In the past, on Earth, it has largely been to exploit foreign resources and to expand the domestic territory.

Antimatter is not a source of energy for us, it's a method of storing energy, compact but inefficient.

Present annual world energy consumption is about equal to the annihilation energy of 4 tons of matter.

The sun and its retinue of planets drift as a group through the vast gulfs of space that separate the stars.

Years of science fiction have produced a mindset that it is human destiny to expand from Earth, to the Moon, to Mars, to the stars.

It would be a pity if, frustrated by the price of travel, we elected to become a society that never made contact, that never gave SETI a fair chance.

No one can deny the excitement of visiting another world.