Tagged Questions

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.

96 views

Linear decrease in temperature during a redox reaction?

This is physics-related, don't worry. To calculate the enthalpy change of a solution during a redox reaction, what we did in class was measure the temperature of the solution every 30 seconds (before, ...
5k views

How do you add temperatures?

This will probably be considered very simple, but I am just a beginner: I'm developing a software application where temperatures need to be added and subtracted. Some temperatures are in Celsius, ...
2k views

Thermodynamics for Dummies: Entropy and temperature

I do not study physics and I have never had a course in thermodynamics. I have no idea what it is about, but I am currently taking a course where we had something about entropy. Would be great if ...
192 views

How long does it take plasma to radiate its heat?

Lets say we have 1 gram of plasma (Argon) at 1 million kelvin confined in a vacuum with electromagnets. If we keep the magnets on but shut down the device that heated the plasma, how long will it take ...
3k views

Zeroth Law of Thermodynamics, temperature, and ordering

In my thermodynamics course (and in other places on the internet) it is asserted that the Zeroth Law of Thermodynamics can be used to define the concept of temperature. One statement of the Zeroth ...
69 views

I quickly plunged a room-temperature thermometer into very hot water, the mercury level went down briefly before going up to a final reading. Why?
77 views

Are temperature increases discrete? [duplicate]

Are temperature increases ever discrete in nature, or is it a continuous variable? If a discrete case exists, is there any material that exhibits particularly strange behavior?
88 views

Capacitor-like-thing for controlling temperature of fluid?

I want to minimise the Gibbs' phenomenon like thing i.e. sudden peaks (temperature peaks here) in a container. Assume you have a cone where you want to block the transmittance of the temperature into ...
44 views

extreme heat to extreme cold (define the endstate)

Contemporary cosmology frequently has space temperatures just after the 'big bang' in the regions of millions of degrees and with inflation and expansion of the universe this is now down to a couple ...
711 views

Mixing mild and cold water, which one to pour first?

Suppose for example that a person like me likes his water in-between. A bit colder than the room temperature but not very cold. If you have a water dispenser that pours rtp water and cold water, which ...
420 views

Dimensionless entropy interpretation

Measuring temperature in joules instead in the artificial units of Kelvin would render entropy as a dimensionless quantity. This is quite appealing since entropy has always been quite a misterious ...
119 views

A physicists perspective on a material science/engineering problem

I am looking into some research that involves engineering and material science. As a physicists I wondered what other physicists would think of this problem and how they would approach it. Much of the ...
117 views

How is CMB related to the temperature of the universe

As I understand it, CMB (cosmic microwave background) is the radiation emitted when matter decoupled at the early stages of the big bang. The thing I don't understand is do all stars emit this kind of ...
243 views

Milk-First School

I have always been struck by the huge amount of different arguments about the issue: When you make a cup of tea, the milk should be poured first or added to the cup after the tea? Wikipedia, ...
6k views

Does extreme cold make **everything** extremely brittle?

First of all, I'm genuinely sorry if this question isn't "serious" enough for this forum! A common cliche in movies and tv is that a very tough object (eg the villain) is frozen, and then hit with ...
3k views

Relationship between temperature and energy

What is the definition of temperature in relation to energy? I'm mostly interested in general dimensional terms. Is temperature the kinetic energy per mass? Or kinetic energy per volume?
69 views

Modelling the fluidity of a fluid (grease) based on temperature

I am trying to create a statistical model of a lubrication system. A central grease pump takes grease from a tank and injects it into some cavities (via grease lines) until a pressure set-point is ...
126 views

What's the difference between energy and temperature in field theory?

I'm familiar with the formalisms for both zero temperature and finite temperature field theory, but (somewhat embarrassingly) I don't actually have a good physical intuition for when physical ...
1k views

Didn't we mess up with the temperature?

The following passage has been extracted from the book "The Feynman Lectures on Physics-Vol l": The mean kinetic energy is a property only of the "temperature." Being a property of the "...
2k views

Relations between pressure and temperature

I have several questions concerning thermodynamics and I order them in 4 points that may be related: What's the difference between heat and work at the atomic level? Isn't heat simply work between ...
169 views

For which temperatures are the ENDF cross-sections given?

In ENDF there are cross-sections given for different types of nuclear interactions. For example, this file gives the cross-sections for different neutron energies. However, it is not clear, which ...
3k views

How can a metal heated at 600° emit thermal photons at 4000°+?

Suppose we have a cube of metal inside a room at temperature 27°. If we heat the metal up to 600° using uniform radiation of that energy, no part of it should have higher T°, but nevertheless it will ...
66 views

minimum possible absolute temperature in the universe? [duplicate]

Sorry guys i went wrong in my previous question , actually my question is what is the minimum possible absolute temperature in the universe of what ever substance...?
65 views

Is It Possible To Have Temperature Below Absolute Scale? [duplicate]

Guys I have a doubt Is it possible to maintain the temperature of any Substance Below the Absolute Scale?
177 views

How to define the thermodynamic temperature

I've been reading derivations of the thermodynamic temperature scale. I'm assuming these are using Kelvin's method. I follow the math and the conclusion of the argument, but I don't understand how it ...
2k views

Temperature of a neutron star

In our everyday experience termperature is due to the motion of atoms, molecules, etc. A neutron star, where protons and electrons are fused together to form neutrons, is nothing but a huge nucleus ...
343 views

What does temperature look like at the subatomic level?

