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)

0
votes
1answer
58 views

Compressed air in a volume: Can I determine its temperature?

Using a compressor, I augment the pressure in a volume (using atmospheric air). I only measure the pressure inside. I now that the density will increase however, the temperature decreases. Can any one ...
0
votes
1answer
120 views

Do ideal gases at zero Kelvin have potential energy?

Do ideal gases at zero Kelvin have potential energy?
2
votes
1answer
60 views

Details in the derivation of the second law starting from the phase space volume

I had a question on one of the details of the derivation of the second law of thermodynamics starting from the phase space volume. I'll type out what I understand so far: Letting the Hamiltonian ...
0
votes
1answer
42 views

What Material for reflective surface of a solar grill/barbecue? [closed]

I have been planning on building a solar grill for quite a time now, and the one problem, which is also the biggest - I need to shape a mirror into a paraboloid, so it bundles solar energy ...
2
votes
2answers
766 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?
3
votes
2answers
94 views

Temperature as frequency spectrum of stress-energy tensor?

I am currently learning general relativity, and in the textbooks that I am reading, temperature seems to be treated as a scalar field, extraneous to the geometry of spacetime. This is puzzling me, ...
7
votes
3answers
214 views

Temperature; Why A Fundamental Quantity?

Temperature is just an indication of the combined property of mass of the molecules and their random motion. We can explain no effective energy transfer between two conducting solid bodies in contact ...
0
votes
1answer
104 views

Earth's Temperature [closed]

I have a question regarding earth's temperature... How come the average temperature in the middle east (Israel, Saudi Arabia, Sudan or lower) is always so much significantly higher than in Europe ...
2
votes
1answer
99 views

if one electric heater makes the room 25 degrees, will two make 50?

The question in the title is of course childish and the answer is NO... But then how much if not 50 degree ? lets give some more data: we have a electric heater with NO temperature regulation and ...
1
vote
1answer
70 views

Thermodynamics, temperature below 0 Kelvin [duplicate]

I read a news article about how they were able to create a negative temperature, below absolute zero, and my question is how does this work? I know that there are different definitions of ...
0
votes
2answers
166 views

If quantum gas goes below 0K, is calling 0K absolute zero irrelevant?

Lord Kelvin defined the absolute temperature scale in the mid-1800s in such a way that nothing could be colder than absolute zero. Physicists later realized that the absolute temperature of a gas is ...
1
vote
1answer
49 views

Unheated intermediate room - positive or negative effect on flats temp. insulation?

This is a question I have heard quite some contrary opinions, so I want to ask it here, as it deals with physics in principle:) The question is basically that, if having a unheated intermediate (in ...
0
votes
1answer
76 views

Can Planck's temperature ever be reached?

Planck's temperature is theorized to be the highest possible temperature in the universe. But, has it been reached? Or, will any object or phenomenon ever reach this absolute temperature?
0
votes
3answers
72 views

Temperature of thermally isolated space region

If we thermally isolate a region in space, say using a hypothetical material of $0$ conductivity, and measure the region's temperature, will it be 2.7K?
-2
votes
1answer
28 views

What is the suitable temperature for a motor to work without failing? [closed]

How much body temperature can a motor withstand along with the ambient temperature to work without failing?
4
votes
1answer
165 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, ...
0
votes
0answers
32 views

Optimal temperature for Mpemba Effect

Is there an pptimal temperature for the Mpemba Effect? Is there an optimal initial water temperature for speedy freezing? If so, what is it? If a specific example is needed: There is a 100 milliliter ...
8
votes
3answers
503 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 ...
1
vote
1answer
65 views

What is the de Sitter temperature as of now?

It is claimed that de Sitter temperature is $$T=\frac{1}{2\pi}H,$$ where $H$ is the Hubble constant. I presume it is expressed in natural units with which I am not familiar. So what it will be in ...
0
votes
1answer
19 views

The common major difference in thermal conducting properties between a random rock sample and metal?

what are some common major differences in thermal conducting properties between a random rock sample(non-metal) and metal?
2
votes
1answer
114 views

Setting up an equation for calculating how long it takes a body to change temperature in its sorroundings

The United States has just recently been hit by a massive vortex of Arctic air. These unusually bitter temperatures have sparked my interests to ask the following rheotical question: How much time ...
6
votes
1answer
155 views

How would a physicist measure temperature of molten metals in 1850-1920s?

How would a physicist measure temperature of molten metals in 1850-1920s? What equipment would be used?
0
votes
2answers
3k views

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 ...
0
votes
1answer
69 views

Semiconductors: why the mass action law is not valid for very low temperatures?

I thought that it was valid for very low temperatures since for it to be valid I think that it is necessary to be in the non-degeneracy condition, which requires $E_G >> k_B T$ (with $E_G$ being ...
0
votes
0answers
30 views

What is highest temperature which is attainable? [duplicate]

We all know that there is a limit to the lowest temperature which can be achieved i.e. $0K$. But I wanted to know if there is a limit to the highest temperature which can be attained. And if there is ...
0
votes
1answer
96 views

is this heat calculation equation correct?

