# Tag Info

## New answers tagged temperature

2

The uncertainty principle is a fundamental property of quantum systems, and is not a statement about observational success. No particle either free or in crystal can have zero momentum otherwise a nonsensical infinity is required for the standard deviation of position $\Delta x$, in the uncertainty principle $\Delta x \Delta p \geq \hbar / 2$. $0 \cdot ... 0 As far as I know, your AC is kicking in automatically when you select defogger, so the system is cooling the air just as if you were using your air-conditioner though the vents. 4 Assuming the cooling system is just a radiator, water and a pump then you can't cool the fluid below the ambient temperature of the radiator. A refrigerator manages this by compressing the fluid in the cooling circuit, extracting the excess heat and then expanding it to make it colder. If your system uses a phase change, a compressible fluid or a peltier ... 9 Your question seems to be about human body heat rather than other human activities that contribute to global warming. Humans body heat doesn't actually add any energy to the whole-Earth system (see below) but for a moment, I will assume that it does. Instead of looking at the mean temperature of humans, it's easier to look at the amount of energy our ... 1 Light itself has temperature. If you let it fall upon a cold black body long enough, the body would warm up to that temperature and emit light of that temperature itself. What's the temperature of sunlight on the earth? About 5000K. It's the temperature that the surface of the sun had about 8 minutes ago. The sun could have extinguished 8 minutes ago, but ... 3 The temperature 2.73 K is not calculated, it is measured. The cosmic microwave background (CMB) has the properties of a blackbody radiation at the temperature 2.73 K. It is based just on the measurement of CMB, no calculation of dark matter or dark energy is involved. Temperature does not simply depend on mass or gravity. Temperature is a quantity which in ... 1 Mass in and of itself will not generate heat. Heat comes about when two objects interact with each other i.e. when they change from one state with a given energy to another. More specifically, if an object has more energy after an event than it did before, the net gain in heat would be negative for the surroundings (the environment becomes colder), and vice ... 0 The law of mass actions says that in steady-state or equilibrium the product for electron concentration$n$and hole concentration$p$is a constant at all locations in a semiconductor, $$np=n_i^2$$ It's true that the intrinsic carrier concentration$n_i$is a function of temperature but the law does not break down as this would break charge neutrally. ... 2 According to the same Wikipedia article you cite, ...the zero point is determined by placing the thermometer in brine: he used a mixture of ice, water, and ammonium chloride, a salt, at a 1:1:1 ratio. This is a frigorific mixture which stabilizes its temperature automatically: that stable temperature was defined as 0 °F (−17.78 °C). The second point, at ... 1 The story is this, as much as I remember. Fahrenheit chose the zero point on his scale as the temperature of a bath of ice melting in a solution of common table salt (a routine 18th century way of getting a low temperature). He set$32^{\circ}$as the temperature of ice melting in water. For a reproducible high point on the scale he chose the temperature of ... 4 Let a quantum system with Hilbert space$\mathcal H$and hamiltonian$H$be given. If the system is in equilibrium with a heat bath at temperature$T$, then the system is in a so-called mixed state and is modeled by a linear operator on$\mathcal H$instead of as a vector in$\mathcal H$. This operator is called the density matrix (or density operator). ... 0 The confusion arises because there are two kinds of classical limits, depending of the system under study. Let's start with fermions, which distribution is$n_F(\epsilon)=\frac{1}{e^{(\epsilon-\mu)/T}+1}$. The first classical limit (corresponding to the case mentioned in the question) is$T\gg \epsilon-\mu\$. This corresponds to the case where the ...

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The introductory paragraph you quote with horror says temperature ''high enough'' to avoid quantum effects. (It did not say anything like ''arbitrarily large''.) If the temperature is too low, things like Bose--Einstein condensation can occur, which invalidate Maxwell--Boltzmann statistics. The temperature should be high enough so that it is unlikely to ...

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Before looking for the critical parameters, let's review how mushroom clouds work. A large amount of energy is released at the source of the explosion, effectively a point source for our discussions. That large energy release causes a blast wave that propagates outward and leaves behind a core of very hot, high density gas. If the blast wave was strong, the ...

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both M.k.S. and C.G.s. unit of temp. are kelvin as well as time has a same unit that is Sec.

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The answer is that a decrease in temperature does decrease the mass, though in most cases that change is exceedingly small. Temperature is a macroscopic phenomenon, so you can't really talk about the temperature of a single string or an atom. However consider the following analogy: If you have an isolated string (or atom) in some excited state, then to ...

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Fahrenheit and Celsius scales begin at different arbitrary points, so there cannot be a simple ratio between the two. Imagine if we asked two identical twins how many years it's been since they reached the legal drinking age - one lives in the US, where the drinking age is 21, and the other in Germany where the drinking age is 18. At the age of 21, the ...

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