"F. Kuik" wrote in message
...

"Androcles" schreef in bericht
news

"Martin Hogbin" wrote in message
...

"Androcles" wrote in message
...

"Martin Hogbin" wrote in message
...

"Androcles" wrote in message
...

No reason, if you have enough energy you can.

For 'enough' read 'infinite'.

Prove it.

How much do you think is needed then?

Martin Hogbin
.
E = 1/2mv^2, v = c = 1, m = 1, so in the units I've chosen, 0.5.
You can convert to SI units if you wish.
Androcles


E=1/2mv^2 is NON-relativistic. Relativistic it would be E=gamma*m*c^2.
Gamma
would be
1/(sqrt(1-v^2/c^2)) 1.

You really dont understand physics my friend

Floris
Oh, but do. I understand quite a lot of hogwash too.
When you have proof that "light is always propagated in empty space with a
definite velocity c which is independent of the state of motion of the
emitting body" then you'll be able to claim to know physics and I don't.
Until you have that proof, I'm afraid it is you that really doesn't
understand physics, or mathematics either. You bandy your gamma around as
though it is of consequence. It isn't. It was derived from an equation of
Einstein's,
1/2[tau(0,0,0,t)+tau(0,0,0,t+x'/(c-v)+x'/(c+v))] = tau(x',0,0,t+x'/(c-v)),
and the 1/2 was pulled out of nowhere, purely assumption. If you can prove
that 1/2 was other that I state, then you'll be on your way to showing me
your gamma.
Relativity isn't physics, relativity is hogwash.
Oh, and by the way, light is source dependent in interstellar space.
Recurrent novae aren't stars that blow up, settle down to normal, then blow
up again.
What they actually do is go around in long period orbits, shining light in
all directions as stars do, and the light that comes to us arrives with
their motion added. This means that for some stars nearly all the light from
a complete orbit can arrive here at once, giving the appearance of a very
bright star for a short while. This causes astronomers to get excited for a
short while, then, when the star settles back to being dim and ordinary once
more, forget all about it. of course, you can believe they blow up
repeatedly if you want to and call it physics that I don't really
understand, but I understand it all too well. You might as well tell Kepler
he doesn't really understand the Ptolemaic epicyclic movement of the planets
while you are about it.
And another btw: the energy required to accelerate something to c is very
small indeed. Photons do it all the time. :-P
See
http://www.androc1es.pwp.blueyonder.co.uk/
for more information.
Androcles

"Jean" wrote in message
om...
My Query is quite simple........


Why can't a body simply accelerate and exceed the velocity of
light????????

Just increase the velocity by some m/s for some time to reach the C ....!

Your question is simple, but the answer is not. First, I'm assuming you
want to know what the (special) theory of relativity predicts and I'm not
going to get into arguments about whether relativity acurately predicts how
the universe actually works.

According to the theory, speeds are relative. You have to say that a
spaceship, for example, moves at a speed relative to something else. The
spaceship can accelerate away from the earth and go faster and faster
relative to it, but actually it might be catching up to the speed of a star
that is already moving away from the earth. So although it is moving faster
relative to the earth, it is moving slower relative to the star. Which is
right? Is the ship accelerating or decelerating? The theory says there is
no absolute standard against which you can measure your speed. You have to
say relative to what.

So once you've decided from whose view you are going try and measure the
speed, you hit another problem. The theory says that the speed of light is
constant for everyone. This means that a beam of light travels at c no
matter who measures it. So if the spaceship accelerates away from the
earth, a beam of light measured travelling at c by someone on earth will
still be measured going at c by someone on the spaceship. It doesn't matter
how fast the ship goes relative to the earth, both meaure the light beam
travelling at c. This is pretty weird and leads to all sorts of odd ways of
looking at space and time. The ship can't catch up with the light beam and
can't even reduce the speed the light is travelling relative to it. It
always remains c.

To someone on earth, though, the ship is getting faster and faster, and
closer to the speed of light all the time.

So the ship keeps accelerating, going faster and faster relative to the
earth, but never catching up with the light beam. This acceleration is
caused by the thrust of the ship's engines, and even though they seem to be
working exactly the same way, giving the same thrust from the ship's point
of view, from the perspective of the earth the ship will be accelerating
less and less as it gets closer to the speed of light.

