# Is there any feasible way to inhabit the sun?

Is there any feasible way to create a long-term sustainable habitat on the sun?

My target region for habitation is the temperature minimum at the bottom of the solar atmosphere. Metals would have to be flown in through the outer atmosphere, but at a mere 4100 K, it's at least cool enough for basic molecules like CO2 and water to form. I'm hoping to condense these out to serve as the basis of some farming agriculture, from which I'll derive oxygen and solid carbon for my colonists.

The main problem is whether I can get the AC up and running. Without it, all of my colonists are going to rapidly do some combination of boiling and burning. However, I'm not sure what technologies could be used to cool a habitat down from a temperature of 4100 K. I'm also not sure if there are any materials which could remain solid at 4100 K if I need some sort of shell on the outside of my habitat that I can't cool down on its own.

Is there any possible way to do this with sufficiently advanced technology that could theoretically exist without a massive paradigm shift occurring in our knowledge of physics?

• It could make for an excellent prison, a la Alcatraz. Almost impossible to get to, and even harder to get away from. Crossing the corona would probably require heavy ablative shielding, and the need for that kind of shielding on the return trip as well, plus enough fuel to escape the gravity well of the sun, would require a ton of resources and some large, specially constructed vehicles. Dec 8 '14 at 22:12
• Go there only at night??? Dec 8 '14 at 23:03
• Hey guys! Let's all go live on the mercurial gravitational equipotential of a 400 million terawatt thermonuclear detonation in a near vacuum at triple the melting point of Platinum! Dec 9 '14 at 2:21
• @imallett: Your comment sounds like the perfect reason to live on the Sun. BECAUSE WE CAN! (If we actually can, I mean) Dec 11 '14 at 6:50
• On the sun, mothers tell their kids to hurry up and eat their dinner before it gets hot. Feb 17 '16 at 15:52

cooling? no, where is it going to 'move' the heat to?

My best guess would be some kind of special shielding. Most likely force fields. You are already going to need advanced tech in order to have artificial gravity since the surface of the sun is 28 times that of earth. It would crush us like a bug with an anvil.

The surface is also 1/4 as dense so the gravity fields would have to both prevent those inside from being crushed and keep the station from sinking into the surface of the sun. The shielding would also have to 'redirect' the heat around the station to keep it from turning into metal play-dough. If you want to synthesize stuff from the 'atmosphere' you will need a way to capture it, bring it through the shielding and cool it down.

On top of all these the surface is very turbulent. we all know about flares, but the size of a flare or an eruption can eject mass the distance of 30 earth diameters and the mass would be enough to easily 'drown' a space habitat in it's path. That much more work the shielding will have to handle.

Of course the good news is you will have plenty of energy to power this tech...

ETA As someone pointed out even if the shielding was perfect, there would still have to be some level of cooling for the inside, as people and machines give off heat. though this is a much smaller amount of energy to move out. the shields might have a 'chimney' affect to help funnel the heat in one direction. This should be 'relatively' easy after figuring out the anti-gravity system and regular heat shield.

• ... to power it first split second, until photoelectric panels would melt. +1 Dec 8 '14 at 17:35
• Just 30 Minutes ago I stumbled upon a question where this star forge was linked.
– JFBM
Dec 8 '14 at 17:47
• Power could potentially be drawn from the magnetic field of the sun, which would create significant currents in internal circuits in the structure if the habitat was moving across the surface of the sun, possibly sailing on solar wind systems. It seems like iron might be useable as a cooling fluid for open-cycle cooling in an outermost shell made of something like Hafnium carbide. An onion-like structure of progressively cooler shells could create a habitable area in the middle, but I hadn't thought about gravity. Dec 8 '14 at 18:23
• Even if you had "perfect" shielding, that same shielding would prevent you fro disposing from heat generated within the structure (machines, animals, humans) so temperature would slowly raise and raise. Dec 8 '14 at 22:26
• Why should cooling be such a problem? We have figured out how to cool by now, and have such tech in every house. We call it "fridge", and it is pretty much the same tech we use in power plants and many other places for heat transfer. It consists of a compressor and work because changing pressure changes temperature. There doesn't seem to be a good reason this can't work in higher temperatures (maybe we need a different coolant, but apart from that?) Dec 10 '14 at 10:39

The David Brin novel Sundiver featured a solar explorer spacecraft cooled by a "refrigerator laser" which expelled the heat in the form of X-rays. If I recall the light pressure from this also provided for some part of the propulsion of the ship.

