It's always tough when one of your favorite television
shows blows the science. For me it makes it difficult, if not impossible, to
enjoy the rest of the show. Case in point, this weeks
Doctor Who,
which is a huge favorite of mine, laid a giant, big, bad science goose egg with the
episode "
Kill
the Moon".
Some mild spoilers to follow after the logo below, so be warned.
In this episode, the Doctor comes
across a recently deceased giant spider of an alien. It looks very menacing, it
attacks one of the main characters (big mistake) and it subsequently
dies. This is all quite normal for the show. You expect there to be scary
aliens. You expect the Doctor, as a time-travelling uber-genious, to give all
of us some helpful background on all of the scary aliens he bumps into. But you
don't expect a line like this:
"It’s the size of a badger! It’s a prokaryotic unicellular life form with
non-chromosomal DNA, which as you and me know, yes, scientists know--this is a
GERM!"
Ugh. There's so much wrong with this statement, it's painful. So, let's start
with the part that's ok.
Prokaryotic is a misnomer, as the name (pre-nucleus)
implies that organisms without nuclei are awaiting the nuclei they someday hope
to have. They're not. But that's not that bad, even the textbooks cling to that
mistake. And I like the way
Peter Capaldi says "prokaryotic."
But a unicellular life form the size of a badger? That looks suspiciously like
a well known invertebrate with teeth? That part grates on the science nerves.
There are some strang unicellular life forms deep in the ocean, such as
xenophyphores, that can reach the tremendous size of up to
4 inches long. This is pretty impressive, but they're the size of a golf
pencil, not a badger.
And, this is a
Eukaryote, the largest bacterium
-- ok,
prokaryote for now -- is
Thiomargarita
thamibiensis. This prokaryote can reach 0.75 mm, which is huge for a
little cell, but still no bigger than the size of a pin head.
 |
| Xenophyphores, giant unicellular life, if 4 inches fits your definition of giant. |
This too I think I can handle, because who knows maybe
there ARE large unicellular life forms out there. The “biggest” label should
correctly be the “biggest currently known.” So, ok my teeth were clenching and
then the final “non-chromosomal DNA” sets in. Why, Doctor? All
prokaryotes have chromosomal DNA, their
DNA is non-nuclear but it’s still chromosomal.
Here’s hoping the next time the Doctor runs into these
spider-germs he says, “These spiders are the size of badgers! And they’re attacking
like germs do on Earth.” That be fine. Just
fine. Despite, the science rant, I will be watching the next episode – where
the scary alien is a mummy!
