Relativistic train on relativistic wheels

mlwo...@wp.pl

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Oct 21, 2016, 5:15:52 AM10/21/16

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The wheels of a train have l diameter.
The train accelerates to 0.99c relative to ground observer.
1)Is it possible?
2)What is the period of its wheel cycle (measured by ground observer)?

Wonder what our self-appointed gurus will say about
it...

Sylvia Else

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Oct 21, 2016, 7:37:46 AM10/21/16

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On 21/10/2016 8:15 PM, mlwo...@wp.pl wrote:
> The wheels of a train have l diameter.

I suspect they have infinitely many.

Sylvia.

mlwo...@wp.pl

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Oct 21, 2016, 9:43:07 AM10/21/16

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?????
The wheels have infinitely many ... what?

Dirk Van de moortel

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Oct 21, 2016, 10:36:47 AM10/21/16

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Op 21-okt-2016 om 15:43 schreef mlwo...@wp.pl:

Infinitely many diameters.
And all disintegrating at a speed of about 0.000001 c.

Dirk Vdm

Jim Barthel

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Oct 21, 2016, 11:00:40 AM10/21/16

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Dirk Van de moortel wrote:

>>>> The wheels of a train have l diameter.
>>>
>>> I suspect they have infinitely many.
>>
>> ????? The wheels have infinitely many ... what?
>
> Infinitely many diameters. And all disintegrating at a speed of about
> 0.000001 c. Dirk Vdm

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Dirk Van de moortel

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Oct 21, 2016, 11:58:15 AM10/21/16

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Op 21-okt-2016 om 17:00 schreef Jim Barthel:

And... DO NOT STARE AT THE LIGHTS!

Dirk Vdm

Alan Folmsbee

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Oct 21, 2016, 12:48:18 PM10/21/16

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Not possible. The amount of coal that the train would need to carry would be astronomical. The wheels would fly apart after it reached a speed of 123,000 miles per hour. Steel only has a tensile strength of 0.99 gigapascals per square furlong.

JanPB

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Oct 21, 2016, 1:31:22 PM10/21/16

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On Friday, October 21, 2016 at 8:00:40 AM UTC-7, Jim Barthel wrote:
> Dirk Van de moortel wrote:
>
> >>>> The wheels of a train have l diameter.
> >>>
> >>> I suspect they have infinitely many.
> >>
> >> ????? The wheels have infinitely many ... what?
> >
> > Infinitely many diameters. And all disintegrating at a speed of about
> > 0.000001 c. Dirk Vdm
>
> http://russia-insider.com/en/us-blames-northern-lights-russia-imposes-sanctions/ri17149

Looks like The Onion.

--
Jan

Sylvia Else

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Oct 23, 2016, 8:24:42 PM10/23/16

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I wonder if mlwozniak has figured out yet how his thread went so awry.

Sylvia.

abu.ku...@gmail.com

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Oct 24, 2016, 2:06:38 PM10/24/16

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yeah, 18,60,00/1,00,00,00 = 0.99,99,99,99Gp/fl

> > l diameter.
> > The train accelerates to 0.99c relative to ground observer.
> > 1)Is it possible?
> > 2)What is the period of its wheel cycle (measured by ground observer)?

mlwo...@wp.pl

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Oct 25, 2016, 2:32:03 AM10/25/16

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W dniu poniedziałek, 24 października 2016 20:06:38 UTC+2 użytkownik abu.ku...@gmail.com napisał:
> yeah, 18,60,00/1,00,00,00 = 0.99,99,99,99Gp/fl
>
> > > l diameter.
> > > The train accelerates to 0.99c relative to ground observer.
> > > 1)Is it possible?
> > > 2)What is the period of its wheel cycle (measured by ground observer)?
>
> > astronomical.

