It's the physical property that indicates the degree/intensity of heat present in a substance or an object. It can be expressed and measured according to various scales.

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equation related to room temperature and air conditioner temperature and flow rate? [closed]

i want to find and equation that related the air room temperature and air conditioner temperature and flow rate. i want to model a cooling system. the input to the room are air conditioner supply and ...
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0 Kelvin body moving

As many books say: Temperature is (proportional, almost, etc...) average kinetic energy of particles. My question is this. "Suppose there is a body somewhere in empty space which moves at ...
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181 views

A physical explanation for negative kelvin temperatures

Just to get the thoughts rolling... Consider a two state system with discrete energy levels $E_1$ and $E_2$ where $E_2 > E_1$ which contains $N$ particles. We can easily deduce that the state of ...
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Why does a water drop on a hot plate at 150°C evaporate faster than on a plate at 200°C?

I recently read that: A drop of water landing on a hot plate at 150°C (300°F) evaporates in a few seconds. A drop of water landing on a hot plate at 200°C (400°F) survives a whole minute. How ...
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How hot can plasma get?

I remember reading about an experiment where fine rods of tungsten were super-heated with millions of amps of electricity, melting them into ionised gas and were then compressed (by magnetic fields?) ...
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unit conversion issue

I have the following equation where $ T_0(x) $ measures the temperature in Celsius at point x. The parameter values are as follows. My question is how to handle the second term $Q_m \over ...
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Equilibrium temperature of closed system

Body X of temperature 0° C is brought into thermal contact with body Y of temperature 100° C. X has specific heat capacity higher than of Y. The masses of X and Y are equal. By my reasoning, the ...
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51 views

Temperature of system in canonical ensemble

Upon reading Reif's explanations relating to systems exchanging energy and the canonical ensemble (Reif, Fundamentals of statistical and thermal physics, p. 95ff and p. 202ff), I am led to conclude ...
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Is there any metal or any material that can survive the Sun? [closed]

If we were to send a unmanned spaceship through the Sun. What material can survive?
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65 views

Methane under pressure [closed]

A tank is filled with liquid methane. Then it is closed. It sits in an infinite room at STP (standard temperature and pressure). (Initial temperature is not important; assume density of liquid ...
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1answer
39 views

Time to decrease water temperature by 5F from different initial temperatures

Is the time to (naturally) decrease temperature of water by 5 degrees the same, regardless of the initial temperature? Imagine 3 glasses of water (a, b c) in a room temperature of 70F. There are 3 ...
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72 views

Electrons and photons at absolute zero?

I know that molecules can't move at absolute zero (hypothetically of course). But what happens to electrons and photons?
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31 views

Resistance including temperature - tungsten

I am doing a paper on calculating temperatures of tungsten filament inside a halogen lamp. I have measured different voltage-current levels and calculated the resistance. Then, I have used formula ...
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Why does an infrared thermometer display very low temperature when being directed to the outer air?

I'm toying with an infrared thermometer - one which you point onto an object, press the button and it instantly measures the temperature by estimating the infrared radiation from the object. It shows ...
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Visualising gas temperature and gas pressure

Gas pressure is created when gas molecules collide with the wall of the container creating a force. Gas temperature is a measure of how fast the molecules are moving / vibrating. However, they both ...
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800 views

Why isn't the Earth's core temperature the average of its surface temperatures?

Assuming that the earth is spherical, that its temperature is continuous, and that some other more or less realistic conditions hold, we might think that the Earth's core temperature should be about ...
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Thermal AdS3 in Chern Simons

I am currently working with (2+1) gravity in Chern-Simons formulation and I have a question about thermal AdS. The way I understand that one retrieves thermal AdS is by Wick rotation and ...
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3answers
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Can a single particle be “heated” by radiation?

From the point of view of statistical thermodynamics, a single particle doesn't have a phase (state of matter), nor temperature. What would happen if heat is transported to this single particle via ...
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81 views

What is the significance of the Debye temperature from a materials perspctive?

If I look at a table of different metals and their Debye temperatures, what does the variation in these temperatures tell me about these materials?
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Temperature of a falling meteor

I am reading "What if?" article https://what-if.xkcd.com/20/ and I'm interested in it's scientific background. Mr. Munroe writes: As it [the meteor] falls, it compresses the air in front of it. ...
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Is temperature a Lorentz invariant in relativity?

If an observer starts moving at relativistic speeds will he observe the temperature of objects to change as compared to their rest temperatures? Suppose the rest temperature measured is $T$ and the ...
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Why don't objects radiate off all of their heat energy?

Imagine a solid box in deep space. Solids are as far as I know constructed by positive nuclei in some sort of coherent structure, with electrons orbiting nearby too. Both the nuclei and the ...
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Would an ideal gas be colder at higher altitude due to gravity?

Since gas molecules are affected by gravity, wouldn't that make gas molecules at higher than average elevation slower (at the top of their ballistic parabola) and thus colder than air molecules ...
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1answer
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why there is no temperature and density in the formula of the electrical resistance?

Why there is no temperature and density in the formula of the electrical resistance? We all know, that the electrical resistance depends on length, temperature, density( material). Why is the ...
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2answers
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Why does heat added to a system cause an increase in entropy that is independent of the amount of particles in the system?

