The Equivalence of Gravity and Acceleration


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Topic: Science > Physics
User: "Nick"
Date: 07 May 2007 11:49:36 PM
Object: The Equivalence of Gravity and Acceleration
Einstein's Equivalence Principle states that gravity and an
accelerating frame are both equivalent to a rate of change of
velocity. A rate of time is behind any change such as change in
velocity. So a rocket firing its engines has an acceleration defined
as its rate of change of velocity through space.
That same rocket sitting on the launch pad has the equivalence of an
acceleration of 1G yet it is not moving. Since it isn't moving NO
[I]RATE[/I] OF CHANGE can apply. Time does not effect the kind of
relative acceleration this rocket has sitting on the launch pad. It is
in a manner of speaking an unmoving acceleration; a timeless one
similar to instantaneous change.
So Einstein's Equivalence Principle should not be as strict as to say
that time rate is involved with both kinds of acceleration.
What is interesting is that once you remove the rate that side of the
principle becomes equivalent to a change in velocity alone. This
change has a maximum limit of below a light speed change. So without
rate timeless acceleration has a limit. Not so for the accelerating
rocket firing its engines. It has a time rate of change in velocity
and this logically means that it has no limit on acceleration. Bear
with me. You can see this by shrinking the time involved in achieving
near light speed. As the time interval gets smaller acceleration goes
up apparently without limit; it is potentially infinite because it
could reach almost light speed in much less than a second This is an
acceleration beyond 1C.
Gravity and acceleration are equivalent as Einstein said but there is
a difference between the two. This means that there is a way to know
whether you are in gravity or you are accelerating. It is by weighing
something.
MITCH RAEMSCH -- LIGHT FALL --
.

User: "The TimeLord"

Title: Re: The Equivalence of Gravity and Acceleration 08 May 2007 12:37:35 AM
Nick wrote in sci.physics.relativity:

Einstein's Equivalence Principle states that gravity and an
accelerating frame are both equivalent to a rate of change of
velocity. A rate of time is behind any change such as change in

Actually that is not the Equivalence Principle. The Equivalence
Principle just states that inertial mass and gravitational mass are
equivalent.

velocity. So a rocket firing its engines has an acceleration defined
as its rate of change of velocity through space.

That same rocket sitting on the launch pad has the equivalence of an
acceleration of 1G yet it is not moving. Since it isn't moving NO
[I]RATE[/I] OF CHANGE can apply. Time does not effect the kind of

[...]

could reach almost light speed in much less than a second This is an
acceleration beyond 1C.

That is what happens when people try to discuss Relativity without
understanding Relativity or its math.


Gravity and acceleration are equivalent as Einstein said but there is
a difference between the two. This means that there is a way to know
whether you are in gravity or you are accelerating. It is by weighing
something.

Wrong. The result of the Equivalence Principle (used correctly) is
that you can _not_ tell the difference between acceleration due to
gravity and acceleration due to changing velocity. The two end up
being equivalent.
--
// The TimeLord says:
// Pogo 2.0 = We have met the aliens, and they are us!
.

User: "Uncle Al"

Title: Re: The Equivalence of Gravity and Acceleration 08 May 2007 09:15:57 AM
Nick wrote:


Einstein's Equivalence Principle states that gravity and an
accelerating frame are both equivalent to a rate of change of
velocity.

[snip crap]
http://en.wikipedia.org/wiki/Equivalence_principle

MITCH RAEMSCH -- LIGHT FALL --

MITCH RAEMSCH -- IDIOT --
--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/lajos.htm#a2
.

User: "Tom Roberts"

Title: Re: The Equivalence of Gravity and Acceleration 08 May 2007 09:06:35 AM
Nick wrote:

Einstein's Equivalence Principle states that gravity and an
accelerating frame are both equivalent to a rate of change of
velocity.

No. The equivalence principle states that to first order an acceleration
and a gravitational field are equivalent (meaning experimentally
indistinguishable). There's no mention of "rate of change of velocity",
which seems to be where you get confused.
This is sometimes stated as "inertial mass and gravitational
mass are equal". That is not general enough, as in GR
mass is not the only "source" of gravitational fields.

A rate of time is behind any change such as change in
velocity. So a rocket firing its engines has an acceleration defined
as its rate of change of velocity through space.

Huh?? This is pure word salad.

That same rocket sitting on the launch pad has the equivalence of an
acceleration of 1G yet it is not moving.

Well, not moving RELATIVE TO THE LAUNCH PAD. Remember that "moving" is
only defined relative to some coordinate system or object.

