Re: starship-design: Air born Viruses

[Timothy van der Linden <Shealiak@XS4ALL.nl>]

Hello Jonathan,

>         In watching many Sci-Fi movie, I've come across two different
>points that contradict each other, and you probably have too. In WAR OF
>THE WORLDS, the invading aliens are killed by viruses and bacteria that
>they are not immune to; in another movie, however, I forget which, it
>said the viruses and other agent have not adapted to use of human cells.
>I was wondering which of these is more likely of happening.

This is a difficult question since we do know little about how foreign such
virii and bacteria will be.

Virusii need compatable DNA to multiply. Unless somehow our DNA is
compatible, virusii won't make much of a chance.
(The reason virii can cross species is that we have many genes that are the
same or at least very similar.)
So the question is whether life has a rather similar way to solve problems,
thus whether it will use similar DNA sequences to create a biological being
on Earth or on some distant planet.
Then again if virii attack us at those similar points, our body likely has
already some distant solution for it.

About bacteria, they will be detected by our immune system, since virtually
everything foreign is not accepted by our body. (Hence organs are sometimes
rejected in after a organ transplantation. (They use medicine to counteract
that.))
So detection of a foreign being usually is fast, and the body will react by
changing its temperature (this usually will slow down they enemy's growth).
Unfortunately our immunesystem may take a while to find a more effective
way of stopping "nasty critters", but by then it may be too late. My guess
is that the more foreign the critter, the longer it will take.

This may sound as if bacteria make a good chance. And yes they would,
assuming they would find our body comfortable enough to live in. I could
conceive that if most creatures on the foreign planet had a bodytemp 10
degrees below ours, that only few bacteria would be able to thrive in our
body.
There are many other factors than temperature alone that need to be near an
optimum for a bacteria to make much of a chance. So once again how creative
is nature in finding solutions.

So while virii may not be a danger if nature has found different DNA sets
to solve the same problem. Whether that is true, has yet to be determined.
However bacteria have a lot more chances, since they are less choosy.
Especially if the larger creatures and circumstances are Earthlike (eg.
warmblooded animals and an average global temperature of 15 degreesC)
bacteria make a good chance.

Timothy


BTW. Why "AIR BORN" in the subject?
As far as I know an airborn virus is the last mutation a succesful virus
will go though to reach it fullest potential. It does this by creating
relative large hairs that will make it float better. (Eg. like seeds blown
by the wind)