Re: Special Relativity

Ian Goddard (
Tue, 23 Jun 1998 01:16:50 -0400

At 08:51 PM 6/22/98 -0400, Daniel Fabulich wrote:

>You just don't get it, do you? OK, try this on for size:
>B perceives A to be smaller than B. A perceives B to be smaller than A.
>Who perceives other to be larger than self? If the answer is "no one"
>(and it is!) thenthere is no positive sign on the identity chart. Period.

> In one line, tell me in what reference frame A gets larger.

IAN: A gets larger with reference to B: A
observes that B is smaller and therefore
he himself is larger than B. B observes
that A is smaller and therefore that
he is larger than A. Pretty simple.

This is what A sees, his ruler and B's:

Their ruler: |||||||||||
My ruler: | | | | | | | | | | |

Please notice that "my" ruler is larger.
B also sees "my" (i.e., his) ruler larger.
This entirely answers your latest rebuttal.

>> The fact that both observers witness
>> the same thing does not break this
>> symmetry of relational structure.
>> Both observers see themselves
>> as larger than the other:
>> A B (how I appeared)
>> A 0 +
>> B + 0
>Did you make another error here? "Both observers see themselves as
>larger than the other..." 0 is self, and 0 is SMALLER than +, not

IAN: This is what the charts say
for A, which is reading down from A:

A | 0 - |
| |
B | - 0 |

A: I stayed the same size to me
(0), and B got smaller (-) to me.

A | 0 + |
| |
B | + 0 |

A: I stayed the same size to me,
but I got larger relative to B.
(Which is also what B observes,
that he (B) got larger than A.)

The first chart defines what happens to the
other guy's ruler relative to me as I see it
and the second describes what happened to
my ruler relative to other as I see it.

>When they get moving, B's meter stick looks to be 0.8m long. So, you want
>to say A's meter stick is growing? Relative to what? Not B: B perceives
>A's meter stick to be SHRINKING, not growing. What is A growing relative

IAN: A is growing relative to B. You
see, A observes B to be smaller, but
has A gotten larger than B? The only
way for A to know is look at B. If B
is smaller, then A has gotten larger.
This is because size is relative.

>> Because B was also size 1, it could
>> be stated now that A = 1.5, for no
>> point of size-reference is absolute.
>Except that this is true in no reference frame, for if you measure A from
>B's reference frame, you do NOT get 1.5: you get 0.5. If someone, ANYONE,
>measured that meter stick to be 1.5m long, I'd agree. Except A never
>measures any meter sticks to be longer than 1m, and neither does B. So,
>from what reference frame is A 1.5m long?

IAN: From A's reference frame his ruler
is as long as (actually) 2 of B's rulers,
if A's rulers is twice as long as B's.

>> IAN: There is no absolute size, you cannot have
>> "got smaller" free from "got larger." Observer
>> A will measure the situation and see that there
>> are two sides of the relative change: he himself
>> got larger than B because B got smaller than A.
>Relative to WHAT? A got larger relative to B? <BZZT> No, A got SMALLER
>relative to B. Try again.

IAN: A sees B, A measures A relative
to A's observation of B, A does NOT
measure A relative to how B sees A.

>Until you can provide a reference frame in which B grows (that is, from
>the perspective of observer X, B is 1.5m long) you haven't proved
>anything. And unfortunately, from A's perspective all sticks are <= 1m.
>Same for B. And with that, you're out of perspectives.

IAN: I've now answered this about 15x now.
The implicit phrasing of the charts is a
little confusing. But this is cleared up.
As we can see, if A appears larger than
B, then A is said to be larger than B.


"A new scientific truth does not triumph by convincing its
opponents and making them see the light, but rather because
its opponents eventually die, and a new generation grows
up that is familiar with the idea from the beginning."

Max Plank - Nobel physicist

"The smallest minority on earth is the individual.
Those who deny individual rights cannot claim
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