Tag Info

Hot answers tagged

37

You're right that as the temperature increases, shorter wavelengths receive a higher proportion of thermally radiated power, and longer wavelengths a smaller proportion, because of the shifting Boltzmann distribution of your molecules' kinetic energy, and therefore the shifting power spectrum of the light they emit. However, most of the objects you see ...


13

Planck's Law gives us the intensity of black body radiation as a function of temperature: $$B(\lambda,T)=\frac{2hc^2}{\lambda^5}\cdot \frac{1}{e^{\frac{h c}{\lambda k_B T}}-1}$$ If we plot a normalized plot of this curve for different temperatures, you see the following: As you can see, it does look like the higher temperatures make the relative ...


6

In some sense yes. The temperature is defined as an imaginary time in Matsubara Green's functions or some path integrals. Thus, a negative inverse imaginary temperature can be considered as a time. Here is a quotation from Alexander Altland, Ben Simons "Condensed Matter Field Theory": "Thus, real time dynamics and quantum statistical mechanics can be ...


5

In a thermodynamical settings in particle physics, the highest temperature will be the temperature at which point you reach an equilibrium with particle creation from the random particle collision. The Hagedorn temperature is the temperature at which quarks, when heated, will produce more quarks, which will lower the temperature back.


4

Kelvin is the SI unit. It is far more common than Rankine. I cannot recall ever encountering Rankine temperature units, except in historical or humorously-backward contexts. Note that these measure temperature, not heat. The SI and "imperial" measures of heat is are the joule and the BTU, respectively. To avoid causing headaches, use SI for everything — ...


4

In a given orbital, electron motion has nothing to do with temperature. Atoms do have a variety of electronic states and, at higher temperatures, the higher energy states are more likely to be populated. Temperature, however, is most commonly determined by the translational motion of the nucleus of the atoms. Let $v$ be the speed of a nucleus of an atom ...


3

The calibration of the digital devices drifts. When calibrating some temperature probes for a neutrino experiment we used a deionized-water ice bath. The four laboratory digital thermometers we found (all claiming between $\pm 0.05$--$0.25\,^\circ \mathrm{C}$ accuracy) read between $-0.5$ and $+1.8\,^\circ\mathrm{C}$. Clearly some were well outside their ...


3

I found an answer to my own question. The quote is from "Is there an absolute maximum temperature?" "Answer We posed this question to Sam Gregson, High Energy Particle Physicist at the University of Cambridge... Sam - The temperature of a system is simply related to the amount of energy in that system. Because the system can't have a ...


2

I expect it's impossible to cross the Planck temperature, just like it's impossible to cross absolute zero or the speed of light. At the Planck temperature, you start producing miniature Planck-mass black holes, which are the hottest black holes that can exist. If you try to put more energy in the system, you would get larger black holes, which are cooler, ...


2

Yes, more or less. You don't need the volume of the object, because temperature is what's called an intensive quantity--it doesn't matter how much "stuff" there is. What you need to know is what kind of molecules you're dealing with. According to the equipartition theorem each degree of freedom gets $\frac{1}{2} k_B T$ energy, where $k_B$ is Boltzmann's ...


2

Yes! You have to think about the amount of energy that is hold in the coffee. The amount is (almost) exactly the same the moment before you add the milk than just in the moment after adding it. So if you consider the energy of a cup at room temperature as zero energy, the amount of energy stays the same as the milk adds no energy. But(!) the temperature ...


2

Let me quote this line which says that: I touch it that it's temperature did not drop down Its better to use thermometer to check the readings as it gives you accurate reading. Please check this link as it shows what you did wrong: Why does cold metal seem colder than cold air? The process of touching and determining its temperature is wrong. There ...


2

If you graph the temperature of your copper strip as a function of time you're going to get something like: This is because you have two effects. The light from the Sun heats the copper strip, but at the same time the strip cools. The equilibrium temperature (the dashed line) is the temperature at which the cooling balances the heating. If the intensity ...


1

I think you might have actually touched on something interesting here. One explanation for the difference in temperature is simply that part of the energy removed from the balloon + air system comes from the air, so the balloon will cool more slowly when filled with air. But there might be more to the story. I haven't done any calculations on this, so it's ...


1

So far, you have three answers to the "how is the heat transferred" part of your question, but nobody's answered the other part: How does a thermometer measure the [temperature] of atmospheric air? The answer is that both the glass and the liquid inside the glass expand when they are warmed and contract when they are chilled, but they expand/contract ...


1

The bond that holds water as a liquid is a simple static electricity bond. it has a strength and will 'break' with sufficient energy. this happens all the time. water evaporates, when a random chance of circumstances through thermal agitation and exterior pressure are at the right amount the molecule leaves the liquid and goes flying off as a gas. the higher ...


1

I am not particularly familiar with the primon gas you are linking to, but similar ideas have been tossed around for a long time; see, for example this page for many references (including the topic you mention). The first two topics (quantum mechanics and statistical mechanics) are particularly relevant to your question; I'll concentrate on the second one, ...


1

I tested it against a control and it worked. Used longneck glass bottles. Didn't measure the difference but the difference was notable to the touch after half an hour.



Only top voted, non community-wiki answers of a minimum length are eligible