Are there warm places in space?

[caudor]

I've read that the temperature of space is very cold, somewhere around -456 degrees Fahrenheit.

Yet is stands to reason that the closer you get to the sun the hotter things get. Is there somewhere out in space, say between the Earth and the Sun, that the temperature is a comfortable 70 degrees?

This might be a dumb question, but I can't see how you could freeze when very close to the sun.

 

[Thunderfoot]

I've read that the temperature of space is very cold, somewhere around -456 degrees Fahrenheit.

Yet is stands to reason that the closer you get to the sun the hotter things get. Is there somewhere out in space, say between the Earth and the Sun, that the temperature is a comfortable 70 degrees?

This might be a dumb question, but I can't see how you could freeze when very close to the sun.

What an incredibly strange an intriguing notion. It has never occurred to me to ponder this. It seems that all of our temperature measurements as we get closer to the sun are of relative planet temperatures. The next question is, does heat transfer through a vacuum or must other arable gasses be present for heat to register? (i.e. is there actual ambient temperature fluctuation in the void of space or do you just go from frozen to fried outside of any sort of "true" atmosphere?)

I may not sleep tonight.

 

[Umbran]

Okay, here's the thing. Space is not cold.

"Hot" and "cold" are states of matter - they are measures of the average speed of atoms or molecules. Space is a vacuum - no molecules to move, so no temperature. If you put an unprotected person out in an arctic winter, they'll freeze to death in short order - the heat of their body gets transferred to the low-temperature air. If you toss an unprotected person out in space, they'll die due to lack of air, but it will take a long time for them to chill down - there's no air to lose heat to, so you only lose heat by slowly radiating it away as infrared.

So, the big backpack on your arch-typical spacesuit is not air and a heater, it is air and a cooler.

Matter (like a planet) near a star catches a lot of light from the star, and that gets turned into heat. Matter far away from a star does not catch as much sunlight, and so are cooler. But the space itself is not really hot or cold.

 

[LightPhoenix]

"Hot" and "cold" are states of matter - they are measures of the average speed of atoms or molecules. Space is a vacuum - no molecules to move, so no temperature.

This is not strictly true. Interstellar medium permeates "space," so that there is in fact molecules and temperature.

 

[freyar]

Okay, here's the thing. Space is not cold.

"Hot" and "cold" are states of matter - they are measures of the average speed of atoms or molecules. Space is a vacuum - no molecules to move, so no temperature. If you put an unprotected person out in an arctic winter, they'll freeze to death in short order - the heat of their body gets transferred to the low-temperature air. If you toss an unprotected person out in space, they'll die due to lack of air, but it will take a long time for them to chill down - there's no air to lose heat to, so you only lose heat by slowly radiating it away as infrared.

So, the big backpack on your arch-typical spacesuit is not air and a heater, it is air and a cooler.

Matter (like a planet) near a star catches a lot of light from the star, and that gets turned into heat. Matter far away from a star does not catch as much sunlight, and so are cooler. But the space itself is not really hot or cold.

To amplify on what Umbran says, if someone talks about the temperature of space, they're talking about something in space. So the temperature of a few degrees above absolute zero refers to the radiation left over from the Big Bang, which passes through all space.

The radiation from the sun is a little more complicated. It's about 5500C when it leaves the surface of the sun. As it travels, it keeps its same distribution of colors, but it gets diluted, so there's not as much energy in a given volume as you'd expect at 5500C. After it has traveled a bit, it doesn't properly speaking have a temperature. But it does have energy, so planets can absorb that and heat up to a given temperature themselves.

 

[freyar]

This is not strictly true. Interstellar medium permeates "space," so that there is in fact molecules and temperature.

