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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What temperature is achieved in focus point by 5000 flat 1x1cm mirrors onto a satellite dish?

There is this video ("R5800 Solar Death Ray") where teenager built a 5,800 mirror device which concetrates the solar rays which is showing the potency of the mosaic method of concentrating sunlight ...
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21 views

Thermal conductivity in gases

I've been musing about thermal conductivity and came upon the following question. Heat is transported through matter by molecules passing their kinetic energy onto other molecules, or simply by the ...
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1answer
34 views

Why do tires need to be inflated when the temperature changes?

Why do you need to add air to your tires when the temperature drops? The temperature inside and outside of the tire is the same (let's assume that you aren't currently driving, and your car has been ...
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23 views

Limit Of Temperature [duplicate]

The last couple of days i have been thinking about temperature and heat and i thought : What happens to temperature if i continually supply a particle with energy? Then i thought at sometime i ...
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2answers
27 views

Is the temperature rise caused by reflection of sunlight linear?

I have saw a YouTube video showing large Fresnel lens can focus sunlight into a spot which can melt iron. I am very interesting of that, but large Fresnel lens are not that popular, so I was ...
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0answers
14 views

Calculating entropy [duplicate]

Suppose 30 gram of metal Gallium melts at 36 °C. The specific heat of fusion is 80.3 kJ/kg and the melting temperature is 29.9 °C. Explain if the melting of the Gallium in this process is ...
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Why does filling a compressed air cylinder produces heat?

And the opposite follow-up question: why does opening the air cylinder makes the air cooler? What I know is that I can't find these answers using the ideal gas law, because that is an equation of ...
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0answers
20 views

Gay-Lussac's Experiment with an Unmixed Gas [duplicate]

I would like to know the temperature and corresponding pressure of one unmixed gas (such as nitrogen) when its container's volume is held constant. It is very likely that this experiment has already ...
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0answers
26 views

Temperature and Pressure results for any Gas

I'm looking for data (experimental results) for the pressure and temperature of any gas (such as oxygen or nitrogen) in a contained volume. I would also like to know the surface area of the container. ...
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2answers
37 views

Does measuring the air temperature near a 21 lane asphalt highway impact measurements?

The official temperature in Sydney is measured at the Sydney Observatory. This is located near the city side of the Sydney Harbour Bridge - which is a major highway. My question is Does ...
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1answer
140 views

Can an electron stand in place of proton like a ghost standing in place of you?

The atomic orbital refers to the physical region where the electron can be calculated to be present, as defined by the particular mathematical form of the orbital 1. The picture below shows the $1s$ ...
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Hysteresis in liquid–solid-phase transitions such as Agar

I'm wondering how it is possible for a substance to have a significantly different melting point than its freezing point. What physical interaction "locks" a substance such as Agar into the phase that ...
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0answers
165 views

What is the minimum volume in which, for a given temperature difference $\Delta T$, natural convection would occur?

I'm trying to figure out if convection will occur in a plastic bottle slice and what length of slice would be optimal to achieve high R value transparent insulation on the cheap. The bottle slice is ...
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1answer
44 views

Would an ideal gas be colder at higher altitude due to gravity?

Since gas molecules are affected by gravity, wouldn't that make gas molecules at higher than average elevation slower (at the top of their ballistic parabola) and thus colder than air molecules ...
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1answer
57 views

AdS/CFT dual of $N$ D$p$-branes at finite temperature

The gravity dual of $N$ D$p$-branes at zero temperature is $$ ds^2= H^{-1/2}(r)(-dt^2+dx_p^2) + H^{1/2}(r)(dr^2 + r^2d\Omega_{8-p}^2) $$ with $$ H(r) = 1 + \left(\frac{R}{r}\right)^{7-p} $$ what ...
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35 views

Temperature dependence for specific thermal diffusivity in the diffusion formula

I recently found this answer about the diffusion equation (nice one actually), but have one doubt about the temperature dependence of this formula. If the "packet" of energy (terminology suggested ...
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1answer
33 views

Dry adiabatic lifting

If an unsaturated air parcel ascends adiabatically in the atmosphere with an initial temperature, would the final temperature of the air parcel, when it reaches it's destination, be the same at the ...
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1answer
65 views

If hot air expands in all directions why is the balloon moving up?

