Question about heat

This isnt really school related, but it is something I have been wondering for some time now. Is it possible for heat to exhist without oxygen? I mean in space there is no oxygen and it is very cold from what I have read, so does that mean heat cannot exhist without oxygen?

Heat is a measure of how fast molecules are moving. The faster a molecule moves the hotter it is. If a molecule wasn't moving at all it's temperature would be 0˚ Kelvin, or -273˚ (Or so) Celsius, which is -459˚ Fahrenheit.

So, you can have heat without Oxygen, but you need at least one molecule. That's why space has no temperature, it's a vacuum, which means that there are no molecules (well, incredibly few) to move.

However, heat can be transfered without any molecules for it to move through, which is why we feel heat from the sun.

Wait, doesn't the heat that we feel travel through the molecules in the air? If heat is transferred through molecules, then it would have to be that the heat from the sun travels through the air molecules (and maybe others in the air), and reaches us that way. Isn't it that way that it works?

BTW, it's just an idea. After seeing you say heat has to travel through molecules, and then say it can travel without molecules, I had to ask.

Well, there's two distinct questions here.

First of all, the "heat" of a particle is a measure of its rate of movement. All matter has heat, be it Oxygen, Plutonium, Sodium Chloride, or DNA.

As to the second question space is not completely empty, but contains a very small concentration of "space dust" particles (which, of course, have heat) and electromagnetic radiation, which is abosrbed by particle it contacts, increasing their energy and, therefor, their heat. In both these sences, space has a temperature.

Originally Posted by Godsmack'd

Wait, doesn't the heat that we feel travel through the molecules in the air? If heat is transferred through molecules, then it would have to be that the heat from the sun travels through the air molecules (and maybe others in the air), and reaches us that way. Isn't it that way that it works?

BTW, it's just an idea. After seeing you say heat has to travel through molecules, and then say it can travel without molecules, I had to ask.

I think you misunderstood GDwarf. Heat doesn't need to travel through molecules. Rather, heat is created by the vibration of molecules. The faster they move, the more heat they produce.

And there is no air in space for heat to travel through.

Originally Posted by mmmmm_PIE

First of all, the "heat" of a particle is a measure of its rate of movement. All matter has heat, be it Oxygen, Plutonium, Sodium Chloride, or DNA.

Theoretically, it is possible for matter to exist without producing heat. Its molecules would simply remain still.

Now, if that were the case, would the matter be in its most solid form?

No, Heat is directly related to Pressure and Temperature.
Paritcles with absolutely no heat would have absoultely no volume, and therefore, cease to be matter.

When temperature approaches Absolute Zero, particles do slow down to the point where movement is undectible. In the resulting states, it is possible for multiple particles to occupy a single point in space, creating something a state of matter with 0 viscosity, being at the same time "more solid than any solid and more liquid than any liquid", called a Bose-Einstein_condensate

Originally Posted by Godsmack'd

Wait, doesn't the heat that we feel travel through the molecules in the air? If heat is transferred through molecules, then it would have to be that the heat from the sun travels through the air molecules (and maybe others in the air), and reaches us that way. Isn't it that way that it works?

BTW, it's just an idea. After seeing you say heat has to travel through molecules, and then say it can travel without molecules, I had to ask.

Earth isn't heated by the rays of the sun directly. It's heated by thermal radiation.

The insolation (INcoming SOLar radiATION) from the sun reaches the Earth as short-wave radiation, and passes through the atmosphere. Once it reaches the Earth's surface, the lithosphee, it is changed to long-wave radiation, and becomes trapped in the Earth's atmosphere: The Greenhouse Effect. That's thermal radiation.

.....I didnt understand a word any of you guys said, but you I did manage to make out that heat can exhist without oxygen, that is all I wanted to know! You may lock this thread if you wish too now....

To clarify: Space itself has no temperature because there is nothing in it. At first glance, this would seem to mean that heat could not travel through space. However, heat can be transfered through three methods:
Conduction, Convection, and Radiation.

Conduction is the simplest, molecules that are moving due to heat hit other molecules and cause them to move at a similar speed, transferring the heat.

Convection is the same process as conduction, only it occurs in liquids/gases. Since hot liquids/gases rise this causes a sort of circular pattern as the liquid/gas heats up and rises, then cools of and falls. This simply changes where the heat is transfered to, not how it's transfered.

