Need help crafting a cataclysm (for SF novel)

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  • #1

I'm in the process of writing a novel and there is one specific event that I need help nailing down. The story is very much fantasy / science fiction, so reality is no barrier, however I want to stay as true as possible to laws of physics.

Skipping background details, imagine a mini star coming into life and immediately dying on the surface of an earth-like planet. Essentially a sudden and absurdly powerful thermonuclear explosion that wipes out all life.

If we excuse the impossibility of this... how would it go down?
Let's say this thing charges to an energy equivalent to 10-20% of the 'binding energy' of said planet, and spawns and dies in like 10 seconds ...Here's how I vaguely picture such a cataclysm (as a layman!):

1. The gravity of this 'star' spawning out of nowhere would immediately start ripping the planet apart, triggering volcanic eruptions, not just at location, but world-over, decimating most life instantly.

2. It would also start pulling surrounding satellites / stations / debris from orbit. Could it also distort the orbit of the planet's moon(s)?

3. At full charge/explosion, the sharp gravitational hike would completely decimate all life, flatten surrounding land, blow a chunk in the surface, and destroy any near-by orbiting objects.

Again, this is my layman's interpretation of what might roughly happen. What do you disagree with? Anything else worth detailing? I've not mentioned heat... I assume that kind of intense energy would instantly fry the planet's atmosphere?

Answers and Replies

  • #2
A literal "mini star" - like our sun, but say only a kilometre across - isn't a thing. What do you want to happen ?

Does it just pop into existence, then naturally dissipate ?

A 10 second black hole would produce a ridiculous amount of energy, and be a surface extinction event from hurricanes verging on supersonic, and dust, but it only weighs as much as a small office building, so there's no gravitational effects worth mentioning. There would be an easily visible-from-the-Moon plume, and you might end up with a faint but pretty dust ring around the planet : the world would be hotter for a month, then much colder for a much longer time.

Anything less immediately self-destructive would have to magically pop out of existence.

Maybe the core of an electroweak star (ex Wikipedia: size of a baseball, two Earth masses) : satellites wouldn't fall out of the sky nor even notice the event, though their orbits would be slightly changed. Tidal effects would probably cause temporary moonquakes.

On Earth, things would get . . . interesting - in the Chinese proverbial sense - as everything tried to move towards the strange-star core at as much as 3g acceleration. No clue about radiation.

(fair warning : I hang out here sometimes, but am not even remotely a physicist)
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  • #3
Thanks for the reply!
The concept of this 'mini star' coming into existence is 100% borne of imagination and fantasy. But I'm interested in the realistic impact such a phenomenon would have (the details of destruction).

An electroweak star sounds like the closest thing to what I'm trying to picture. Sounds like it would be sufficiently disruptive enough to get the job done.

I was equally interested in the idea of gravitational impact, and the simultaneous destruction of nearby orbiting objects (stations, satellites etc). If gravity wouldn't be a factor in causing much damage to them, I wonder if the sheer heat of such thermonuclear energy would be able to take them out..
  • #4
Yeah, my bad : EM and cosmic radiation from the micro BH would definitely kill any satellites that could see it, and anybody on them. Also the "as much as 3g" bit in my previous post is wrong - it'd be more.

I've no idea what a theoretical electroweak star puts out, radiation-wise. Gravitationally, satellites won't care : they're small enough to be effectively immune from tidal forces, unless it's a seriously close flyby. Of course, the closer their orbit takes them to the new grav point source, the stronger it would be, so some of the lower down ones could be plowed into the atmosphere or even the ground.

If nobody with any real knowledge signs in here, maybe give a shot at the Cosmology sub-forum. After all, you're looking for facts.

Roche limit
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  • #5
I'd say that a piece of a neutron star being teleported to the surface of a planet is your best bet. Without the gravity of the neutron star to compress the material, it should react...violently.
  • #7
IIRC, there's a book called 'Space Eater' where a worm-hole generator pinches off a portion of an otherwise well-behaved, several-solar-mass black hole, destroying itself, but transporting nipped mini black hole into a solar system. On collision course for planet...
VERY BAD THINGS will ensue unless protagonists mcgyver a fix...

As the folk above have indicated, sadly the wrong mix of disaster for your scenario...

Back in the 'golden days' of SciFi, there was a fun tale of a world where its tiny neutron moon orbited inside the planet, causing interesting tidal effects. I don't think the math or physiscs stand up to modern scrutiny...

FWIW, there was also an underground eco-system of 'strange matter' animals, including 'stone birds' that liked to 'fly' close to surface, accidentally destroying building foundations 'en passant'. Protagonist realized said 'birds' had some way of avoiding voids, so devised 'picket fences' of empty well-holes until foundations of 'air-bricks' could be built...

Um, 'Plan_B' for a 'roll your own' cataclysm could be a 'Cosmic String' or 'Loop'. The math is sufficiently 'out there' to fend off complaints, and the perp may be but a tiny scrap, a cosmic paint-shard from some supra-cosmic branes' fender-bender...
  • #8
Let's say this thing charges to an energy equivalent to 10-20% of the 'binding energy' of said planet, and spawns and dies in like 10 seconds ...Here's how I vaguely picture such a cataclysm (as a layman!):

Gravitation binding energy of Earth is 2.2 x 1032J. The ton TnT is about 4.2 x 109 joules. So a 10 zettaton explosion. That is about 100 million times the energy released by the Chicxulub impact.

The molecules near the event would all be ionized. There might be some modification of nuclei from cosmic ray spallation. A significant mass of the plasma would blow out into space and not come back. Rather than unbinding 20% of Earth less than 1% (not sure) gets blown out of the solar system.

The atmosphere would directly lose the gas above a tangent plane. Some of the blast will go into the continental shelf. The upper part of the crust will bounce off the mantle and spray over the horizon.
The crust below ground zero gets ionized and bounces out to space. The shock wave will travel through the core. crater will have a few hundred kilometers depth before the magma flows back and fills it back in.

The far side of Earth gets hit by a p-wave. The Earth changes orbital velocity by a few hundred meters per second. That should shake the continental shelves and give things under pressure a chance to pop. Things that can fall probably do that. In areas where the shift is perpendicular to the ground oceans will flop over the continents and continental plates should buckle. The continents will have shifted towards the crater and the far side will have rifts.

Some of the continental crust that was pushed horizontal and slightly down by the blast can arc over the atmosphere and then re-enter. A few centimeters ash thickness is enough to destroy everything. While it is reentering the entire sky will be white hot. That will cook everything on the surface.
  • #9
Stefan - thanks for the extra detail! Really really helpful. This physics forum is pretty awesome..

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