Since it isn't moving NO
[I]RATE[/I] OF CHANGE can apply. Time does not effect the kind of
relative acceleration this rocket has sitting on the launch pad. It is
in a manner of speaking an unmoving acceleration; a timeless one
similar to instantaneous change.

More word salad with no content.

So Einstein's Equivalence Principle should not be as strict as to say
that time rate is involved with both kinds of acceleration.

You are confused -- the equivalence principle doesn't mention "time
rate" at all.

Gravity and acceleration are equivalent as Einstein said but there is
a difference between the two.

Certainly. Equivalence does not mean equality or identity.

This means that there is a way to know
whether you are in gravity or you are accelerating. It is by weighing
something.

No, that is not sufficient -- that is a first order measurement, and
look above to see the correct statement of the equivalence principle. To
distinguish between the two you must either perform a second order
experiment (e.g. measure tides), or must look outside to see whether you
are in a rocket or near a planet (etc.).
Tom Roberts
.
User: "BURT"

Title: Re: The Equivalence of Gravity and Acceleration 08 May 2007 10:39:15 AM
On May 8, 7:06 am, Tom Roberts <tjroberts...@sbcglobal.net> wrote:

Nick wrote:

Einstein's Equivalence Principle states that gravity and an
accelerating frame are both equivalent to a rate of change of
velocity.


No. The equivalence principle states that to first order an acceleration
and a gravitational field are equivalent (meaning experimentally
indistinguishable). There's no mention of "rate of change of velocity",
which seems to be where you get confused.

This is sometimes stated as "inertial mass and gravitational
mass are equal". That is not general enough, as in GR
mass is not the only "source" of gravitational fields.

A rate of time is behind any change such as change in
velocity. So a rocket firing its engines has an acceleration defined
as its rate of change of velocity through space.


Huh?? This is pure word salad.

EAT YOUR OWN SALAD.


That same rocket sitting on the launch pad has the equivalence of an
acceleration of 1G yet it is not moving.


Well, not moving RELATIVE TO THE LAUNCH PAD. Remember that "moving" is
only defined relative to some coordinate system or object.

Since it isn't moving NO
[I]RATE[/I] OF CHANGE can apply. Time does not effect the kind of
relative acceleration this rocket has sitting on the launch pad. It is
in a manner of speaking an unmoving acceleration; a timeless one
similar to instantaneous change.


More word salad with no content.

TAKE OUT THE RATE


So Einstein's Equivalence Principle should not be as strict as to say
that time rate is involved with both kinds of acceleration.


You are confused -- the equivalence principle doesn't mention "time
rate" at all.

Einstein defined acceleration as the rate of change of velocity and he
said that this was equivalent to gravity alone.


Gravity and acceleration are equivalent as Einstein said but there is
a difference between the two.


Certainly. Equivalence does not mean equality or identity.

This means that there is a way to know
whether you are in gravity or you are accelerating. It is by weighing
something.


No, that is not sufficient -- that is a first order measurement, and

IF YOU MEASURE WEIGHT IN A SHIP ACCELERATING AT ABOVE 1C
IT WILL WEIGH MORE THAN IT EVER COULD IN GRAVITY.
THAT IS HOW IT WILL BE KNOWN.
.


User: "Nick"

Title: Re: The Equivalence of Gravity and Acceleration 08 May 2007 12:08:08 AM
On May 7, 9:49 pm, Nick <macromi...@yahoo.com> wrote:

Einstein's Equivalence Principle states that gravity and an
accelerating frame are both equivalent to a rate of change of
velocity. A rate of time is behind any change such as change in
velocity. So a rocket firing its engines has an acceleration defined
as its rate of change of velocity through space.

That same rocket sitting on the launch pad has the equivalence of an
acceleration of 1G yet it is not moving. Since it isn't moving NO
[I]RATE[/I] OF CHANGE can apply. Time does not effect the kind of
relative acceleration this rocket has sitting on the launch pad. It is
in a manner of speaking an unmoving acceleration; a timeless one
similar to instantaneous change.

So Einstein's Equivalence Principle should not be as strict as to say
that time rate is involved with both kinds of acceleration.

What is interesting is that once you remove the rate that side of the
principle becomes equivalent to a change in velocity alone. This
change has a maximum limit of below a light speed change. So without
rate timeless acceleration has a limit. Not so for the accelerating
rocket firing its engines. It has a time rate of change in velocity
and this logically means that it has no limit on acceleration. Bear
with me. You can see this by shrinking the time involved in achieving
near light speed. As the time interval gets smaller acceleration goes
up apparently without limit; it is potentially infinite because it
could reach almost light speed in much less than a second This is an
acceleration beyond 1C.