• Cool idea, but I am afraid it goes against thermodynamics.. such laser would produce more waste heat than it would emit. Dec 8 '14 at 20:43
• As long as you have a good energy source onboard, the laser would work. See here. Dec 8 '14 at 21:48
• Irigi the waste heat also goes out with the X-rays. If you think this violates thermodynamics you must also not believe Peltier coolers work. Of course they do work; they do generate more waste heat than they absorb but there's a difference between total heat versus where the heat is going; that's how ALL refrigeration works. In order to refrigerate one thing you just have to raise the temperature of something else with the combined heat of the thing you're trying to cool plus the waste heat from the cooling device. X-rays are very high temperature and you're putting the heat into the X-rays. Dec 9 '14 at 14:52
• It's not the energy you need to get rid of, it's the entropy. And a laser has extremely low entropy (that's the whole point of a laser: it's coherent light). The laser may have a lot of energy, but it is not hot (of course the energy can subsequently be used to generate heat, as any energy form can, but it is not hot by itself). Note that lasers (although not X-ray ones) are used to cool atoms in traps down to extremely low temperatures by shining them onto the atoms (laser cooling). This would not work if lasers were hot. Dec 9 '14 at 20:17

On the sun is as dubious as on Jupiter due to nothing solid to build on. On Jupiter you can solve this with balloons floating in the atmosphere. On the sun it is just too hot. For my taste it is more reasonable to back off some distance to where you get enough power coming in from the sun's radiation without burning up. This is typically a structure like Niven's ring world (or the Halo rings) or a Dyson Sphere, or the plates from Bank's Culture novels.

Getting closer to the sun is good for things like computronium or Matrioshka brains that need the energy to power computation. At that level of technology colonists are either virtual, running inside the computing parts, or perhaps adapted to be so much closer to the sun. Or both, perhaps the living "real" ones do maintenance.

If you do need a difficult to get to prison, perhaps it could be at the bottom of a mine shaft on Mercury. It would be inaccessible during daytime (88 earth days long). Perhaps there are two prisons and you transfer the nightfall ones to the daybreak side. This leaves a tiny window of vulnerability for rescues surrounded by harsh sunlight conditions.

• Our of curiosity, what would you fill the balloons with on Jupiter? The atmosphere's made of hydrogen and helium; helium balloons might actually sink in regions of hydrogen. Dec 9 '14 at 3:24
• Hot hydrogen and helium. Dec 9 '14 at 6:29
• Speaking of balloons, here is a NASA idea for Venus: spectrum.ieee.org/aerospace/space-flight/… Dec 18 '14 at 5:40

My main concern with this wouldn't be with heat... It would be with the magnetic fields of the Sun and sunspots. A delta class sunspot (one penumbra with 2 opposite polarity umbra's) would play absolute havoc with any station in orbit and unfortunately our ability to predict these is pretty non-existent (observe and classify is about where we are at here). These sunspots are often at the heart of solar flaring and potentially CMEs. The Sun's surface is considerably cooler ($4000-8000\;\text{K}$) than the $10-100 \cdot 10^{6} \;\text{K}$ that these flares can reach (that isn't a typo - 10 million Kelvin is a flare's temperature)... A station would be nearly instantly disintegrated had it been in the proximity of a flare.

To give you an idea of the energy involved in these events, here is quote from Wikipedia:

A solar flare is a sudden flash of brightness observed over the Sun's surface or the solar limb, which is interpreted as a large energy release of up to $6 \cdot 10^{25}\;\text{J}$ of energy (about a sixth of the total energy output of the Sun each second or $160,000,000,000$ megatons of TNT equivalent, over $25,000$ times more energy than released from the impact of comet Shoemaker–Levy 9 with Jupiter).

It's hard to give an earth comparison to this that doesn't get into the range of silly. Imagine Mount St. Helens has erupted with the same ferocity as its 1980 eruption and has continued to provide an eruption at the same intensity once a month every month since then. I'd imagine a full city built on the caldera of this fictional Mount St. Helens would have a better chance of survival.

• How possible would it be for a mobile structure to predict and avoid the solar flares? If delta spots are magnetically complex, and I just track where they are and keep far away from them? Dec 10 '14 at 4:29
• Had to think on this one for a while...current technology is a definite no. Our knowledge on planetary and interstellar magnetism is pretty weak (I mean interactions with stellar winds could be driving these for all we know). They develop quickly, but quickly on a sun's timeline is still a few days. If you were travelling at an insane rate (maybe enough to reverse some gravitational effects?), you might be able to dodge them, but it adds this constant danger element where one lapsed judgement or one missed sign, or one unpredictable event would means 100% loss. Dec 10 '14 at 16:51

Proposal: A quantum teleportation-based heat distributor.

