How can we make something hotter than the sun?


It’s the sun, it’s literally a burning ball of gas providing energy to countless things millions of kilometers away… How can humans make something that is hotter than that? And how is lightning hotter than the sun?

Edit: just to clarify how is it TECHNOLOGICALLY possible? Like what do you have to do to make something hotter than the sun?

In: Physics

The trick is that those temperatures don’t last very long. A lightning strike is incredibly hot, but it’s also incredibly short-lived and the temperatures quickly dissipate to ambient levels. In comparison, the Sun will only get hotter and hotter for billions of years.

The sun is incredibly hot in some places like its centre and actually quite cool on the surface. It’s 5000k on the surface and 100’s of millions in the core.

It’s easy to get to 5000k. My gas welding torch does that. 5000k is the temperature produced when you burn acetylene in Oxygen. An arc welder has a plasma of 50,000 degrees, just like lightning and they are essentially the same thing. Lightning is a lot of electrical charge in a very small space so it heats up the ionized air to a very high temperature

Because our sun is relatively small so far as stars go, and, generally speaking, the larger a star is, the hotter it burns. For instance, there’s a star in the Pistol Nebula of the Milky Way named the pistol star that’s 100 times the size of our sun and it’s about 10,000,000 times as bright.

It may help to remember that although the *total* energy emitted by the sun is tremendous, the energy emitted *relative to its size* is not all that large. A fire here on Earth is only a little bit cooler than the Sun’s surface, and fires are pretty bright. If you imagine the whole Earth on fire, you can imagine that would be *really* bright, and that’s more or less why the sun’s really bright. (To be clear, the sun isn’t on fire; the heat comes from an entirely different reaction. But the idea – that it’s only moderately bright per area but that there’s a ton of area – is what’s important here.)

The surface of the Sun isn’t that hot, 5000˚K. Lots of plasma cutters are hotter. The Sun is much hotter at the core where fusion is taking place, but that heat has to go into all the other gas and making it hot enough to glow.

> just to clarify how is it TECHNOLOGICALLY possible? Like what do you have to do to make something hotter than the sun?

Interior heat? Blow up a nuke. Take powerful lasers and aim them at a very small object. Smash together subatomic particles at nearly light speed in the CERN machine

> just to clarify how is it TECHNOLOGICALLY possible?

Temperature can be loosely understood as the *average* energy in the system. So temperature is something like “energy / size”. The sun has a high temperature because it has a *lot* of energy, even at its massive size.

But having a lot of energy is not the only way to have a high temperature. It’s easier to just reduce the size of the system. So, technologically, you can make something extremely hot, **millions** of times hotter than the sun’s core, by taking some unimpressive amount of energy but squeezing it into a *tiny* area.

Any time you have some quantity that equal to “A divided by B”, you can make that quantity extremely large if you can get ‘B’ to be small. Lots of examples of this in engineering/physics, but the classic example is power (energy / time). If you make your timescales short enough, you can make the power of a system become basically as high as you want.

Nuclear bombs have powers matching that of the sun’s entire output, but only for a fraction of a second. For unbiased comparisons, look at *energy*. Energy is what makes the world go round, and there’s no technological trickery you can apply to get more of it.