No matter how much thrust the ships engines develop, from the earth's
viewpoint the ship will never accelerate enough to get to lightspeed. Of
course from the ship's viewpoint, whatever speed it is travelling at
relative to the earth, the speed of that light beam remains the same
(discounting even more weird stuff arising from acceleration).

That's what the theory says, and as best as I understand it, the explanation
is that's just the way the universe works. Space and time aren't arranged
the way they seem to be. Not very satisfying, perhaps, and you can always
ask the creator when you see Him why He set it up that way. (Or didn't, if
you agree with the sceptics.)

Jonathan

skip

E=1/2mv^2 is NON-relativistic. Relativistic it would be E=gamma*m*c^2.
Gamma
would be
1/(sqrt(1-v^2/c^2)) 1.

You really dont understand physics my friend

Floris
Oh, but do. I understand quite a lot of hogwash too.
When you have proof that "light is always propagated in empty space with a
definite velocity c which is independent of the state of motion of the
emitting body" then you'll be able to claim to know physics and I don't.
Until you have that proof, I'm afraid it is you that really doesn't
understand physics, or mathematics either. You bandy your gamma around as
though it is of consequence. It isn't. It was derived from an equation of
Einstein's,
1/2[tau(0,0,0,t)+tau(0,0,0,t+x'/(c-v)+x'/(c+v))] = tau(x',0,0,t+x'/(c-v)),
and the 1/2 was pulled out of nowhere, purely assumption. If you can
prove
that 1/2 was other that I state, then you'll be on your way to showing me
your gamma.
Relativity isn't physics, relativity is hogwash.
Oh, and by the way, light is source dependent in interstellar space.
Recurrent novae aren't stars that blow up, settle down to normal, then
blow
up again.
What they actually do is go around in long period orbits, shining light in
all directions as stars do, and the light that comes to us arrives with
their motion added. This means that for some stars nearly all the light
from
a complete orbit can arrive here at once, giving the appearance of a very
bright star for a short while. This causes astronomers to get excited for
a
short while, then, when the star settles back to being dim and ordinary
once
more, forget all about it. of course, you can believe they blow up
repeatedly if you want to and call it physics that I don't really
understand, but I understand it all too well. You might as well tell
Kepler
he doesn't really understand the Ptolemaic epicyclic movement of the
planets
while you are about it.
And another btw: the energy required to accelerate something to c is very
small indeed. Photons do it all the time. :-P
See
http://www.androc1es.pwp.blueyonder.co.uk/
for more information.
Androcles
There are some articles and measurements to proofe that light is always
coming in with c and also that timedilation does exist (movement of
doublestars and mesonlifetime and M&M)
It's a question of accepting experimental data.
Or you give a better explanation than state of the art physiscs.
Rudi

"Androcles" schrieb im Newsbeitrag
...

"Rudolf Drabek" wrote in message
...

"Androcles" schrieb im Newsbeitrag
...

"Rudolf Drabek" wrote in message
...
Indeed its very simple. Look into the FAQ files for the Twin
Paradoxon.
The moving twin coming back e.g. from Sirius needed only e.g. 4
years
on
his
clock.
And the distance is about 8 lys. so 16ly years in 4y shiptime gives
about
avg. 4c.
But observers on earth measure that the ship has never exceeded 1c.
Its a question of where you are.

rgds Rudi
Nonsense.

pls give some comment on "nonsense" and explain your background to say
it.
Would be simply polite to behave so.
Certainly, be glad to do so. The question posed was clearly intuitive and
based on an acceptance of the vector addiction of velocities, or, as
Einstein called it, the Principle of Relativity. In introducing his
second
postulate, for which there is no experimental evidence whatsoever, the
first
postulate was modified by the composition of velocities. In other words,
the
second postulate is incompatible with the first. The answer you gave
involves time dilation, is confused at best, hopelessly wrong anyway, and
has no bearing on the question asked.
As to my personal background, that is irrelevant to the issue and not open
to discussion with strangers.
Androcles


pls see also my other posting (double stars mesons, M&M)
rudi

"F. Kuik" wrote in message ...
"Pmb" schreef in bericht
...

"Jean" wrote in message
om...
My Query is quite simple........


Why can't a body simply accelerate and exceed the velocity of
light????????

Just increase the velocity by some m/s for some time to reach the C
....!

