Questions tagged [temperature]

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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Manual jack up of Maxwell-Boltzmann scale parameter?

I first noticed this phenomenon when i was a child, about 4 decades ago. I needed a piece of wire but could not find a pair of pliers with which to cut the wire. So i used a technique i once saw my ...
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How much change in Earth's orbital distance to change average temperature by 1°C?

How much closer/farther would the Earth need to be to/from the Sun to effect a $1 \sideset{^{\circ}}{}{\mathrm{C}}$ increase/decrease in average temperature?
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Change of specific internal energy due to temperature and volume

The change of internal energy due to temperature and volume may be written as $$ dU=C_V dT + \left( T\left(\frac{\partial S}{\partial V}\right)_T-P\right) dV$$ where $$\left(\frac{\partial S}{\partial ...
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Renormalization group flow when temperature $T < T_C$, $T_C$ being critical point temperature

Does renormalization group flow have to decrease temperature when $T<T_C$, with $T_C$ being critical point temperature? I think not, but my professor suggests something like that. Maybe I ...
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Which emits more radiation - a warming blackbody or a cooling blackbody?

My intuition says a cooling blackbody would emit more radiation as any body that emits radiation is itself losing that energy, causing its internal temperature to decrease.
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Yi's Bell sound and how it relates to temperature?

Yi's Bell is an ancient chinese musical instrument that plays different sound frequencies when its heated than when its in room temperature. My question is Why does that happen? Why does higher body ...
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Mass-energy equivalence and heat capacity

From Wikipedia: Einstein's mass–energy equivalence states that anything having mass $m$ has an equivalent amount of energy and vice versa, with these fundamental quantities directly relating to one ...
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Is specific volume a function of temperature only (in liquids)?

As far as I know, you can take the equation $pv=RT$ (with $v$ being the specific volume) for ideal gases. But I had a question in a quiz asking about this, and the answer was "dependent on ...
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68 views

Why hot molecules have higher velocities

I'm looking for a something different than the "T is average KE, heat is energy, so adding heat increases the KE and therefore T" explanation. Let's call that the "thermo" side of the argument, which ...
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Does a hot object in space/vacuum gets cold? how? [duplicate]

I'm trying to understand QM and many stuff gets in conflict in my head. Black body radiation means a hot object produces light in certain frequencies. Meaning it's losing energy. Yet they talk about ...
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What exactly is temperature? [duplicate]

I'm trying to have a really deep understanding of quantum physics and so I went back to what is blackbody radiation until suddenly I realized that my understanding of temperature is that of... well, ...
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Does the critical dynamical exponent z of a 2D Ising model (simulated with Metropolis) vary with the temperature?

I have found in the literature that the critical dynamical exponent $z$ of an Ising model simulated with a local algorithm (such as Metropolis) is something around 2 near the critical temperature, ...
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Temperature distribution with advection problem

A very long pipe enters an oven at $x_1$, with oven temperature set to $T_{\infty}$. Fluid flows through the pipe at mass flow $\dot{m}$ (flow speed is $v$), initially at temperature $T_0$. Flowspeed ...
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Why don't you get burned by the wood benches in a sauna?

When you go to the sauna you may sit in a room with 90°C+. If it is a "commercial" sauna it will be on for the whole day. How does it come that when you sit on the wood you don't get burned? I ...
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Human perception of temperature

I had the following thought experiment recently: Suppose we have a vibrating plate for which we can tune the amplitude and frequency of vibration, and imagine we hold a finger against the plate. For ...
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Is there a difference between the red sky in the morning and in the evening?

It certainly has a different feeling to it, but does the temperature or earth's rotation or the clouds or anything else really make it two different physical phenomena or at least different colors? ...
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Why hot soup is tastier than cold soup? [closed]

My physics teacher recently asked me this question. Can anyone answer the question?
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How many temperatures has a plasma?

In nonthermal plasma, not all particles move in the same way. The electrons are different from other particles. Both can be described as having a temperature separately. But that would mean, one piece ...
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Temperature excursion energy on Mars [closed]

Could we use the high range of temperature excursion on Mars, for example applied on gases or liquids, to produce some usable energy? Let's assume that the day-night excursion is +20 Celsius (day) and ...
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Why is a liquid nitrogen canister not cold on the outside when inside the temp of the sealed liquid is -320F? [closed]

...or IS the inside temperature ambient temperature? Surely the insulation of the container is not sufficient to seal in that cold? I.e. if you had an unsealed bowl of liquid nitrogen with the same ...
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Is the triple point of water exactly 0.01 $\deg$C?

Is the triple point of water exactly $0.01 \deg$C, or is this an empirical value/is there some uncertainty to it? If so, how do we know it is exact, and why?
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How to calculate energy (KWh) from Temperature (T),Air quality (Co2), and illumination (lux)?

I have data of temperature, air quality, and illumination.I want to calculate energy consumption (KWh) from these parameters.My data is shown in the image . Also, examples are also shown in image 2 .
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Is there an influence of the air humidity on the air expansion by a temperature change?

I have found the following formula to calculate the expansion of air by a temperature change, if the pressure stays at the same level: ΔV = ​ɣ * V0 * ΔT This would give me an expansion of 46.96m3 in ...
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If the Sun had a larger surface temperature how would that affect its appearance to us in the sky?

