pan <pan### [at] syixcom> wrote:
> Train wheels gripping track exponentially gets looser
> the greater the speed of the train. At c or near c the
> track will have to move almost the entire speed of the
> train; else the instability will overwhelm your system.

> ergo: the track and train muts be coupled, else you
> would be asking about trains and tracks on separate
> unique vectors. (Unpredictable vectors btw)

> unless of course your train wheels and track rails are
> made of unobtanium held together in the grip of
> stick-but-slick-enough-to-let-the-wheels-move goop.

> Think dentures under a lot of strain.

  I don't even understand what you are trying to say.

  But if the contact with the train and the track bothers you, then
assume maglev.

-- 
                                                          - Warp

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>  But if the contact with the train and the track bothers you, then
> assume maglev.

What about when the trains have to turn when the track splits?  That is the 
bit that bothers me most at those speeds...

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scott <sco### [at] laptopcom> wrote:
> What about when the trains have to turn when the track splits?  That is the 
> bit that bothers me most at those speeds...

  The trains and the double track segment can be really long, meaning that
the turn can be very subtle.

-- 
                                                          - Warp

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And lo on Mon, 07 Jan 2008 17:32:22 -0000, Darren New <dne### [at] sanrrcom>  
did spake, saying:

> Phil Cook wrote:
>> And lo on Fri, 04 Jan 2008 19:19:43 -0000, Darren New <dne### [at] sanrrcom>  
>> did spake, saying:
>>
>>> Phil Cook wrote:
>>>> Though won't the double track also seem foreshortened?
>>>
>>> Yes, but the oncoming train will seem *more* foreshortened.
>>>
>>>> travelling so fast it'll just sail straight over the gap without  
>>>> falling far enough to get stuck.
>>>
>>> Not ... exactly. The problem isn't that he doesn't fall far enough.  
>>> The problem is that the bottom of the train starts falling before the  
>>> top does, kind of.
>>>
>>> And in that case, there are only two speeds involved (the track and  
>>> the train), rather than the three in Warp's original problem.
>>   From an outside observer's pov both trains are shorter then the  
>> double track so should pass without problem; I was trying to reconcile  
>> it with the traindrivers' view. The oncoming train is shorter, but so  
>> is the double track; so they should still collide?
>
> No, because the oncoming westbound train is coming at the eastbound  
> train faster than the tracks are coming at the eastbound train, so the  
> westbound train appears to be smaller than the siding as seen from the  
> eastbound train.

Check my later comments on how this could still mean they collide; I think  
I've got it now anyway thanks.

-- 
Phil Cook

--
I once tried to be apathetic, but I just couldn't be bothered
http://flipc.blogspot.com

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Funny enough, when I was in university, some of the EE students were 
talking about these trains you couldn't stop, had a big length, and had 
to get routed around switching like this, and you had to figure out when 
to schedule a track switch to keep them from colliding.

Turns out they were talking about optical networks with optical 
switching, rather than actual trains. :-)  Very confusing for a while, tho.

-- 
   Darren New / San Diego, CA, USA (PST)
     It's not feature creep if you put it
     at the end and adjust the release date.

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"Warp" <war### [at] tagpovrayorg> wrote in message 
news:47831ea6@news.povray.org...
> pan <pan### [at] syixcom> wrote:
>> Train wheels gripping track exponentially gets looser
>> the greater the speed of the train. At c or near c the
>> track will have to move almost the entire speed of the
>> train; else the instability will overwhelm your system.
>
>> ergo: the track and train muts be coupled, else you
>> would be asking about trains and tracks on separate
>> unique vectors. (Unpredictable vectors btw)
>
>> unless of course your train wheels and track rails are
>> made of unobtanium held together in the grip of
>> stick-but-slick-enough-to-let-the-wheels-move goop.
>
>> Think dentures under a lot of strain.
>
>  I don't even understand what you are trying to say.
>
>  But if the contact with the train and the track bothers you, 
> then
> assume maglev.
>

Hmmm ... your lack of understanding must equal my dislike of
poorly done thought experiements.

Reset your conceits to some unitary object and no one
will bother you about real world dynamics.

Using atrains as your main object of conjecture implies
a necessary co-consideration of the track and the system
that the track and train comprise. To do otherwise
is laziness and sloppy. You obviously wanted a situation where
a inevitable collision of two trains served as a constraint
that was included only to heighten interest and (ahem) impact.

Much better models will serve you better to learn about
relativisitic effects.

"There was a young fellow named Fisk,
A swordsman, exceedingly brisk.
So fast was his action,
The Lorentz contraction
Reduced his rapier to a disk."


There was a young lady named Bright,
Whose speed was far faster than light
She set out one day
In a relative way,
And returned home the previous night.

Arthur Buller    (1874-1944)

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pan <pan### [at] syixcom> wrote:
> Using atrains as your main object of conjecture implies
> a necessary co-consideration of the track and the system
> that the track and train comprise.

  No, it doesn't. The length of the train doesn't depend on the properties
of the track.

