h2g2 The Hitchhiker's Guide to the Galaxy: Earth Edition

alright there
wouldn't a missile fired east travel less than 1000 miles, while a missile fired west would travel farther,
because of the rotation of the earth?
Perhaps there is movement of the earths atmospere along with the planet which would cut down on all these effects
by introducing friction

Simplifying... sort of.

Picture an infinite flat plain. The plain is stationary. The missile is stationary. The target is stationary. The missile is fired, and travels to the target, 1000 miles.

Now picture exactly the same system, but the plain, and every single point on it, is moving at a *steady* speed relative to an arbitrary fixed point - it doesn't matter what that speed is, or what direction, but let's say it's 1000 miles an hour. This means that the missile and the target are both moving in the same direction at 1000 miles per hour. So, although with respect to that fixed point they're moving very fasy, with respect to *each other*, they're stationary. Like you and your PC screen, geordie jo - you're both moving around the sun at several thousand miles an hour, but relative to each other, you're not moving at all.

When you fire the missile, it will have a certain velocity relative to the fixed point BUT its velocity relative to the target will be exactly the same as it was in the example above.

This is because in both examples, with the plain stationary and with it moving at a steady speed, you are dealing with an INERTIAL FRAME OF REFERENCE - i.e. the system you are considering is not experiencing any changes of speed (i.e. accelerations)

Firing missiles around the equator, you don't get any changes of speed, because all the points on the equator are moving at the same speed.

Only when you fire things north or south do you start to notice the difference, because points on the equator are moving faster than points elsewhere.

You are right that all of this assumes no air resistance. Speaking of air - the Coriolis effect is actually responsible for the direction in which weather systems move.

It's worth checking out a couple of other entries on this subject... links to follow.

(thanks for reading this and commenting, btw. How did you find it?)


H.

Actually, all the links that are any use are in the entry - which come to think of it is how it should be! Doh!

H.

hiya,
(what is btw short for?)
Thanks for your posting. I don't understand it yet but it's interesting, I'll read it some more
(I found the thread after doing a search for sun)
toodlepip

btw = by the way
imho = in my humble opinion
rtfm = read the f***ing manual
lol = laughing out loud
rofl = rolls on floor laughing
lmao = laughing my a**e off
ttfn = tata for now.


Any others?
Thanks for reading, and commenting...

H.