I am trying to get a better understanding of the definition of temperature at the subatomic level. I have a background in molecular biology with some college physics, but no deep quantum mechanics ...
226 views

Why doesn't water in water barometer boil?

I have read that the pressure in a water barometer at the top of the water column is around 0.5 psi and at such low pressures water should boil at around ~26°C (Room temperature). [1] [2] How ...
Does the Grashof number lead to the answer? The Wikipedia article (https://en.wikipedia.org/wiki/Grashof_number) yields an equation for vertical plates $$Gr_L = \frac{g\beta(T_s-T_\infty L^3)}{\nu^2}... 2answers 319 views Balloon gas temperature experiment in water In this problem set I have a passage that describes an experiment that looks at the changing temperature as an air filled balloon rises to the surface from the bottom of a water filled tank. The graph ... 1answer 255 views How does pressure influence temperature in liquids? Lets say we have a tank with a fixed mass of liquid at atmospheric pressure and room temperature. How do we influence the temperature when we exert pressure (e. g., with a piston) on the liquid? Are ... 2answers 407 views Practical (maybe naive) question on boiling water I put a glass bottle in a big pot, bottleneck up, I fill both pot and bottle with very hot water. The bottle is submerged except a few cm of the bottleneck and filled to the brim so some water ... 2answers 310 views What conditions do a bunch of atoms need to satisfy to have a temperature? What conditions do a bunch of atoms need to satisfy to have a temperature? Suppose that we have a beam of helium atoms travelling in a common straight line, equally spaced with the same velocity. If ... 4answers 5k views Do objects gain and lose heat at the same rate? For example, if I take an item out of the refrigerator, set it on the counter for a period of time, allow it to warm up a bit (but not so long that it reaches room temperature and stabilizes), and ... 1answer 194 views Does a cooler, submerged in water, keep beer colder, longer? Looking around the web, I see some submerged bucket-like things, without insulation, and some floating coolers, where the actual cooler is not submerged. Given that your water temperature is lower ... 2answers 217 views How hot is aurora? Has anyone done research on how hot aurora is? I mean if it is plasma it should be hot and since it is emitting mostly green light due to nitrogen (~78%) in the air, could it then be considered that ... 2answers 1k views When they say that the universe cooled after the big bang, where did the heat go? Layman here, Stumbling through some physics stack posts and started reading the Wikipedia for the chronology of the big bang. In it, it states The very earliest universe was so hot, or energetic, ... 0answers 276 views Copper mean free path dependence on temperature I'm doing simulations of copper, where the temperature can reach up to ~1300 K. Some calculations depend on the mean free path (MFP) of copper. The only value I've found for it is 39nm and it's ... 1answer 1k views The effect of A/C and global warming I had been thinking about the way an air conditioning system moves heat from one place to another. The unit runs and drops the temp. in the building and raises the temp. outside. Also there is ... 0answers 143 views Temperature of Bose-Einstein-Condensate in space Recently I heard a talk by Bill Phillips, who talked about the coldest temperatures in the universe. Among others, he sayed that the coldest temperatures created at the moment are BECs, which can ... 2answers 366 views Can we measure temperature of a object just by the sound it makes? I been thinking if temperature is a basic property of macroscopic objects rather than of quantum or microscopic objects and it is as a result of average kinetic energy of particles residing in the ... 4answers 852 views Existence of negative temperatures and the definition of entropy How negative temperatures can be possible has been treated on StackExchange before (several times in fact), but in light of some recent academic discussion, most of these answers seem to be possibly ... 3answers 737 views How is heat transferred to a thermometer? Quick question. I can't seem to find a satisfactory answer online. How does a thermometer measure the average kinetic energy of atmospheric air? I assume that the energy is transferred by molecular ... 2answers 1k views Will a tall narrow cup keep a cup coffee warmer than a more evenly dimensioned cup? I noticed a colleague had a tall narrow cup for his coffee, and it got me thinking about whether it would retain heat for longer or not. Assume two cups, both are cylindrical, and both hold the same ... 1answer 635 views What's the most fundamental definition of temperature? What's the most fundamental definition of temperature? Is it the definition concern about average energy, number of micro states, or what? By "fundamental", I mean "to be applied" in such general ... 8answers 7k views Will a blanket warm you if you are underwater? Suppose a man falls into very cold water and gets their foot stuck under a heavy rock. Fortunately, his head is above water and someone is able to call for help. The paramedics want to keep him warm ... 2answers 85 views Invariance of Temperature in Classical Physics How can we explain that Temperature is a classically frame-independent quantity to high school kids? 4answers 1k views Hot water freezing faster than cold water This question has puzzled me for a long time. There is already a question like this on Physics.SE. John's answer to the question seems quite satisfying. But when I googled the cause I found this and ... 1answer 124 views Why quantum spin liquid has negative Curie-Weiss temperature? In a table in wikipedia, the Curie-Weiss temperatures of quantum spin liquids are listed. Among them, the \Theta_{cw}(K) are less than zero. Why are they negative? Since temperature is defined as$$...
I was looking at at puddle when I thought that this puddle will evaporate tomorrow but then it occurred to me that the boiling temperature of water (aka to turn into gas) is $100$ degrees under 1 ...