If the Sun is able to keep Earth warm while being millions of miles away, shouldn’t it get warmer and warmer the closer you get to it (like when you go to space)? Like how it would get warmer if you were to approach a burning house for example?
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Yes, you have the right idea.
In this case “temperature” requires physical matter to be there to feel it; the space between the Earth and the Sun is “cold” because there is nothing there to be warmed. It’s sort of a if a tree falls in the forest and no one hears it, does it make a sound type riddle.
But if say, you, were floating in this space receiving the sun’s light you’d be very hot indeed. For example, the parts of the International Space Station that are lit by the Sun are roughly 250F. As you approached the sun it would get warmer and warmer until you burned to a crisp and back to “cold” again.
So there are two different methods of heat transfer at play here:
-Electromagnetic radiation (light)
-Conduction
Conduction is when something hot comes into contact with something cold – like the air around a burning house getting heated up by the fire.
Space is empty, so there is no conduction. The Sun heats the earth by emitting electromagnetic radiation (light), which can travel through the vacuum of space until it hits the earth and warms it up.
Temperature measures heat energy in matter. No matter means no temperature.
The sun radiates energy as light. When radiated light interacts with opaque matter, the matter converts light into heat (infra-red light) itself begins to radiate energy.
The closer an object is to a radiant energy source, the more of the source’s energy interacts with the object. This is why fires feel hotter as you aporoach them. But the radiant energy doesn’t heat anything until it interacts with something, like your face.
Air is transparent to light, but relatively opaque to infra-red. The sun’s light transits the atmosphere and heats the ground. The ground then radiates infra-red which heats the air.
The space between the Sun and Earth contains no meaningful matter, thus temperature doesn’t really mean anything there. So it’s not that the space is cold. Just that temperature is meaningless.
As the other person already said physically speaking, heat is the amount of energy that an atom has. So if the rays from the sun arrive in our atmosphere there are plenty of atoms that „receive“ this energy from the ray. But until the ray reaches our atmosphere and earth there are no(almost no) atoms. If I remember correctly 6 electrons per m^3 and therefore no atoms to give that energy to and make it hot.
Similar as with sound. The soundwaves in space are still „there“. There is just no medium to carry the wave anywhere so we don‘t hear anything.
But, I think it‘s called heat potential, atleast that‘s what it‘s called in my native language, is way higher in space and increases the closer you get to the sun. Heat potential basically means, how hot would something be if it were in a certain place.
The space between earth and sun is not hot nor cold its empty. Temperature is realy only defined for something not nothing.
Space is neither hot nor cold. It’s space, and it’s empty.
If there were an object, perhaps a satellite or the planet Mercury, those things get very warm while in space. But space itself has nothing to be warm.
All stuff is made up of particles. This includes the air/gas in our atmosphere, as well as the more tangible physical stuff. These particles move around at various speeds based on a number of factors, with one important factor being temperature. Faster particles means more heat.
Heat is a form of energy. The sun’s heat is transferred by radiation, meaning it kinda flows out from the sun and hits whatever is in its reach. As the heat energy flows out from the sun and hits stuff, that heat energy transfers to the staff’s particles. Those particles get more energy, move faster, and heat up.
Space is pretty close to absolute 0 degrees (which would be -273°C). It would take quite a lot of energy to heat you up from there to about 15°C which is a fair average temperature for current purposes — an increase of 288°C. This would require quite a lot of energy going into your body. However, since you are tiny (compared to a planet) there are very few particles (compared to a planet) which can speed up and heat up.
Space is also a vacuum, meaning there is no stuff — not even air. This means there are no particles to to speed up and no stuff to get hot. To make a small object like you heat up in space would take a lot more heat energy than what your body can pick up just from the sun. This is why all the gaps and small things in space stay cold, and why only the bigger objects like planets get warmed by the sun.
It’s kinda like how a car’s surface becomes extremely hot when under sunlight, while the air around the car isn’t as hot. Air is less dense than the car’s metal, so it doesn’t catch as much of the Sun’s energy. There is even less matter in space, almost none actually, so it catches even less heat.
The short answer is that that space is hot, but before getting there we have to be careful when talking about the temperature of space.
The temperature of an object is straightforward enough to describe. We look at the kinetic energy stored in the object at the molecular level, recognizing that that’s the quantity that will come into equilibrium if two objects are placed in contact with each other and allowed to transfer heat between one another.
That definition falls on its face when we start looking at the temperature of nearly empty space–no vacuum is perfect. If it were perfect vacuum then there would be no matter to have kinetic energy, thus rendering the notion of average kinetic energy meaningless. However, since there are a few particles here and there we could take their average kinetic energy and come up with a temperature. That temperature has no real relationship with what temperature an object would be heated to if left in that position, though. For example, the ISS orbits in Earth’s thermosphere which is nearly a vacuum, but the remaining gas particles at that altitude have a temperature of up to 4,500 degrees F. That’s plenty to melt most materials, but it poses no risk to the ISS because there’s not enough gas there to actually transmit meaningful amounts of heat.
That gives rise to a better definition of temperature in space: if you were to put a thermometer out there, what temperature would it be heated to? Since heating via conduction (touching) and convection (moving fluids) are negligible this just leaves heating through thermal radiation. In deep space there’s basically no heating from any direction except the sun, but that heating is substantial. If you put a thermometer in direct sunlight in space then it would be heated to be rather warm–it’s basically being left out on a summer day at permanent high noon in a tropical climate, but also with no heat being blocked by the atmosphere and no heat being moved around by air or water.
The problem with this definition is that it’s highly dependent on the shape and color of the thermometer in question. If the thermometer was long and skinny and oriented just a tiny end towards the sun then it would shed lots of heat along its length and report a lower temperature. Make it more like a disc and orient the flat surface towards the sun and it would be more effective at catching the sun’s light. Paint it to be shiny and it’ll reflect most of the sun’s energy, but paint it black and it absorbs a lot of energy.
That’s how there are so many different temperatures that can be used to describe space. For example, the James Webb Space Telescope makes use of a multi-layer sun shield that is designed to reflect the sun’s energy away from the telescope. That leaves the cold side only subjected to the radiation from deep space, which is just a few Kelvin. The ISS takes a more moderate approach, but it has large radiator fins on one side (they look like solar panels, but they’re white and oriented 90 degrees off from the panels). These have most of their surface area oriented towards deep space to shed heat in that direction, while parts of the ISS are bathed in sunlight and heated to fairly high temperatures (a couple hundred F on the high end).
The extremely simple answer is this:
The heat coming off of the sun does so in the form of countless tiny little bullets. Each bullet delivers a tiny packet of heat to whatever it runs into. Stuff like you or me or planets are really, really big targets that get hit by lots of bullets, so the tiny heat packets from the constant spray of bullets adds up, and rather quickly, too.
Space itself, at least in our neck of the woods, is never *quite* empty. There’s always going to be a stray particle or two or ten wandering around. When people talk about the temperature “of space”, they mean this stuff.
This is an extremely vast and spread out cloud of targets, where each target is so small that it’s in the same order of the size as the sun’s little heat bullets. The sun is effectively machine gun firing bullets at… other bullets. From light-minutes away. As you can imagine, hits aren’t very common purely because the target to hit is so ridiculous.
Even if a hit does happen, the next hit will take so long that the particle struck will probably have ample time to cool off before then. It’s like the universe’s slowest, most inefficient rotisserie.
The end result is that space itself is quite cold, while large things in the same exact spot won’t be. Bigger target = more hits = more heat.
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