[RadioAstronomer]

"then how come none has visited earth?"

Because of the distances and energies involved. The Fermi Paradox is pure codswallop IMHO.

[longshadow]

Fermi Paradox Redux

[furball4paws]

Amen brother.

It is really difficult for most people to grasp the vast distances and times and costs to cross those distances.

However, I think we will try it in some way at some future time.

Besides, those who wonder should check out the theory of Directed Panspermia - a realistic solution, but it begs the question of the initial source for galactic life.

[AndrewC]

Because of the distances and energies involved. The Fermi Paradox is pure codswallop IMHO.

I take it then that you don't believe humankind can ever explore another solar system. (because if we can then it is a process of time and reproduction etc....)

[Joe Hadenuf]

Because of the distances and energies involved. The Fermi Paradox is pure codswallop IMHO.

I concur.

[edsheppa]

Because of the distances and energies involved...

They aren't as great as they seem, in cosmic terms of course. It's entirely reasonable with realistic improvements in current technology to cross the galaxy in a million years or so. Basically you'd need a 100 fold increase in rocket exhaust velocities. I think that'd be easily achieved with nuclear based propulsion.