# Tag Info

## Hot answers tagged temperature

6

Temperature is a measure for how much kinetic energy the molecules in a substance have. If the temperature is high, they are moving pretty fast, if the temperature is low, they are moving a lot slower. If molecules are moving slow, they bundle up and you get a solid. Once you heat it up a bit, the substance starts to become liquid. When you heat it up even ...

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Modern processors are built from CMOS technology. These digital circuits consume relatively little current when sitting in one state or the other. However, there is some inevitable capacitance on every node. When the output of a digital gate changes state, that capacitance is charged or discharged, which means current has to flow. The total average ...

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Just for completeness, when a gas expands its temperature does not necessarily change. The temperature of the gas only changes if it does work on something, for example its container as discussed in Danu's answer. If a gas is expanding into a vacuum it does no work and (to a first approximation) its temperature does not change. This type of expansion is ...

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If you want absolute temperatures, then the answer would be no. If you don't care about scales, but just numerical value, I'd say yes. The Celcius scale is a 'relative' scale, based on the freezing and boiling points of water, and the temperatures in $^oC$ do not have much meaning. Whatever they tell, they only tell it with respect to freezing and boiling ...

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The light that we see coming from the Sun is mainly due to black body radiation at its surface. The spectrum of black body radiation is statistical in origin, and as long as there are enough processes contributing to it the black body spectrum is independant of the microscopic details and depends only on the temperature. There is a discussion of this in the ...

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Imagine spinning a roulette wheel, but instead of dropping in one ball, you drop in 100. They all rattle around at different speeds, like the molecules in water. You can cool them down by spinning the wheel slower, so they bounce about less; heat them up by spinning faster so they bounce more; you can freeze them by stopping the wheel and waiting till ...

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Consider a gas in a container. When the container expands, the gas cools down. The crux is in thinking about why the container expands. The reason the container expands is because there are gas particles hitting the walls, pushing them outward: they do work on the walls! This work on the walls costs them some energy, so that they now have less kinetic ...

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George Goble won the 1996 Ig Nobel Prize in Chemistry by pouring liquid oxygen on a barbeque containing unlit charcoal briquettes and a smoldering cigarette. It did not put out the cigarette. It melted the barbeque. If he had soaked the briquettes in liquid oxygen first, it would have been the equivalent of lighting the barbeque with sticks of dynamite. ...

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Assuming the total heating power entering the system will be constant, the only factor to minimise is the wasted heat leaving by air convection and radiation. To minimise that, you want to keep the pot as cold as long as possible, because all such heat transfer mechanisms are vastly more efficient when the temperature difference (as well as absolute ...

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It may actually work, as evaporating liquids need heat to evaporate, and water will somewhat evaporate even in the fridge. I am not sure it works in practice, because the paper also causes an adverse effect, it provides insulation, Hard to tell which effect is dominant. I'm pretty sure that the balance of both effects depends in a very large part on the ...

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Yes - you can have a state where increasing the pressure would create a supercritical fluid See Phase Diagram

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See this explanation from here: Right at the heart of the Earth is a solid inner core, two thirds of the size of the Moon and composed primarily of iron. At a hellish 5,700°C, this iron is as hot as the Sun’s surface, but the crushing pressure caused by gravity prevents it from becoming liquid. Surrounding this is the outer core, a 2,000 km thick layer of ...

2

The boiling temperature of a liquid is not the temperature at which it can enter the gaseous state. Rather, it is the temperature at which the saturation vapor pressure $e_s$ is equal to ambient atmospheric pressure. This is why, for example, water boils at lower temperatures at higher altitudes. Furthermore, water is always evaporating. It is also ...

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Your description of the disturbance wrought on the system by the thermometer is sound. You may be able lessen the effect with a thermal diffusion model of the thermometer and by calculating what the system's temperature was before it brought the thermometer into equilibrium with itself, but for that approach to work, one must know the system's heat capacity ...

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The velocity distribution is related to the temperature by the Maxwell-Boltzmann distribution. You cannot find the disordered kinetic energy of each particle because they are randomly distributed, however you can use the Maxwell-Boltzmann distribution to calculate what that random distribution looks like.

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Basically, the egg-white (just another protein structure) is made of long chains of amino acids. They're held in shape by weak bonds. When you heat the structure, the energy you put in, is enough to break those bonds, thereby destroy the structure. This process has a name for it. Once the temperature is high enough, new covalent bonds can form between the ...

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The Verdet constant is a coefficient which sums up the magneto-optical properties of the medium. So, the temperature and wavelength dependence are wrapped up in it. Fundamentals of Photonics by B.E.A. Saleh expresses the Verdet constant in terms of the wavelength as $$V\simeq-\frac{\pi\gamma}{\lambda n}$$ where $\lambda$ is the wavelength of the light ...

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I believe the 'urban legend' you are referring to is about cooling a bottle when you do not have a refrigerator. On a hot and windy day you could store your bottle in the sunlight, but it would be better in the shade, but if you really wanted to cool the bottle by a few more degrees, the 'myth' says wrap it in wet paper or cloth. During the time when the ...

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At the boiling point the gas is produced inside the liquid, but at the surface you constantly have molecules going in and out. If the environment is kept quite dry, then few molecules will come back in with respect to the ones that leave. Off course the higher the temperature, the easier will be for a molecule to get enough energy to break free, but this can ...

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If you have forced heat flow by lets say an electric stove the temperature increases linearly with time and both ways should take the same time and also same energy (constant power, no heat losses on stove and pot assumed). If heat transfer is driven by temperature difference as with a gas stove ($T(t)= T_{15}+(T_{100}-T_{15})(1-e^{-\frac{k A }{m c_p}t})$, ...

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I think that you can state that it can not measure the temperature of a substance before it have been test but it can measure the temperature after it have come in equilibrium with the substance. For example, in an experiment that need to push a liquid to T temperature, what you do is heat up the liquid with the thermometer already inside. With this you ...

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You are absolutely right that the limit in which this approximation holds is $$\beta(\epsilon - \mu) \gg 1 \,,$$ which is not trivially the 'high-temperature limit', and indeed looks rather like the low temperature limit. However, it also looks like the limit of large negative $\mu$. If we want to know how temperature will affect the exponent, we need to ...

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