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RE: starship-design: WHERE ARE THEY?

> There is some recent theoretical work suggesting that gamma-ray
> bursts are non-isotropic, meaning that they do not radiate
> equally in all directions.  These models claim that gamma-ray
> bursts happen when a massive star in a particular mass range
> undergoes a core collapse; a black home forms in the core, an
> accretion disk forms around the black hole from matter that has
> not yet fallen into the core, and the accretion disk creates two
> extremely energetic relativistic particle beams perpendicular to
> the disk.  These blast through the outer layers of the star and
> create the gamma-ray burst when they impact the interstellar
> medium.  So from two directions you can see a gamma-ray burst,
> but from other directions the star looks mostly like a normal
> supernova.
> If this is true then gamma-ray burst events are even more common,
> but we can see only those whose beams point at us.  However, it
> is then unlikely that gamma-ray bursts can sterilize galaxies.

No, it doesn't change the end result at all as far as the equation is
concerned. It just means that there are more of them to make up the
difference. Statistically, the end result is the same. We seem to have just
been extremely lucky in that none have been pointed our way in somewhat more
than the allotted amount of time.

> I have heard other claims that our large moon influenced the
> development of life on this planet, but your summary of Guillermo
> Gonzalez's claim that intelligent life is somehow connected to
> the presense of solar eclipses doesn't even attempt to speculate
> why these necessarily have to be connected.

True, it wasn't germane to my point. Actually Gonzalez doesn't really say
that there is a casual connection. Only that a large moon is required to
stabilize a planet's normally erratic orbital tendencies and that left
unstabilized, wild rotational shifts would cause sufficient climatic
instability to discourage the rise of complex life forms. An examination of
our own climatic past lends credence to this theory. The relatively few
problems the Earth has undergone have resulted in wholesale extinctions -
particularly among higher life forms.

I would think that the odds might actually be somewhat better. The theory
does not allow for twin planets rotating around a common center. I am not
certain that this arrangement would not be tidally locked however.

Lee Parker