"Donal" wrote in message
...

"Jeff Morris" wrote in message
...

"Donal" wrote in message
...

In fact, I think that your use of the word "float" reveals that you
don't
understand the situation at all. Your astronaut wouldn't feel any
difference between a free fall orbit and a headlong race into
deepest
space, - would he?

So tell us, what is the difference?

Acceleration.

No, the acceleration is the same, more or less. (Not counting the
difference in
distance from the Earth, or air resistance, etc.) The only real
difference is that
the astronaut has enough velocity (hopefully) to miss the Earth as he
falls.


That was a very revealing answer.

Earlier in the thread you were confident enough about your position to
question my lack of education.

Now you seem to think that an object travelling at "x" miles an hour in a
straight line ("headlong into space") has the same acceleration as a body
travelling at "x" miles an hour in orbit.

Actually, I was saying that any body under the influence of Earth's gravity will
"feel" the same force, more or less. It doesn't matter whether its falling off a
cliff, in orbit, or leaving orbit into space. The pull of the Earth is the same,
adjusting of course, for the distance.

It turns out that most non-technically inclined people think that these are three
completely different situations (as they are, in some respects) but in all three the
body is being accelerated by gravity exactly the same.

Sorry Donal, that's physics. If you had taken a physics course, you might understand
that. Your continued rant is making you look rather silly.




It's probably time that you consulted your physics partner. Before you let
him read what you have written, you should make sure that there is a
cloakroom near the PC. Otherwise, have a potty close at hand - because he
is really going to **** himself when he reads your words.


Actually, my partner was given a PhD in Astrophysics only if he promised to continue
as a programmer.

How about my former boss, he won the Nobel Prize in Physics a few years ago.





Haven't you ever seen astronauts floating?

Yes.... but they are constantly changing direction.... and therefor they
should be aware of the effects of acceleration.


I must admit this subtlety has perplexed me - clearly the don't feel the G
force,
since it the same as a car in a tight turn. But I keep thinking it should
be
detectable, if only because the path is curving.

Yeah. It's called acceleration - a bit like G-force.

Please note that "a bit" = "exactly" in European understatement.




He must feel a constant force as his direction
of travel changes. I wonder if this has been documented on the
Internet?

http://science.howstuffworks.com/weightlessness1.htm

That is a very simplistic explanation. It refers to the fact that the
astronauts will feel the acceleration at take-off, and yet it doesn't
seem
to understand that a change of direction is also acceleration.

We humans can detect acceleration. If you sit in an automobile with
your
eyes closed, then you can feel an increase or decrease in speed .... or
a
change of direction!! As the astronauts are subjected to a constant
change
of direction, I suspect that they might not feel that they are
completely
free-floating.


Of course, from a General Relativity, Gravity Well point of view, the
obital path is a
straight line in curved space. I should know the answer here - let me
cogitate ...

No, you don't know the answer. Trust me. Despite my dreadful education, I
am confident that someone who doesn't understand the basic principles of
acceleration is incapable of getting their head around the TGR. Cogitation
would be a complete waste of your time.

OK, why don't you explain to us? How does someone in orbit determine they are
travelling a curved path. No fair using outside references. No fair looking for
effects over time. What sort of device will instantaneously tell you the local
gravitational field? I'm not saying its impossible, but its not obvious.








What does your physics friend say about this?
He would probably deplore the lack of education in your country.

Ask him anyway!

Actually, it was Scout's friend. However, you should remember I majored
in physics
and worked for NASA doing spacecraft navigation. I may be rusty now, but
25 years ago
I really knew this stuf!

GULP!!!

So why do you not seem to understand the difference between "velocity" and
"speed"?

Where did I talk about that??? You're losing it Donal.

So, please explain to all of us: what is the difference between velocity and speed,
and how was that relevent to anything I said?








Perhaps, if you allowed him to read the thread, he might be amazed at
your
lack of reading ability. After all, I've already explained that I gave
up
Physics at an early stage.

I haven't forgotton that. It was just a little dig since usually you
Brits complain
about our sorry education.

Little digs are very welcome. I appreciate a good insult - and calling me
"you Brits" is definitelay a reasonable insult. You're not lagging too far
behind Joe! He called me a Brit about six months ago.


Oh, sorry, I forgot. That explains your lack of education.