OT - Physics Question on Anti-Matter

[Will]

Well, it's a bit more complicated than that. First, it's gonna be a nasty volume integral, since the gravity will be different along points from the surface to the core. Then, there isn't an easy way to tell how much of the energy from the annihilation will be converted to kinetic energy instead of heating up bits of former-earth. And it would probably not be the case that the annihilation happens all at once, or that the energy flux would be uniform across the unit sphere, so you cannot be certain where the center of gravity will be.

Anyway, with all that, I would say that it is safe to assume that the amount of anti-matter needed is bounded by the mass of the Earth.

[Thy_Reaper]

All my data is from Google, so ask it to back me up

Earth has a mass of 5.9742 x 10^24 kg.
Escape velocity is 11 km/s approx.
7.228782 × 10^32 (72,278,200,000,000,000,000,000,000,000,000) Joules are needed to blow the planet up.
Based on e = mc^2, 8.0431047 × 10^15 kilograms of a matter/anti-matter mix is needed to detonate the planet, so just inject 4.02155235 x 10^15 kg of anti-matter into the core.
That's 4,021,552,350 million kilograms of anti-matter... ouch.

Well, good luck on getting that

[PvK]

E = mass x C^2 is valid to give the energy for total conversion from matter to energy. But ya, assuming that's what you can get from an anti-matter bomb is an assumption.

Nuclear weapons kilotons are in terms of equivalent explosive force compared to a certain mass of T.N.T., which of course has its own conversion factor involved. I bet it's not too hard to google up.

There is of course another web page with lots of discussion about what it takes to destroy a planet in various ways.

[PvK]

According to that theory, the universe seems to exceed the "escape velocity from the Big Bang".

However, this is all rather presumptuous speculative interpretation about the meaning of what we're seeing from our perspective.

A mere few hundred years ago, the general idea was you fell off the edge of the earth once you sailed past the Azores from Europe...

I'm not convinced that modern cosmologists have got it nearly as right as some people might assume.

PvK

[PvK]

The Expanding Universe theory is that gravity is too weak to slow down something moving quickly away that is already an astronomical distance away. Gravity gets weaker and weaker the farther something is away. There is a limit to how much its force will ever add up to beyond a certain distance, so if the distance is increasing, and effect of gravity decreasing, things can escape gravity. The question then became exactly how massive is the universe, and how far is it apart, how fast does it seem to be expanding?

However, after many years of trying to figure that out based on all sorts of assumptions (which made sense, but are still just theories), cosmologists are starting to decide that some even more basic assumptions seem to likely be not correct, such as that the rules of the universe remain constant over time and distance...

The idea that we are seeing the universe all receding at increasing speeds at great distance is all based on assumptions about how to interpret the light we see based on a mountain of theories. It's an extremely sophisticated mountain of theories, but it's still an active volcano, so to speak.

PvK

[Renegade 13]

Hmmm, that's an interesting link, thanks Capnq! So there is a theory for the asymmetry between antimatter and matter, though unproven.