-
Posts
54707 -
Joined
-
Last visited
-
Days Won
322
Content Type
Profiles
Forums
Events
Everything posted by swansont
-
That’s the process - see if you can poke holes in an idea. Falsifiability is a key component of science. And I’m telling you it’s a rare occurrence. The photon gan go in many directions, and you require a specific one, over and over again. If they can’t be observed how can they be responsible for heat transfer? Isn’t heating something up an observable process? There’s no evidence it works this way, since the evidence we have says it doesn’t. Wishing does not make it so. Yo predicted a time for heat transfer, which depends on this speed. Why does the light for heat transfer behave differently than other light? (without resorting to magic or special pleading, please)
-
Energy and momentum will be conserved regardless of the direction the photon is emitted. The difference is whether any energy and momentum is imparted to the atom. Your proposed mechanism is not observed to happen. i.e. your prediction fails. And since the photons can be emitted in other directions, this happens only rarely. You did more than that. You predicted a speed. Does thermal conduction happen at the speed that your idea predicts?
-
The emission is not preferential in that direction. The atom doesn’t “remember” the direction a photon came from. It’s simply in an excited state, and the subsequent emission probability is symmetric. It’s just as likely to emit in the direction the photon came from as in the opposite direction. How does an atom “know” the difference between these photons? We can measure how long it takes for light to pass through various materials. Polyethylene, for example, has an index of refraction of around 1.5 for infrared light. So light goes at around 2/3 c through it.
-
My PhD dissertation was based on laser cooling and trapping and I did projects based in it for 30 years. Your summary misses the point. Cooling happens on moving atoms (because the hot atoms are moving) but the photon absorption interaction is not dependent on that. “for me” isn’t how science works. If you don’t have experimental evidence for a notion, it’s worthless. Then derive this relationship. Physics is based on models.
-
No. Laser cooling (Nobel prize 1997) wouldn’t work if the photon was emitted in the same direction, since no net momentum would be imparted to the atom. But that’s not what happens. The emission is symmetric and not preferential, so momentum is imparted to the atom. (And depending on the specifics, could heat or cool the atoms. Cooling is usually more experimentally useful) The momentum would be imparted regardless of separation distance. This wouldn’t seem to explain the T vs T^4 difference we observe for conduction vs radiation.
-
No, this is patently untrue. S-B gives the radiated power. It does not require thermal equilibrium. Once there’s a gap there is no conduction. It’s why a dewar flask works so well; radiative heat transfer is fairly small for low temperatures, but becomes important owing to the T^4 behavior Being unaware of facts does not make them untrue. It gets to be frustrating to be told that they aren’t simply because you don’t know much about physics.
-
But radiative heat transfer depends on the difference of T^4, while conductive heat transfer depends linearly on the temperature difference. A small vacuum gap between the solid and liquid has a huge change in behavior, but should make no difference if it’s radiation, since all of the photons would still be emitted from the solid.
-
Oh, good grief.
-
IS IT POSSIBLE TO VIDEO RECORD INSIDE AN INCUBATOR?
swansont replied to POTATOPERITTO's topic in Equipment
My experience with GoPro from a few years back is that the battery only lasts a few hours. You’d need an external power source, unless they’ve gotten a lot better. -
Did contaminated fuel cause the Baltimore bridge disaster ?
swansont replied to toucana's topic in Engineering
I’m not sure deficiency is the right word. Ships were smaller when the Key bridge was built in 1977. https://commercial.allianz.com/news-and-insights/expert-risk-articles/shipping-safety-22-losses.html “Container-carrying capacity has increased by around 1,500% since 1968 and has almost doubled over the past decade [referenced to 2022]. Ever larger vessels are on order.” The Dali’s capacity is almost 10000 teu, almost triple the biggest ship when the bridge was designed. -
Curvature versus Expansion: Both Relativistic Observations of Space
swansont replied to Maartenn100's topic in Speculations
Useful as an exercise, perhaps, but it’s not the universe we live in. Your opinions mean little; in science it’s the evidence you have to support a falsifiable idea Can we stick to the topic? You keep avoiding addressing the question of the connection of relativity to the expansion of the universe -
Curvature versus Expansion: Both Relativistic Observations of Space
swansont replied to Maartenn100's topic in Speculations
But we (scientists) are aware of relativity, so there is no difference in understanding. It’s a given that the measurement was made with our clock. And this has no impact on expansion. You could make the same flawed argument about any measurement affected by relativity, and yet GPS (for example) still works. You are overstating the impact of relativity; it does not render things unknown. It merely makes measurements frame-dependent, but with a known transform between frames. It's like saying that the fact that things can be written in both English and German means language has no meaning, as if one can’t translate between the two. -
Any time or length measurement will be the same, but there will be length contraction of the object, and it will experience time dilation. Two observers measuring the decay of muons, for example, will get the same answer for the half-life, but it won’t agree with the lab frame measurements. Without relativity you could not reconcile the discrepancy.
-
Did contaminated fuel cause the Baltimore bridge disaster ?
swansont replied to toucana's topic in Engineering
I was reading that the protective mini-islands are called dolphins https://en.m.wikipedia.org/wiki/Dolphin_(structure) -
TFG or That Florida Guy? Either way, can the GOP win in 2024?
swansont replied to Phi for All's topic in Politics
Marilyn Lands’ victory in Alabama should also paint a picture. I expect the polling numbers to skew toward Biden once the campaign ramps up the ads showing TFG’s support for overturning Roe and the GOP’s plans make it national, and to get rid of IVF and contraception. -
Kelvin Klein. For your absolute unit.
-
You do realize there are countries that are not friendly towards the US, right? So they might not be inclined to sell uranium to the US. Areas that were part of the USSR are currently big producers of uranium. Hard to cut off the supply to someone when it’s under their direct control How/why is that more ethical or acceptable? You failed to address this.