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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How does a vacuum oven work?

I am doing some research on vacuum oven, but I cannot find out any website/book to tell me the theory. To my knowledge, it works better than regular oven. However, I have no idea why it is. Please ...
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91 views

Freeze and “break apart” an object. How?

Is it possible to freeze an object, say an apple, and then drop it so that is will break apart into pieces? And if so, how can it be achieved?
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Why does the monitor make a cracking noise?

After switching off the monitor, there's a single crack after a while. I wonder where exactly it comes from. I know that this is normal and not an indicator of being defect. This sound is also not ...
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1answer
333 views

How much energy Maxwell's demon will earn?

Suppose we have one mole of one-atom ideal gas at temperature $T$. Suppose Maxwell's daemon has separated molecules into two sections, one with speed below mean and another with speed above mean. ...
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901 views

Liquid with freezing point above 0 Celsius that could be use at ice rinks

Please help me with an answer to my dilemma: Is there a liquid that could be used to fill an ice rink (non-explosive, non-poisonous, etc), and have the freezing point above 0 Celsius?
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488 views

How to interpret Stefan-Boltzmann's law?

The Stefan-Boltzmann equation states $e=\sigma T^4$, but how do we interpret this? Is this completely wrong: A body of size $s^2$ generates the radiation/temperature $T^4$ for a given size and a ...
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0answers
57 views

Maximum temperature that can be achieved [duplicate]

Possible Duplicate: Why is there no absolute maximum temperature? Is there any upper limit of the temperature that can be achieved? Is the speed of light a kind of barrier?
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2answers
483 views

Is the proper interpretation of temperature missing in this book?

In Randall T. Knight’s textbook “Physics for Scientists and Engineers” in the first chapter on thermodynamics (Ch. 16: A Macroscopic Description of Matter) one of the first conceptual questions is ...
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29 views

Impurity scattering [duplicate]

Possible Duplicate: Impurity scattering temperature dependence Is there any temperature dependence of relaxation time in impurity scattering of conducting electrons? It seems to me that ...
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1answer
136 views

What are the optimal conditions to fuel your car?

I was filling my car earlier today, and noticed a sticker posted on the pump. This pump dispenses fuel at a volumetric amount measured in standard gallons (231 cubic inches). It does not adjust ...
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1k views

What is Curie-Weiss temperature?

What is Curie-Weiss temperature? What is the difference between Curie-Weiss temperature and Curie temperature?
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774 views

The analogy between temperature and imaginary time

There are many statements about the relation between time and temperature in statistical physics and quantum field theory, the basic idea is to interpret (inverse) temperature in statistics as "time" ...
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220 views

Activation energy and entropy

First assertion If a system is already in a high temperature, adding energy, will increment the entropy in a low amount (compared with a system in a lower temperature). Question (if assertion is ...
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485 views

Limit of Fermi-Dirac distribution as $T$ goes to zero

Hopefully this is a simple question, I just can't seem to get my mind around it. I'm to take the limit of the Fermi-Dirac distribution for $T \rightarrow 0$. In this limit the chemical potential is ...
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326 views

What is temperature?

Recently I read an interesting article about negative temperature. I was puzzled because I thought before that temperature has definite meaning in thermodynamics: it tells about how fast atoms jiggle. ...
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1answer
133 views

Which came first, movement or heat?

According to my measly understanding of the universe, when particles hit one another, some of their kinetic energy is transformed into heat. But when we heat particles (for instance, putting a bucket ...
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4answers
341 views

Why can $\beta$ not be linearly proportional to $T$, that is $\beta = constant \times T$?

$\beta$ in statistical mechanics is equal to $\frac{1}{k_BT}$ in in thermodynamics, but I do not understand why $\beta\propto T^{-1}$ instead of, say, $\beta\propto T$?
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278 views

Temperature and density

As temperature rise the density become lower,When temperature goes down, density is higher but in higher temperature the body become bigger so why density become lower?
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The difference between heat and temperature

So as I understand it, heat energy of an object is the SUM of all the kinetic energies of the molecules of the object (upto constant factor). The temperature on the other hand is the AVERAGE of the ...
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219 views

Temperature of a gas (assumptions about the particle speeds)

Temperature is related to average of particles kinetic energy. I would like to ask about a singular state of a particle system of a little time interval. The question is: If all particles were ...
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258 views

Temperature of a black-body in LEO on the dark side of the Earth

Questions about the temperature of something in space are often very hard to pin down (example), since there is radiative transfer to/from many different regions in the field of view at dramatically ...
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125 views

Why is the gas halo of the Milky Way so hot?

I have read on the webpage of NASA that there is a massive hot gas halo around our galaxy. Its temperature is between 100,000 and 1 million Kelvins or more. I do not understand why is it so hot. The ...
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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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Why less temperature at high altitude

Why there is always cold at high altitudes. e.g. at peak of mountains. Also as we go high from see level, temperature starts decreasing, so why is it.
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265 views

Ideal gas and diatomic gas with same temperature

If a box of ideal gas and another box of diatomic gas are in thermal equilibrium, does it mean that the average translational energy of ideal gas particle (A) is the same as that of diatomic gas ...
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386 views

Why there is no negative temperature [duplicate]

Possible Duplicate: Prove that negative absolute temperatures are actually hotter than positive absolute temperatures Proof of existence of lowest temperature $0 K$ On the Kelvin ...
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119 views

“This is not a perpetual motion machine, because reservoir temperatures are changing.” Is it a valid argument?

