Physics question about moving through air and water.

[Someone]

It may be RW enough for the original question, but it would still bug me... the same argument would suggest that the fly spell would propell the character at infinite speeds in a vacuum.

If the spell provides a thrust (force), ignoring relativistic effects, and having infinite time and a perfect vacuum, yes, you could reach infinite speed.

I would apply a 1/4th speed penalty: it abstracts out some of the surface area stuff (so no 1/50th speed), but still makes a huge difference.

You may be right, more or less. IIRC, air and water resistance increase proportionally with the speed^2, so the speed at wich the force provided by the spell and viscous resistance are equal is, in water, 1/(square root of 20). That means air speed=4,47 times water speed.

 

[Plane Sailing]

Oh, and if you are going to post to ridicule me for trying to include physics reality into my fantasy game world, don't bother. I genuinely don't care about your opinion.

Sheesh, when are you guys going to learn that when you mix real world science with magic, you get nothing but trouble?

Vaxalon, please don't bother to post this kind of comment when someone has specifically asked for it to be avoided. It doesn't make any contribution to the thread and even if it was meant tongue in cheek it can come across as a put down.

Regards,
Plane Sailing - (Mod)