The faster the body goes the greater its mass becomes since mass is a
function of velocity even though your rest mass remains the unchanged. As
you appoach c your mass will become infinite. That means the momentum
becomes infinite since mass is defined as the "m" in p = mv.

relatively speaking momentum is defined as p=M*v*gamma. if you leave out the
gamma you could still exceed speed of light.

That's true if the "M" in that relation is proper mass (aka 'rest
mass'). I was not refering to proper mass. I explained that the m I
was refering to was the "m" in p = mv. Relativly speaking
'relativistic mass' = m is defined as gamma*'proper mass.' If the
proper mass, m_o, is not zero then

m = m_o/sqrt[1-(v/c)^2]

See -- http://www.geocities.com/physics_wor...rtial_mass.htm

Pmb

"Androcles" wrote

1) I write m(v) = p/v. That would make m() a function of v, but what is p?

That's not what *I* wrote. *You* are defining an unknown, i.e. "m" in
terms of an unknown, i.e. "p." That is not the way *I* defined "m." As
I explained, "m" is defined such that mv is conserved. Once the
expression for "m" then *define* p as p = mv.

Once that is done then the rest follows. Did you read the derivations
in the link that I posted?


That's the way mass is defined in classical mechanics too. All the
gruesome theoretical details can be found in

"The Classical and Relativistic Concepts of Mass," Erik Eriksen and
Kjell Voyenli, Foundations of Physics, Vol. 6, No. 1, (1976).

Pmb

"Rudolf Drabek" wrote in message
...
skip

E=1/2mv^2 is NON-relativistic. Relativistic it would be E=gamma*m*c^2.
Gamma
would be
1/(sqrt(1-v^2/c^2)) 1.

You really dont understand physics my friend

Floris
Oh, but do. I understand quite a lot of hogwash too.
When you have proof that "light is always propagated in empty space with
a
definite velocity c which is independent of the state of motion of the
emitting body" then you'll be able to claim to know physics and I don't.
Until you have that proof, I'm afraid it is you that really doesn't
understand physics, or mathematics either. You bandy your gamma around
as
though it is of consequence. It isn't. It was derived from an equation
of
Einstein's,
1/2[tau(0,0,0,t)+tau(0,0,0,t+x'/(c-v)+x'/(c+v))] =
tau(x',0,0,t+x'/(c-v)),
and the 1/2 was pulled out of nowhere, purely assumption. If you can
prove
that 1/2 was other that I state, then you'll be on your way to showing
me
your gamma.
Relativity isn't physics, relativity is hogwash.
Oh, and by the way, light is source dependent in interstellar space.
Recurrent novae aren't stars that blow up, settle down to normal, then
blow
up again.
What they actually do is go around in long period orbits, shining light
in
all directions as stars do, and the light that comes to us arrives with
their motion added. This means that for some stars nearly all the light
from
a complete orbit can arrive here at once, giving the appearance of a
very
bright star for a short while. This causes astronomers to get excited
for
a
short while, then, when the star settles back to being dim and ordinary
once
more, forget all about it. of course, you can believe they blow up
repeatedly if you want to and call it physics that I don't really
understand, but I understand it all too well. You might as well tell
Kepler
he doesn't really understand the Ptolemaic epicyclic movement of the
planets
while you are about it.
And another btw: the energy required to accelerate something to c is
very
small indeed. Photons do it all the time. :-P
See
http://www.androc1es.pwp.blueyonder.co.uk/
for more information.
Androcles
There are some articles and measurements to proofe that light is always
coming in with c and also that timedilation does exist (movement of
doublestars and mesonlifetime and M&M)
It's a question of accepting experimental data.
Or you give a better explanation than state of the art physiscs.
Rudi
Rudi, experimental data is open to interpretation. it is 'experimental' data
that a stick in water appears bent. Does that mean we should accept the
stick is bent?
Of course not. It is an illusion caused by refraction of light. Light that
ISN'T travelling at c in a medium.
Let's take your vague reference to "doublestars" as an example. Suppose that
the orbital period is 1 year. That's a reasonable choice, it would place two
stars at about the same distance from each other as we are from the sun.
Now, if one star were moving directly toward us, the speed of light it
emitted in our direction would be 1.0001c, and as it receded, it would be
0.9999c.
The pair have to be close enough for us to resolve them, or we couldn't tell
if it was a binary system.
Because the light is travelling faster than c, the star will appear closer
sooner that we expect. But how can we determine its distance when it is
moving directly along our line of sight? Let's suppose that the system is at
such a distance that the time of arrival is one day early. For our chosen
period, it would have moved just 1 degree. What is the difference between
sin(90)= 1.0
and
sin(91) = sin(89)=0.99985?
Negligible. We are looking at an ellipse edge on, trying to determine the
exact distance the star has moved toward us from a difference so small as to
be impossible to determine while staring through a telescope. If we viewed
the system face on, then yes, we might be able to tell how far it moved, but
then it is no longer coming toward us, so the speed of light it emits isn't
added to it's speed. What about at a 45 degree angle? That might work, now
we can see how far it moved and how fast, from its doppler shift. From that
we can apply Kepler's laws and determine the orbit. Except that because it
has moved a degree further than we expect, the calculation will show a
rotation of the longitude of periastron of 1 degree. This is the distortion
you see, but you cannot go to the star system to find out what the orbital
parameters really are. You are left looking at a bent stick and concluding
it is really bent. You can't move your head to get a better view, the stick
is so far away you need a telescope to see it at all. The binary system was
the argument deSitter gave, and it doesn't stand up to scrutiny. If you like
you can choose a binary system that will deny my argument.
As for MMX, that clearly shows that the speed of light is both source
dependent AND observer dependent. Both are relatively at rest.
I have no idea what you are referring to with mesons.

