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)

4
votes
3answers
535 views

Room temperature and fan orientation [duplicate]

So I'm in a tiny dorm room and I normally point my fan blowing outside the window to cool my room off. I've been in some debates on blowing air out or in is more effective, so I'm hoping to get some ...
1
vote
1answer
577 views

Does increasing the density of a solution decrease the rate of temperature change?

I did an experiment to compare whether salt water (5% concentration of salt) or fresh water of the same volume took longer to heat up to a certain temperature. We found that salt water took longer to ...
0
votes
1answer
202 views

Predict final temperature by taking temperature samples?

Is it possible to predict what the final temperature will be by taking temperature samples. For example, an object is 0ºC and moved to a room above 0ºC. I'm taking temperature of the object using a ...
0
votes
3answers
1k views

Is rate of temperature change constant?

Is the rate of change in temperature for an object constant? For example, from 0ºC to 25ºC, or from 25ºC to -10ºC? Does it take the same amount of time to increase temperature from 1º to 2º as 24º to ...
4
votes
2answers
464 views

Ideal gas concentration under temperature gradient

I'm trying to calculate the concentration of an ideal gas in an adiabatic container as a function of position where the top and bottom plates of the container are fixed at temperatures $T_1$ and ...
10
votes
3answers
6k views

Does sound propagate further in freezing weather?

A few days ago I went for a walk in the evening. We're having winter with a little snow and freezing temperatures. We're in a quiet, shallow valley with a train station about 1km from us. I heard a ...
2
votes
3answers
260 views

Temperature in space

Temperature is a measure of kinetic energy transferred to particles, henceforth, space being vacuum, temperature cannot be measured. But then, there is cosmic background radiation. It is the leftover ...
3
votes
1answer
304 views

Does electric potential have a temperature?

When I took my first thermo class a tucked away chapter introduced Exergy in terms of electrical energy, meaning that the amount of electrical energy you could get from something is functionally its ...
3
votes
2answers
993 views

With ideal gases, varying quantity of moles, and having a constant volume how do temperature and pressure behave?

I'm trying to build a simulation of gases so I ended-up trying to use law of ideal gases ($PV = nRT$). In my scenario: volume is constant ($V=1\rm{m}^3$); a known quantity of moles are being added ...
3
votes
1answer
315 views

Why aren't two systems in thermal equilibrium the same as one system?

I am reading Molecular Driving Forces, 2nd ed., by Dill & Bromberg. On page 53, example 3.9, we consider why energy exchanges between two systems from the point of view of the 2nd law. We ...
0
votes
1answer
553 views

How to simulate temperature change of oven?

I am trying to write a software, which will model the oven temperature change when turning on/off. The data I can get is graph, by taking temperature reading each second from T0 time up to some ...
2
votes
0answers
73 views

How can I read density fluctuation from microwaves?

The Cosmic Microwave Background Radiation shows temperature differences. The red and yellow areas are warmer. The green and blue areas are cooler. For example consider this picture of CMBR ...
1
vote
2answers
202 views

How to get “real-time” temperature from sensor?

The following is LM35 Thermal response time in air The following is temperature reading from LM35 sensor. Horizontal axis is time in sec. So this is not "real-time" temperature graph. The ...
2
votes
3answers
615 views

Less than absolute zero possible? [duplicate]

Possible Duplicate: Temperature below absolute zero? According to this article http://www.sciencemag.org/content/339/6115/52 (preprint: http://arxiv.org/abs/1211.0545) it is. What do you ...
15
votes
3answers
542 views

Could temperature have been defined as $-\partial S/\partial U$?

When coming up with a definition of temperature, it's typical to start with an empirical definition that a system with a hotter temperature tends to lose heat to a system with a colder temperature. ...
4
votes
1answer
483 views

How can gas from compressed air can “take” heat from surrounding environment?

I have recently been reading about why a can of compressed air gets cold when the air it contains is discharged. From what I understand the change from a liquid to a gas requires energy and therefore ...
11
votes
3answers
909 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 ...
2
votes
2answers
2k views

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 ...
0
votes
1answer
120 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?
3
votes
1answer
2k views

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 ...
1
vote
1answer
367 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. ...
2
votes
2answers
2k 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
617 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 ...
4
votes
0answers
69 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?
4
votes
2answers
799 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 ...
0
votes
0answers
32 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 ...
1
vote
1answer
153 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 ...
0
votes
2answers
2k views

What is Curie-Weiss temperature?

What is Curie-Weiss temperature? What is the difference between Curie-Weiss temperature and Curie temperature?
5
votes
2answers
1k 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" ...
1
vote
2answers
261 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 ...
3
votes
1answer
671 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 ...
4
votes
4answers
423 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. ...
5
votes
1answer
174 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 ...
4
votes
4answers
441 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, $\beta\propto T$?
0
votes
3answers
588 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?
10
votes
6answers
15k views

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 ...
4
votes
3answers
268 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 ...
0
votes
2answers
409 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 ...
5
votes
2answers
154 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 ...
6
votes
1answer
2k views

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 ...
11
votes
5answers
15k views

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 sea level, temperature starts decreasing. Why is it?
5
votes
1answer
437 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 ...
3
votes
1answer
496 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 ...
1
vote
0answers
137 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 ...
3
votes
2answers
2k views

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 $T_C > 0$, ...
1
vote
2answers
102 views

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, ...
11
votes
3answers
5k views

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 ...
0
votes
2answers
5k 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 ...
5
votes
1answer
302 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 ...
1
vote
2answers
625 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 ...