Radiation is very different from the previous two. Heat can be transfered as an electromagnetic wave (Called Infrared radiation). Electromagnetic waves are, well, waves. However, unlike waves on an ocean they don't actually need anything to move through. Light is an electromagnetic wave, as are X-Rays. The heat we feel from the sun is all radiated heat.

Now, radiation is the least efficient way to get rid of heat, conduction/convection are far quicker. Which is why thermoses (Well, good ones) have a thin layer of vacuum between the inside and the outside.

really? I thought all electromagnetic waves (not just infrared ones) transfer heat. visible light would transfer very little heat compared to infrared, but...
hmmm, are you sure GDwarf...
be careful, I'll believe whatever you say next...

Ah, actually yes, you'd be correct. Infrared is simply the radiation emitted by objects at the temperatures found on Earth.

My explanation of radiated heat is also slightly off. It isn't heat that is transfered by electromagnetic radiation, what happens is molecules absorb it causing them to heat up. However, the difference between that and my explanation is rather small, since the end result is the same.

Originally Posted by GDwarf

To clarify: Space itself has no temperature because there is nothing in it.

Not entirely. Outer space proper is not, as is the popular myth, "empty," but rather the molecules between astronomical bodies are very thinly spread. "Space" as it is, contains trace amounts of elements present throughout the universe (primarily hydrogen and helium). These elements are so spread apart that the pressure is nearly non-existent and interaction between the molecules are few and far between. For general purpose, you can consider space to be "empty" but it does, in fact, contain a gaseous "medium" that has a temperature as the few existing molecules do collide occasionally.

A similar situation can be seen with "insoluble compounds" like lead (II) sulfate. When placed in an aqueous solution, lead sulfate has an extremely low dissociation constant (a measure of how much of a substance dissolves in solution). For general use, we can safely assume that the dissociation of lead sulfate in deionized water is so trace that it can be ignored. That does not mean that the lead sulfate does not dissociate at all, however.

Originally Posted by Charybdis

Not entirely. Outer space proper is not, as is the popular myth, "empty," but rather the molecules between astronomical bodies are very thinly spread. "Space" as it is, contains trace amounts of elements present throughout the universe (primarily hydrogen and helium). These elements are so spread apart that the pressure is nearly non-existent and interaction between the molecules are few and far between. For general purpose, you can consider space to be "empty" but it does, in fact, contain a gaseous "medium" that has a temperature as the few existing molecules do collide occasionally.

I realize this, but, as you point out, it doesn't really change anything.

so... what can you tell me about 0 kelvin?
(yay... I'm learning new stuff)

please continue...

0 Kelvin? That's (approximately) the coldest anything could be, since at that point molecules would stop moving. However, since Volume is directly proportional to Temperature and Pressure if you ever did reach 0K whatever it was that was that cold would have no volume, which isn't possible. This means that we can get infinitely close to 0K, but can never actually reach it.

I thought volume is inversely proportional to pressure... (directly to temperature), so 0K would mean volume is cero or pressure is cero... how do you choose which one?
I imagine you have to put some pressure to the 0K material and only then the volume becomes cero...
what do you think about that?

I need to proofread these posts of mine, it goes like this: The product of the pressure and volume (P · V) of a gas is directly proportional to the temperature.

Anyways, 0K cannot actually be obtained, since that would require a volume of 0, which would require an infinite amount of pressure (Not to mention the fact that you'd have to have a molecule that didn't actually take up any space, which is equally silly.), which isn't possible.

If P*V is directly proportional to temperature, (P is inversely proportional to V) we can say this:

P*V = k*T where k is a constant... (I know the PV= nRT equation, but we can write it like that because we are working with a constant amount of mass here)...

so if T = 0 then

P*V = 0

Now, this last equation never implies the necesity of infinite pressure... you just need V = 0 or P = 0 or both...

Furthermore... if pressure is infinite and volume is zero, then temperature would not necesarily be zero...
so, I'm a little confused here...

(I'm not confortable just knowing "what", I also need to know "why"...)

so... what are your thoughts?

Actually, you can't use the ideal gas law (PV=nRT) when considering this problem as it breaks down at low temperatures. The reason is that the ideal gas law tells us how an ideal gas would behave. An ideal gas is, as you may know, considered to consist of identical particles without volume or intermolecular forces (between molecules). Most of the time it is a good approximation but in this case, it can't predict anything.

The problem is that there is no perfect gas that could get 0 volume, there would always have to be at least one molecule. In order to reduce a molecule to 0 volume would require an infinite amount of energy.