Phil wrote:
"Tom Roberts" wrote in message
m...
there are things which _physically_ propagate
faster than c, such as [...]the crossing point of a (gedanken)
pair of scissors [...]. While these cannot be used to send information
faster than c, they can all be measured so "physical" certainly applies.

I don't think the crossing point of the scissors can exceed the speed of
light.

It requires an unusual "pair of scissors", for which the blades are
moving not from a pivot but all along their length. Think of two slabs
that will overlap like scissors blades, having angled edges, moving
towards each other such that the point of intersection of the angled
edges of the slabs moves rapidly perpendicularly to their motion -- for
small enough angle the point can move arbitrarily fast sideways. But it
cannot transfer information, because the entire slabs were already put
into motion.

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| | |
. | v
. |
. |

"Tom Roberts" wrote in message
et...
Phil wrote:
"Tom Roberts" wrote in message
m...
there are things which _physically_ propagate
faster than c, such as [...]the crossing point of a (gedanken)
pair of scissors [...]. While these cannot be used to send information
faster than c, they can all be measured so "physical" certainly
applies.

I don't think the crossing point of the scissors can exceed the speed of
light.

It requires an unusual "pair of scissors", for which the blades are
moving not from a pivot but all along their length. Think of two slabs
that will overlap like scissors blades, having angled edges, moving
towards each other such that the point of intersection of the angled
edges of the slabs moves rapidly perpendicularly to their motion -- for
small enough angle the point can move arbitrarily fast sideways. But it
cannot transfer information, because the entire slabs were already put
into motion.

|------------|
| |
| | |
. | v
. |
. |
.

.
. |
. |
. | ^
| | |
| |
|-----------|


Tom Roberts

Sure, that makes sense.

Phil

"Sorcerer" wrote in message .uk...

"Dirk Van de moortel" wrote
in message ...
|
| "Rudolf Drabek" wrote in message
ups.com...
|
| Tom Roberts schrieb:
|
| Rudolf Drabek wrote:
| c with the value of +-300000 km/s is the physically infinite value
for
| speed.
|
| The very bad PUN you use on the word "infinite" is neither helpful nor
| useful. Use words with their normal meanings or you risk serious
| misunderstandings (as evidenced around here daily).
|
| I said and mean "physically infinite".
| What I want to express is, that adding a velocity to the "physically
| infinite value of c" the sum remains the same, as in math .
|
| But velocities are not added at all.

HAHAHAHA!
"But the ray moves relatively to the initial point of k, when measured in
the stationary system, with the velocity c-v"

[Not for Androcles]

This is about closing velocity, aka relative velocities
between two objects:
A measures B to have velocity u.
A measures C to have velocity v.
So A will measure the distance between B and C to
change with (closing/relative) velocity u - v.
This is closing/relative velocity (vector) addition/subtraction.

The other situation is
A measures B to have velocity u.
B measures C to have velocity v.
So A will measure C to have velocity
( u + v ) / ( 1 + u v/c^2 )
This is not addition/subtraction.

The fact that Androcles At School's brain has insufficiently
developed to be able to see the difference, is another reason
why we love him so much :-)

He should have listened to Miss Windy:
http://users.telenet.be/vdmoortel/di...esAtSchool.gif

Dirk Vdm

"Dirk Van de moortel" wrote
in message ...
|
| "Sorcerer" wrote in message
.uk...
|
| "Dirk Van de moortel"
wrote
| in message ...
| |
| | "Rudolf Drabek" wrote in message
| ups.com...
| |
| | Tom Roberts schrieb:
| |
| | Rudolf Drabek wrote:
| | c with the value of +-300000 km/s is the physically infinite
value
| for
| | speed.
| |
| | The very bad PUN you use on the word "infinite" is neither helpful
nor
| | useful. Use words with their normal meanings or you risk serious
| | misunderstandings (as evidenced around here daily).
| |
| | I said and mean "physically infinite".
| | What I want to express is, that adding a velocity to the "physically
| | infinite value of c" the sum remains the same, as in math .
| |
| | But velocities are not added at all.
|
| HAHAHAHA!
| "But the ray moves relatively to the initial point of k, when measured
in
| the stationary system, with the velocity c-v"
|
| [Not for Androcles]
|
| This is about closing velocity, aka relative velocities
| between two objects:

HAHAHAHA!
c-v is an opening velocity, ****head, and there is only one
velocity between two objects, you ****in' moron.
ROFLMAO!