-- 
                                                          - Warp

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Here's another alternative: using the Z Machine based on Heim's quantum 
theory...!  ;op


-- 
-Nekar Xenos-

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Alain <ele### [at] netscapenet> wrote:
> Warp nous apporta ses lumieres en ce 2008/01/02 15:53:
> > Darren New <dne### [at] sanrrcom> wrote:
> >> It's funny how many people won't deny something unintuitive like quantum
> >> mechanics or relativity, stuff that's really hard to understand properly
> >> even *with* math, but they're happy to deny the possibility of
> >> evolution, which is easy to explain without any mathematics.
> >
> >   That may be because we can check the theory of relativity here and
> > now, but we can't go back in time a few million years to check evolution
> > nor we can perform evolutionary experiments which require a few millions
> > of years.
> >
> There have been some evolutionary experiments that have been done. Some using
> mice, others using insects. Take a mice colony and have it live in a lightless
> environment, another in a chilly one, a third in a very hot one, a fourth in a
> place where possible living area are far from food sources. Another one
> prevented females from copulating for an increasing time.
> Do the experiment over a few decades (some are still going on after over a century).
> In the dark environment you get mice with atrophied eyes, longer wiskers and
> larger ears, and a high albinism incidence.
> In the cold, you get longer hairs, increased body fat, short tails and smaller ears.
> In the heat, shorter hairs, slightly longer and spindly paws.
> The ones that had to travel a lot devoloped longer, stronger legs, larger
> stomach. They also devoloped hamster like cheeks.
> In the last case, the longevity increased very significantly! Increases in the
> order of +200 to 300% to the life span! We are now doing that experiment in a
> very large scale: The whole Human Western and Asian populations! Asia, Europe,
> the Americas, parts of Africa and Oceanya. From the middle ages to now,
> generation time went from about 15 to 16 years to over 30~33 years...
>
> Those are called "forced evolution experiments". The key is to use speciment
> that have a short generation time.
>
> --
> Alain
> -------------------------------------------------
> There will always be beer cans rolling on the floor of your car when the boss
> asks for a ride home from the office.

And yet, the animal that results is still a rat. Within its genes are the needed
variability. All the conditions you described seem to me to be based on hormone
production, not gene mutation or evolution.

The human population increase in life span isn't based on evolution, but on
better nutrition and heathcare. But maybe our brains "evolved" enough to
realize we needed better nutrition.

Leef_me

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Leef_me nous apporta ses lumieres en ce 2008/01/09 13:58:
> Alain <ele### [at] netscapenet> wrote:
>> Warp nous apporta ses lumieres en ce 2008/01/02 15:53:
>>> Darren New <dne### [at] sanrrcom> wrote:
>>>> It's funny how many people won't deny something unintuitive like quantum
>>>> mechanics or relativity, stuff that's really hard to understand properly
>>>> even *with* math, but they're happy to deny the possibility of
>>>> evolution, which is easy to explain without any mathematics.
>>>   That may be because we can check the theory of relativity here and
>>> now, but we can't go back in time a few million years to check evolution
>>> nor we can perform evolutionary experiments which require a few millions
>>> of years.
>>>
>> There have been some evolutionary experiments that have been done. Some using
>> mice, others using insects. Take a mice colony and have it live in a lightless
>> environment, another in a chilly one, a third in a very hot one, a fourth in a
>> place where possible living area are far from food sources. Another one
>> prevented females from copulating for an increasing time.
>> Do the experiment over a few decades (some are still going on after over a
century).
>> In the dark environment you get mice with atrophied eyes, longer wiskers and
>> larger ears, and a high albinism incidence.
>> In the cold, you get longer hairs, increased body fat, short tails and smaller
ears.
>> In the heat, shorter hairs, slightly longer and spindly paws.
>> The ones that had to travel a lot devoloped longer, stronger legs, larger
>> stomach. They also devoloped hamster like cheeks.
>> In the last case, the longevity increased very significantly! Increases in the
>> order of +200 to 300% to the life span! We are now doing that experiment in a
>> very large scale: The whole Human Western and Asian populations! Asia, Europe,
>> the Americas, parts of Africa and Oceanya. From the middle ages to now,
>> generation time went from about 15 to 16 years to over 30~33 years...
>>
>> Those are called "forced evolution experiments". The key is to use speciment
>> that have a short generation time.
>>
>> --
>> Alain
>> -------------------------------------------------
>> There will always be beer cans rolling on the floor of your car when the boss
>> asks for a ride home from the office.
> 
> And yet, the animal that results is still a rat. Within its genes are the needed
> variability. All the conditions you described seem to me to be based on hormone
> production, not gene mutation or evolution.
Still mice or rats, yes. A new sub-race of the generic mice or rat, YES!
The observed changes do remain, unchanged, for many generations after the 
populations have been put back into "normal" environnements. There are cases 
where specimens from different environnements have become mutualy incompatible: 
they can no longer cross bread!
> 
> The human population increase in life span isn't based on evolution, but on
Not yet!
> better nutrition and heathcare. But maybe our brains "evolved" enough to
> realize we needed better nutrition.
Beter alimentation and health increase the longevity. Improve them and longevity 
increase immediately. Remove it and longevity immediately go down. There is no 
hereditary effect.

Late reproduction slow down the aging process. It becomes hereditary. It takes 
10's of generations to have an effect. For humans, it will take some more 
centuries. Remove that and the slowdown remains for 100's of generations. A few 
millenias for humans.
> 
> Leef_me
> 
> 
Evolution need many generations, usualy 100's to 1000's, in an environnement 
forcing some adaptive evolution. Recent studies show that the dodo evolved from 
the common pigeon, but no dodo could cross bread with a pigeon. Humans, chimps, 
gorillas and orangoutans only differ geneticaly by one FRAGMENT of one 
chromozome (two in the case of the gorilla: two fragments switched between two 
cromozomes).

-- 
Alain
-------------------------------------------------
You know you've been raytracing too long when you hope that you can render your 
ideas on your PC before you die.
Sven Rudolph (Germany)

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