Re: Is my friend full of BS?


"Edwards" <edwards@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
news:slrneek4ae.8dm.edwards@xxxxxxxxxxxxxxxxxxxxxxxxx
| On 2006-08-18, Sorcerer <Headmaster@xxxxxxxxxxxxxxxxxx> wrote:
| >
| > "Edwards" <edwards@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
| > news:slrneecgib.r7s.edwards@xxxxxxxxxxxxxxxxxxxxxxxxx
| >| On 2006-08-17, Sorcerer <Headmaster@xxxxxxxxxxxxxxxxxx> wrote:
| >| >
| >| > "Edwards" <edwards@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> wrote in message
| >| > news:slrnee9ilb.ehu.edwards@xxxxxxxxxxxxxxxxxxxxxxxxx
| >| >| On 2006-08-17, srp <srp2@xxxxxxxxxxxxxxxx> wrote:
| >| >| > Ben Newsam a écrit :
| >| >| >> On Thu, 17 Aug 2006 13:54:22 GMT, "Sorcerer"
| >| >| >> <Headmaster@xxxxxxxxxxxxxxxxxx> wrote:
| >| >| >>> "Ben Newsam" <ben.newsam@xxxxxxxxxxxxxx> wrote in message
| >| >| >>> news:q8r8e2lb4fhioveu9b8gghk2bientu6pk4@xxxxxxxxxx
|
| >| >| >>> | As I said above, there is no difference between your
experience
| >| >| >>> | of
| >| >| >>> | gravity in your chair on earth, and in your chair in a
| >| >| >>> | continuously
| >| >| >>> | accelerating spaceship. The effects are the same.
|
| >| >| >>>
| >| >| >>> Can't be, I move in the spacecraft relative to the ground.
| >| >| >>> I do not move relative to the ground while sitting in my chair
and
| >| >| >>> the Earth is quite definitely not expanding.
| >| >| >>
| >| >| >> I made no mention of what was actually happening, whatever that
| >| >| >> means
| >| >| >> anyway, merely that you cannot tell the difference. Your
instruments
| >| >| >> will not be able to tell either. You will measure 1g in both
cases.
| >| >| >
| >| >| > In your spacecraft, the acceleration is a steady 1 g, and if you
drop
| >| >| > a ball from shoulder high, the craft will accelerate at a steady 1
g
| >| >| > towards it. But on the ground, at sea level at some locations on
the
| >| >| > planets, if you have exactly 1 g at your ground level, an
identical
| >| >| > ball dropped from shoulder high will start by being submitted to
an
| >| >| > acceleration slightly less than 1 g, that will gradually tend to 1
g
| >| >| > as it reaches the ground.
| >| >| >
| >| >| > The final kinetic energy of the ball-ground collision will be
| >| >| > slightly
| >| >| > less on the earth and this can be very precisely calculated and
| >| >| > measured
| >| >| > by instruments.
| >| >|
| >| >| If you've got instruments that can "precisely calculate and measure"
| >| >| the difference between 1/(R_e + R_s)^2 and 1/(R_e)^2, where R_e is
the
| >| >| radius of the earth and R_s is the distance from your feet to your
| >| >| shoulders, then you've either got some truly amazing instruments
whose
| >| >| working principles I would dearly love to hear about, or else you've
| >| >| got the highest frigging shoulders I have ever heard of
| >| >| (i.e. communications satellites flying up your nose is a frequent
| >| >| problem for you).
| >| >|
| >| >| Either way, that situation is actually _completely irrelevant_ to a
| >| >| discussion of the principle of equivalence to which Ben Newsam was
| >| >| alluding above:
| >| >|
| >| >| > So, even from within your spacecraft you can know that you are not
| >| >| > sitting somewhere on the planet, but are in a steadily
accelerating
| >| >| > spacecraft.
| >| >|
| >| >| The principle of equivalence is concerned with _local_ measurements.
| >| ^^^^^^^^^^^^
| >|
| >| > ROFL!
| >| > Locally the world is flat, buddy, and locally I'm not obeying the
| >| > principle of equivalence because locally I'm not accelerating, I'm
| >| > balancing forces (locally)
| >|
| >| And you can _measure_ this how?
| >
| > By sitting in a chair, locally.
|
| What aspect of "sitting in a chair, locally" will _distinguish_
| between "balancing forces" in a gravitational field and "balancing
| forces" under an acceleration of the room the chair is attached to
| (e.g. a rocket ship)?

Relative to an external frame of reference (such as the Earth or
the rocket exhaust), the ship will be accelerating, energy will be
expended. Sitting in a chair at my desk, no energy is expended.
The principle of equivalence is myopic, just as its creator was.


| >| (Excluding _nonlocal_ measurements
| >| a la "looking out the window".)
| >
| > The principle of equivalence is concerned with _local_ measurements,
| > and outside my window I see my locality. Do you think local stops at
| > the window glass then? Your definition of "local" is rather vague.
|
| _My_ definition is vague? At least I can tell the difference between
| _locations_ inside and outside my window.
|
| > Have you been listening to Humpty Roberts?
| >
| > Humpty Roberts let out a great sigh.
| > " <sigh>", he said.
| > "The nuances of English. I was discussing the usage of words and
| > not the concepts they represent."
| > -- Tom Humpty Roberts tjroberts@xxxxxxxxxx
| > news:ZDmYf.51582$2O6.5573@xxxxxxxxxxxxxxxxxxxxxxxxxx
| >
| > You underlined _local_, did you not? What is the boundary of local,
| > "Edwards"?
| >
| > (And if you haven't understood it yet I'm taking the piss out you,
|
| Well, duh, I can hardly take someone seriously who in one breath
| enthusiastically agrees with someone claiming to be able to measure
| differences in the earth's graviational field between their shoulders
| and feet, and in the next breath exudes Zenlike pseudowisdom about the
| whole world, both inside and outside their window, being in their
| "locality".

I don't care whether you agree or not, whether you are a Muslim
or not, whether you prefer to travel by plane or car or not.
If you can't tell the difference between acceleration and force
it's not my problem.

|
| > so get wise and shove off.)
|
| Careful, you might actually _scare_ me at some point.
|
| >| > so the principle of equivalence is the principle
| >| > of local bull***, there is nothing equivalent about being in a local
| >| > centrifuge and sitting at my local desk.
| >| ^^^^^^^^^^
| >|
| >| Red herring, of course noone said it was (or could be) _exactly_
| >| equivalent to a rotating frame.
| >
| > Who is noone? I've never met him. Perhaps you mean "no one"
| > and your English is poor. Chicago word, is it?
|
| A language flame? That's rich.
| google "'androcles' 'english word ago'"
|
| > Rotating frames are quite common, actually.
|
| Never said they weren't. I said they're not what the equivalence
| principle is about, and therefore it's a red herring for you to bring
| them up.

acceleration is a red herring... ok. Have a nice life, but forget about
physics, you don't know any.
Androcles


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