If there's nothing in space, how is there heat?

Question

because i think that heat is the speeding up of atoms or molecules or something, so if space is a vacuum, and there's nothing in space, how can there be heat? or the lack thereof?

this is kinda like the "if a tree falls in a forest..." thing.

Answer 1

You are correct "heat" is a measure of atomic motion.  The hotter something gets the more agitated the atoms in the material become.  The faster they bump into you the more heat you feel.  In a vacuum there is nothing (or nearly nothing) to bump into you for this effect.

However, you can absorb radiant energy which travels just fine through a vacuum.  Ever been sitting in the shade and feel the sun's warmth on a part of your arm in the light?  The air in the sun is not notably warmer than the air a centimeter away in the shade but you feel the temperature easily.

So, even in space this radiant energy can warm you up.  The Cosmic Microwave Background is the temperature of the overall universe.  At a few degrees above absolute zero it is not much but it is there.  This is the "echo" of the Big Bang itself.

Answer 2

Infrared radiation which is the way heat is transmitted through space. this is a special frequency given to photons that will heat up matter when it comes in contact with it. so there really is no heat without matter but as has been previously mentioned space is not excactly a vacuum.

Answer 3

there is heat in space because radiation  can pass through space thats it reaches earth unlike conduction and convection i am 12 yay me i samrt

Answer 4

The sun.

Answer 5

Heat is transfer of thermal energy. It can occur by conduction, convection, or radiation.  Conduction and convection involve "speeding up of atoms or molecules."  But radiation can occur in a vacuum.  Radiation is electromagnetic energy, such as light or infrared light or radio waves etc, which needs no medium to travel through. There is not "nothing" in space, it's just a near vacuum compared to the surface of the earth.

In space near the sun, the radiation of the sun would heat you up.  If you go out into interstellar space, you would cool down pretty quickly because you would radiate your heat out, but nothing would radiate heat back to you.  That would still be heat, mind you, just the loss of heat to the universe, rather than gain of heat from the sun.

Answer 6

Heat can be in different forms, radiant heat (infra-red radiation) does not require a medium.

Answer 7

There are  3 ways that heat travels. Conduction  and the one that goes through space is radiation..

Answer 8

Space is technically a vacuum, but radiation can pass easily through a vacuum.  And sunlight is radiation.

Light has a dual nature: it can be thought of as both a wave and a particle, as it has properties of both.  Thought of as a wave, light is radiation.  Indeed, the visible spectrum (ROYGBIV) wavelengths make up only a tiny sliver of the electromagnetic spectrum, which also includes what we ordinarily think of as radiation: gamma and X rays, and radiation that we don't consider to be such: microwaves, and radio and television waves.

There is no heat in space because, as you've noted, there are no (or insufficient) molecules to become excited by the sun's radiation (light).  However, when that radiation enters the Earth's atmosphere it heats up the molecules here on earth and, voila, heat!  We can feel that effect on our skin on a sunny day, and too much will burn us!  Indeed, if you concentrate sunlight through a magnifying glass you can start a fire.

As for the tree in the forest, here's the trick: it makes a noise, but not a sound.  Sound is a perception and needs a perceiver.  If no one (human or animal) is there to hear it, there is no sound, only a noise.

Answer 9

Space is not empty - it is full of fast and hot particles, but because of their low density, we actually perceive the space as very cold.

What transfers heat in space best is radiation - for example light from the sun or Infrared radiation a close planet.

Answer 10

Space isn't really a vacuum.

Space "contains a low density of particles, predominantly hydrogen plasma, as well as electromagnetic radiation. Hypothetically, it also contains dark matter and dark energy."

Answer 11

It contains lots of supercharged particles... so small and dense you can't see with the naked eye.

these particles mainly hydrogen, helium, frozen water, and CO2

all fly through space at feroscious speeds.

and when the atoms speed up in space.. because of gravity if creates heat.

another way is by solar radiation from the sun and near stars and planets reflecting the suns radiation.. making space full of radiating heat from stars. hope that helps