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.

learn more… | top users | synonyms (1)

1
vote
1answer
132 views

Why is the logarithm of the number of all possible states of a system differentiable?

Temperature of a system is defined as $$\left( \frac{\partial \ln(\Omega)}{ \partial E} \right)_{N, X_i} = \frac{1}{kT}$$ Where $\Omega$ is the number of all accessible states (ways) for the system. $ ...
2
votes
2answers
102 views

Temperature of fusion in the Sun vs. fusion in controlled experiments on Earth

I recently learned that hydrogen fusion (i.e., hydrogen to helium) experiments on Earth have been successful at temperatures in excess of 100,000,000 degrees Celsius. However, I also learned that ...
3
votes
1answer
60 views

Temperature dependence of magnetic domains

Does the size of magnetic domains depend on temperature ? Not able to find any papers on this subject, maybe because there is no such dependence...
10
votes
5answers
1k views

How many fixed points does a Kelvin scale have?

I have a book that says: In the absolute Kelvin scale, the triple point of water is assigned the value of 273.16 K. The absolute zero is taken as the other fixed point. But, then another ...
1
vote
0answers
15 views

Is delta temperature dependent on the initial temperature? [closed]

All computer hardware testing sites i know test cooling solutions (CPU/GPU coolers) based on the temperature difference from the initial (room) temperature. This is a good way to compare, but i don't ...
1
vote
1answer
29 views

Finding total thermal conductivity (Ksys) for n-number of connected materials

I was playing around with the idea of finding a "total" K value for 2 solid, flush touching pieces of metal. The original problem involved the two touching inline bars with a two different maintained ...
3
votes
0answers
42 views

What is the spheroidal temperature of water?

I understand that when a hot plate reaches a certain temperature water will no longer wet the surface, but will form perfect spheres on the surface of the plate. The temperature at which this happens ...
5
votes
2answers
202 views

Can a black hole have negative temperature?

Stephen Hawking said that black hole also have temperature and it is related to its mass so in other words a black hole can also be shown to have a negative temperature! I know that nothing is colder ...
0
votes
0answers
10 views

Reactor opening and total time to reach a specific temperature

Let's say I have a reactor (we assume that its shape can be approximated by a horizontal cylinder) in which there is air at the temperature of 1000K and at pressure of 1.5 bar. Now, I want to open it ...
0
votes
0answers
28 views

Why does an optical pyrometer read low in the open?

An optical pyrometer relies on the fact that the brightness of heat radiation from a body depends on its temperature. I have come across the fact that an optical pyrometer invariably reads low when ...
0
votes
0answers
26 views

Expansion in bimetallic strip

Suppose there is a bimetallic strip with thickness 't' .The coefficient of linear expansion on heating the metals are alpha 1 and alpha 2.Now if the bimetallic strip is subjected to a temperature ...
1
vote
3answers
34 views

Hot Chocolate- cooling itself down

If a hot cup of hot chocolate is just standing there, can it cool itself down by transferring the kinetic/thermal energy that the liquid has into the mug/cup?
1
vote
1answer
21 views

Why are negative temperature coefficient thermistors accurate for measurements of low temperatures?

Why are negative temperature coefficient thermistors accurate for measurements of low temperatures? How does higher resistance at low temperature accurately measure the temperature?
4
votes
1answer
41 views

Estimate post-shock temperature of nuclear explosion

I was recently shown a very interesting sequence of images depicting the expansion of the fireball of Trinity explosion, a nuclear weapon's test conducted in New Mexico in 1945. I read here that ...
3
votes
1answer
57 views

Maximum Temperature?

I have been reading a lot about wavelengths of light and Planck's law and such. Curious as to whether a minimum wavelength of $h$ (Planck's Constant) indicates that there is in some way an absolute ...
1
vote
0answers
41 views

First law of thermodynamics with additional term

I read in a paper that a "known expression for the heat received by a body" is $$dQ=dU+pdV-\mathbf{v}\cdot d\mathbf{P}$$ where $\mathbf{P}$ is the linear momentum of the body, $p$ is the pressure, ...
1
vote
1answer
52 views

How to calculate max temperature craft needs to withstand near the Sun

The Solar Probe Plus fact-sheet states that the craft will approach to the distance of 9 solar radii to the surface of the Sun (Approx 6.26e6 km) and its heat shields must withstand 1644K of heat. I ...
-1
votes
1answer
45 views

Managing nuclear waste [closed]

Suppose you are trying to dispose of used uranium fuel rods. Once they are cooled and contained in zirconium pods, how would one try and send those pods to the earths core? This is all hypothetical. ...
1
vote
1answer
25 views

Compute affect of a shower on density altitude

As a pilot I have a basic understanding of density altitude, how temperature affects the effective air pressure: I noticed recently that I have difficulty breathing when I take a shower in Santa ...
0
votes
1answer
32 views

Infrared light and heat

I know that mid wave IR, long wave IR, and far IR are all infrared light that we feel as heat. Often, even when it is cold and windy, if I face the sun in a sunny spot it feels like it is 80 degrees F ...
1
vote
0answers
15 views

Cooldown of a 1 meter wide sphere of water at 10C° in space [closed]

I am wondering how long would it take for such a sphere of water to totally be under 0C°. Let's suppose that the surface tension is enough to keep the topology of the sphere intact an that it will ...
1
vote
1answer
350 views

If I mix 1 unit of water at at 30C° with 1 unit of water at 60C°, is the resulting water at 45C°? [closed]

I'm curious how temperatures work when mixing water. I'm not very good at physics but I'm always learning. Let's say I've 1 gallon of water at 30C° and 1 gallon of water at 60C°, and I mix them ...
1
vote
0answers
50 views

The effect of 8 hours 20 degrees C sunshine on the temperature of a stationary car's engine block? [closed]

What temperature of the engine block could be achieved by parking a car (Mazda 3) in full sunlight and facing south all day. Average day temperature 20 degrees Celsius no wind. And then how long to ...
1
vote
0answers
12 views

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 ...
3
votes
3answers
61 views

How do we know that the rate at which a body loses heat is proportional to the difference between its temperature and that of its environment?

Did someone do an experiment, or was that fact derived from other ideas we had about how the world works?
20
votes
5answers
2k views

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 ...
0
votes
2answers
36 views

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 ...
0
votes
1answer
24 views

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 ...
-2
votes
1answer
92 views

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?
0
votes
1answer
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?
0
votes
1answer
38 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 ...
1
vote
1answer
30 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 ...
0
votes
1answer
64 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 ...
1
vote
1answer
50 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 ...
1
vote
0answers
34 views

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 ...
2
votes
8answers
107 views

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 ...
2
votes
1answer
80 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?
0
votes
2answers
118 views

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 ...
1
vote
3answers
97 views

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 ...
2
votes
1answer
38 views

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 ...
2
votes
2answers
92 views

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 ...
1
vote
1answer
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 ...
0
votes
1answer
46 views

Are atoms more attracted to each other when you raise or lower the the temperature? [closed]

Are atoms more attracted to each other when you raise or lower the temperature?
0
votes
2answers
65 views

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 ...
0
votes
0answers
25 views

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 ...
1
vote
1answer
99 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 ...
0
votes
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 ...
0
votes
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 ...
1
vote
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)
-2
votes
1answer
61 views

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 ...