I've already faced this situation several times: given a statement (in area of thermodynamics) I used it to provide an example of some perpetual motion machine (of first or second kind). Therefore, I ...
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Does negative temperature in Carnot cycle yield a counterexample of the second law of thermodynamics?

By Carnot Theorem, the efficiency of Carnot cycle is$$\eta=1-\frac{T_C}{T_H}$$ where $T_C$,$T_H$ are the absolute temperature of the cold reservoir and hot reservoir respectively. Since $T_C > 0$, ...
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Statistical Weighting Factor on thermal neutron importance

The problem is concerning the use of a thermal fluxed squared weighting factor in a thermal reactor. I have seen in sources the thermal flux in a reactor is squared as a statistical weighting factor, ...
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273 + degree Celsius = Kelvin. Why 273?

Temperature conversion: 273 + degree Celsius = Kelvin Actually why is that 273? How does one come up with this? My teacher mentioned Gann's law (not sure if this is the one) but I couldn't find ...
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Ideal gas law, pressure increase and temperature

If I had a container, full with air, and I suddenly decreased the volume of the container, forcing the air into a smaller volume, will it be considered as compression, will it result in an increase in ...
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253 views

How do I measure the temperature of a tiny water droplet?

How do I accurately (+/- 0.1 degrees Celsius or better) measure the temperature of a small (5 to 50 microliter) water droplet without noticeably affecting its temperature? The mass of a thermistor or ...
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2answers
383 views

What happens when atoms speed up to extreme velocity?

The title might be misleading, but my question is in regard to what happens when we reach temperatures close to absolute zero (Kelvin). I've found different quotes as to what happens on the low end of ...
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How can I determine density of a gas only given temperature?

I have a homework problem where exhaust is traveling through an exhaust system (assumed to be air for simplicity) from and engine and then released into the atmosphere. The exhaust is at a temperature ...
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177 views

Heat Equation Equalities

While studying the heat equation, I ran into a few equalities that I cannot understand. For example, Fourier's law of heat conduction claims that $$\varphi(x,t)=-K_0\frac{\partial u}{\partial x},$$ ...
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Where does the heat flow in the Earth's crust switch from primarily solar to geothermal?

Ok, maybe more of a geology question than physics, but maybe somebody has been involved in modeling these heat flows? Essentially I'm asking if we know what sort of depth the heat source becomes ...
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257 views

Dependance of temperature on color of metals

I asked this question because I supposedly did last year, Stanfor Klein which belongs to the Solar Energy Laboratory of the University of Wisconsin says that "the color of a car does not affect its ...
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1answer
157 views

How do the energy eigenvalues of rotational degrees of freedom in statistical mechanics come about?

I want to understand the hierarchy different degrees of freedom of a mechanical system. Specifically, I want to understand which subsystems equibrilate faster and why. This question comes up: Why ...
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Is temperature an extensive property, like density?

I was thinking about it some time ago, and now that I've discovered this site I would like to ask it here because I couldn't work it out then. I know that the higher temperature the air in my room ...
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How do Temperature Scales work?

How exactly do temperature scales work? If my understanding is correct, the Celsius scale has two fixed points: (definitions of temperature irrespective of scale) 1. The freezing point of pure water ...
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1answer
649 views

How to calculate Temperature Humidity Wind Index?

I would like to know how to calculate Temperature Humidity Wind Index (THW Index)? I know how to calculate Heat Index and Wind Chill. I am asking this because my weather station Davis Vantage Pro2 ...
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7answers
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Is it theoretically possible to reach 0 kelvin?

I'm having a discussion with someone. I said that it is -even theoretically- impossible to reach 0K, because that would imply that all molecules in the substance would stand perfectly still. He said ...
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3answers
960 views

Units of Distance, Pressure, and Temperature [closed]

I need to store data. I'd like to store them in Metric units and use a tool to convert them to and from other units that these data points will be displayed in. As the title states, my constraints ...
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1answer
132 views

Is it possible to use a powder-based firearm in space?

A firearm relies upon some kind of explosive powder to drive the slug out of the barrel. My guess however is that in space (at GEO, or higher) a firearm would be unusable due to the extremes of ...
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1answer
175 views

Temperature and latent heat

Building a bronze stature we make a mold and pour in the liquid bronze when the bronze hardens we remove the mold. The mold is made of 3 Kg of steel and the statue has a mas of 1 Kg. The specific ...
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Why I will feel colder when I get out from a swimming pool? [duplicate]

A friend of mine told me that because water heat capacity is higher. He also mentioned that it was similar to alcohol on skin effect. Assume that there are 3 situations. 1. I did not get wet 2. I got ...
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Why is the temperature outside the airplane lower than the ground temperature?

seems the airplane is nearer to the sun, so the sun should more directly shine on the plane. But when I travel, the airplane temperature is much lower than the ground. Why is the temperature so low?
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Using resistance and temperature coefficient formula

What is the correct way to use the resistance and temperature correlation formula from http://hyperphysics.phy-astr.gsu.edu/hbase/electric/restmp.html? In particular, does R have to be the higher ...
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506 views

How to liquefy Hydrogen?

I have got a science project and my teacher has recommended me to do "Liquefying Hydrogen". I have been continuously thinking about that but I have not come to a solution. Can anyone please tell me ...
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Do you pay more for gas when the day is warmer?

Found this at the gas station yesteday - got me thinking...