Re: starship-design: Re: FTL travel

[Curtis Manges <clmanges@worldnet.att.net>]

Well. Steve, the gold star is yours, and thanks for your help and indulgence.

Now I get to start over, I guess. I figured out why it's been such a hassle
for me to even get my objections into a clear statement; I think I'm at the
steepest part of the learning curve with this, the place where you don't yet
know enough to ask intelligent questions. The secret source of life's most
embarrassing moments.

I was a little nervous waiting for a reply to my statement. I didn't see how I
could possibly be altogether correct, given that this stuff has been worked
over by the greatest  minds of the twentieth century, and my own not being one
of them, for sure!

> I have seen different people approach teaching counterintuitive subjects
> in different ways.  Some like to start with the theoretical basis and
> work towards practical understanding only after the theory has been
> completely explained.  Others may try to give at least some practical
> understanding without explaining all the theory behind it first, the
> idea being that intuitive understanding often comes from being able to
> play with a concept even if you don't fully understand it yet.

And now I'm not sure _which_ kind of book would work best for me, as my
preference in texts came out of my experience with more intuitive subject
matter.

> It also occurs to me that there is another book on relativistic physics
> that I can recommend which you might like better: _Six Not-So-Easy
> Pieces_ derived from Richard P. Feynman's Caltech physics lectures.  It
> also has an excellent discussion of mathematical symmetry in physics in
> the first couple of chapters.

Maybe I need a "Spacetime Physics for Dummies" . . . (I'd better watch myself,
it's probably in print!)

> Also note that the spacetime interval is _not_ Pythagorean;

this made the most difference for me, immediately, at least. I said, "Ah,
_that's_ where I screwed up." As you said, if you use faulty assumptions, you
reach faulty conclusions. I just needed to know where my assumptions were at
fault. As for the rest, it's going to take me a while to absorb. Part of my
problem is that it's been about twenty years since my mostly unused formal
education; my math skills are gone to rust and I've forgotten too much of the
other basic stuff that would make this easier for me. Another part of my
problem is in getting used to thinking this way; I've always been
uncomfortable with abstractions.

This brings me to the topic of counterintuitive thinking. Now, I'm a real fan
of intuition and instinct, these are great things, parts of a marvelous
package of powerful tools (including intellect, of course) which have made it
possible for our species to evolve to where we are today. I've had to admit,
though, that you don't even need to get sub-orbital, as in Zenon Kulpa's
examples, before intuition fails; it begins to break down the minute you do
something as simple as putting a couple of wheels under you. I recently bought
a motor scooter, and I love to ride, but learning how to steer one is the most
counterintuitive thing I've ever done: to make it go _right_, you push the
wheel to the _left_. I tried to figure that out, and my poor brain just
fizzled. The best I've been able to do is to state the conditions, thus: at
any speed above that of a walk, the steering characteristic can reverse
dramatically, and it has nothing to do with your speed or the sharpness of the
curve, and everything to do with the amount of acceleration you apply. If the
front wheel feels acceleration, the bike will tend to go left when steered
right; during deceleration, it will go right when steered right. This is why
they tell you not to brake when you're in a turn; I did one day and almost got
a flying lesson out of it. This is schizophrenic. And bikers wonder why people
think they're crazy? It's an intuitive judgment, of course!

My conclusion is that intuition fails for _any_ kind of mechanized travel, so
I suppose that the sooner we get used to the idea, the better, _especially_
for space travel.

Anyway, thanks again, and keep looking up

Curtis