­xkcd thread

Appears to be an equal and opposite reaction to the strong force.

Reminds me of a back and forth we had some years ago about GRBs. IIRC …

I was positing an end-of-inhabitable-planet scenario whereas the esteemed @Stranger_On_A_Train suggested that the GRB acts so fast it’d sterilize only the half of the planet facing that way with slim to no effect on Earth’s opposite side.

Which could have (but did not) lead to a further fascinating discussion about biology re-colonizing a half-sterilized otherwise mostly-intact planet. Maybe we need a GRB thread to get this worked out before Randall’s astronomers get their wish.

Even before I read the mouseover text, I was thinking that there was some ambiguity in just where that peak lies, because it’s difficult to attach relative weights to the benefits and drawbacks.

There’d still be effects on the other side, though. The flashed side will see the formation of a lot of opaque nitrogen oxides, and unless the direction to the burst was near a pole, a lot of those opaque gases will quickly migrate to the other side, leaving the planet with significantly reduced sunlight for several years.

And I’m not qualified to even begin to guess at the ecological effects of half the planet being flash-sterilized. At first, all the dead stuff won’t start rotting, because the rot bacteria will be killed off, too, but they’ll re-colonize from the edges, and having a whole bunch of dead biomatter is going to have to have some effects. Maybe, for instance, all of the carrion birds migrate to the all-you-can-eat buffet, leaving a shortage of them on the live side.

Oh yeah, I was on your team for sure. IMO the non-GRB side would be in for a LOT of ecological disruption, mass extinctions, etc. Starting that afternoon and lasting for millennia.

I thought the opposite opinion of “one half affected; one half untouched” would either be pretty well limited to only the prompt effects or would be wrong. I don’t think we ever hashed that part out.

For context, by “GRB” you mean “gamma-ray burst”?

Wouldn’t that just create a bunch of Incredible Hulks?

OK. Never mind. I’ll just leave.

How deep into the soil would a GRB penetrate? I would guess no more than a couple of inches. That would leave plenty of soil bacteria to start the rotting process. Of course, the bacteria would need to recolonize the sterile soil before any rotting could take place.

This is fascinating to think about. There goes my productivity for today.

Maybe one of the hard s-f BNAs could get on it. I could see a trilogy about repopulating the sterilized half, kind of like like Kim Stanley Robinson’s Mars trilogy.

Yes, sorry. I should have spelled that out long-form too.

That’s part of what I liked about the idea. The half-planet is far more hospitable than Red Mars or even Blue Mars was.

Geophysically, the dead half would be perfectly hospitable to life (hand-waving away any climate disruptions). Unlike e.g. a fresh lava field that nothing will grow on until there’s been decades to centuries of weathering to recreate soil.

The rotting (or non-rotting) of the now dead bio-hemisphere would be a big obstacle. At the very minimum you’d have massive forest blow-down (fall-down actually) akin to Tunguska or Mt. St. Helens. Not that they’d been explosively knocked down, just that there’d be this enormous tangled deadfall everywhere, utterly overwhelming the normal natural recycling capacity of bacteria, fungi, insects, etc. Most of whom would be dead too.

From a human social / political perspective this story has a lot of legs too. Depending on what got steriziled the prompt effects might kill WAG 10% or WAG 90% of human population. And might destroy one or more major global powers, or might leave them mostly unscathed while wrecking lots of minor players. It might preferentially have wrecked the rich world or the poor world. Again ignoring climate disruptions, the deeply interconnected rich world would have far more to lose and are in some ways much less resilient than are the subsistence farmers. But the rich world also has more springing-back capability.

Lots to noodle on.

What concerns me more than the dead side / alive side dichotomy would be those opaque oxides of nitrogen. How long would it take for those to break down?

There is no doubt this would be a mass extinction event - on par with the Permian-Triassic extinction event, certainly. Think about it. Depending on which side is exposed to the GRB, a vast majority of terrestrial life would immediately die. Aquatic life would also be deeply affected.

So we’re looking at within the first day:
*On the exposed side, roughly all terrestrial life being wiped out. Nearly all the terrestrial soil bacteria being wiped out (I just looked it up - gamma rays can penetrate soil up to a couple of meters.) All the aquatic life shallower than 10 meters dying. Would caves be affected by the initial burst?
*Much of the atmospheric oxygen getting bound into nitrogen oxides, creating a GRB winter and reducing oxygen levels overall.
*Something glaringly obvious that I am missing.

I don’t see humanity surviving long term. Short term, I would expect civilization to break down quickly as the survivors compete for dwindling resources.

Personally, I would rather be on the exposed side than to have to try to barely survive on the “safe” side.

Didn’t Asimov write a story about being on the night side when a massive solar flare occurs?

You’re probably thinking of Niven’s “Inconstant Moon”. One of the best SF short stories ever, to my tastes.

I think you’re right. I was conflating Inconstant Moon with Nightfall.

Not to mention the oxygen production of half the Earth’s plant life wiped out.

Alongside the corresponding animal consumption of that oxygen.

Good bet if a force, any force, hits an ecosystem that hard it’s gonna go careening off into crazyland. And probably largely crash. Only to re-emerge as something very, very different.

You’d likely get an enormous fungal bloom first (some fungal spores should survive a GRB - some might even thrive more). Similar to what happened after the K-Pg extinction.

Not a concern for fungi, of course.