Probably a magnetar. The scales of these things make me feel a deep sense of existential dread

Eh, let it happen.

Have you read Death's End? Stop dreading and start living.

Out of curiosity, do you have any insight into why the existence of something large would make you feel dread?

Probably because a magnetar could sterilize everything in a radius of dozens of light years if it has hiccup.

All ordinary "room temperature and pressure" matter that we're used to -- that we're made of -- can be thought of as bathtub foam compared to a neutron star stuff that is more like a tungsten brick in that analogy.

Well, not quite, because that analogy misses ten orders of magnitude of density difference. That just hurts my brain.

Magnetars are a whole other level of eldritch madness. The energy density of their magnetic fields is ten thousand times the density of lead.

Let that sink in for a minute.

The vacuum around a magnetar contains so much energy in the magnetic field alone that thanks to the E=mc² conversion ratio between energy and mass it has a "mass density" that is the direct equivalent to every single atomic bomb on the planet blowing up all at once and the released energy of all of that getting packed into a cubic centimeter.

I need a hug.

aren't pulsars and magnetars very small when talking about stars and planets? Google's AI says about 20km in diameter but would need to double check that. On the other hand, IIRC the energy output of a pulsar compared to its physical size is pretty scary. You wouldn't want one in your neighborhood.

Yes. Here are fact checks for those who don't trust the easy AI answer:

https://www.britannica.com/science/pulsar

https://en.m.wikipedia.org/wiki/Magnetar#Description

They are both forms of neutron stars, which average around 20km but are the densest objects known to man. Fun fact, one sugar cube of their material would weigh about as much as a mountain (https://imagine.gsfc.nasa.gov/science/objects/neutron_stars1...).

> but are the densest objects known to man

Only in the sense that black holes don't have finite densities.

idk but theres a whole subreddit dedicated to it https://www.reddit.com/r/megalophobia/

magnetars have got nothing on quasars, an entire galactic core with a 10 billion solar mass black hole in the middle pounding out radiation. (I'd say you'd have a whelk's chance in a supernova in one of them, but they're bigger than a supernova.)

> scales of these things make me feel a deep sense of existential dread

Perhaps ironically, what instills in me this sense of existential dread are supervoids, more than any massively destructive structure.

I can't really explain why, but something about the idea of a incomprehensibly vast nothingness really rubs me in the wrong way.

I used to feel this way too. It’s not really nothing if that helps. It still has 3 dimensions. Light and gravity pass through it. It has “vacuum energy” and virtual particles. There are still atoms, albeit further apart.

I know, but it is still a pretty dreadful thing to think about.

I mean, the radius of Boötes Void is 330M light years across. I can't fathom that amount of nothing. A photon enters the Boötes void, and if it travels through its center it will take more than half a billion years to reach the other side.

In a sense it's the same thing when I think of the end of the universe. There's a comfort in thinking of a great collapse. A sense of finality, like a board game being put back in the box. In the other hand, the possibility of a heat death is absolutely dreadful. Just a never ending lingering darkness with white dwarfs slowly fading into black. No ending, no great boom, no blaze of glory.

Cheer up! If the universe is really inside a black hole from a parent universe eventually it may evaporate via hawking radiation if the same laws of physics hold. :) Maybe heat death is just the flip side of Hawking radiation?

That would be much nicer indeed. A cozy universe.

That is very very slow for a pulsar. I guess it's possible but it would be weird. Pulsars are usually in the range of milliseconds to seconds.

Its obviously a Slow Rotational Pulsar (SRP) - I get naming rights as I invented it :-)

> Unlike traditional pulsars, which are produced by neutron stars and spit out radio signals every few seconds or milliseconds, LPTs emit pulses at intervals of minutes or hours apart — a period previously thought to be impossible.

Pulsar's pulse comes from their spin contorting the magnetic field lines. When they slow down, they lose energy, and at some point they don't have enough to create XRays.

I wonder if they could figure out if there were two periods, a horizontal and vertical one.