> We humans have a hard time going at 30 km/sec (19 miles per
> second) or 0.001% light speed. At 0.001% light speed, that
> takes ten billion years to cross the galaxy.
We have a hard time achieving that speed or a hard time surviving
A hard time achieving that speed. We and everything else in the
galaxy are going a lot faster relative to the microwave radiation
background, but it is relative motion that counts.
A speed of 30 km/sec is not impossible with current, deployed
technologies. However, such a speed is expensive either in resources
or in time -- either the speed requires a lot of chemical fuel which
produces fairly high acceleration or it requires a long time with the
low acceleration of an ion engine. (NASA has done ground experiments
with a mini-magnetospheric plasma, which should provide reasonable
accelerations and speeds with an appropriate energy source, such as a
Robert J. Chassell GnuPG Key ID: 004B4AC8