It's a little hard to distinguish plain bad science from science
which the author made up for the purpose of the story. There are
a couple of clear cases:
Then there are
things that conflict with very well-established theories, e.g.
Keplerian orbital dynamics:
- in films like Star Wars, exploding spaceships
(or just ships with their engines running)
tend to be audible through a vacuum
- people exposed to vacuum come apart almost immediately
(for the true story, see here)
Common misunderstandings of theories that the authors would probably
say they accept:
- planets orbiting red dwarf stars, close enough that water is
liquid on their surfaces, but having "years" about as long as
Some more that look pretty ridiculous to many of us:
- a superconductor of electricity is also a superconductor of heat
- the rate of evolution is proportional to the intensity of gene-damaging
hard radiation. Richard Dawkins points out in one of his books that
the actual brake on Earthly evolution is the fact that most species are
already quite well adapted to their environments; I remember reading
somewhere that crossover (sexual reproduction) can create very varied
organisms from the existing supply of genes, with no mutation needed.
- if a certain modification to a life-form is desirable, evolution
will inevitably produce it (sometimes dressed up as "Gaia hypothesis")
Admittedly we have no observations to confirm or deny these. Other
- evil aliens who find humans highly desirable either nutritionally or
romantically (and ignore sheep for both purposes)
- good aliens who have evolved completely separately from humans
but can interbreed with them easily
- ecosystems with carnivores but no herbivores (or something like that).
However, Isaac Kuo points out that,
"At first glance, most ocean environments appear to have carnivores
but no herbivores. You'd have to look closer to find the teeming
herbivores behind it."
- cyberpukes who spend a few years programming on DOS, and can therefore
understand and break any alien computer system in a few minutes.
Geoffrey Landis says: "[t]he Wiedemann-Franz law states that for metals, the ratio of
thermal conductivity to electrical conductivity is a constant proportional
to the temperature [Kittel, Introduction to Solid State Physics, 5th
edition, 1976, page 178]. It happens that this law does not hold for
superconductors, but that's not obvious." (As I understand it, superconductors use
a different mechanism for conducting electricity than normal conductors, and that
mechanism doesn't work for conducting heat.)
Chris Neufeld says:
"the relationship is quite strong in the
reverse direction; it is a fairly common trick in low temperature physics
to use superconducting materials as heat switches, with the
superconducting state being used as a thermal insulator, then an applied
magnetic field destroying the superconductivity and driving it normal,
increasing the thermal conductivity by a factor of about three-hundred.
This gives a heat switch with no moving parts, something quite important
when working at low temperatures where frictional heating is a concern."