First, let’s define terms. By destroy I mean blow it into chunks that would scatter into the solar system. So were not talking about some pansy-ass “kill all humans” or “render the planet unfit for life” bomb.
And by big, I supposed we need to talk the measurements of nukes – megatons, gigatons, and I don’t know the terminology for the higher-up measures, which will probably be needed for an answer.
Oh, and boiling the earth away by making the sun explode or go nova or something doesn’t count.
Mods, please be reassured. I have no actual plans to destroy the earth. But I do suggest that if I or anyone else asks for plans on how such a bomb can be built, that thread should be closed promptly.
That’s cool! When I was a kid I was scared shitless by the cold war meme that we had enough explosives to crack the earth in half. I’ve know for awhile that it wasn’t true, but it’s still cool talking about it hypothetically.
Well, that tells me how much energy WON’T destroy the earth. I do kind of like the neutronium and anti-neutronium slugs fired to met at the center of the earth. I’m gonna have to read that Greg Bear book.
Well, we can calculate the energy that it would take to launch a given chunk of mass with escape velocity. To blow it into bits that would ‘scatter into the solar system’, pretty the entire mass of the earth would have to reach escape velocity, otherwise most of the remains would clump back together. With escape velocity of 11 km/s, and a mass of 6x10^24 kg, the kinetic energy is given by:
.5 * 6x10^24 kg * (11x10^3 m/s)^2 = 3.6x10^32 J
A one megaton bomb releases 4.2x10^15 J of energy. To a first approximation, you’d need a 10^17 megaton bomb to blow the earth to tiny pieces – that’s one hundred million billion megatons. Also, you’d probably need even more energy to break up all of the solid pieces of the earth.
(All values taken from Wikipedia. Consult an expert for any actual planet destroying purposes.)
Well, the web page does mention using 25*10[sup]12[/sup] tonnes of antimatter. Combine that with an equal amount of matter, and convert it to energy at the centre of the earth, and that should be enough to disrupt the planet (according to the web page).
So…5010[sup]12[/sup] tonnes of total mass to be annihilated (converted to energy) = 5010[sup]15[/sup] kg.
Using E = mc[sup]2[/sup], we have
E = 5010[sup]15[/sup] kg * (310[sup]8[/sup]m/s)[sup]2[/sup]
= 5010[sup]15[/sup] kg * 910[sup]16[/sup] m[sup]2[/sup]/s[sup]2[/sup]
= 45010[sup]31[/sup] kg·m[sup]2[/sup]/s[sup]2[/sup]
= 45010[sup]31[/sup] J
= 45010[sup]31[/sup] J / 4.184410[sup]9[/sup] J/megaton (energy)
= 107.5*10[sup]22[/sup] megatons (energy)
There is no evidence connecting me to any any world-destruction plots. I am offended by the suggestion, and your veiled accusations will not go unnoticed.
Not that I’m planning on releasing thousands of mutant fire ants on you or anything like that. I’m just saying.
Us I understand it, about 4.5 billion years ago we got hit by an object the size of Mars, and all we got out of it was a Moon - not scattered across the solar system in bits. Kinda hard to imagine anything much less than the sun going nova that would really get the job done.
By my figuring that’s about…100 exatons. (An exaton is 1000 petatons. A petaton is 1000 teratons. A teraton is 1000 gigatons. A gigaton is 1000 megatons.)
