On 8 fév, 10:43, "harry" wrote:
wrote in message

...
On 8 fév, 09:39, "harry" wrote:

wrote in message

...
On Thu, 7 Feb 2008 wrote:

[...]

f(x)=c [sqrt(4ax + x^2)) / (2a - x)]

For a=0 that gives:

f(x)=c [sqrt(x^2)) / (- x)] = -c

What does your negative speed mean?!

: Not applicable.

: In context since either energy is present
and then velocity is in the direction of motion
or energy is absent and then velocity is zero.

: There is no such thing as less energy than zero
energy.

I agree! I'm afraid that your equation isn't applicable...

You are wrong. It totally applies.

As I wrote, it's important to be clear as to what you mean by
"relativistic". I've now asked twice for clarification. Let me ask a
third
time: exactly what do you mean by "relativistic"?
I mean relativistic mass increase with velocity.

OK, that's straightforward - Newtonian mechanics has been adapted
to SRT in just that way.

: Really?

: Then, show me how the kinetic energy has equation has
been transformed.

All standard textbooks of the 80s show that, such as Feynman's lectures on
physics.
See for example:http://www.bartleby.com/173/15.html

Invalid. The gamma factor is assumed, not derived.

andhttp://en.wikipedia.org/wiki/Mass_in_special_relativity

Invalid demonstration, for the same reason.

Show me real physics.

[..]

What does Galilei-relativistic means ?

Newtonian mechanics uses Galilean relativity between inertial frames.

: So it refers to relative localization.

NO, it refers to laws of nature independent of used reference frame.
Classical relativity is at the basis of Newtonian mechanics.

Whst has inertial classical relativity got to do with
relativistic mass increase ?

: Not applicable in context.
: Talking about absolute velocity related to local quantum of energy.

Doesn't sound as if you talk the same language, sorry. :-)

Can't be helped.

and
this was in the context of pointing out the importance of defining
terms
such as "relativistic". Most people would not say that Newtonian
mechanics is "relativistic",

Then "most people" don't know much. It is in no way relativistic.

Read that again: you answered like "most people" who "don't know much".
:-)

: Tried to see the shade of meaning, but didn't see it. I really meant
: that those who think that Newtonian mechanics is relativistic don't
: know much.

I know that you meant that: it implies that you belong to "most people" who
don't know about classical relativity. :-O)

No it means that I belong to people that understand that classical
mechanics is not relativistic in any way shape or form.

André Michaud