Back when Star Trek was first produced, showing a
space ship landing on a
plannet would have cost more than
the budget for an entire episode. The special
effects for the transporter beam were within the
technology and budget of the
day. Warp drive, the
universal translator, shields, tractor beams and
sexy
aliens were all plot devices to tell an
entertaining story. I thought that
impulse
engines were similar
phlebotinum, but it turns
out impulse
engines on space ships were (still are, and probably
will be
again) a genuine, real-world investment scam.
Dilithium, trilithium,
unobtainium, quantium 40,
naquadah, kryptonite, adamantium, mithril and
resublimated
thiotimoline are all fictional plot devices. In the
real world
each different element has a different
number of protons. Protons have a
positive charge,
so they repel each other with the electromagnetic force,
but
the attract each other with the strong force. The
strong force between two
protons is not strong enough
to hold them together against electromagnetic
repulsion.
If you add one neutron, that adds another source of strong
force
without contributing more positive electrical
charge so two protons and a
neutron or two form a
stable nucleus. If you add too many neutrons to a
nucleus, one of the neutrons will decay to a lighter
proton. The strong force
has a limited range. If you
try to make a nucleus with lots of particles, it
gets to big for the strong force to hold it together.
These restrictions limit
the number of
stable elements to 82 - and you can buy all of them.
All the
elements after atomic number 82 (lead)
are radio active. The lighter ones have
half lives
long enough that they remain in sufficient quantities
to be found
in the Earth's crust millions of years
after they were formed in an exploding
star. The
heavier ones have half lives that are so short
that it is really
difficult to prove that any atoms
of them were made in laboratories. All
elements
emit and absorb light at characteristic frequencies.
We can determine
the elements in the distant stars
from the colour of their light. The element
Helium
was discovered from the spectrum of the sun years
before any was found
on Earth. The point is, we know
what all the elements are. There are no gaps
leaving
room for the possible existence of trilithium or
any other magic
stable element from fictional stories.
In physics, a field is some
property that can
have a different value at different points in space.
In the
real world, there are temperature fields,
electric fields, gravitation fields
and so on.
In Star Trek, a force field is a magic barrier
used as a plot
device. In the real world, a magnetic
field can be used to contain fusing
plasma. Star
Trek used their magic barriers as containment fields
because
people were used to them being part of
the TV show. In the real world, creating
fields with
an abrupt change in value is really difficult.
The Alcubierre
metric requires fantastically abrupt
changes in gravitational field strength.
Perhaps
you could make one using fantastically abrupt
changes in
electromagnetic field strength, but then
you have to find some way of making
such fields.
If Star Trek magic barriers existed, using one to
make an
Alcubierre metric would require
fantastically abrupt changes in the barrier,
which
would require something equally fantastic to
create them. The next bit
of fun Heisenberg's uncertainty
principle. The more accurately you know the
position of
an object, the less certainty you can have about its
momentum. If
you somehow get something positioned
accurate to 10^-32m, it will get going
really fast
in an unknown direction.
Gene Rodenberry had enough sense
not to let the
laws of physics get in the way of telling a story.
If he ever
asked for scientific
advice on Star Trek, then he ignored almost all of
it.
The Alcubierre metric is consistent with theories
that have not yet
been proved wrong even by our most
expensive experiments. In science fiction,
you can
ignore those theories when they are inconvenient.
The good thing about
the Alcubierre metric is that
the scientists studying it do not hide behind a
magic barrier whenever the theory predicts an extreme
requirement for making
the metric. Here is one
such requirement.
You can measure the force on a
small magnet at
different places near a big magnetic. All such force
measurements taken together are the magnetic field
created by the big magnet.
If you move the big magnet,
its magnetic field moves. If you keep the small
magnet
still, and suddenly move the big magnet, you will see
a time delay
before the force on the small magnet
changes to match the new position of the
big magnet.
Changes in a magnetic field travel at the speed of
light.
The same thing applies to gravitation fields.
If you move a
mass, the gravitation field
(distortion in space-time) moves, but it takes time
because changes in gravitational field move at the
speed of light.
The
Enterprise avoids the inconvenient problems
of travelling faster than light by
distorting space
so the distance is travels is shorter than the distance
between its start point and destination. From the
outside, it is as if it were
travelling faster than
light. The distortion is space has to move faster than
light or the Enterprise would overtake it, and re-enter
flat space. If you put
the warp field generator on the
Enterprise, the distortions in space it creates
are
limited to light speed and cannot get ahead of the
Enterpise. For faster
than light travel,
you need lots of warp field generators on the proposed
route already in place so each can create a portion
of the Alcubierre metric
ready for when the
Enterprise is going to go past.
By all means, enjoy
Star Trek, or get a degree
in physics. You can even do both, but please do not
mix up to two. Accurate science can easily mess up
an otherwise interesting
story.
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