In other words you gave no proof at all, you relied vaguely on the word of
others to back your claim.

Nor did you respond in any way to the argument I presented, you simply
ignored it. That is not how science is conducted.
Isaac Asimov wrote in "Quasar, Quasar, Burning Bright" ,
ISBN 0-380-44610-3
(concerning life after death)
If you want to argue the point, present the evidence.
I must warn you, though, that there are some arguments I will not accept.
I won't accept any argument from authority. ("The Bible says so")
I won't accept any argument from internal conviction ("I have faith it is
so")
I won't accept any argument from personal abuse ("What are you, an
atheist?")
I won't accept any argument from irrelevance ("Do you think you have been
put on this Earth just to exist for a moment of time?)
I won't accept any argument from anecdote ("My cousin has a friend who went
to a medium and talked to her dead husband")
And when all that, and other varieties of non-evidence are eliminated, there
turns out to be nothing.

So present your evidence, I won't accept any argument from authority
(FAQ's), anecdote ("there are articles that proofe.."), personal abuse,
sarcastically given as "Or you give a better explanation than state of the
art physiscs." or internal conviction, which is all you've offered.
I've presented mine, without reference to authority (what are your
credentials?), internal conviction (although I have it, but I'm not
asserting it as my argument), personal abuse (I haven't called you names or
made sarcastic comment), irrelevance (we are discussing the subject at hand)
or anecdote (I've done the work myself).
If you refuse to look, then there is nothing I can do about it.
But I will reply to your answer to the question asked, with "nonsense". That
is because it is, and I say it the way it is without mincing words. When you
people stop answering simple questions with nonsensical answers that you
cannot back up yourselves, merely parroting what you've read, and start
thinking of the nature of the evidence you accept so readily when it has
been interpreted for you, you can start calling yourselves scientists.
I have given a better answer than state of the art physics.
A simpler answer.
Androcles

"Gauge" wrote in message
om...
"Androcles" wrote

1) I write m(v) = p/v. That would make m() a function of v, but what is
p?

That's not what *I* wrote.
You wrote (and I quote) is:
"When mass is defined as the "m" in p = mv it follows that m is a
function of speed (when the object is a normal object, i.e. it has a
finite rest mass)."
I'm trying to put that in equation form.
If y is a function of x I write y(x) = something.
m(v) = something. The only variables I have at my disposal are m, v and p.
p = mv, be definition of p.
Hence m(v) = p/v = mv/v = m.
Hence if m is a function of v, it is a constant function. To me, that would
indicate that m is independent of v.



*You* are defining an unknown, i.e. "m" in
terms of an unknown, i.e. "p." That is not the way *I* defined "m." As
I explained, "m" is defined such that mv is conserved. Once the
expression for "m" then *define* p as p = mv.
So give an expression for m, because what you wrote doesn't do that. There
nearest I found was vague reference to the rest mass for a normal object.
Androcles

"Jon Hurwitz" wrote in message
...

"Jean" wrote in message
om...
My Query is quite simple........


Why can't a body simply accelerate and exceed the velocity of
light????????