A balloon is moving up. The hot air inside the balloon is expanding in all directions and cold air outside the balloon acts with force on the balloon from all directions (higher pressure force). Why ...
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2answers
39 views

Why is it that in a warm shower water feels hotter near the head?

When the water first hits your body, it feels warmer than when it streams down towards your feet. I realize that part of this is due to the water cooling down by dissipation to the surrounding as it ...
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2answers
55 views

How does the temperature in a bucket of water with ice change over time?

I'm curious what happens to the temperature of the water in a bucket of water with ice in it. Let's start with a bucket with just ice in it, and we add water, in a room which is room temperature. It ...
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4answers
140 views

What happens when I place an ice cube into boiling water

My friend tried this experiment at home: She put an ice cube into boiling water. The water in the container stops boiling while the ice melts to water. My question: Why does the water stop boiling ...
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0answers
27 views

Simple gas in cylinder modeling

I want to do a simple (physically plausible but not physically accurate) simulation of a gas in a cylinder as it works on or is worked on by a piston. Wikipedia gives a good example of an adiabatic ...
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1answer
34 views

How does the physical motion of atom lead to photon emission?

It's known that what we call a temperature is in fact molecular motion at microscopic scale. But at which point the emission of photons happens due to this physical motion, so that we can talk about ...
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42 views

What is the refractive index of air at high temperatures (> 200 °C)

Is there a method/formula to calculate the refractive index of air at high temperature (e.g. 400 °C - 800 °C)? I could only find formulas specified up to 100 °C and our physicist at university ...
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2answers
57 views

How hot particles can get [duplicate]

One way in which an object is affected by temperature rise is that the wavelength of the radiation it emits is gets smaller and smaller. Another way of looking at it is that as an object gets hotter, ...
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1answer
63 views

(Why) is dumping liquid nitrogen on your head dangerous?

A chemist who dumped liquid nitrogen on his head described the act as very dangerous; yet, at the same time, he mentioned that the Leidenfrost effect would protect him from the dangers of this act. ...
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81 views

Is the coldest place in the universe likely to be artificial or natural?

The Boomerang Nebula is often cited as one of the coldest natural places in the universe at 1 K, but that's about 10 orders of magnitude off from what's been created in a lab. Are there theoretical ...
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2answers
44 views

Inside vs outside humidity

I have a practical problem that I want to reduce the humidity inside our house. I know the inside and outside temperature (degrees C) and the relative humidity (both inside and outside). How do I ...
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3answers
4k views

How can interstellar space have a temperature of 2-3K?

Several different sources online state that the average temperature of interstellar space (or the universe in general) is around 2-3K. I learned that temperature is basically the wiggling of matter, ...
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33 views

Showing the thermal expansion coefficient is the sum of the linear expansion coefficients

Given that the thermal expansion coefficient is defined as: $$ \beta=\frac{\frac{\Delta V}{V}}{\Delta T} $$ and the linear thermal expansion coefficient is defined as: $$ \alpha = \frac{\frac{\Delta ...
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35 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, ...
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10answers
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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, ...
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1answer
128 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 ...
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1answer
54 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 ...
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130 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 ...
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44 views

Thermometer reading

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?
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69 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?
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41 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 ...
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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 ...
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3answers
103 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 ...
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67 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 ...
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74 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 ...
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1answer
58 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 ...
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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, ...
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3answers
253 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 ...
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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?
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1answer
35 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 ...
5
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2answers
74 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 ...
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3answers
804 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 ...
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139 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 ...