: "noRm d. plumBeR"
: Lots of things are that way. If you know it can be done, that seems
: to be the most uphill part of the battle. If you know it can't be
: done, there's little point in trying.
:
: Of course we -know- that the speed of light is an absolute boundary.

In much the same way, and with much the same class of justification,
that we know the laws of thermodynamics hold true. So, manufacturing
energy from literally nothing (not even the "vacuum energy") is just
about as likely as exceeding lightspeed.

And, interestingly enough, cosmological inflation pretty much
involves violating both of those, at least functionally.

So... I guess my point is, "you can get from point A to point B FTL" and
"you can sustain a chain reaction" are two very very very very different
kinds of "can be done"s (or, conversely, before they are done, "can't
be done"s). And to note that in some relevant ways, we *don't* know
that the speed of light is an absolute boundary (depending on precisely
what phenomenon you're talking about). Points. My *two* points are...

: If you -know- a thing can be done, that is one thing. If you -assume-
: it can be done, that's another thing. Given the amount of stuff men
: have "known" in the past, and learned later to be false, it makes one
: wonder why assuming a thing can be done doesn't give the same boost
: that "knowing" it does.

There are, of course, some science fiction stories about that.
One such yasid is from Analog in the '70s, where a guy buys a bunch
of weird mad-scientist-lair widgetry for his... well, for his lair
in a disused coal mine, and by and by, the whole thing blows up in a
many-tens-of-kilotons-TNT explosion. Examining his notes, the government
discovered he'd been working on some nuclear phenomenon which should have
lots of practical applications such as portable nuclear power generators,
and started a big project to duplicate the work (but more carefully,
of course). Turns out that the guy *thought* his notions would lead
to those applications, but he didn't have the resources to do it.
And couldn't get a grant, or anybody to listen to him. But he *did*
have the resources to set up shop in an abandoned coal mine (abandoned
not because there was no more coal, but because it was non-economical
to continue mining), grind up kilotons of coal dust dispersed into the
confined atmosphere in the mine over a long time, and light a match.

And then of course there's Heinlein's "Methuselah's Children", where the
world government believes the Howard Families have the secret of extreme
longevity, and when they escape, they reverse engineer it and come up
with the "secret" themselves. Neveryoumind that the Howard Families
had no such secret...

And so on and so forth.

But the thing is, the speed of light "barrier" is not the same kind of
thing as chain reactions, the sound barrier, longevity, or many another
"impossibility" which turned out not to be impossible. Don't confuse
impossibilities of the first kind (impossible for reasons of basic theory,
like energy conservation, or lightspeed invariance) and impossibilities
of the second kind (impossible for reasons of engineering difficulty,
like the sound barrier or reaching the moon). And then there's
impossibilities of the third kind, where nobody really said them,
like "bumblebees can't fly".

The boundaries between the categories aren't razor sharp, and things that
are only engineering-difficult can masquerade as theory-difficult (eg,
the bit that was common in some early space opera, where you can't have
a heat ray that heats the target hotter than the emitter, for reasons
of optics and thermodynamics... and then you have the laser to show
it wrong; and another example, the bit about cosmic inflation above),
and some ambiguity whether something like the sound "barrier" is of the
second kind or third kind). Plus a bit of difficulty as to where
to fit things like "continental drift is implausible, but
plate tectonics is OK".

But on the whole, very useful distinction to keep in mind, imo.
Because it's a regular ploy to cite cases of the second kind as support
for confidence that cases of the first kind will eventually be resolved,
if only people would stop being such negative nellies.

Just lumping all "impossibilities" together is counterproductive.
In the sense that it leads one not to make a probable-return-on-
investment judgment ... judiciously.


"You can't beat Captain Implausible. It's impossible!"
--- Pinhead Pierre, from Phineas and Ferb episode "Out of Toon"


Wayne Throop http://sheol.org/throopw