# Re: colp, why did AE use the word "relativity"?

*From*: Uncle Ben <ben@xxxxxxxxxxx>*Date*: Sun, 20 Jun 2010 12:12:02 -0700 (PDT)

On Jun 20, 2:34 pm, "Sue..." <suzysewns...@xxxxxxxxxxxx> wrote:

On Jun 20, 1:57 am, Uncle Ben <b...@xxxxxxxxxxx> wrote:

colp, you complain that SR implies a contradiction: each twin is

younger than the other, which is absurd. No one has yet explained to

you why, in SR, it is not absurd.

Consider two trains passing in opposite directions.. I am in one

train and you are in the other. I say I am stationary and you are

moving; you say you are stationary and I am moving.

We go to a seance and the medium let's us ask the ghost of Galileo

who is right? Galileo says, "motion is relative!" We agree then that

we are both right, each relative to his own rest frame of reference.

Consider now the first phase of the symmetric twin puzzle: each twin

calculates from SR that the other is aging slower than himself.

Absurd? No, each is correct relative to his own rest frame.

==============

Still looking for a book written since 1905?

Einstein

discovered that time is relative!

No he didn't. He placated the adherents of Newton's

corpuscular light notions by stipulating it

that way and specifically excluding the

physical nature of light.

<<There is only one demand to be made of the

definition of simultaneity, namely, that in

every real case it must supply us with an

empirical decision as to whether or not the

conception that has to be defined is fulfilled.

That my definition satisfies this demand is

indisputable. That light requires the same time

to traverse the path A —> M as for the path B —> M

is in reality neither a supposition nor a hypothesis

about the physical nature of light, but a stipulation

which I can make of my own freewill in order

to arrive at a definition of simultaneity.”>>http://www.bartleby.com/173/8.html

You don't want to believe that time is relative,

Perhaps he has cracked a book or two written

after 1918.

<< Application of Noether's theorem allows physicists to

gain powerful insights into any general theory in physics,

by just analyzing the various transformations that would

make the form of the laws involved invariant. For example:

* the invariance of physical systems with respect

to spatial translation (in other words, that the laws

of physics do not vary with locations in space) gives

the law of conservation of linear momentum;

* invariance with respect to rotation gives the law

of conservation of angular momentum;

* invariance with respect to time translation gives

the well-known law of conservation of energy >>http://en.wikipedia.org/wiki/Noether%27s_theorem#Applications

because you have no

experience moving at even 0.001 c, but people have measured the

effect, and Einstein was right.

Was he right in 1905 or right in 1920?

<< Einstein's relativity principle states that:

All inertial frames are totally equivalent

for the performance of all physical experiments.

In other words, it is impossible to perform a physical

experiment which differentiates in any fundamental sense

between different inertial frames. By definition, Newton's

laws of motion take the same form in all inertial frames.

Einstein generalized[1] this result in his special theory of

relativity by asserting that all laws of physics take the

same form in all inertial frames. >>http://farside.ph.utexas.edu/teaching/em/lectures/node108.html

[1]<< the four-dimensional space-time continuum of the

theory of relativity, in its most essential formal

properties, shows a pronounced relationship to the

three-dimensional continuum of Euclidean geometrical space.

In order to give due prominence to this relationship,

however, we must replace the usual time co-ordinate t by

an imaginary magnitude

sqrt(-1)

ct proportional to it. Under these conditions, the

natural laws satisfying the demands of the (special)

theory of relativity assume mathematical forms, in which

the time co-ordinate plays exactly the same rôle as

the three space co-ordinates. >>http://www.bartleby.com/173/17.html

<< where epsilon_0 and mu_0 are physical constants which

can be evaluated by performing two simple experiments

which involve measuring the force of attraction between

two fixed charges and two fixed parallel current carrying

wires. According to the relativity principle, these experiments

must yield the same values for epsilon_0 and mu_0 in all

inertial frames. Thus, the speed of light must be the

same in all inertial frames. >>http://farside.ph.utexas.edu/teaching/em/lectures/node108.html

Sue...

Uncle Ben- Hide quoted text -

- Show quoted text -

Sue, you haven't lost your touch. In spite of your advanced age, you

still manage to post almost as much irrelevant material as our friend

mpc755.

But I've already read this stuff. Please find something new next

time. How about the Magna Carta, or one of Shakespeare's plays?

UB

.

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