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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Luminosity and entropy of a relativistic shell

I am looking to understand more about gamma ray bursts. The review I am reading through describes in equations (111), (112) the luminosity of a relativistic plasma shell, in an inertial frame at rest ...
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25 views

Computing color and brightness of a hot material

Every blackbody color calculator I've managed to find only calculates hue and saturation; they completely ignore brightness, which severely limits their usefulness if you're trying to model the actual ...
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2answers
182 views

Does running water out of a faucet prevent the pipes from bursting? If so, why?

I have been told that, during especially cold periods during winter, one should run water out of the tap to ensure the pipes do not burst. Does this really help? If so, why? If true, at what ...
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2answers
107 views

Temperature of a Diamond in a Boiling Pot of Water

Suppose I have a boiling pot of water (100 degrees C) and drop a diamond in. Does the diamond eventually reach 100 degrees C? Since the diamond is a rigid structure, its molecules do not vibrate ...
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1answer
180 views

An object glows red at around 1000K while a red star is around 3000K. What causes this misalignment in spectra?

According to the H-R diagram, a red star is 3000K, a yellow star is 6000K and a white star 10000K. But a hot metal appears red at 1000K, yellow at 1500K and white at 2000K.(approximately) Why is ...
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91 views

What is the wavelength of a hot metal when its temperature 400 C? [closed]

I would like to know what will be the wavelength of a hot steel which temperature is 400 degree C
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1answer
92 views

Temperature dependence of spectra

I have a question that is short and sweet: Are spectra (both fluorescence and absorbance) of any molecule dependent on temperature? In particular, is the spectral lineshape function of any molecule ...
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2answers
47 views

The quickest way to reduce an isolated system's temperature

If you are in an isolated room, having an air conditioner and a ceiling fan. What is the quickest way to cool the room. Using only the air conditioner or both of them?
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1answer
117 views

Why doesn't water get 'increasingly thicker' as it gets colder?

It's my understanding that the colder liquids get (or anything else for that matter) the slower the constituting particles move. That being the case, why is H$_2$O either 'water' or 'ice'? Given that ...
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36 views

If an object's motion through space-time at speed $c$ corresponds to ageing, would cooling it down to slow ageing mean it doesn't move at $c$?

I get that all objects must move at the speed of light (c) in their reference frame because of the 2-part vector of space-time. For a case where the vector is pointing directly at time (because it is ...
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1answer
86 views

Can you blow bubbles on top of Mount Everest?

Can you blow bubbles on top of Mount Everest? How would they be different in low temperatures and pressures?
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61 views

What allows some objects to have a high specific heat capacity?

I know that temperature is a measure of thermal energy associated with the KE of molecules. But when heat enters an object, surely those molecules now start vibrating and translating, so this results ...
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1answer
224 views

How can I estimate the cooking time of a roast?

I never remember what worked before, or to write it down someplace. In any case the size and starting temperature will vary. The instructions I learned from refuse to give a time at all, and the ...
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1answer
22 views

estimate air temperature changes from changes in sea surface temperature

Consider a body of water, where the change in temperature for a given time period can be estimated by: $$ \frac{dTw}{dt} = \frac{Q_{net} \times A}{\rho \times C_{pw} \times V}$$ where $dt$ is the ...
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51 views

Holographic dual of pure-classical systems

There are classical systems (eg. see Sections VII and VIII of Kogut's review) that shares many of the properties of a pure-gauge SU(N) quantum theory including factorization and mass-gap, but with ...
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4answers
1k views

Temperature below absolute zero?

I saw this Nature article today, which cites e.g. arXiv:1211.0545. And it makes no sense to me. The temperature of a collection of particles is the average kinetic energy of those particles. Kinetic ...
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4answers
5k views

How is it possible that it can get hotter in the car than it is outside?

The Law of Thermodynamics says that two bodies will eventually have equal temperatures. How is it possible that when you leave your car in the sun, it gets hotter in the car than it is outside? Why ...
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2answers
123 views

Why can't liquid nitrogen be sealed in gas cylinders?

By observing the phase diagram of nitrogen, hydrogen and carbon dioxide, I discovered the supercritical region. I can easily buy a gas tank of carbon dioxide at 250 Bars. However I never saw any ...
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1answer
165 views

Is average kinetic energy equal to the total thermal energy of a gas?

"Average KE" as in this equation: $$K_{average} = \frac{3}{2} kT$$ Since potential energy in ideal gas model is eliminated, I guess this equation is also for the total thermal energy of a gas/a ...
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216 views

What is the most efficient way to use a blow torch?

Let's start with a torch and a piece of titanium. What is the fastest way to get the titanium up to red hot? Whenever I ask my science-y friends they like to point out that the bright blue tip is ...
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2answers
71 views

Why do people say “finite temperature” instead of “nonzero/positive temperature”? [duplicate]

This question is about terminology. The term "finite temperature" is often used to mean positive temperature, or equivalently finite inverse temperature $\beta = 1/T$. It seems to me that better ...
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4answers
4k views

What happens when I place an ice cube into boiling water

My friend tried this experiment at home: She put an ice cube into boiling water. The water in the container stops boiling while the ice melts to water. My question: Why does the water stop boiling ...
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3answers
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Why does humidity cause a feeling of hotness?

Imagine there are two rooms kept at the same temperature but with different humidity levels. A person is asked to stay in each room for 5 minutes. At the end of experiment if we ask them which room ...
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1answer
259 views

Explain Stefan-Boltzmann Law?

