Gorkamorka wrote:

In Charles Stross book Iron Sunrise someone iron bombs a sun to make it go nova (No spoilers here the books starts with the BANG!). In that case it's done by manipulating time and making the core of the sun age until it turns to iron. It took a long time. Then letting the iron ball out of the time loop it's in. When that happens the sun goes BOOM.

Arenamontanus wrote:

I haven't seen anything. I assume they might be alluding to the neat trick Stross described (essentially briefly change the Calabi-Yao manifold of spacetime to create a mini-universe with ultra-fast time - very much ETI-level tech).

The spacetime trick from [i]Iron Sunrise[/i] is alluded to separately from the actual iron bombardment. And my interest in the iron bombardment itself is largely pure academic; it's not as much for an EP-campaign (that kind of antagonist powerlevel isn't really something I'd want to introduce; I much prefer shadowy organizations and emergent intelligence). I was more interested in the technical aspects of iron-bombarding the Sun because I'm toying with ideas for a non-EP sci-fi story, and I wanted a dangerous but not overshadowing plot. I originally wanted to see if iron bombardment could change the luminosity of the Sun enough to move the Earth out of the habitable zone, but once you reach a Charon-mass of iron, it becomes more efficient to just park the Charon-mass in the Earth-Sun L1 point, seeing as Charon is the perfect size to cause a permanent eclipse. (Of course, the L1-point would be more contested space than, say, cis-Mercurial space, and hence more difficult to hold for whichever antagonist can move Charon around. However, moving Charon around would mean it had an engine with the rough power-equivalence somewhere between "cracking the Earth's crust in a single second" and "reducing the Earth to gravel and moving the pieces to infinity in a single second", not to mention the exhaust at 0.7 AU being roughly as hot as the surface of the Sun.)

Arenamontanus wrote:

I think there could also be the photodissociation of [sup]56[/sup]Fe above 5 billion degrees K, turning it into 13[sup]4[/sup]He + 4n and losing 124.4 MeV. This causes core collapse as the rising temperature is absorbed by the reaction, and hence the pressure does not go up enough to stop the implosion. This apparently mainly happens in more massive stars, while electron capture is what gets smaller stars.

Oh, that is interesting. I didn't know that there was a difference in the processes involved in going supernova to that degree.

Arenamontanus wrote:

I think the problem is that the Chandrasekar limit is 1.4 solar masses: normally the inert core needs to be above this to trigger a supernova, and that is pretty unlikely for the sun. The limit is set by when gravitational attraction becomes larger than the electron degeneracy pressure. So a "fake" supernova might occur if one could add something to the sun that has a very low degeneracy pressure; my favorite is stable strange matter. Given that we have seen star spectra with lithium levels suggesting they have swallowed planets, it seems likely that such a mass would not cause a supernova.

The Sun, obviously, can't go nova all by itself, I knew that. And I'm not really interested in novaing the Sun, because that makes any threat I introduce to a setting/campaign scale really badly. ("Yesterday, you stopped the Sun from novaing. Today, a spree-killer with three non-permanent murders so far is loose in a 20,000-ego habitat.") I was mostly inspired by the movie [i]Sunshine[/i] where it's necessary to blow away a small spacetime-anomaly using a really huge bomb. However, the spacetime-anomaly in [i]Sunshine[/i] wasn't all that realistic, and the kind of technology needed to make one would probably be Third Law-level technology, hence not appropriate for enemies of not-quite-EP-level-transhumanity, and especially not near-EP-level-transhumanity splinter factions. (My main inspirations are basically [i]Blindsight[/i], [i]Deus Ex[/i] and EP, for the record.)

Arenamontanus wrote:

But it might well cause a super-flare. Consider the situation where a fairly biggish mass of iron falls into the sun. It would locally drop the temperature, increase the density, and then I presume it could cause local electron capture. The density would not go up enough to stop the neutrinos, so they would be radiating away a lot of energy. All of this would likely cause some pretty impressive churn, which could get deep solar material to move towards the surface along the channel. Magnetic fields and whatnots would be disturbed, and some very nasty flare might occur. I suspect the only way to be sure is to run very complex magnetohydrodynamic simulations, which might be excessive for a RPG (but fun, if you can do it!)

Well, I haven't the faintest clue how to set up complex magnetohydrodynamic simulations of large iron bodies falling into the Sun, but I have just spend the majority of the last three days running delta-V and mass/power/energy-calculations on Charon and Pluto-sized bodies, so I don't mind the math in of itself. (Partial derivatives are like the most awesome thing ever!) Though I guess I can live with "some very nasty flare might occur" for the purposes of the story; it would certainly be an appropriate-level threat, even though I'm details-and-numbers-obsessed.

Arenamontanus wrote:

Personally I would look for some other supertech. I wonder what happens if you dump an open wormhole like a gate into the sun, allowing core pressure to drain out somewhere else.

Do you have any suggestions for what kind of supertech to look into? And with regards to a wormhole-iike gate inside the Sun, I'd suggest you read [i]Redmption Ark[/i] by Alastair Reynolds. It doesn't actually use a wormhole, but the principles of the [b]really cool thing[/b] in [i]RedArk[/i] are pretty much the same.