sci.physics.relativity

"PD" wrote in message
news:d98b978b-1669-4a52-ba6b-b17f645c12f2@...
On Mar 5, 9:31 am, "kenseto" wrote:
> The SRians in this NG claim that a longer pole can be trapped inside a
> shorter barn from the barn frame point of view.

>Please define term "trapped". Does this mean
>a) that there is an instant when both ends of the pole are inside the
>barn at the same time?

Yes.

, or
b) that the doors of the barn can be shut and left shut overnight and
the pole will still be inside in the morning?

No idiot the pole is moving.

>> This can only happen if
>> there is real physical contraction

>Please define term "real physical contraction". This has no meaning as
>it is.

The longer pole length can be inside the shorter length barn for a brief
period without hitting the simultaneously closed doors. That's real physical
contraction.

>> of the pole from the barn frame point of
>> view. OTOH SR deny physical length contraction.

>Please define term "physical length contraction". This has no meaning
>as it is.

When you freeze a pole that's real physical length contraction.

>> It says that length
>> contraction is a geometric projection effect.

>But 4D onto 3D, not 3D onto 2D. And the 4D isn't all spatial and
>Euclidean, either.

There is no 4D. It is made up by you SRians to explain that projection
effect can be physically real or physically not real.

> Much like

Much like. Not exactly like. At all.

> that you see me to
> be shorter from a distance and you see me to be shorter from a distance.
It
> seems that the SRians want to have it both way.
>
> The proper SR interpretation should be as follows:
> 1. There is no physical length contraction.
> 2. All observers will say that the physical length of the pole remains
> unchanged.
> 3. The barn observer will say that the light path length of the moving
pole
> is different than the light path length of the pole if it is at rest in
the
> barn frame.

None of these "interpretations" mean anything until you define
"physical length contraction", "physical length", "light path length".

Physical length contraction means the physical length of a pole is shorter
than its proper length. An example of physical contraction is freezing a
metal ruler.
Physical length: It is the length of a physical ruler at STP.
Light path length: It is the distance light need to travel to cover the
physical length of a rod. In the observer's frame SR and IRT assumes that
the light path length of a rod is the physical length of the rod. In SR the
observer will predict that the light path length of a moving rod is L/gamma.
In IRT the observer will predict that the light path length of a moving rod
is L/gamma or L*gamma.

Ken Seto

>
> The math for the above concepts are as follows:
> L = the light path length of the pole at rest in the barn frame.
> L' = the light path length of the pole moving wrt the barn frame.
> L' = L/gamma
>
> The above concept is included in a new theory of relativity called IRT.
IRT
> includes SRT as a subset. However, the equations of IRT are valid in all
> environments, including gravity. A description of IRT is available in the
> following link:/kn_seto/
> Also visit my website:/kn_seto/
>
> Ken Seto