If light travels billions of miles from distant stars to reach us ...?

When you blow a balloon up, the skin gets thinner and thinner. That's because it's the same amount of material but the surface area has been increased. It's the inverse square law where the intensity drops of with the square of the distance, double the distance and the intensity drops to 1/4 of what it was. A billion miles is a very long distance so the heat and the light would've dropped to 1 / a billion squared of what it was. If you think a billion is big, a billion squared is humungous. We see the inverse square law in practically everything, from gravity to light to magnetic fields. It's one of the reasons why we know that space is three dimensions aside from time, it would be the inverse cube law if space was four dimensions aside from time.

The heat from those stars do reach Earth just as the light does but as a star is much dimmer than our Sun, the heat is equally unnoticeable. Also, the atmosphere absorbs and re-radiates heat ( the greenhouse effect ) so it's not entirely transparent to infrared ( heat ). That's why we send our infrared telescopes into space.

Heat from the stars travels as infrared light. So yes, it does reach us. But the intensity is reduced the futher away you are. Same as moving away from a fire you dont feel as much heat. The amount of IR radiation that reaches us is just too small to be noticeable.

Your instinct is correct. Here's why:

Light travels in distinct particles called photons, and so it arrives unchanged when we see a star at night.

However, heat is radiated as infrared radiation, and so it dissipates into space and in weakens as it travels farther from the source until it dissipates completely.

Think of a fireplace in a large room. The light from the fire reaches everyone's eyes no matter where he is in the room, but people standing just a short distance away from the fire cannot feel much of the heat because it dissipates throughout the room and loses its intensity fairly quickly because it is radiated outward as infrared radiation, in waves that weaken as they move farther from the heat source.

Stars are so far away that the heat they give off dissipates long before it can reach us over the vast distances it must travel, while the light keeps on going as photons that remain as descrete packages rather than as radiated waves.

The heat DOES reach us, in the form of infra-red radiation. But it is very very weak by the time it gets to us, because it spreads out so much. Actually, the star light is also very very weak. Try reading outside in the middle of the day, with sunlight -- very easy. Now try it at night, without any moonlight. Using only starlight, it's impossible, even though there are thousands of stars shinning in the sky.

Professional telescopes use infra-red radiation to study stars.

heat doesn't travel as far as light. Think about it, look at a candle in the dark from 50 feet away, you can see the light, but you don't feel the heat.

Also, many planets don't give off heat, the light you see if just the light reflecting off it from other stars.

Hope this helps :)

Heat don't travel as far

The heat *does* reach us. That's why it's warm at night when there's no sun.