I think we need to keep in mind that you two are using different definitions of "space." I think you (and the OP) are using a colloquial definition, which includes the general contents of the regions between planets and stars as part of "space." (Note then that space is very different in our solar system vs between stars in our galaxy vs between galaxies.) The response from Umbran's argument is that you're again talking about stuff in space, not space itself. Space is the stage upon which matter struts its stuff and has no temperature itself. With that strict definition, he's right, space has no temperature.* I'll also add, as in my last post, that you can't always define a temperature for a given lump of matter or radiation.


*Until you start talking about quantum gravity. Stephen Hawking is famous for demonstrating that there are at least some situations when you should think of space itself as having a temperature. But I think that's a different subject.

 

[caudor]

Wow, thanks for the replies. This topic is even more mind-boggling than I first imagined.

Let me re-phrase the question. Let's ignore, for a moment, the fact that deadly things like lack of air and radiation might kill me fast. If I jump out of a spaceship without the protection of a space suit, but with a supply of air (you can call it space scuba diving), what will happen? Do I chill slowly, freeze fast, or fry?

Even though space does not have a temperature, is it the lack of temperature that kills me? Or something else?

 

[Theo R Cwithin]

Even though space does not have a temperature, is it the lack of temperature that kills me? Or something else?

I imagine you'd get a killer sunburn!

The light that heats up the planets is, more generally, radiation of all kinds: xrays, radio waves, gamma rays, ultraviolet, visible infrared, etc. The high energy stuff (gamma, X, and UV) doesn't get through the atmosphere to bother us (except a little UV, to cause sunburn), but outside the atmosphere it will do some serious cell damage in relatively short time-- at least to your skin. So what do you call that: "fry", i guess?

Not sure, though, if it would eventually burn deep enough to actually kill outright; or if that would kill faster/slower than the eventual freezing solid that Umbran mentioned as your body slowly lost its heat into space.

Either way, I'm pretty sure it would be unpleasant

 

[Mustrum_Ridcully]

I imagine you'd get a killer sunburn!

The light that heats up the planets is, more generally, radiation of all kinds: xrays, radio waves, gamma rays, ultraviolet, visible infrared, etc. The high energy stuff (gamma, X, and UV) doesn't get through the atmosphere to bother us (except a little UV, to cause sunburn), but outside the atmosphere it will do some serious cell damage in relatively short time-- at least to your skin. So what do you call that: "fry", i guess?

Not sure, though, if it would eventually burn deep enough to actually kill outright; or if that would kill faster/slower than the eventual freezing solid that Umbran mentioned as your body slowly lost its heat into space.

Either way, I'm pretty sure it would be unpleasant

No cheating. That's radiation, even if not what we might normally, in "layman's" turn describe as such.
But of course you are correct, this is indeed an issue in space. The Space Shuttle for example constantly rotates to avoid heating up on one side and being damaged due to the temperature differentials.


If he was space scuba driving in the shadow of Earth... I have no idea how long it takes. I think one of the nastier things happening is that you will swell up somewhat (but that doesn't mean you explode or anything.)

The most definitive guides to what happens when you are exposed to space is probably this site: Explosive Decompression and Vacuum Exposure

It seems as if when you avoid the vacuum effects of low pressure and can keep breathing, not much bad things would happen. You would slowly cool out. One could probably calculate the rate on some basic physical properties of a human body. Though one should not forget that a human body is also creating his own heat, so this might slow the process, assuming it's faster than you dying from thirst or starvation. I would not discount the possibility that, given also food and water, you would never cool out.

 

[Umbran]

This is not strictly true. Interstellar medium permeates "space," so that there is in fact molecules and temperature.

One can define a temperature on the large scale, yes. However, I maintain that you cannot really call it "hot" or "cold" in the standard human sense of those terms.

The article you reference is talking about particle densities around one atom per cubic centimeter. That is not enough to transfer measurable amounts of heat energy into or from an object. For all of our practical purposes, it is non-existent. Yes, the medium is there, but it is only relevant when you are talking about things acting on interstellar scales (like, a ship traveling at a significant fraction of the speed of light between stars).