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.
Questions tagged [temperature]
3625 questions
161
votes
7 answers
Is temperature a Lorentz invariant in relativity?
If an observer starts moving at relativistic speeds will he observe the temperature of objects to change as compared to their rest temperatures?
Suppose the rest temperature measured is $T$ and the observer starts moving with speed $v$. What will be…
Sahil Chadha
- 2,833
150
votes
10 answers
Why is my hand not burned by the air in an oven at 200 °C?
I have this problem from University Physics with Modern Physics (13th Edition):
The inside of an oven is at a temperature of 200 °C (392 °F). You can put your hand in the oven without injury as long as you don't touch anything. But since the air…
InfZero
- 1,493
146
votes
7 answers
Why doesn't water boil in the oven?
I put a pot of water in the oven at $\mathrm{500^\circ F}$ ($\mathrm{260^\circ C}$ , $\mathrm{533 K}$). Over time most of the water evaporated away but it never boiled. Why doesn't it boil?
Hovercouch
- 1,451
127
votes
10 answers
Why do spaceships heat up when entering earth but not when exiting?
Recently I read up on spacecrafts entering earth using a heat shield. However, when exiting the Earth's atmosphere, it does not heat up, so it does not need a heat shield at that point of time yet. Why is this so? I know then when entering earth,…
QuIcKmAtHs
- 3,795
- 4
- 19
- 40
104
votes
4 answers
Would a pin head heated to 15 million degrees Celsius kill everyone in a 1000 mile radius?
The YouTube video How Hot Can it Get? contains, at the 2:33 mark, the following claim:
A pin head heated to 15 million degrees will kill everyone in a 1000 miles radius.
On what basis can this claim be true?
Some of the things I can think…
Jus12
- 3,463
- 4
- 25
- 30
100
votes
8 answers
Why does hot water clean better than cold water?
I had a left over coffee cup this morning, and I tried to wash it out. I realized I always instinctively use hot water to clean things, as it seems to work better.
A Google search showed that other people get similar results, but this Yahoo answer…
user-2147482637
- 1,103
96
votes
4 answers
Why don't miners get boiled to death at $4$ km deep?
The Mponeng Gold Mine is nearly $4$ km deep. It has the largest elevators in the world and is considered one of the most dangerous mines in the world.
The geothermal gradient is $25$ degrees Celsius per kilometer, which would be $100$ degrees.…
Ambrose Swasey
- 4,534
- 6
- 32
- 65
88
votes
8 answers
Will a hole cut into a metal disk expand or shrink when the disc is heated?
Take a metal disc and cut a small, circular hole in the center.
When you heat the whole thing, will the hole's diameter increase or decrease? and why?
What will happen to the diameter of disc?
jojo
- 897
84
votes
8 answers
Why is there no absolute maximum temperature?
If temperature makes particles vibrate faster, and movement is limited by the speed of light, then I would assume that temperature must be limited as well.
Why is there no limit?
serg
- 1,483
81
votes
6 answers
Why does water stop boiling immediately after turning off the heat?
When I am heating water on a gas stove, it begins to boil after some time and bubbles of air can be seen escaping out.
However, as soon as I increase the amount of heat in the stove, the rate of escape of air bubbles increases immediately, and as…
Mrigank Pawagi
- 1,131
77
votes
7 answers
Is the Boltzmann constant really that important?
I read a book in which one chapter gave a speech about the fundamental constants of the Universe, and I remember it stated this:
If the mass of an electron, the Planck constant, the speed of light, or the mass of a proton were even just slightly…
EXVII
- 3,783
76
votes
8 answers
If I stood next to a piece of metal heated to a million degrees, but in a perfect vacuum, would I feel hot?
A friend of mine told me that if you were to stand beside plate of metal that is millions of degrees hot, inside a 100% vacuum, you would not feel its heat. Is this true? I understand the reasoning that there is no air, thus no convection, and…
Peter_Browning
- 919
76
votes
4 answers
How does water evaporate if it doesn't boil?
When the sun is out after a rain, I can see what appears to be steam rising off a wooden bridge nearby. I'm pretty sure this is water turning into a gas.
However, I thought water had to reach 100 degrees C to be able to turn into a gas.
Is there an…
Malcolm Crum
- 1,053
- 1
- 7
- 11
74
votes
11 answers
Could a candle theoretically melt iron?
The title question is rather illustrative. I suppose the real question would be:
Is heat cumulative?
Put back into an example:
If I have a lit candle right beneath an iron bar, assuming the candle will remain lit indefinitely, and that the…
user1869935
- 1,209
70
votes
3 answers
What makes cheese so effective at absorbing microwaves?
Whenever I put a meal in the microwave which contains cheese, why does the cheese get hot before the rest of the meal is heated through?
Robert Frost
- 851