🚀 go-pugleaf

> CALVIN@JHUIGF.BITNET ("That's not lake Minnetonka...")
> [...] know precious
> little about relativity, although I am a pure mathematician.

>   At (near?) c, this force would become infinite, and thus, acceleration
>              past c is impossible
>   THEREFORE, c is the highest attainable speed by an accelerating body.
> [...but...] c is a finite number, being 3x10^8 m/s
> Then, why would the force required to accelerate a
> body past c be infinite if c isn't infinite?

Why is this surprising?  Especially to a "pure mathematician"?  Take
the function (1/abs(x)).  The limit is infinity as x->0.  So how can a
function "become infinite" when the domain is zero?  How do you get
infinity from nothing at all?

The real question is why anybody finds this surprising.  Not
"surprising that reality is modeled by such a function"... that *is*
perhaps surprising.  I mean "surprising that a finite domain value can
'map to' infinity" (very, very loosely speaking).

> How can it be assumed that a
> body will become infinitely massive at c if c itself is not infinite, UNLESS
> one assumes, subtlely, that c already is the fastest attainable speed (that
> is, c is in effect, infinite).

No, the assumption that is made in SR is that everybody "sees" light
travel at the same speed, regardless of the speed of the emitter or
observer.  (This "assumption" is pretty safe, since it is actually
what seems to happen with real light in the real world.)  From there,
Einstein used simple algebra to work out the consequences of this.
One of the consequences is that as v->c, force required to increase v
increases without bounds.

--
You run and you run to catch up with the sun, but it's sinking,
racing around to come up behind you again.
The sun is the same in a relative way, but you're older,
shorter of breath, and one day closer to death.
                              --- Pink Floyd
-- 
Wayne Throop      <the-known-world>!mcnc!rti!xyzzy!throopw