I thought about this when I came across wiens displacement law which says the higher the temperature, the lower the peak wavelength. If the sun was a lot hotter, and its peak wavelength wasn't in the ...
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John Dalton's temperature scale? [closed]

Could some one give me a brief explanation of what Dalton's temperature scale is? I have tried to refer to understand this scale but there are not that much information out there in the internet. ...
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Temperatures of Galaxy Clusters

Recently I've read about clusters of galaxies and have tried to understand how one can measure their mass and temperatures. Clearly, we can physically measure a couple of things such as the flux of X-...
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Relation between Temperature and heat current

This problem: I was able to solve it doing this: But I think i have nowhere " exploited " the equivalence given above. How can this be used in this problem?
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What happens to a liquid nitrogen canister under pressure if left at room temperature? Will it eventually explode? Or forever stay cold?

If I put a strong, sealed container of liquid nitrogen on a table at room temperature, will it always stay cold? Or will it slowly heat up until the canister bursts? Assume it is an extremely strong ...
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What boundary conditions does a steady state initial temperature profile that evolves according to the heat flow equation obey?

A cylindrical rod of length $L$ is insulated over its curved surface. The end of the rod at $x = 0$ is in contact with a heat bath at temperature $\Theta_0$ and the end of the rod at $x = L$ is in ...
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Dependence of melting/boiling on external electric or magnetic fields

$H_2O$ is a rather strongly polarized molecule ($\epsilon_r\approx 80$) and it is also diamagnetic ($\chi_m \approx -9\cdot 10^{-6}$). My question is how does the melting or boiling $p-T$ curve ...
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Why does a dense, hot, opaque body produce blackbody radiation?

I read from a textbook that a dense, hot and opaque body produces black body radiation, for example the heated filament of an incandescent light bulb. Why is it so? The explanation given is if a ...
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Why is bringing two object to their initial temperature an irreversible process?

In the lectures, given in here, it is stated that We can imagine thermodynamic processes which conserve energy but which never occur in nature. For example, if we bring a hot object into ...
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Which one is better to boil water, using high heat or less heat?

Consider that I have a water boiling kettle as below. Assume that it is made of metal, not plastic (but plastic probably also will do). Assuming I can adjust the power it uses to boil the water with ...
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If I leave a glass of water out, why do only the surface molecules vaporize?

If I leave a glass of water out on the counter, some of the water turns into vapor. I've read that this is because the water molecules crash into each other like billiard balls and eventually some of ...
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Absolute Heat With Kinetic Energy

I’ve read some of the questions posted here about absolute hot. Planck’s temperature. I understand that that temp comes from the natural units. Where my question comes into play is when thinking ...
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Why is the change in resistance not directly proportional to the change in temperature?

Change of resistance with respect to temperature is defined as $$\frac{\mathrm{d}R}{R}=k\mathrm{d}T$$ where $k$ is a proportionality constant, $R$ the resistance, $T$ the temperature and $\mathrm{d}R$...
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Horizon Problem: How did different regions of space acquire different temperatures?

I'm trying to understand the Horizon Problem. Inflation describes how non-causally connected parts of the universe (that we see today) could once have been in causal contact. The reasoning goes that ...
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What is the closest distance for an undiscovered old neutron star and how long would it take to get here? To help people scared of neutron stars

This is to help people who are scared of neutron stars. My questions are What is the faintest a neutron star could be How close could it be and not yet be detected How long would it take to get here ...
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Stress in a rod clamped between two rigid walls when the temperature is increased

The usual approach to calculate stress is to equate thermal expansion in the unclamped condition to the magnitude of contraction caused by strain produced due to the walls. I have some questions about ...
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How do photons give atoms more heat energy?

this is a duplicate of this question but I came away not understanding the answer, even after reading the links. so my question is: how does light increase the heat energy of an atom? eg. if you ...
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what has the higher entropy: tap water or hot coffee?

I can't get this simple question out of my head. Does tap water have higher entropy since its temperature is almost in equilibrium with the surrounding? Or does hot coffee have higher entropy since ...
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Math notation for heating object

An object with mass $m$ and heat capacity $c_{p}$ is exposed to heating $P_{th} $[kW] and thermal losses $\dot q$ [kW/°C]. The energy equation illustrating the process of heating it from $T_{max}$ to $...
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How much does temperature affect the time of sunrise?

Please forgive me if this is a dumb question, or if my understanding of basic physics is wrong. Please feel free to correct me. As I understand it, if the Earth didn't have any atmosphere, then the ...
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Cooling photons to a solid state

Can we cool photons so the stop moving completely? So they can behave like particles in a solid.
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Bring energy into mixing hot and cold taps

Are you able to bring energy into your equation? I like to know if there is a way to calculate the required energy necessary to obtain a given temperature and flow at the outlet of the mixer when hot ...
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What does the area under the curve of a temperature-time graph represent?

I’m trying to calculate the total heat produced by a system over a period of time and I’ve gotten a regression line of y= log x to represent the best produced by the system. To calculate the total ...
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Understanding Ising Model in Statistical Mechanics

A section on the Ising model in the text "Introduction to modern statistical mechanics" by Chandler states the following: "We consider a system of $N$ spins arranged on a lattice. In the ...
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Magnetic Field Strength Measurement at Extreme Temperatures

I have just been given a project at work and we are magnetically stress testing DUTs at extreme temperatures going from -40 Degrees Celsius to 200 Degrees Celsius. I need to come up with a way that we ...
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Is there any change in temperature due to special relativity? [duplicate]

Say I am travelling in a spaceship very close to the speed of light. Would there be any change in temperature in the spaceship relative to outside the spaceship? Please explain in detail.
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Water mixture at different temperatures

Let's say that we mix homegeneously and instantly cold water at $t^\circ $ C and hot water at $T^\circ$ C (like in a water tap) in ratio $p:1$. My question is the following: What is the instant ...