Gravity and acceleration are equivalent as Einstein said but there is
a difference between the two. This means that there is a way to know
whether you are in gravity or you are accelerating. It is by weighing
something.

MITCH RAEMSCH -- LIGHT FELL --

There is a possibility of telling the difference between gravity and
acceleration by distinguishing the weight that is caused by an above
1C
acceleration of a rocket. That is how it would be done. All you need
to
know first is the rest mass of what you are weighing in the rocket;
and that is rather simple to achieve.
MITCH RAEMSCH -- LIGHT FELL --
.

User: "Eric Gisse"

Title: Re: The Equivalence of Gravity and Acceleration 08 May 2007 02:07:25 PM
On May 7, 9:49 pm, Nick <macromi...@yahoo.com> wrote:
[...]
_______ ____ ____
|__ __/ __ \ / __ \
| | | | | | | | |
| | | | | | | | |
| | | |__| | |__| |
|_| \____/ \____/
_____ _____ ______ ______ _____ _____ _ _ _ _______
| __ \_ _| ____| ____|_ _/ ____| | | | | |__ __|
| | | || | | |__ | |__ | || | | | | | | | |
| | | || | | __| | __| | || | | | | | | | |
| |__| || |_| | | | _| || |____| |__| | |____| |
|_____/_____|_| |_| |_____\_____|\____/|______|_|
______ ____ _____ __ ______ _ _
| ____/ __ \| __ \ \ \ / / __ \| | | |
| |__ | | | | |__) | \ \_/ / | | | | | |
| __|| | | | _ / \ /| | | | | | |
| | | |__| | | \ \ | | | |__| | |__| |
|_| \____/|_| \_\ |_| \____/ \____/
.
User: "BURT"

Title: Re: The Equivalence of Gravity and Acceleration 09 May 2007 06:00:43 PM
Einstein's Equivalence Principle states that gravity and an
accelerating frame are both equivalent to a rate of change of
velocity. A rate of time is behind any change such as change in
velocity. So a rocket firing its engines has an acceleration defined
as its rate of change of velocity through space.
That same rocket sitting on the launch pad has the equivalence of an
acceleration of 1G yet it is not moving. Since it isn't moving NO
[I]RATE[/I] OF CHANGE can apply. Time does not effect the kind of
relative acceleration this rocket has sitting on the launch pad. It
is
in a manner of speaking an unmoving acceleration; a timeless one
similar to instantaneous change.
So Einstein's Equivalence Principle should not be as strict as to say
that time rate is involved with both kinds of acceleration.
What is interesting is that once you remove the rate that side of the
principle becomes equivalent to a change in velocity alone. This
change has a maximum limit of below a light speed change. So without
rate timeless acceleration has a limit. Not so for the accelerating
rocket firing its engines. It has a time rate of change in velocity
and this logically means that it has no limit on acceleration. Bear
with me. You can see this by shrinking the time involved in achieving
near light speed. As the time interval gets smaller acceleration goes
up apparently without limit; it is potentially infinite because it
could reach almost light speed in much less than a second This is an
acceleration beyond 1C.
Gravity and acceleration are equivalent as Einstein said but there is
a difference between the two. This means that there is a way to know
whether you are in gravity or you are accelerating. It is by weighing
something.
MITCH RAEMSCH -- LIGHT FALL --


[...]
_______ ____ ____
|__ __/ __ \ / __ \
| | | | | | | | |
| | | | | | | | |
| | | |__| | |__| |
|_| \____/ \____/

_____ _____ ______ ______ _____ _____ _ _ _ _______
| __ \_ _| ____| ____|_ _/ ____| | | | | |__ __|
| | | || | | |__ | |__ | || | | | | | | | |
| | | || | | __| | __| | || | | | | | | | |
| |__| || |_| | | | _| || |____| |__| | |____| |
|_____/_____|_| |_| |_____\_____|\____/|______|_|

______ ____ _____ __ ______ _ _
| ____/ __ \| __ \ \ \ / / __ \| | | |
| |__ | | | | |__) | \ \_/ / | | | | | |
| __|| | | | _ / \ /| | | | | | |
| | | |__| | | \ \ | | | |__| | |__| |
|_| \____/|_| \_\ |_| \____/ \____/

.
User: "Uncle Al"

Title: Re: The Equivalence of Gravity and Acceleration 09 May 2007 09:44:15 PM
BURT wrote:


Einstein's Equivalence Principle states that gravity and an
accelerating frame are both equivalent to a rate of change of
velocity.

