value of the transition might be e.g. 1 eV, but the value of any particular photon might be slightly higher or lower than 1 eV. Not a negative amount, since the linewidth is on the order of MHz to GHz, but a negative contribution because the energy is smaller than the average

If you invoke magic (or any other unphysical phenomenon) then you can make up any rules you want.

Things that sounds like “that’s simply not done because we’ve never done it” i.e. a very conservative, non-empirical response. Consistent with the description John Cleese gives in “A Fish Called Wanda” Wanda, do you have any idea what it's like being English? Being so correct all the time, being so stifled by this dread of, of doing the wrong thing Not “don’t do that, it tastes awful” which would be empirical though subjective. Or “do it if it’s to your liking” No, it’s “that’s not the proper way to do it, personal enjoyment be damned”

What is the connection to conservation of momentum? The issue is tunneling. The contribution can average to zero; the value being slightly larger or smaller than the average.

It’s not supposed to be a visually faithful depiction, so that the picture doesn’t reveal the answer. You’re supposed to use math skills rather than measurement.

I fund it interesting that the pushback I’ve seen on this is that it goes against tradition rather than evaluating whether or not it makes for better tea.

If they are in the box when opened, they were placed there before.

! Moderator Note Yeah, no idea why. Moved, since this seems like a Schrödinger’s cat question. No, that’s not consistent with what we know. The contents of the box is likely a classical situation, not a quantum superposition, so the contents would be determined when the items were placed in the box.

“The chemist who told us to put salt in our tea explains why she did it” “While it might seem outlandish, the idea of adding a pinch of salt to tea in order to reduce the bitterness is rooted in science. Sodium ion is a key element of salt, and it interacts with the chemical mechanism that produces the perception of a bitter taste.” https://www.newscientist.com/article/2414348-the-chemist-who-told-us-to-put-salt-in-our-tea-explains-why-she-did-it/

You didn't present an hypothesis. You just ranted about some strange straw man concocted about the big bang. What you've presented here isn't an hypothesis, either. It's a hand-wave, a seed of an idea. What one discusses at 2AM after imbibing certain chemicals that temporarily alter the brain. In terms of science, 99% of it is missing - there's no math, there are no specific predictions that one could use to falsify the idea.

! Moderator Note So do we. Since your contribution here is science-free (and is a violation of rule 2.13), and we’re a science discussion site, this is closed.

Um, no. There’s nothing inherent in an electric motor that would make this true. Terrestrial EVs generally have more horsepower than ICE cars. More efficient, too. https://electricvehiclehub.com.au/information-centre/are-electric-cars-as-powerful-as-petrol-cars/

Come up with a mathematical model and show how it fits the data. As pzkpfw notes, you are criticizing a straw man of the big bang.

They used to, though. Figuring out what was in coal tar and figuring out uses for the compounds was big in the late 1800s. (there was a “Connections” episode on this, IIRC) https://en.m.wikipedia.org/wiki/Coal_tar It’s still considered water. Your mention of it suggested that a different isotope was a different compound, which is the topic of discussion. That there is a difference in some interactions is interesting but not what the article is discussing.

Different isotopes of an element don’t create different molecules. H2O is water, regardless of whether you have O-16, O-17 or O-18

You could calculate how much oxygen you need by looking at the combustion reaction. Or just use an electric vehicle.

There are lots of ways to combine three or more atoms when you have 100+ to choose from. A lot will not last very long or only exist under specific conditions, and some are difficult to synthesize because some other compound is energetically preferred