If I have a line of copper wire (lets say $\textrm{1 meter}$ long, $\textrm{1 mm}$ thick) and one end is a flattened disk of copper about the size of a quarter, and I apply a lot of heat to it (I'm ...
3
votes
2answers
120 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. ...
1
vote
1answer
38 views

Why would the environmental lapse rate be slower near the ground?

I have data taken from over 2300 ascents through the atmosphere at various locations around the world, for every 500 meters vertically upwards I have averaged the temperature and plotted it: Its ...
1
vote
1answer
142 views

How is NASA's mod II Stirling engine so powerful yet so small?

Is it because of the temperature difference? I just don't understand how it can propel a car. Here's the link to the engine: ...
0
votes
1answer
151 views

How effectively does heat flow through copper wire?

If I have a line of copper wire (lets say 1 meter long, 1mm thick) and one end is a flattened disk of copper about the size of a quarter, and I apply a lot of heat to it (I'm talking 800 Celsius) will ...
0
votes
1answer
81 views

How do Stirling engines work?

How do Stirling engines work? I understand the heating and cooling of air, but how much faster (or more force, I'm not sure which to use) does the piston move per degree Celsius that the temperatures ...
1
vote
1answer
35 views

Question about the refraction of Fresnel lenses

If you line up the suns rays parallel to a Fresnel lens, the light is concentrated, and the focus directly underneath. However, what happens if the sun is off to the side, making the light hit at an ...
22
votes
6answers
3k views

Is it possible to “cook” pasta at room temperature with low enough pressure?

It is known fact, that boiling point of water decreases by decreasing of pressure. So there is a pressure at which water boils at room temperature. Would it be possible to cook e.g. pasta at room ...
-5
votes
1answer
41 views

Does thermal energy change within a chamber depending on what's in it, where it is, what it is?

I have noticed that some people will say that, when you put more mass in an oven, it takes longer for both to cook than if just were one. Some others will say that timings are the same. Assume we ...
9
votes
1answer
629 views

Is temperature of a single molecule defined? [duplicate]

Is temperature of a single molecule defined? This question just cropped up in my mind as I have often heard of laws being violated when it comes to the scale of a single molecule. Does this happen in ...
35
votes
3answers
935 views

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 ...
7
votes
5answers
22k views

Which direction does air flow?

I remember learning this in high school, but have forgotten it, and can't seem to find it anywhere online. Air travels from areas of high pressure to low pressure...correct? So if I have a cold room ...
2
votes
2answers
558 views

Absolute zero and Heisenberg uncertainty principle

I got to read Feynman vol I and there was written that at absolute zero, molecular motion doesn't cease at all, because if so happens, we will be able to make precise determination of position and ...
4
votes
2answers
2k views

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, ...
3
votes
1answer
140 views

How can ambient cooling cool a system to below the ambient temperature?

How does sub-ambient cooling work? There are water cooling systems for computers that can cool components to below room temperature. The problem I see here is that the water is cooled using room ...
9
votes
1answer
205 views

How much does increased world population contribute to global warming?

In 1974 there where 4 billion people on earth. Now in 2013 we passed 7 billion people. So the world population is nearly doubled in 40 years. Every living human being also haves a body temperature of ...
1
vote
0answers
80 views

Second derivative of vapor pressure from a cubic equation of state

It is quite easy to compute the first derivative of vapor pressure with respect to temperature from a cubic equation of state at least at the critical point since there is a continuity with the ...
0
votes
0answers
37 views

Linearity of the critical isochore?

When looking at the pressure-temperature diagram along the critical isochore (up to quite high reduced temperatures) a very linear trend can be observed. From a theoretical point of view, is the ...
6
votes
3answers
190 views

If the universe is full of dark matter, why is it only 2.73 K cold?

people! I am just a physics layman, but I recently watched a documentary about the universe and it was told that the universe is full of dark matter and energy and the universe is empty, so that ...
2
votes
2answers
129 views

What is the logic behind the Fahrenheit scale?

The Fahrenheit scale is defined by fixed points on the scale. What interests me is the apparent arbitrary chosen numbers in these fix-points. First wikipedia wites from 32 to 212. -and later in the ...
1
vote
1answer
136 views

What is the temperature of a quantum particle in a box?

Some simple examples in textbooks include simple 1D systems such as particle in an infinite potential well or in harmonic oscillator potential. It is also said that at absolute temperature of the ...
5
votes
1answer
81 views

What is the name of the temperature limit beyond which an explosion will form a mushroom cloud?

Many months ago I saw a picture that was taken many years ago of an explosion, possibly in the Atlanta area. If I recall the explosion was caused by fuel in railroad cars. However, the explosion ...
0
votes
4answers
1k views

Temperature in CGS (Gaussian) units

I've been struggling with conversion from Gaussian to SI units for sometime, trying to figure out how derived units in CGS (current, charge etc) relate to the SI units. But I couldn't find any ...
2
votes
0answers
73 views

How Temperature, Pressure and Altitude are related in the atmosphere?

I'm looking for an approximation for the temperature of the atmosphere at any height and pressure. Both altitude and pressure are known variables, I've derived this equation using maxwell's ...
8
votes
4answers
376 views

Doesn't the use of a thermometer alter the temperature of the system?

If I place a mercury thermometer in hot water, heat energy will transfer from the water to the mercury inside the thermometer. Will this continue until thermal equilibrium is reached and thus the ...