swansont

We don't break out the energy stored in rotational modes as a separate term when doing an energy balance Q = mc∆T If temperature is only the translational motion, you'd need an additional term to account for the energy in the other degrees of freedom, but you don't do this, or need to, because you already accounted for it in the heat capacity. Equipartition of energy means that you can't separate the translational from the rotational modes in terms of energy. If the temperature changes, all of the modes gain or lose energy, and the temperature is proportional to this. The distinction shows up in calculations of the internal energy U = aNkT = aPV Seems to me there's no unambiguous argument in either direction, because the equipartition force the energy to be shared between the modes. I see nothing in literature making the distinction that it's only translational KE in systems with additional degrees of freedom. Nothing shows up in the equations, and IMO it's confusing to make that distinction when it doesn't show up in or matter to the calculation.

I think I understand what you mean, but IMO this isn’t the way to express it. Of course the other degrees of freedom contribute to the temperature; it’s right there in the equation. As you said, each degree of freedom has an energy of ½kT. If the other degrees don’t contribute, why does their energy depend on T? If you place an object with 3 degrees of freedom in contact with one with 5, they will still equilibrate at the same temperature. It’s just there are more modes in which you store the thermal energy in the second object. If it’s not temperature, how is the energy accounted for in any of the thermodynamic potentials?

That's the electrostatic interaction, which involves virtual photons. That's typically not referred to as EM radiation, which consists of real photons. The vibrational modes of a solid can be described in terms of phonons (not photons); there are non-radiative ways of changing those states. https://en.wikipedia.org/wiki/Phonon

The translational modes, which are the vibrations mentioned elsewhere

The original topic was about a solid, so the ideal gas law and kinetic theory is moot. However, the kinetic theory shows that it’s the KE of the atoms that matters; these atoms collide elastically with other atoms - these are the analogue of the vibrations in a solid. There is no “internal EM energy” You can’t have motion of atoms, having KE, and have a bunch of EM radiation interior to the system, and have the theory work. kT is directly related to mv^2 (with a constant related to degrees of freedom) If there’s energy stored as EM radiation, there’s less KE, but that means a lower temperature.

! Moderator Note It looks like these are just stock images, so you’re not off to a good start. Your description of the women as bossy and laughing at you indicates you should be talking to a mental health professional. We are not qualified to diagnose issues or give you the help you need.

! Moderator Note You may upload an image, but requiring people to follow a link is against our rules

People used to believe is a lot of things. I remember reading that sneezing was thought to be the body trying to expel demons, hence the response of “God bless you.” Now we know that it’s a cold or an allergy, or irritation from dust. You were supposed to bless a glass of water before you drank it, to keep the devil from entering your body. But now we understand getting sick from drinking bad quality water. So I don’t put much stock in stories from long ago about demons and devils, or in modern stories about aliens being attributed to them. It’s just so much baloney.

You can’t use the Newtonian kinematics equations if the motion is relativistic. There is no terminal velocity - terminal velocity requires an opposing, speed-dependent force.

You can alter the linear motion, but it’s a very small effect, since the momentum of EM radiation is p=E/c. Negligible for bulk material. Small even for an atom. Plus, if this is an excitation, the photon gets re-emitted, reversing the effect. And if the radiation is isotropic the net momentum is zero. And above all, temperature is not affected by linear motion. Yes. So it’s not higher just because the temperature is higher. The power per unit area of the material is the relevant quantity, as given by the Stefan-Boltzmann law.

But only for what you think is in the proposal. You don’t have those details (or haven’t shared them), so we don’t know - you’re just guessing. I’ve pointed out a few logical things that might have been in the proposal that you did not include. I’m not making any argument. I’m just pointing out the incompleteness of your assertion, and asking you fill in the gaps. Instead of doing so, or even engaging in exploration of it, you attack. It’s quite telling. It’s also quite obvious.

If the energy from the result approaches or exceeds a few percent of mc^2, that an indication that you need to use a relativistic treatment

Accelerating charges radiate. During a collision, atoms are deformed, temporarily giving them a dipole moment, while they are accelerated. What’s your evidence of this? The spectrum from blackbody sources I’ve seen look like a continuum. How can emitting EM radiation cause particles to acquire KE? That violates conservation of energy. Again, you need evidence of this. The evidence we have is that the emission spectrum depends on temperature. The radiated power depends on the surface area, but a hot source can radiate less power than a cooler source, e.g a 100L pot of boiling water will radiate more power than a 1 cm^3 chunk of solid at 150 C.

