Re: Einstein swinging from a rope

On Mon, 20 Feb 2006 19:32:50 +0000, Mark wrote:

A few days ago on PBS news radio one of the original inventors of
the electric car was interviewed.

HO HO a good one. How old was this dude?

Electric cars have been around for nigh onto a century.


He and some others from MIT and
Cal-Tech worked together in the 1960s.

That's maybe 50 years after the invention of the electric car.


They came up with 2000
pounds of batteries in a VW bus.

Today the guy took a hybrid car getting about 50mpg and increased it
to 93mpg. He is so proud of himself, an automotive genius. What he
did was install an adapter and plug the batteries into the wall at
night.

Plug in hybrids are a big deal. You don't seem to be aware of that.
Their _invention_ was obvious and even trivial, once hybrids were on
the market; the thing that isn't trivial is publicizing them and
getting the car companies to build them.

Among the reasons you can't _buy_ a plug-in hybrid right now is a
patent tangle involving the batteries Toyota uses.

The point of the PIH is that electricity can be generated more
efficiently and cleanly at a central plant than mechanical energy can
be generated in an ICE in your car. For starters, you can't run your
car on wind power or nuclear power or solar power or natural gas or
coal ... or anything else except gasoline or (very, very expensive)
alcohol. A central generating plant can be run on any of those
things.

The ICE (Internal Combustion Engine) in your car is, in general, a lot
less efficient than an _external_ combustion engine, which is what the
generating plants use. They can also recapture a lot of the "waste
heat" by siphoning it out of the smokestack with a heat exchanger, which
can boost their thermodynamic efficiency quite a bit; your car can't do
that (unless you happen to own one of the BMW concept cars which has that
capability).


The problem is that he doesn't account for the increased mpg by
taking energy from the power grid.

Certainly he does. Plug-in hybrid proponents certainly do take
account of that, as do electric car proponents. Don't just assume
they're all blockheads. The argument for PIH's, as I already said, is
the same as the argument for electric vehicles: it's possible to
generate the energy more cleanly and efficiently if you do it in a
stationary central plant rather than with a mobile ICE.

Of course, any electric vehicle also benefits from regenerative
braking, but the non-pluggable hybrids already have that advantage.

Now, if you want to attack the use of alcohol or hydrogen on the
grounds that the proponents are leaving out a big piece of the puzzle
when they claim massive advantages, that's another story -- those
items are being pushed by various governments, and it's very hard to
tease apart any real advantage from the effects of subsidies and
book-keeping oversights.


He also doesn't realize that if
everyone plugged their car into the wall at night there would be a
massive brown-out. He also doesn't realize the inherent inefficiency
of the power grid.

This is what happens when people who have a few pieces of a puzzle take a
hammer and make them fit.

Einstein wasn't an idiot.

True.


Mark <markhu@xxxxxxxxxxxxxx> wrote in message
news:dwfKf.3542$UN.2927@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
Einstein's writings indicate that the gravitational field in essence is
non-different from the effect of swinging a box around in a circle on
the end of a rope. There is of course a hypothetical scientist standing
on
the
floor of the box in circular motion.

Any opinions? Please don't get too technical.

"Centrifugal" force and "gravitation" are both treated as "inertial"
forces in general relativity, which is to say the "real force" is that
which is provided by whatever is keeping the object from following a
straight line through 4-space. So, the "real" force on the box is the
centripetal force, and the real force on you right now is provided by
the floor.

The point in this -- and it is a big point -- is that it provides an
explanation for why all things fall identically. What's more, it also
provides a prediction that all things must always fall identically,
because there is no "real gravitational force" involved which might
have acted differently on different materials. Thus, inertial and
gravitational mass must be related by a fixed ratio, according to GR,
which is independent of all other properties of the material.

If Uncle Al's parity experiment showed a non-null result it would be
extremely big news for relativity theory.



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