Cold Sun?

[Spatzimaus]

Well... It would still be hot, is what I'm saying!

Yes, it would. And no, you don't look silly for thinking that. It's just that this is one of those situations where your instinctual reaction doesn't really tell the whole story; it's hot from the point of view of a human, but in cosmological terms it's nothing. It's part of why I went into astrophysics in the first place; this stuff is just WIERD, and that makes it fun to think about. (See also: black holes.)

Besides, this isn't a situation that comes up in real life; while it'd be possible for a probe to fall into the Sun from the outer system through slingshots and such, that wouldn't cause the probe to experience the sorts of extreme temperatures we're discussing. It'd only be absorbing the huge number of photons in the brief period before hitting the surface; remember, flux goes as 1/r^2. The Sun's surface radius is 700,000 km, so go that same distance above the surface and you're getting hit by one-fourth as many photons (dividing your equilibrium temperature by SQRT(2)). A few million kilometers above the surface would knock the temperature down below a thousand degrees, and that's really not a large distance compared to the planetary orbits. (For perspective, Earth is 150 million km away from the Sun; even Mercury is at about 60 million km.) To be stable at this temperature in the long term you'd basically need to be orbiting just above the Sun's surface in a more-or-less circular orbit, and the amount of delta-V needed to do that would be tremendous. For anything else, you'd just need to carry enough coolant for the brief period you're near the star.

Besides, there's not much point in getting that close, so NASA won't be doing anything like that in the foreseeable future, especially if their budget keeps getting cut. (This year's NASA budget is the second-lowest in history, as a fraction of the total federal budget, behind only the partial year in which the agency was founded.) So KSP is really the only place we can try these things...

[Sirrobert]

If the Webb's shielding is reflecting enough energy to lower the "natural" temperature of 300K (the temperature of a conductive, nonreflective object at that distance from the Sun) down to a working temperature of 53K, then that's actually MORE of a decrease than you'd need to lower an object near the Sun (where the natural temperature would be 4000 degrees) down to 900 Celsius (~1200 K). It's a ratio thing; to go from 300 down to 53 you have to reflect about 99.9% of the incoming photons, since energy density goes as T^4, whereas it's more like 99% to go from 4000 to 1200. So you'd need less shielding than the Webb has, although not by much, especially if you add some onboard cryogen to help keep things cold.

(Side note: Webb is basically going to be at the same distance from the Sun as Earth is. It'll be at the L2 Lagrange point, which is slightly further out, but the difference is small. So the same basic math applies to any Earth-orbiting satellites as well.)

As to whether 4000 degrees qualifies as "freaking hot", that's a different discussion. I'd generally agree that it's ridiculously hot, and I definitely wouldn't want to be in a manned vessel in that area, but I'm sure it's possible to make an unmanned probe that could survive it for brief periods. Besides, if you want to land on the Sun without burning up, just wait until night.

Now I'm probably mis understanding this. But isn't 1200 kelvin way to hot for a probe?

[Stranded]

Besides, if you want to land on the Sun without burning up, just wait until night.

You sir, owe me a new keyboard.

[Spatzimaus]

Now I'm probably mis understanding this. But isn't 1200 kelvin way to hot for a probe?

Maybe not. I mean, Aluminum melts at 933K, but Titanium doesn't melt until 1941K, and Iron's melting point is 1811K, so you can definitely make an outer shell that can withstand that temperature. Copper is 1357K, and Gold is 1337K, so your electronics should be fine as long as they're designed for this sort of thing (removing the parts that can't stand up to 1200K temperatures). And if all else fails, you can make it out of Uranium (1405K, and REALLY strong). Those temperatures don't leave you much room for mistakes, but the point is that a probe designed to get close to the Sun probably COULD survive those temperatures. But get a little warmer and it all falls apart...

Again, this is all just theoretical, because in reality something that close to the Sun would probably be warmer than the original post, and that'd probably melt the thing unless you had REALLY good shielding between you and the star.

[Madrias]

I know it's a little (okay, a lot) off topic, but the somewhat-crazy-yet-science-interested part of my mind wants to know: Is it possible to, even for a short instant, make something hotter than the surface of the sun on Earth? It's something that's bugged me for a while.

[UnthinkableThinker]

I know it's a little (okay, a lot) off topic, but the somewhat-crazy-yet-science-interested part of my mind wants to know: Is it possible to, even for a short instant, make something hotter than the surface of the sun on Earth? It's something that's bugged me for a while.

I'm sure that with the right material that you want to heat up and the apparatus should be possible to heat it up, yes, just like it's possible to get to almost 0K on a lab.

[DaveofDefeat]

I know it's a little (okay, a lot) off topic, but the somewhat-crazy-yet-science-interested part of my mind wants to know: Is it possible to, even for a short instant, make something hotter than the surface of the sun on Earth? It's something that's bugged me for a while.

The surface of the sun isn't that hot compared to about anywhere else on the sun, and yes, yes it is.

http://www.dailymail.co.uk/sciencetech/article-2189318/Atom-smashing-scientists-reach-highest-recorded-man-temperature--100-000-TIMES-hotter-Suns-interior.html

[Brotoro]

I know it's a little (okay, a lot) off topic, but the somewhat-crazy-yet-science-interested part of my mind wants to know: Is it possible to, even for a short instant, make something hotter than the surface of the sun on Earth? It's something that's bugged me for a while.

Certainly. Plasma torches. Laser pulses. Nuclear weapon explosions. The photosphere of the Sun is not all that hot.