Because it’s not how temperature is defined. It’s insignificant in most situations anyway, because E/c^2 tends to be small. That’s backwards; the radiation is increased because the temperature is higher. The radiated energy from a blackbody is a continuum; it’s not directly related to electrons jumping between states. IOW any quantum jumps are typically an insignificant part of the spectrum in terms of radiated energy. (in fact it might have no net effect, since the excitations come from the collisional energy) Then I would suggest your understanding is incomplete.

I think kids have fewer options. They don’t get to vote and they can’t negotiate a flexible schedule; they just have to do what the grownups decide. Some jobs have flexible hours. Schools, especially for younger kids, not so much. Though I think this is mitigated somewhat by a trend toward parents dropping off/picking up kids from school, though my limited anecdotal data is for middle-class parents (and leaning toward upper m-c) which also triggers my feeling that these kids are spoiled rotten for not having to ride a school bus, or walk uphill both ways I hated DST with a passion because I used to get up at ~4 AM, which meant trying to get to sleep while it was light out and people out and about making noise, for a couple of month of the year. Even in retirement, it throws me for a loop. Just not quite as much as it used to, without as much of a structured schedule Who uses GMT anymore? It’s UTC, which is completely different (that is, almost exactly the same as far as the average person is concerned)

Engr.Daniel Grossman banned as a sockpuppet of Astrogeomanity

If there is no vibration, how is it compatible with the notion of lattice vibrations? The mass increases because there’s more energy. The two are equivalent statements; mass is a form of energy. But an energy increase does not necessarily mean a temperature increase - a spinning object has more energy than a non-spinning one, but the spinning has no effect on the temperature. In classical terms, temperature is dependent on the KE of the constituent atoms, but not the translational KE of the center-of-mass. QM recognizes that the atoms will undergo collisions, and that can cause excitations, so the distribution of states also indicates the temperature.

Kids waiting in the dark for a bus doesn’t present the same risk as an adult on their commute. How does that magnify it? The idea behind DST is that it better aligns daylight hours with when people are awake. Shouldn’t that tend to mitigate SAD?

No Which isn’t necessarily what’s going on here, with a solid metal, where we have a band structure for electron energy. You don’t have to promote an electron to a higher band. Since the OP specified IR, this means the energy of the photon is probably less than 1 eV

Yes, but that’s not related to the point I was making. I wasn’t advocating for the change. Another option is not changing the rules.

“Parents” is not some monolithic group. Ones pushing for an adjustment in starting time might be the ones who have the flexibility to change their own schedule

But now you have the issue of parents possibly not being home at the beginning of the day to see their kids off, unless they, too, adjust their schedules - if their employer affords that kind of flexibility. Younger kids not supervised makes a lot of people nervous - more than when I was young.

Posts that advertise other threads are routinely hidden.

This is one of those “why are things the way they are” that physics can't address, because we can only observe how things behave. Bare charges and their electric field come as a set.

No, that’s my response to the comment about bias. Had I wanted to characterize a response, I would have quoted the response. The thing is, JC merely said I think we can be biased - it’s not an accusation that either of the criticisms in the thread were based on bias. Yet my response is somehow is? I don’t get it. ”But it would be improper to appeal to bias in order to dismiss legitimate criticism.” Note the future tense. Not present or past. Because such appeals happen. There’s an attitude that criticism of republicans doesn’t have to be addressed because democrats are biased. I did. I wasn’t referring to either of them. I said that not all criticism appears here. Having said that, the suggestion here is that the comments in this thread aren’t legitimate criticism. Why not? What makes the criticism illegitimate? One isn’t permitted to not understand a thought process? That’s not legitimate? There aren’t folks in the GOP that treat women as lesser people? That the GOP hasn’t embraced taking rights away from them? They don’t argue against equal pay for women because men “need to make enough to support their families and allow the Mother to remain in the home to raise and nurture the children”? https://www.refinery29.com/en-us/2017/02/141695/utah-republican-argues-against-equal-pay MTG didn’t say “We came from Adam’s rib. God created us with his hands. We may be the weaker sex, we are the weaker sex, but we are our partner’s, our husband’s wife“? Perhaps she was misquoted. The current speaker of the house once blamed mass shootings on “no-fault divorce, feminism, abortion, and other expansions of social rights that took place in the 20th century.” (quote from article, not directly from the speaker) https://www.the-independent.com/news/world/americas/us-politics/mike-johnson-speaker-shootings-abortion-b2437378.html But sure, the right wing isn’t regressive. Claiming it’s not legitimate to say so is a rock-solid position to take. (It’s not like TheVat was alone in their view https://www.latimes.com/politics/story/2024-03-08/cultural-commentary-bidens-2024-state-of-the-union And quite a few republicans hated Britt’s performance https://m.youtube.com/watch?v=cvasDkMWdXg )