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

Dude, you've got to work on some of your physics stuff. First of, there is no such thing as the "centerfugal" force. That's just a misconception. You may be thinking of the "centripidal" force, but that does not "hold up" a sattelite, it actually pulls the sattelite toward the center of the earth. Grab yourself a physics textbook or something on orbital mechanics. Also, if the gravity acting on a sattelite was to suddenly stop, the sattelite wouldn't fly "up," but more "away." There is no force holding the sattlite "up." There is only one force acting on a sattelite while it's in orbit, gravity. Try to learn more about a complicated subject before you decide to write something about it.

I am not Dude! I am the stragbasher and you sir are a strag.

If you want to argue about precise meanings of words you need to spell them properly first. My entry made no reference to "centerfugal" force because there is, as you correctly pointed out, no such thing.

The original entry as submitted to the editor (who did a great job, btw) did point out that there was no such thing as "centrifugal" force, if that's what you are referring to. But it's a handy way for people to think of the situation and doesn't do any harm - so the caveat was removed in the interests of clarity.

I don't know how you spell such things in your part of the world, but I am aware of something called "centripetal" force. Again it was felt that scientific exactitude detracted from what is, after all, intended as a guide rather than as an authority.

The object of this entry was not to give a lesson on the niceties of scientific language, but to illustrate what was going on in language that ordinary people could understand. I later received an email from a university lecturer who had pointed his students at the article because it did precisely that, so I feel that the policy agreed with the editor was correct.

Have you contributed anything useful here yet or have you spent all your time here decrying the efforts of others?

Perhaps you could write an entry explaining some of the terms used by physicists and engineers in language that ordinary people feel comfortable with? Or perhaps you could offer an alternative version of this entry which is both rigorous and informative to those with little scientific training?

If you do then run it by me first and I'll help you with the spelling.

SB

A satelite is kept in orbit by its constant acceleration to wards the earth, because the earth is a sphere, the ground falls away at the same time, thus a satelite is constantly falling towards the centre of the earth, it just doesn't get there because the surface of the earth falls away at the smae time., if iv'e got this wrong please correct me as i'm taking A-levle physics in june!

have fun, and chill out!

Well, this is all basic Newtonian stuff - which is why I can mostly understand it. Much more interesting is what's going on that enables me to keep finding these postings. I haven't been here for months, and hadn't been here for months when I wrote the previous note.

Both times I got here shortly after someone else. What's going on? Why does nobody ever post here in the middle of my absence, or the day after I disappear again? It's probably quantum. If you pass your A -level and get your degree then maybe you can do some postgrad research into probability-cause-and-effect on the internet. Or some such.

If you get a Nobel prize then remember who gave you your start.

Meantimes, from the point of view of clear english (rather than rigorous physics) I wouldn't describe the Earth as falling away. Where can it be falling to? It's all so confusing to us laymen.

Hey, and don't ask me to correct your physics. That's what your teacher is paid for. And he/she would be better qualified than I am. (I hope!)Why not get him/her to correct MINE, and then hit up the editor with your suggestions for improvements. She's a nice lady and we'd both be glad to see the article refined.

(Actually there needs to be a proper space terminology/hardware project here at the guide, with this entry being just a part of the greater whole. Go for it. It's more interesting than revising. I promise you.)

All the best with your exams.

Just wondering, but how is the earth falling from the satelite. The revolution of the earth goes only in one direction and a satelite in geosync orbit woud eventually find itself in the Earths path.