IDIOT
http://en.wikipedia.org/wiki/Equivalence_principle

MITCH RAEMSCH -- LIGHT FALL --

MITCH RAEMSCH -- IDIOT --


[...]
_______ ____ ____
|__ __/ __ \ / __ \
| | | | | | | | |
| | | | | | | | |
| | | |__| | |__| |
|_| \____/ \____/

_____ _____ ______ ______ _____ _____ _ _ _ _______
| __ \_ _| ____| ____|_ _/ ____| | | | | |__ __|
| | | || | | |__ | |__ | || | | | | | | | |
| | | || | | __| | __| | || | | | | | | | |
| |__| || |_| | | | _| || |____| |__| | |____| |
|_____/_____|_| |_| |_____\_____|\____/|______|_|

______ ____ _____ __ ______ _ _
| ____/ __ \| __ \ \ \ / / __ \| | | |
| |__ | | | | |__) | \ \_/ / | | | | | |
| __|| | | | _ / \ /| | | | | | |
| | | |__| | | \ \ | | | |__| | |__| |
|_| \____/|_| \_\ |_| \____/ \____/

--
Uncle Al
http://www.mazepath.com/uncleal/
(Toxic URL! Unsafe for children and most mammals)
http://www.mazepath.com/uncleal/lajos.htm#a2
.

User: "Tom Roberts"

Title: Re: The Equivalence of Gravity and Acceleration 09 May 2007 09:13:08 PM
BURT wrote:

Einstein's Equivalence Principle states that gravity and an
accelerating frame are both equivalent to a rate of change of
velocity.

Repeating incorrect statements about the equivalence principle does not
change it. Your argument is invalid. And as I said before, weighing
something cannot distinguish between gravity and acceleration -- that
requires a higher-order measurement (e.g. measuring tides).
In GR, a rocket sitting on its launch pad experiences a proper
acceleration of 9.8 m/s^2 [#], even though it is not moving relative to
the surface of the earth. But one does need to understand the basics of
GR, and the standard vocabulary I used, in order to understand that. I
suggest:
Geroch, _General_Relativity_from_A_to_B_.
[#] Plus minuscule corrections due to earth's rotation and
motion around the sun, the moon's motion around the earth, etc.
Tom Roberts
.

User: "Eric Gisse"

Title: Re: The Equivalence of Gravity and Acceleration 09 May 2007 07:36:53 PM
On May 9, 4:00 pm, BURT <macromi...@yahoo.com> wrote:
[snip stupidity]
_______ ____ ____
|__ __/ __ \ / __ \
| | | | | | | | |
| | | | | | | | |
| | | |__| | |__| |
|_| \____/ \____/
_____ _____ ______ ______ _____ _____ _ _ _ _______
| __ \_ _| ____| ____|_ _/ ____| | | | | |__ __|
| | | || | | |__ | |__ | || | | | | | | | |
| | | || | | __| | __| | || | | | | | | | |
| |__| || |_| | | | _| || |____| |__| | |____| |
|_____/_____|_| |_| |_____\_____|\____/|______|_|
______ ____ _____ __ ______ _ _
| ____/ __ \| __ \ \ \ / / __ \| | | |
| |__ | | | | |__) | \ \_/ / | | | | | |
| __|| | | | _ / \ /| | | | | | |
| | | |__| | | \ \ | | | |__| | |__| |
|_| \____/|_| \_\ |_| \____/ \____/
.

User: "Cosmik Debris"

Title: Re: The Equivalence of Gravity and Acceleration 09 May 2007 09:05:48 PM
On Thu, 10 May 2007 11:00:43 +1200, BURT <macromitch@yahoo.com> wrote:

Einstein's Equivalence Principle states that gravity and an
accelerating frame are both equivalent to a rate of change of
velocity.

No it doesn't.
--
Posted via a free Usenet account from http://www.teranews.com
.



User: "Igor"

Title: Re: The Equivalence of Gravity and Acceleration 08 May 2007 10:39:41 AM
On May 8, 12:49 am, Nick <macromi...@yahoo.com> wrote:

Einstein's Equivalence Principle states that gravity and an
accelerating frame are both equivalent to a rate of change of
velocity.

Buzzer! Wrong!
.


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