Conworld random thread

[quinterbeck]

A fun speculative article on donut-shaped planets
A less in-depth video on the same topic

[Man in Space]

I would like to research the specific effects of ramming an asteroid the size of FirstEnergy Stadium in Cleveland into an Earth-like planet. (Assume it is nontrivially hollowed out but still of appreciable heft.) There are a few things I’m after:

- What are the effects of a land versus a sea impact?
- What would specifically happen to the crust at and in the immediate vicinity of ground zero?
- How much global cooling could we expect?
- How long would the post-impact winter be expected to last?
- What atmospheric effects could reasonably be expected?
- How powerful would the shockwave be?
- Would trying to blow up the asteroid before it fell just make things worse by spreading the devastation out over a greater area?

[keenir]

I would like to research the specific effects of ramming an asteroid the size of FirstEnergy Stadium in Cleveland into an Earth-like planet. (Assume it is nontrivially hollowed out but still of appreciable heft.) There are a few things I’m after:

- What are the effects of a land versus a sea impact?

I've heard that a land impact would cause/create/trigger volcanoes, but never saw citations provided, so i'm not sure if thats a hunch or a fact. a coastal impact might cause waves spreading away from the impact site (my hunch, granted) to inundate other coastlines....though I can't rid myself of the mental image of a coastal impact creating a deep depression, into which the sea dives into rapidly - either after or in lieu of the above spreading away.

Would trying to blow up the asteroid before it fell just make things worse by spreading the devastation out over a greater area?

not sure about the other points - sorry - though I think there's a website that calculates such impacts (if i recall, it was originally designed to calculate things like The Big Splat that formed our Moon, and the K-T Impact)

....but to your last question there, you'd essentially be converting it from a cannonball, into birdshot pellets....so yes, the destruction raining down would be over a wider area, but it would have less impact - at least geologically; ecologically, its still Death From Above.

[bradrn]

I would like to research the specific effects of ramming an asteroid the size of FirstEnergy Stadium in Cleveland into an Earth-like planet. (Assume it is nontrivially hollowed out but still of appreciable heft.) There are a few things I’m after:

- What are the effects of a land versus a sea impact?

I've heard that a land impact would cause/create/trigger volcanoes, but never saw citations provided, so i'm not sure if thats a hunch or a fact. a coastal impact might cause waves spreading away from the impact site (my hunch, granted) to inundate other coastlines....though I can't rid myself of the mental image of a coastal impact creating a deep depression, into which the sea dives into rapidly - either after or in lieu of the above spreading away.

I’ve heard of a theory that the Deccan Traps were triggered by the Chicxulub impactor, but I’m not sure how widely accepted it is.

[Ares Land]

I would like to research the specific effects of ramming an asteroid the size of FirstEnergy Stadium in Cleveland into an Earth-like planet. (Assume it is nontrivially hollowed out but still of appreciable heft.) There are a few things I’m after:

- What are the effects of a land versus a sea impact?
- What would specifically happen to the crust at and in the immediate vicinity of ground zero?
- How much global cooling could we expect?
- How long would the post-impact winter be expected to last?
- What atmospheric effects could reasonably be expected?
- How powerful would the shockwave be?
- Would trying to blow up the asteroid before it fell just make things worse by spreading the devastation out over a greater area?

So the Cleveland Stadium is about 260 meters long, assuming an asteroid with that diameter. We're approximately looking at a 800 megatons impact. Let's cut that in half, assuming about half of it's been dug out.
400 megatons is about equivalent to three Krakatoa eruptions, 26000 Hiroshima eruptions or eight Tsar Bombas.

You'd get a crater about 3 kilometers in diameter; the heat and blast destroy all life. The rock is simply vaporized. You'd still get 3rd degree burns a dozen kilometers away.

Using volcano eruptions as a proxy, we're looking at disturbed weather for about a decade. It depends on what and how much gets burned in the resulting mass fire.

In the sea, you'd get a megatsunami, but possibly much less long term consequences.

All of this varies according to angle and speed.

At this size, blowing up the asteroid could work. The trick would be to reduce it to fragments 10 meters in diameter, ideally less than 5 meters. We get these about twice a year and barely notice.

[Raphael]

The description "an asteroid the size of FirstEnergy Stadium in Cleveland" sounds a bit oddly specific to me.

At this size, blowing up the asteroid could work. The trick would be to reduce it to fragments 10 meters in diameter, ideally less than 5 meters. We get these about twice a year and barely notice.