Androcles

"Sorcerer" wrote in message . uk...


[not for Androcles At School, I said]

Androcles At School should have listened to Miss Wendy:
http://users.telenet.be/vdmoortel/di...esAtSchool.gif

Dirk Vdm

****heads should listen to their tin god when he gets it right.


That sucks, this is the English version.
http://www.fourmilab.ch/etexts/einstein/specrel/www/

"we shall, however, find in what follows, that the velocity of light in our
theory plays the part, physically, of an infinitely great velocity."

In kraut:
http://www.physics.utoledo.edu/~ljc/speciaal.html

"wir werden übrigens in den folgenden Betrachtungen finden, daß die
Lichtgeschwindigkeit in unserer Theorie physiaklisch die Rolle der unendlich
großen Geschwindigkeit spielt. "


" der unendlich großen Geschwindigkeit " --- HAHAHA

(English translation --- HAHAHAHAHAHAHAHAHAHA! )

Dork plays the part of the local village dog tord.




| HAHAHAHA!
| "But the ray moves relatively to the initial point of k, when measured
in
| the stationary system, with the velocity c-v" - Einstein.
|

DORK:
| [Not for Androcles]
|
| This is about closing velocity, aka relative velocities
| between two objects:

HAHAHAHA!
c-v is an opening velocity, ****head, and there is only one
velocity between two objects, you ****in' moron.
ROFLMAO!



Androcles

Dirk Van de moortel schrieb:

"Rudolf Drabek" wrote in message ups.com...

Tom Roberts schrieb:

Rudolf Drabek wrote:
c with the value of +-300000 km/s is the physically infinite value for
speed.

The very bad PUN you use on the word "infinite" is neither helpful nor
useful. Use words with their normal meanings or you risk serious
misunderstandings (as evidenced around here daily).

I said and mean "physically infinite".
What I want to express is, that adding a velocity to the "physically
infinite value of c" the sum remains the same, as in math .

But velocities are not added at all.
They are sort of *combined* in the following sense
A measures B to have velocity u.
B measures C to have velocity v
So A will measure C to have velocity
( u + v ) / ( 1 + u v/c^2 )
This is not addition.
Only in the limit for very small u and v it looks like
addition, and in Galilean relativity we deal with small
velocities, so ...

This helped me to understand the weird behaviour of light to be emitted
and received with c even if the receiver is moving with respect to the
emitter.
So the value of 300000 km/s which is not an infinite one, behaves like
an infinite value for light.
Therefore I said that, some lines above.
My surprise of my finding is, that c behaves like an infinite value. I
never heard/read this to date.

I heard it quite a few times.
Even Einstein said it in the very beginning:
http://www.fourmilab.ch/etexts/einstein/specrel/www/
| For velocities greater than that of light our deliberations
| become meaningless; we shall, however, find in what follows,
| that the velocity of light in our theory plays the part,
| physically, of an infinitely great velocity.

Yes, thank's, chapter 4. I have it at home in German and English. It
describes exactly what I want to say.
The same words nearly. How I came to that see beginning of thread.
Finding something by myself really again makes it anyway easier to
understand compared to reading -and not understanding immediate- it.

Tot ziens Rudi
So for me the thread is closed.

