Heat of the Sun?

I googled 'Heat of the sun' and got a bunch of links to a TV show of the same name.

What I'm looking for is the answer to a few questions.

When I stand in sunlight I can feel the heat on my neck, arms...all over.

Am I actually feeling the heat of the sun reaching me?

If so, why is it so cold in outer space?

When a space shuttle travels between the sun and the earth, what is the temperature outside of the shuttle?

If it is cold outside of the shuttle, then why and how can the heat of the sun bypass the area of the shuttle and hit earth?

Also, if I can feel the heat of the sun burning my skin, why doesn't the shuttle literally bake to a crisp out there?

Or, am I just having a total brain fart on this?

Space is not cold. Cold cannot exist in a vacuum. Temperature is the speed of particles motion. Uhm, no particles, no temperature dude.

So space has no convection heat, only radiant.... The sun can warm what exists, not that which does not exist.

This is why thernoses use a vacuum. Its the perfect insulator.

You are feeling the effects of electromagnetic radiation (mostly infrared) on your skin.

Space is not actually cold. Since it is actually close to being a vacuum it doesn't really have much of any temperature.

The skin of any space craft, like your skin, is heated by radiation from the Sun. Depending on how reflective the skin is and how long it is exposed to that radiation, it can get quite hot.

It is not cold outside the shuttle.

Space craft are well insulated to protect what is inside them from thermal effects.

Originally posted by jiggerj
I googled 'Heat of the sun' and got a bunch of links to a TV show of the same name.

What I'm looking for is the answer to a few questions.

When I stand in sunlight I can feel the heat on my neck, arms...all over.

Am I actually feeling the heat of the sun reaching me?

If so, why is it so cold in outer space?

When a space shuttle travels between the sun and the earth, what is the temperature outside of the shuttle?

If it is cold outside of the shuttle, then why and how can the heat of the sun bypass the area of the shuttle and hit earth?

Also, if I can feel the heat of the sun burning my skin, why doesn't the shuttle literally bake to a crisp out there?

Or, am I just having a total brain fart on this?

edit on 7/14/2012 by jiggerj because: (no reason given)

Is because our planet cotains the heat unlike space were the heat is dispersed instantly due to how temperature is not there.

Example: Walk in freezer vs A hot room

Sunlight or Solar Radiation is essentially photons, or packets of energy, emmited from the suns surface, which are able to travel through the vacuum of space at the speed of light. This comes to us in a range of wavelengths, including Visible light, Ultra violet and Infra red radiation.

.
Taken from this source

Maybe that helps a bit?


ETA: others were sooo much faster composing a post!
.

reply to post by Phage


if its not cold in space where do ice particles come from?
just seems strange to me..

reply to post by jiggerj


That is not how it works... If in the full glare of the Sun, the shuttle will get hot. When in the shade, it gets cold.

What you're feeling here on earth is the IR radiation making your molecules jiggle and warm up. The same applies for anything, anywhere, exposed to IR, be it space or here on earth.

reply to post by cantsee4looking

Water radiates away any heat contained in it. When it loses its heat, it freezes.
Your freezer doesn't add cold to water to make ice. It takes heat away.

reply to post by Phage


so,how can water freeze in space if the ambient temperature in space is above freezing??

reply to post by Phage


I am having a hard time wrapping my head around the concept of no temperature. What you wrote makes sense about it being the radiation on a body that is heat but a lack of temperature is confusing. A thermometer placed in the vacuum of space would do what? Would it rise due to radiation? Lower? Stay the same? I am not trying to argue or challenge you, I am just trying to comprehend the concept.

Originally posted by snewpers

Sunlight or Solar Radiation is essentially photons, or packets of energy, emmited from the suns surface, which are able to travel through the vacuum of space at the speed of light. This comes to us in a range of wavelengths, including Visible light, Ultra violet and Infra red radiation.

.
Taken from this source

Maybe that helps a bit?


