# The Temperature of Empty Space?

Authors

After insisting that backradiation is real physics and not just fiction, Roy Spencer takes on to determine the temperature of empty space in Yes, Virginia, the “Vacuum” of Space Does Have a “Temperature“.

By a clever use of quotation marks, Roy states something which can be  “interpreted” in “any way “you” want”.

Let us here try to give Roys’ statement a meaning and see if it makes sense.

In Mathematical Physics of Blackbody Radiation I analyze a model of the radiative transfer of heat energy between two radiating bodies interacting through electromagnetic waves in a vacuum connecting the bodies.

Each body consists of a system of material resonators in form of a lattice of atoms and the temperature of each body is the sum of the temperatures of all frequencies, with the temperature of each frequency being the energy (kinetic + potential energy) of the corresponding resonators. Each body thus has a temperature as a measure of the total energy of the resonators of the body.

The two bodies interact by electromagnetic waves in a vacuum connecting the bodies, but there is no reason to attribute a temperature to the electromagnetic waves since they do not have material nature. One can thus say that the vacuum has no temperature and only acts as a means of communication between the two bodies allowing the warmer body to transfer heat energy to the colder.

As an analogy  one may think of two persons communicating by mobiles (electromagnetic waves) with the “temperature” of each person being the level of knowledge or “excitation” and the more excited person transferring excitement to the less excited. In this case there is no reason to attribute excitement to the electromagnetic waves transferring the excitement.

OK, so we conclude that a vacuum has no temperature, but does it then follow that the “empty space” surrounding the Earth has no temperature? No, because the “empty space” is not empty, but can be viewed as “the other body” willing to absorb heat energy from a warmer Earth.

The conclusion is that empty space has no temperature, but the Earth is not surrounded by empty space and radiates heat energy to a surrounding of low temperature. Again it seems that Roy’s speculations do not describe physics, nor does John O’Sullivan.

Recall that Roy has a leading position in climate science and thus it matters to all of us if what Roy says is correct or not.

1. ### Michael

“Each body consists of a system of material resonators in form of a lattice of atoms and the temperature of each body is the sum of the temperatures of all frequencies, …”

I think it’s like saying that the temperature is an extensive property !!!!!

2. ### donald penman

Empty space might have “dark energy” although the space surrounding the Earth is not empty.I have more respect for Roy Spencer than you do,I think everyones view is worthy of respect ,some people have closed minds on both sides of the climate debate.The debate is getting very nasty and personal and i don’t like that.

3. ### Richard T. Fowler

You may not like it, but this is what happens when one side refuses to try to understand the points that the other is making.

Actually, if you look at the prior post claesjohnsonmathscience.wordpress.com/2012/02/21/can-spencer-describe-the-greenhouse-effect/

you see that Roy has given some ground, though it appears he is not anxious to thank Claes or give him any credit for educating him. And then you wonder why there is rancor?

Personally, I am very grateful that someone in research who is on the other side of this issue has admitted that Claes actually may be right. But when I think of:

* how long it took me (the better part of a year) to figure out that he is closer to the truth than his detractors, and

* that there is intellectual dishonesty out there among some CAGW skeptics who are trying to take Claes down on the issue of backradiation while deliberately refusing to understand what exactly he is saying, and

* that my extended period of sinking-and-swimming while trying to understand him was attributable in part to those intellectually dishonest detractors and their deliberate avoidance of key parts of his heat concepts,

it does upset me. And furthermore, there is simply no way that anyone who has understood that Claes’ work explains the data better than the mainstream hypothesis is going to be quiet and just let the other side continue to promote their ideas. So unless you want to silence everyone and ban all communication regarding atmospheric temperature, I’m not sure from your comment what you expect us to do. If people expect respect, they have to make sure that they give out respect, and avoid giving out disrespect.

RTF

4. ### iceskaterfinland

A perfect vacuum is the absence of atoms and molecules.

Heat is a measurement of atomic and molecular vibrations

A vacuum without vibrating atoms and molecules cannot have heat.

Temperature is what you measure when a mass is in equilibrium with its surroundings

Therefore the temperature of a vacuum is what you measure with a mass in a vacuum that has reached equilibrium while in that vacuum.

So a vacuum has no heat but has a temperature.

• ### Richard T. Fowler

You have not yet addressed the phase state of what you propose to take the temperature of.

If your thermometer is applied to a solid body, then you are measuring the temperature of that body, not of the perfect vacuum which the body resides in.

If your thermometer is applied to a fluid sample, then you are not dealing with a perfect vacuum, and your logic breaks down.

RTF

• ### iceskaterfinland

the thermometer is itself the expanding mass in the vacuum used to measure temperature.

There are no other masses in the vacuum.

• ### Richard T. Fowler

Well all right then; that means you are measuring the temperature of the thermometer. Right?