Cheers,
Dirk Vdm

Sorcerer schrieb:

"Bluewin" wrote in message
...
| "Rudolf Drabek" schrieb im Newsbeitrag
| ups.com...
|
| .....
| .....
| So the value of 300000 km/s which is not an infinite one, behaves like
| an infinite value for light.
| Therefore I said that, some lines above.
| My surprise of my finding is, that c behaves like an infinite value. I
| never heard/read this to date.
|
| You find it in Einsteins famous paper of 1905 (§4, Seite 903):
|
| http://www.pro-physik.de/Phy/pdfs/ger_890_921.pdf

That sucks, this is the English version.
http://www.fourmilab.ch/etexts/einstein/specrel/www/

"we shall, however, find in what follows, that the velocity of light in our
theory plays the part, physically, of an infinitely great velocity."

In kraut:

Thank you, Androcles. I found it.
Are Austrians also Krauts?
Rudi smiling
http://www.physics.utoledo.edu/~ljc/speciaal.html

"wir werden übrigens in den folgenden Betrachtungen finden, daß die
Lichtgeschwindigkeit in unserer Theorie physiaklisch die Rolle der unendlich
großen Geschwindigkeit spielt. "


" der unendlich großen Geschwindigkeit " --- HAHAHA

(English translation --- HAHAHAHAHAHAHAHAHAHA! )
What would de Sitter say to Algol?

Androcles

Sorcerer schrieb:

****heads should listen to their tin god when he gets it right.


That sucks, this is the English version.
http://www.fourmilab.ch/etexts/einstein/specrel/www/

"we shall, however, find in what follows, that the velocity of light in our
theory plays the part, physically, of an infinitely great velocity."

In kraut:
http://www.physics.utoledo.edu/~ljc/speciaal.html

"wir werden übrigens in den folgenden Betrachtungen finden, daß die
Lichtgeschwindigkeit in unserer Theorie physiaklisch die Rolle der unendlich
großen Geschwindigkeit spielt. "


" der unendlich großen Geschwindigkeit " --- HAHAHA

(English translation --- HAHAHAHAHAHAHAHAHAHA! )

Dork plays the part of the local village dog tord.




| HAHAHAHA!
| "But the ray moves relatively to the initial point of k, when measured
in
| the stationary system, with the velocity c-v" - Einstein.
|

DORK:
| [Not for Androcles]
|
| This is about closing velocity, aka relative velocities
| between two objects:

HAHAHAHA!
| c-v is an opening velocity, ****head, and there is only one
| velocity between two objects, you ****in' moron.
Why are you using such expressions?
ROFLMAO!
I do not agree. If c plays the role of an infinte value.
It does not open. It remains c.
But I know that c is no limit for you. That's the point.
rgds Rudi


Androcles|

Sorcerer wrote:
"Dirk Van de moortel" wrote
in message ...
|
| "Sorcerer" wrote in message
.uk...
|
| "Dirk Van de moortel"
wrote
| in message ...
| |
| | "Rudolf Drabek" wrote in message
| ups.com...
| |
| | Tom Roberts schrieb:
| |
| | Rudolf Drabek wrote:
| | c with the value of +-300000 km/s is the physically infinite
value
| for
| | speed.
| |
| | The very bad PUN you use on the word "infinite" is neither helpful
nor
| | useful. Use words with their normal meanings or you risk serious
| | misunderstandings (as evidenced around here daily).
| |
| | I said and mean "physically infinite".
| | What I want to express is, that adding a velocity to the "physically
| | infinite value of c" the sum remains the same, as in math .
| |
| | But velocities are not added at all.
|
| HAHAHAHA!
| "But the ray moves relatively to the initial point of k, when measured
in
| the stationary system, with the velocity c-v"
|
| [Not for Androcles]
|
| This is about closing velocity, aka relative velocities
| between two objects:

HAHAHAHA!
c-v is an opening velocity, ****head, and there is only one
velocity between two objects, you ****in' moron.

Right there is your fundamental break with SR. The a priori
assumption that relative velocity is invariant is incompatible
with the light postulate.

You cannot use that assumption to criticize the mathematics of
SR, because it is not found anywhere in SR.

You can, however, use it to develop an alternative theory, and
let experiment sort it out.