ETA: others were sooo much faster composing a post!
.

edit on 14-7-2012 by snewpers because: too slow.

I want to thank all of you for such prompt replies, but snewpers reply is actually the one I'm looking for. I didn't know how to word what I really wanted to know without sounding like an idiot.

So, photons (and as you say: little packets of energy) are hitting me. We know that photons can be either particles or waves.

Why do photons decide (

reply to post by cantsee4looking


Again, space has no "ambient temperature".

Objects (and material) in space radiate any heat within them in the form of electromagnetic radiation until they eventually reach the level of background radiation which would be at about 2.7ºK.

reply to post by Agarta

A thermometer placed in the vacuum of space would do what? Would it rise due to radiation? Lower? Stay the same?

A thermometer in sunlight would heat up and register a high temperature.
A thermometer not in sunlight would radiate heat away (instead of absorbing it) and very gradually cool down, eventually reaching 2.7ºK (the level of background radiation left over from the formation of the Universe).

reply to post by Phage


well i thank you for the lesson...
peace.
out.

Originally posted by Agarta
reply to post by Phage

 

I am having a hard time wrapping my head around the concept of no temperature. What you wrote makes sense about it being the radiation on a body that is heat but a lack of temperature is confusing. A thermometer placed in the vacuum of space would do what? Would it rise due to radiation? Lower? Stay the same? I am not trying to argue or challenge you, I am just trying to comprehend the concept.

Thank you for this! My mind feels like in a fog, so I didn't know if my questions were answerable by a four year old.

Originally posted by Phage
reply to post by Agarta

 

A thermometer placed in the vacuum of space would do what? Would it rise due to radiation? Lower? Stay the same?

A thermometer in sunlight would heat up and register a high temperature.
A thermometer not in sunlight would radiate heat away (instead of absorbing it) and very gradually cool down, eventually reaching 2.7ºK (the level of background radiation left over from the formation of the Universe).

edit on 7/14/2012 by Phage because: (no reason given)

So, cold is not an energy, but rather a lack of energy? I mean, we can't make something cold, but we can remove the heat out of it. Right?

reply to post by jiggerj

Yes.
Exactly.

Originally posted by Phage

A thermometer in sunlight would heat up and register a high temperature.

But a thermometer in space will register heat only because of the photons affecting the atoms IN the thermometer. It's not like it's telling us how hot it is in the surrounding area. Right?

reply to post by jiggerj

Correct.
A thermometer in space would register the temperature of the thermometer.

Originally posted by cantsee4looking
reply to post by Phage

 

so,how can water freeze in space if the ambient temperature in space is above freezing??

(cue spoon girl from matrix 1)

It's not that the ambient temperature in space is above freezing. There is no ambient temperature in space.

Ambient temperature is something you get on the ground from atmosphere. You don't really have any in space. Space isn't hot or cold. Since there's no ambient temperature because there's no ambiance to have one, you lack a few heat exchange mechanisms you have on the ground. For one, convection's right out. For another, conduction is gone too. They both require some sort of working fluid, you got none.

That leaves radiation. Not the nuclear sort, the IR sort. Also, you've still got evaporation/sublimation in the case of water.

So, your heat budget is - energy from sunshine + Earthshine in, energy to near-absolute-zero infinite heat sink out. The ice chunk is absorbing solar energy, if it's in the sun, and IR/visible shine from Earth. The high albedo of ice sort of reduces the input from the sun. In addition, if you DO start to warm the surface toward a liquid state, the more energetic molecules will leave the ice chunk, cooling it by sublimation.

On the other hand, you've got the rest of the ice chunk not being irradiated by Earth or Sun shedding its heat to the background temperature of space. That's near absolute zero. The high albedo slows that down too, so just how warm the thing gets depends on a lot of unknowns - how clean the ice is, whether it's tumbling, the orbit etc.

In general, though, the sublimation term will dominate until the ice chunk is individual water molecules.

edit to add:

Dang you, OP, now I've got "Warmth of the Sun" stuck in my head.