Just increase the velocity by some m/s for some time to reach the C
.....!

Your question is simple, but the answer is not. First, I'm assuming you
want to know what the (special) theory of relativity predicts and I'm not
going to get into arguments about whether relativity acurately predicts
how
the universe actually works.

According to the theory, speeds are relative. You have to say that a
spaceship, for example, moves at a speed relative to something else. The
spaceship can accelerate away from the earth and go faster and faster
relative to it, but actually it might be catching up to the speed of a
star
that is already moving away from the earth. So although it is moving
faster
relative to the earth, it is moving slower relative to the star. Which is
right? Is the ship accelerating or decelerating? The theory says there
is
no absolute standard against which you can measure your speed. You have
to
say relative to what.

So once you've decided from whose view you are going try and measure the
speed, you hit another problem. The theory says that the speed of light
is
constant for everyone. This means that a beam of light travels at c no
matter who measures it. So if the spaceship accelerates away from the
earth, a beam of light measured travelling at c by someone on earth will
still be measured going at c by someone on the spaceship. It doesn't
matter
how fast the ship goes relative to the earth, both meaure the light beam
travelling at c. This is pretty weird and leads to all sorts of odd ways
of
looking at space and time. The ship can't catch up with the light beam
and
can't even reduce the speed the light is travelling relative to it. It
always remains c.

To someone on earth, though, the ship is getting faster and faster, and
closer to the speed of light all the time.

So the ship keeps accelerating, going faster and faster relative to the
earth, but never catching up with the light beam. This acceleration is
caused by the thrust of the ship's engines, and even though they seem to
be
working exactly the same way, giving the same thrust from the ship's point
of view, from the perspective of the earth the ship will be accelerating
less and less as it gets closer to the speed of light.

No matter how much thrust the ships engines develop, from the earth's
viewpoint the ship will never accelerate enough to get to lightspeed. Of
course from the ship's viewpoint, whatever speed it is travelling at
relative to the earth, the speed of that light beam remains the same
(discounting even more weird stuff arising from acceleration).

That's what the theory says, and as best as I understand it, the
explanation
is that's just the way the universe works. Space and time aren't arranged
the way they seem to be. Not very satisfying, perhaps, and you can always
ask the creator when you see Him why He set it up that way. (Or didn't,
if
you agree with the sceptics.)

Jonathan
Basically correct, that is what the theory says.
Just remember, though, that it isn't theory that says the speed of light is
independent of the source, it is assertion. There is no experimental
evidence to support that. As to what It might say or not say assumes Her
existence in the first place. Does the creator have a penis? if so, what
for? If not, how do you ascribe maleness to it?

Androcles

"Rudolf Drabek" wrote in message
...

"kenseto" schrieb im Newsbeitrag
...

"Rudolf Drabek" wrote in message
...
Indeed its very simple. Look into the FAQ files for the Twin
Paradoxon.
The moving twin coming back e.g. from Sirius needed only e.g. 4 years
on
his
clock.
And the distance is about 8 lys. so 16ly years in 4y shiptime gives
about
avg. 4c.
But observers on earth measure that the ship has never exceeded 1c.
Its a question of where you are.

Ah....but you can't compare the ship's 4 clock years with the earth's
16
clock
years directly. Why? Because the passage of a clock year in the ship is
not
equal to the passage of a clock year on earth. To make the comparison
you
must convert the ship's clock years to the earth's clcok year as
follows:
Converting the ship's time to earth time=gamma*4 ship's clock
years
=16
earth's clcok years.
What this means is that a physical clock is NOT a universal clock. A
clock
second does not contain the same amount of universal time (absolute
time)
in all frames of reference.

Ken Seto

Yes you are right. But I don't know a universal clock.
But the original question was, if its possible to exceed c.

It is not possible. Why? because the energy used to accelerate the ship is
moving at c. The ship cannot move faster than the energy that is
accelerating it.

The gamma of 4 is no question and o.k.
The observation of the rocketeer twin after return is that he needed 4y
and
his twin on earth is 16y older.
So the moving twin knows he had a passage of 16ly in 4y shiptime = 16y
earthtime.
speed in the rest frame was nearly c, speed in moving frame was about 4c.
That's all what Androcles wanted to know I think.

No....speed in the moving frame as dertmined by the earth observer is also
c.
The earth observer convert the ship's time to earth time before using it to
determine speed of the ship..

Ken Seto