flashlights and space ships

Just realized something.

In my last post, I was assuming that you’d be using a very large lightsail for interstellar travel, with an acceleration period measured in years. Current research is showing possible applications for lightsails within the solar system, with acceleration periods measured in months or weeks.

If you stay within the solar system, most of what I said remains true, with the exception of the last bit. The maximum speed would be much lower, meaning that collisions would not be as catastrophically devastating. (However, do note that interstellar space is almost entirely empty, AFAWK. Space within the solar system is a cosmic scrapyard by comparison.)


Of course I don’t fit in; I’m part of a better puzzle.

DW3–

I really like the link you provided. I was pleased to see that it makes two point that I sometimes make. It says that the concept of relativistic mass is technically poor, and is not used by physicists (except occasionally in simplified explanations to non-physicists). It also has link to a page titled: “What is the Mass of a Photon?”, in which it actually discounts common (but technically inaccurate) ways to determine the “relativistic” mass of a photon.