NOT THE VACUUM. A perfect vacuum, by definition, has no temperature, as your reasoning in #1016 shows.

RTF

• ### iceskaterfinland

Just to clarify without a detector in the vacuum you cannot search for vibrational states in the vacuum.

Once a detector is in the vacuum then you measure the effect radiation has on the detector but you are not measuring the heat content of the vacuum

The word heat has no meaning without reference to a specific vibrational level of specific atoms and molecules.

• ### Richard T. Fowler

That is also my understanding.

RTF

• ### iceskaterfinland

There is no such thing as a perfect vacuum. All you can say is that the best possible vacuum exists between point A and point B where there is solid material touching the vacuum.

A thermometer can be surrounded by a vacuum and is therefore in the vacuum

• ### Richard T. Fowler

“There is no such thing as a perfect vacuum.”

I didn’t pick the question, dude. I’m just answering it for you.

RTF

5. ### iceskaterfinland

Going to Roys Site and then coming back here I am not sure what this conversation is about now.

>>The conclusion is that empty space has no temperature, but the Earth is not surrounded by empty space and radiates heat energy to a surrounding of low temperature. Again it seems that Roy’s speculations do not describe physics, nor does John O’Sullivan

Heat energy is not being radiated thru empty space.

Heat energy is the atomic and molecular vibrations of matter – that is not travelling thru space after emission occurs. That matter is back on Earth.

A molecule on earth vibrates less when it emits radiation and we call this less vibration less heat. The energy that was in the form of vibrations is now in the form of EMR travelling thru space.

6. ### claesjohnson

Since temperature is a measure of heat content of a material body, there is no reason to insist that a vacuum has any temperature. If the Earth was surround by complete vacuum then there would be no body to which the Earth could transfer heat energy and so there would be no transfer. Emission from one body must be accompanied by absorption by another body, in the same way as a debt must be accompanied by an asset, or debit and credit must balance.

Bingo.

• ### iceskaterfinland

Measuring the expansion of an introduced mass in a vacuum gives meaning as to the amount of radiation in a vacuum. So if an introduced thermometer reads 2K, then we know that any matter placed into the vacuum will in time have a temperature of 2K.

A temperature is something measured with a mass.

By implication is it clear an introduced mass is in the vacuum and is surrounded by the vacuum and is in equilibrium with radiation sources.

Otherwise you have to say you cannot measure the temperature of a vacuum because adding the thermometer is forbidden

And yet adding the thermometer gives meaning as to the amount of radiation in the vacuum

• ### iceskaterfinland

A vacuum is only what happens when you keep attempting to remove amounts of air to the best of your ability. Nothing else is implied by the word vacuum. Humans cannot create perfect vacuums as far as I know. Space also will not be a perfect vacuum. Space is full of debris

200 years ago it was thought a vacuum contained an ether. It was still called a vacuum

• ### iceskaterfinland

>>Emission from one body must be accompanied by absorption by another body

That implies we know what is beyond the limits of the observed universe.

• ### iceskaterfinland

Or that matter knows the location of matter hundreds of millions of light years away when it emits.

7. ### iceskaterfinland

I think we can also say that the temperature of space has meaning for a scientifically trained person so that a new expression is not required for the experiment where ‘we measure the ability of a thermometer to record its own temperature when placed in what was previously a vacuum before the thermometer was added’

We just say the temperature in the vacuum or the temperature in that space. It could be much hotter or colder in other spaces

• ### Richard T. Fowler

“I think we can also say that the temperature of space has meaning for a scientifically trained person [. . .]”

You apparently think that there are two different and simultaneously valid definitions of “temperature”: one which is rigorous, applies only to matter, and is only for the hoi polloi; and another which is non-rigorous, applies only to empty space, and is only for the “scientifically trained”.

That is wrong on so many levels, my head spins.

RTF

• ### iceskaterfinland

There is only one definition of temperature. There is a reason that the “local weather station temperature” is measured in box called a Stevenson screen where there is almost no air mass touching the thermometer and radiation influences can massively distort the recorded result. In our local area of space away from sunlight the amount of energy able to heat a mass is *very* small. Temperature anywhere is *always* going to be influenced by the amount of radiation that is capable of warming the mass. At the top of the atmosphere in sunlight it is hundreds of degrees and yet there is almost no mass up there. If you place a thermometer in sunlight in the artic circle while the water is freezing on the other side of the boat you will find the thermometer reads you can be comfortable in your shorts. The same effect is true on the moon where one side of your suit is an extreme hot temperature and the other side is an extreme cold temperature.

The temperature of space is the temperature “of a rock in space”. If you had a weather bureau on a rock unheated by the sun you would record with your thermometer in a box the local temperature at that point in space which would be for our local area in space 3K plus whatever local radiation was provided to the box.