Say we have two gas containers of $N_{2}$ at the same temperature of $300 ~\text{K}$, one containing $10^{23}$ particles and the other containing $10^{13}$ particles. If we add a quantity of heat to ...
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1answer
64 views

How does a photon raise the temperature of a gas?

The temperature of a fixed volume of a gas is increased when it interacts with radiation. Why does the temperature increase (i.e. why does the velocity of a gas molecule increase) when a photon is ...
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temperature from a molecular point of view

The electric fan increases the velocity and hence the kinetic energy of the molecules in the air. this would mean that the temperature has increased. What's wrong with a conclusion? I want you to ...
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59 views

Mercury-in-glass thermometer

Question from my textbook: Jason says 'The mercury in the thermometer can be replaced by coloured water. The thermometer will function well after recalibrating using a similar method to calibrating a ...
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How loud is the thermal motion of air molecules?

In other words, given a magical room with walls that produce no vibration and transmit zero vibration from the outside, and nothing on the inside except room temperature air, what would be the noise ...
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How long does it take for space dust to stop irradiating energy?

I heard that space dust is detectable because it irradiates on the infrared part of the spectrum? Does this happen forever? Won't it stop after some millions of years? Does it have to irradiate until ...
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101 views

What is the temperature of the event horizon?

In a discussion with my son about absolute zero, we arrived at the conclusion that the event horizon might be the place to look, as it "absorbs?" all energy, including light. Found this in the ...
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1answer
52 views

What is the difference between temperature difference and temperature change?

In a course of mathematical modelling that I am taking, there is a great confusion between the concepts of temperature change due to a unit heat input at some position $x$ and time $t$, and the ...
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Why can't a gas be liquified by pressure above its critical temperature?

What is the cause behind a gas being difficult to liquify above its critical temperature no matter how much pressure is applied on it?
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1answer
42 views

sudden volume increase piston

I am wondering what happens in the following situation. I have a piston filled with an ideal gas for which I suddenly/instantaneaouly iscrease the volume. In particular I want to know what happens to ...
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4answers
382 views

Why does my house seem to warm faster in summer than it cools in winter? [closed]

In summers when we switch off the air conditioner, the room seems to instantly get hot again. But in winter, when we switch off the heater the room seems to remain hot for some time. Why this ...
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1answer
53 views

Will the heat flow rate be same when temperature difference is not same?

If I give heat with a certain source will the change of temperature difference change the heat flow rate? Suppose I have a aluminium rod which has a weight of 25 gram. I heated it up to 40 degree ...
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1answer
57 views

Heating 2 sets of 1L water vs 1 set of 2L water [closed]

Can heating 2 sets of 1L water or 1 set of 2L water have a variation in terms of fuel efficiency? Can one be more fuel-efficient than the other? (migrated from chemistry site)
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How to calculate the increase in temperature due to drop? [closed]

Question- Calculate the rise in temperature in celcius in a bucket of water after it is dropped from 50 m where acceleration due to gravity is 10. I know that I need to find the amount of energy ...
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1answer
40 views

Does shaking a carbonated soda warm it up?

I had an odd situation where i left a soda near the fridge exhaust and it developed some ice crystals (i could hear it sloshing). When i took it out i instinctively shook up the closed soda can with ...
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Thermodynamic expectation value at $T=0$

The thermodynamic expectation value for an observable $A$ is defined as $$\langle A \rangle = \frac{1}{Z} \sum_n \langle\psi_n| e^{-\beta H} A|\psi_n \rangle, \qquad (1)$$ where $\beta=1/k_bT$, the ...
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Method used to prove emissive power, $E \propto T^4$

Stefan's Law states that emissive power($E$) of a black body is proportional to $T^4$. But how did Stefan arrive at the conclusion? I mean, it is not possible currently to get a perfectly black body, ...
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Why are refrigerators 4 degrees and freezers -18 degrees?

I assume that the refrigerator's temperature of 4 degrees has something to do with the fact that water is densest at that temperature. Does that inhibit microbe growth? But what about the freezer, ...
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50 views

Temperature of a trapped particle

How is the temperature of the center of mass of a trapped particle (e.g. in a Paul or Penning trap with laser cooling) defined? I assume it has something to do with the equipartition theorem and ...
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1answer
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Temperature moderation

Temperature moderation is closely related to the hydrogen bond, as you guys all know. And this temperature moderation happens everyday to human beings through perspiration. As the water in you body ...
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WIll aluminium foil get hot in microoven if I wrap it with paper?

A aluminium foil doesn't get hot easily because of it's heat conductivity. Will it get hot in microwave oven if I wrap it with paper?
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Sliding Wine Glass [duplicate]

Earlier today, I came across a strange phenomenon involving a just-washed wine glass and a countertop. The gist of it is: when you place a warm wine glass upside-down on the wet countertop, it starts ...
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3answers
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The temperature in space is about 3K, however there are almost no atoms in space. How can there be residual heat?

My understanding is that heat is essentially atomic vibrations. If there are almost no atoms, how can there be residual heat? Also, as I understand in space there is no heat transfer via convection ...
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What is the physical explanation for the heat equation?

We know that $\int{\vec v.\vec n \,\ d a}$=$\int{\nabla^2(u)\,\ dx \,\ dy \,\ dz}$ where $\vec v$ is the velocity of the heat flow and $u(x,y,z)$ is the temperature at the point $(x,y,z)$.and $ \vec ...