Can someone explain the Stefan-Boltzmann law in an easy-to-understand way?
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27 views

concerning the effects of temperature and density on the speed of sound [duplicate]

here is my relatively broad question: how does the temperature and density of a medium effect the speed at which sound travels through it? Now I shall elaborate: it is my understanding that there ...
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2answers
2k views

Will heating up an object increase its mass? [duplicate]

According to the $E=mc^2$ equation, will an object whose thermal energy (temperature) rises also weigh more? And by the same token, will the mass of an object decrease as its temperature approaches ...
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1answer
100 views

Temperature and Heat question [closed]

So I have a problem about calculating the specific heat of a metal. I'm using the philosophy "Heat gained = Heat lost". The problem is: When 50g of a metal at 280C is put into a calorimeter ...
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216 views

Negative resistance temperature coefficient of metals

How is it explainable that some metals have their electrical resistance increased while other metals act the other way? When the temperature of a metal rises the molecules move faster and from my ...
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6answers
322 views

Why it is colder in mountains, at high altitudes?

The conventional answer is to say that "lower temperature follows from lower pressure because temperature is average molecular energy (average speed)". For instance "Temperature is a measure of ...
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1answer
38 views

Mono-atomic gas particles coupled by spring forces don't care how many particles are involved?

I calculated the partition function of $N$ classical atoms of identical mass $m$ who all experience a mutual spring forces with identical spring constant $k$. The Hamilton is \begin{align} H = ...
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1answer
95 views

How to calculate relative humidity from specific humidity and temperature?

If I know specific humidity and temperature at a location, can I calculate relative humidity using these two?
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2answers
3k views

Temperature on the surface of the sun calculated with the Stefan-Boltzmann-rule

In a German Wikipedia page, the following calculation for the temperature on the surface of the Sun is made: $\sigma=5.67*10^{-8}\frac{W}{m^2K^4}$ (Stefan-Boltzmann constant) $S = 1367\frac{W}{m^2}$ ...
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40 views

Temperature modelling

I have to find a mathematical model for the temperature vs. time to study the temperature of the environment next to a lamp. This lamp is made off and on on, let's say, a daily basis The lamp is ...
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2answers
93 views

If temperature is dependent on mass, how did the early universe have a temperature?

I am near the end of the book The First Three Minutes by Steven Weinberg. I am reading it in order to get a better picture of the early universe in the Big Bang model. But one thing I am having ...
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1answer
79 views

Water enclosed in a vessel

Suppose I am taking water in a glass or metal or even something else. It s air tight and (so it is water tight). Now imagine, if I keep it heating and none of its molecule escapes from it, what am I ...
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1answer
164 views

How do we measure thermal energy?

My textbook says "The amount of thermal energy is found by measuring the temperature of the substance." However, how is this true? Temperature measures only the average kinetic energy of the particles ...
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0answers
17 views

Why do rotating devices make air colder? [duplicate]

I end up thinking this question frequently recent days. It seems an easy question but i cannot find the answer. You could say "faster the air, cooler it becomes" in that case i am expecting an ...
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4answers
2k views

Prove that negative absolute temperatures are actually hotter than positive absolute temperatures

Could someone provide me with a mathematical proof of why, a system with an absolute negative Kelvin temperature (such that of a spin system) is hotter than any system with a positive temperature (in ...
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1answer
100 views

Is temperature the speed of electrons?

Back in the middle school (which I guess was about 10 years ago) I remember being taught that the temperature of an atom is basically the speed of electrons circling the nucleus which kinda made sense ...
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2answers
4k views

Ice bath is always 3C, why?

I've always learned that a mixture of ice and water should reach equilibrium at approximately 0C. I've actually tried to create that a number of times in different contexts and always fail. First, ...
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2answers
2k views

A draft makes people feel cold. How can that be measured?

On some days our office feels very cold to the point at which we find it difficult to type because our hands have gone numb. But our facilities manager insists it is the same temperature as always. ...
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4answers
13k views

What is the effect of an increase in pressure on latent heat of vaporization?

What is latent heat of vaporization ($L_v$) in the first place? Wikipedia seems to indicate that it is the energy used in overcoming intermolecular interactions, without taking into account at all any ...
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How does liquid convert to gas on getting thermal heat energy?

Say for example, when we heat, water converts to steam gas. How does it happen? What happens underneath giving rise to breaking of bond between molecules in liquid state and spreading them in gas ...
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1answer
81 views

When to use Kelvin over Rankine and vice versa

Kelvin and Rankine are both used by scientists over Celsius and Fahrenheit to record heat, but are they both used interchangeably, dependant on the country or preference of an individual, or are there ...
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74 views

unchanged temperature of balloon inside freezer

I'd tried to put a balloon in the freezer and after enough time (several hours), I took it out and noticed that as I touch it that it's temperature did not drop down . I took an empty balloon ( not ...
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1answer
108 views

Calculating the Surface Temperature of the Sun with a Metallic Strip from the Surface of Earth

I am trying to calculate the surface temperature of the sun with a copper strip. I have a temperature sensor to calculate the temperature of the strip and that's it. Assuming the rate at which energy ...
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3answers
451 views

How is heat transferred to a thermometer?

Quick question. I can't seem to find a satisfactory answer online. How does a thermometer measure the average kinetic energy of atmospheric air? I assume that the energy is transferred by molecular ...
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1answer
105 views

Can electrons reflect light?

Lately, I have been watching sparks while connecting my electronic devices and I can notice that electricity is kind of blue, and theoretically it's blue because it reflects blue wavelengths?? And ...
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5answers
32k views

Does wrapping a wet paper towel around a glass bottle really speed up the cooling process?

There are claims like this one that you can improve the cooling speed of beverages when you put them wrapped in a wet paper towel inside the refrigerator/freezer. I've just tried it by myself and ...
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6answers
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Can UV light make us invisible?

For an object to create different EM waves, it needs to increase the temperature, so what if we or some material could be so hot, that it would emit ultraviolet light, and thanks to that be invisible ...