Nope, we can beat that too!
First, we all upload into a universe simulator. Then we spend the rest of
all time increasing the simulators execution speed, for example using delta
compression techniques (once you have a few trillion people, the
differences between there actions and thoughts are negligible). As long as
we can come up with optimizations faster than the approach of heat death,
we can live "forever"!
:-)
-David Summers
On Tue, Mar 3, 2020 at 11:24 AM Rand Simberg <simberg@xxxxxxxxxxxxxxx>
wrote:
As is eventual heat death of the universe. Why bother? :-)
On 3/3/20 1:18 PM, William Claybaugh wrote:
Henry:
We agree with respect to the horse you seem to be beating.
I am making a still larger point: dense spacecraft constellations
intended to last millennia are a bet against the Black Swan. It does not
matter how resilient such a system design might be, eventual failure is
statistically near certain.
Bill
On Tue, Mar 3, 2020 at 12:59 PM Henry Spencer <hspencer@xxxxxxxxxxxxx>
wrote:
On Tue, 3 Mar 2020, William Claybaugh wrote:
It looks to me that this scheme does not require a stupid mistake to
create a runaway chain reaction. It appears to initiate upon *any*
mistake, ever.
I was addressing a somewhat higher level: the stupid mistake is even
attempting such a scheme without incorporating generous margins against
such a perfectly-foreseeable problem.
Relying on a complete absence of errors is not realistic -- one of the
stupid mistakes we've made in spaceflight is building systems that fail
unless everything is done perfectly. What can be done is to fairly
reliably catch errors before they do harm, design the system so it can
usually tolerate the ones that slip through, have ways of limiting the
damage when even that fails, and learn from those cases so repetitions
are
caught earlier. This is done, routinely, in many real-world technical
fields; it is not some unsolved mystery that is beyond our grasp. The
fact that we so seldom do things that way in space is our stupid mistake,
not a law of nature.
For example, any scheme with so many objects in similar orbits probably
wants a fast-response capability to *clean up* the debris from an
accidental collision, so it *doesn't* cause a runaway chain reaction.
(NB, in solar orbit, "fast" typically means months, not minutes. Even
so,
yes, this probably means that the first responders need propulsion
systems
that free them from constraints like launch windows -- it can't be done
with chemical rockets but there's nothing impossible about it.)
Kinda looks like a bad bet to me....
I quite agree that if it were built the way we usually build space
systems
today, it would be a bad bet. But assuming that a project on this scale
would never even *try* to do better is silly.
Henry