But isn't it the case that a lot of tiny fragments have the same kinetic energy as one big thing?

[Ares Land]

The description "an asteroid the size of FirstEnergy Stadium in Cleveland" sounds a bit oddly specific to me.

I wonder about that too! Did Cleveland have a really bad season or something?

At this size, blowing up the asteroid could work. The trick would be to reduce it to fragments 10 meters in diameter, ideally less than 5 meters. We get these about twice a year and barely notice.

But isn't it the case that a lot of tiny fragments have the same kinetic energy as one big thing?
[/quote]
Yes, that was unclear. The idea is that tiny rocks will be destroyed in the upper atmosphere, so the kinetic energy is dispersed before it can do much damage.

The threshold for that seems to be somewhere under a diameter of 10 meters.
If the debris is about ~20 m on average, though, you'd get a hundred of Tunguska events.

I think the Cleveland Stadium is about the maximum size where you could try blowing it up.

[Richard W]

So the Cleveland Stadium is about 260 meters long, assuming an asteroid with that diameter. We're approximately looking at a 800 megatons impact. Let's cut that in half, assuming about half of it's been dug out.
400 megatons is about equivalent to three Krakatoa eruptions, 26000 Hiroshima eruptions or eight Tsar Bombas.

But I doubt the stadium is anything like 130m deep, so there's even less mass to worry about. However, should we include the car parks when considering the size?

I've been wondering about the relative velocities. Doesn't that matter?

[Ares Land]

So the Cleveland Stadium is about 260 meters long, assuming an asteroid with that diameter. We're approximately looking at a 800 megatons impact. Let's cut that in half, assuming about half of it's been dug out.
400 megatons is about equivalent to three Krakatoa eruptions, 26000 Hiroshima eruptions or eight Tsar Bombas.

But I doubt the stadium is anything like 130m deep, so there's even less mass to worry about. However, should we include the car parks when considering the size?

I've been wondering about the relative velocities. Doesn't that matter?

Yep, I'm assuming this is an average asteroid here about the length of the stadium in diameter.

Oh yeah, relative velocity matters a lot; the kinetic energy released varies according to the square of the relative velocity.

The table I use assume an average density for the asteroid (and these things are heavy!) and an object moving at 17 km/s.

[Richard W]

The table I use assume an average density for the asteroid (and these things are heavy!) and an object moving at 17 km/s.

And for comparison, the Earth's speed relative to the solar system is 'nearly 30 km/s' and the escape velocity from the Earth is 11 km/s. So these numbers are looking at an object moving in an orbit close to the Earth's and in roughly the same direction. A head-on collision would be much worse.

[Raphael]

Could life evolve on a planet where there are major earthquakes (well, name-of-planet-quakes) everywhere all the time? Could some form of intelligent life evolve under such circumstances? Could some form of intelligent life produce a technological society under such circumstances?

[keenir]

Could life evolve on a planet where there are major earthquakes (well, name-of-planet-quakes) everywhere all the time? Could some form of intelligent life evolve under such circumstances? Could some form of intelligent life produce a technological society under such circumstances?

Yes to all.

do you mean constant (or near constant) landquakes over the entire globe? I think Earth's Moon has something like that, though they aren't very powerful quakes

[Raphael]

I got the idea for those questions when I was reading a book on the Tangshan Earthquake and started to wonder, "What if things were like that everywhere all the time? Could anything work under such circumstances?"

[doctor shark]

I like money. (Just finished making this.)

[Raphael]

Neat! Where did you get the head from?

[doctor shark]

Neat! Where did you get the head from?

Thanks!

I actually got the head by designing it with a free online program called "MetaHuman Creator" (designed for outputting 3D models for games, but I'm using still frames from it for the bases for the busts).

[Travis B.]

Nice. I have to say I always love your currency.

[Man in Space]

I like money. (Just finished making this.)

I keep forgetting to message you with a picture. I’m still interested.

[Rounin Ryuuji]

I like money. (Just finished making this.)

I'm iffy on the concept of money, but this conbanknote is very nice.

[Qwynegold]

Nice designs!

I actually got the head by designing it with a free online program called "MetaHuman Creator" (designed for outputting 3D models for games, but I'm using still frames from it for the bases for the busts).

Huh, I noticed that at least the two last notes had pretty young people on them. Is this a conscious choice? Because I'm used to seeing only old people on real world money.