Right. According to your Shit - faster the train
is moving slower the wheels rotate.

al...@interia.pl

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Oct 25, 2016, 1:44:55 PM10/25/16

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W dniu piątek, 21 października 2016 11:15:52 UTC+2 użytkownik mlwo...@wp.pl napisał:
> The wheels of a train have l diameter.
> The train accelerates to 0.99c relative to ground observer.
> 1)Is it possible?

a speed of the top of a rotating wheel is:

--> wr
O---> v
<-- -wr

-------> 2v
----> v - a speed of the center of the wheel
>0

thus a limit for a speed of the wheel is 0.5c

> 2)What is the period of its wheel cycle (measured by ground observer)?

v = 2piR/T => T = 2pi R / v, always.

JanPB

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Oct 25, 2016, 2:06:16 PM10/25/16

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On Tuesday, October 25, 2016 at 10:44:55 AM UTC-7, al...@interia.pl wrote:
> W dniu piątek, 21 października 2016 11:15:52 UTC+2 użytkownik mlwo...@wp.pl napisał:
> > The wheels of a train have l diameter.
> > The train accelerates to 0.99c relative to ground observer.
> > 1)Is it possible?
>
> a speed of the top of a rotating wheel is:
>
> --> wr
> O---> v
> <-- -wr
>
> -------> 2v
> ----> v - a speed of the center of the wheel
> >0
>
> thus a limit for a speed of the wheel is 0.5c

Incorrect. The original question was framed within relativity. You are
using Newtonian mechanics.

--
Jan

al...@interia.pl

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Oct 25, 2016, 2:35:50 PM10/25/16

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Under the SR model everything is the same,
due to the simple math convention:

t' = c'/c t; an artificial time-parameter.

Thus the correct: c' = c-v, is simply replaced by c' = c,
and the pseudotime:
t' = ble ble.
The rest remains the same, because: r' = c't = ct' = r';
geometry doesn't care about human's stupidity at all.

JanPB

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Oct 25, 2016, 3:13:58 PM10/25/16

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No, wrong. 2v =/= 2v/(1 + v^2).

--
Jan

al...@interia.pl

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Oct 25, 2016, 3:23:12 PM10/25/16

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W dniu wtorek, 25 października 2016 20:06:16 UTC+2 użytkownik JanPB napisał:

Using the real Lorentz contraction,
for v = c:

|---> c
|
|---> c
|
|---> c
============== some road

the all point of the circle moves at c.

The top speed is not 2c because there is the extremal contraction...
dL/dt = -c.
2c + -c = c

similarily the point on bottom:
0 + c = c.

because at this point the expansion is extremal: dL/dt = +c,
etc.

Look at a middle point:
the speed is usualy: sqrt(v^2 + (wr)^2) = sqrt2 v;

but in this stupid example it is equal to c too,
because now the contraction is infinite,
thus the central part of the wheel is infinitely dense:
the mass just flows from this point with zero speed, but with infinite density:
m * v = const.

JanPB

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Oct 25, 2016, 6:23:02 PM10/25/16

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Before answering your mistakes, let me ask you this elephant in the room
type question:

Do you really think, even for a split second, that you CAN be correct here?
You know what this would imply, don't you.

(Just testing if you're simply too far gone or it's merely a language
problem.)

--
Jan

al...@interia.pl

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Oct 26, 2016, 10:12:31 AM10/26/16

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The problem is infinitely too hard for you,
and for any other childern in the sci.

More! This problem is over the actual science in general...
This's a type of PDE-problem in fact, not any stupid cinematics.

al...@interia.pl

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Oct 26, 2016, 10:23:29 AM10/26/16

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The SR formula for addition is just a rescaling speed wrt the maximal speed,
thus to light speed.

Look at this:

v' = dx'/dt' = ble ble

the actual speed is in fact: dx'/dt,
so if you want to rescale this number by the light speed,
then you must use c' in a role of an unit of speed:

dx' / dt * c/c', what is just: dx'/dt',
bacause: r' = cdt' = c'dt => dt' = c'/c dt

This is the same like using the naked number: v/c = <-1,1>
in place of the speed v = <-c,c>.

Dirk Van de moortel

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Oct 26, 2016, 4:27:23 PM10/26/16

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Op 24-okt-2016 om 02:24 schreef Sylvia Else:

Apparently not :-|
Language barrier.
Intelligence barrier.

Dirk Vdm