TechTakes

Good news everyone, there's 2 bonkers pieces about the stars and the galaxy on LW right now!

Here's a dude very worried about how comets impacting the sun could cause it to flare and scorch the earth. Nothing but circumstantial evidence, and GenAI researched to boot. Appeared in the EA forum as part of their "half-baked ideas" amnesty

https://www.lesswrong.com/posts/9gAksZ25wbvfS8FAT/a-new-global-risk-large-comet-s-impact-on-sun-could-cause

The only thing I'd note about this is that even if the comet strikes along the plane of eliptic (not an unreasonable assumption), the planet would still have to be exactly in the right place for this assumed plume of energy to do any damage. And if it hits the Sahara or the Pacific, NBD presumably.

(Edit turns out the above is just the abstract, the full piece is here:

https://docs.google.com/document/d/1OHgc7Q4git6OfDNTE_TDf9fFNgrEEnCUfnPMIwbK3vg/edit?usp=sharing)

Then there's this person looking really far ahead into how to get energy from the universe

https://www.lesswrong.com/posts/YC4L5jxHnKmCDSF9W/some-astral-energy-extraction-methods

Tying galaxies together: Anchor big rope to galaxies as they get pulled apart by dark matter. Build up elastic potential energy which can be harvested. Issue: inefficient. [...] Not clear (to me) how you anchor rope to the galaxies.

Neutrino capture: Lots of neutrinos running around, especially if you use hawking radiation to capture mass energy of black holes. So you might want to make use of them. But neutrinos are very weakly interacting, so you need dense matter to absorb their energy/convert them to something else. Incredibly dense. To stop one neutrino with lead you need 1 lightyear of matter, with a white dwarf you need an astronomical unit, and for a neutron star (10^17 kg/m^3 density, 10km radium) you need 340 meters of matter. So neutrino capture is feasible,

(my emphasis)

Black Hole Bombs: Another interesting way of extracting energy from black holes are superradiant instabilities, i.e. making the black hole into a bomb. You use light to extract angular momentum from the blackhole, kinda like the Penrose process, and get energy out. With a bunch of mirrors, you can keep reflecting the light back in and repeat the process. This can produce huge amounts of energy quickly, on the order of gamma ray bursts for stellar mass black holes. Or if you want it to be quicker, you can get 1% of the blackholes mass energy out in 13 seconds. How to collect this is unclear.

(again, my emphasis)

Same author has a recent post titled "Don't Mock Yourself". Glad to see they've taken this advice to heart and outsourced the mocking.