• Heat equilibrium may happen because of quantum entanglement:

“Finally, we can understand why a cup of coffee equilibrates in a room [...]: Entanglement builds up between the state of the coffee cup and the state of the room.” - Source

• Quantum teleportation can transfer states between objects far apart:

“Quantum entanglement allows for carrying out quantum teleportation, wherein a quantum object, for example, an atom, in a certain state in one laboratory transmits its quantum state to another object in another laboratory.” - Source

Setup:

1. Entangle a bunch of particles.
2. Set some around the Sun colonists.
3. Send their counterparts (the particle's, not the colonists) to a frigid planet - say, Pluto.
4. (Wait, I take that back) Bonus stage: Send the Sun colonist's counterparts to Pluto as well. Create a colony there.
5. As the Sun colonist's ship approaches the corona, the heat state will be shared between both environments. Pluto colony will heat up, Sun colony will cool down.
• The article discusses how entanglement leads to tge "arrow of time". It doesn't have anything to do with heat being transferred to entangled partners! In fact, doing something to one of the particles cannot make something happen to the other. Jan 6 '16 at 23:05

If you're not 100% concerned with complete science, turn it into a power generation plant which vents its heat out (via portals/wormholes and some form of heat transfer ) to an orbital thermal powerplant orbiting earth. Presto, two problems solved in one. "Accommodation" for the solar system's most dangerous prisoners, and limitless power.

You've even got a plausible reason for establishing such a strangely OTT prison - free labour. Simply have it so the portals cut out if the power dies, and you have the perfect reason for having them continue to work. If the power dies, the station gets too hot to live in, and the robot custodians step in, jettison the dead bodies into the sun and start the portals up again.

(why not run it with robots? Sunspots play havoc with them so they can only run for short periods)

Sure, it's hot, unpleasant and sometimes dangerous work running the AC and heat convertors, but the New World Government doesn't care about "Cruel And Unusual" - just so long as they get their power.

EDIT: as for how you keep it where it is - have some power syphoned off before it gets to earth to keep it in geostationary orbit. Advanced Ion thrusters should do the trick.

In David Brin's Sundiver, a "refrigeration laser" was used to shed heat. In Stephen Baxter's Lieserl a wormhole is used to vent gas to a station outside the sun.

I think the laser idea would work in a hard SF story.

A habitat could be encased in a thermal superconductor that carries energy up a teather to the next step in the heat sink. Plasma can be controlled with magnetic fields, like in fusion experiments. Say that under these conditions a field line is like wood, and with (patented mechanism) they are controlled and the outside force just makes them stronger, as long as a temperature differential exists.

Unlike what others say I believe the AC is just barely possible, although material limits might mean it won't actually work.

Tantalum hafnium carbide still has 388 degrees left before it melts in that environment. Thus just about the entire outside of your base is going to have to be the radiators. Inside that you will need a layer of very good insulation to cut down on the amount of heat you have to remove. The radiators have to be hotter than the environment they are radiating into and you're awfully close to the limit—and remember that a metal near its melting point isn't nearly as strong as it is cold. Whether the outerworks of your base hold together is questionable but not categorically impossible.

There are two showstoppers, though—support (I really doubt you can build a lighter-than-sun craft with a thick metal skin) and gravity (it's crushing.)

• What about a craft that uses active propulsion to keep aloft? Perhaps using an internal fusion reactor to drive the ambient plasma via a magnetic field? Dec 10 '14 at 4:31
• Also, any idea what sort of temperature difference I'd be looking at between the top and bottom of a craft if it were 1km or so in diameter? I'm wondering if I can place evaporative cooling systems on the top where they're shaded by the rest of the craft and maybe use that to run some cooling to keep the bottom further under the absolute limit. Dec 10 '14 at 4:33
• @ckersch If the base is inside the surface of the star the top won't be much cooler at all. Furthermore, evaporative cooling means you need a major resupply of whatever you are evaporating. Dec 10 '14 at 20:13
• @ckersch active propulsion just adds even more heat into your system. The stuff that falls off the space shuttle as it launches is frost...from the liquid hydrogen cooling system that keep the thrusters from melting. interspacenews.com/FeatureArticle/tabid/130/… Dec 18 '15 at 15:30

What about a Dyson sphere which is a hypothetical megastructure that completely encompasses a star and captures most or all of its power output. The concept was first described by Olaf Stapledon in his science fiction novel Star Maker (1937), and later popularized by Freeman Dyson in his 1960 paper "Search for Artificial Stellar Sources of Infrared Radiation".Dyson speculated that such structures would be the logical consequence of the escalating energy needs of a technological civilization and would be a necessity for its long-term survival. He proposed that searching for such structures could lead to the detection of advanced, intelligent extraterrestrial life. Different types of Dyson spheres and their energy-harvesting ability would correspond to levels of technological advancement on the Kardashev scale.

Since then, other variant designs involving building an artificial structure or series of structures to encompass a star have been proposed in exploratory engineering or described in science fiction under the name "Dyson sphere". These later proposals have not been limited to solar-power stations, with many involving habitation or industrial elements. Most fictional depictions describe a solid shell of matter enclosing a star, which is considered the least plausible variant of the idea. In May 2013, at the Starship Century Symposium in San Diego, Dyson repeated his comments that he wished the concept had not been named after him