[ExI] Tabby's star

[John Clark]

On Mon, Dec 12, 2016 at 12:07 PM, spike <spike66 at att.net> wrote:

​> ​
> If we gather all the metals available in the system into one big lump, we
> end up with a sphere perhaps thrice to five times the diameter of the
> earth.  Last I heard, it is still unknown if Jupiter has a rocky core, so
> there is plenty of uncertainty in this analysis,


​I think the consensus is Jupiter does a rocky core and its between 12 and
45 times earth's mass. ​



> ​> ​
> so let us assume all the metals combined, throwing away the hydrogen and
> all noble gases


​H
elium would still be useful, you'd want to keep your brain as cool as
possible
​ because
the minimum energy needed for
​anything​
 to change one bit of information is kT*ln2 where k is Boltzmann's constant
and T is the temperature in degrees kelvin of the object doing the
computation.
​ I suspect that cooling piped would take up more of the volume of a
Jupiter Brain than logic processors and memory chips combined, and Helium
would be ideal for that.
Helium liquefies at 4.2 K but when it gets below 2.17 K it becomes
a super-fluid
​called Helium-2 ​that has
 zero viscosity, provided that the pipe the helium is flowing through does
not have a diameter smaller than 10^-9 meters.
​And Helium-2
is also by far the best conductor of heat known, it conducts heat so fast (
​over 20 meters a second) ​
 that there are no hot spots in it and thus no bubbles
​ to interfere with the free flow of fluid. If you put a bucked of
 Helium
​-2​

​on a hot plate​
​all of it would remain at the same temperature so you's see no boiling no
bubbles, all the
 vaporization
​would​
 takes place at the surface.
​

It also occurs to me that if you start to run low on structural materials
for your mega-structure you might want to consider ice, it's not nearly as
strong as carbon nanotubes but it is made of the first and third most
abundant elements in the universe. And if ice is just too weak try pykrete,
a mixture of 86% ice and 14% wood pulp that is almost as strong as concrete
at cold temperatures; and wood pulp is made primarily of Carbon Oxygen and
Hydrogen, the sixth third and most abundant elements in the universe.

But all of what I think I know what the guts of a Jupiter Brain would look
like could turn into bullshit if Quantum Computing turns out to be the real
deal. Google claims that within a year it will be able to demonstrate what
they call "quantum supremacy" by making a machine that can do something
​, anything,​
that even the largest supercomputer can't do, like factoring very large
numbers or doing chemistry without
​a ​
test tube by simulating molecular structure from first principles
​
. If Google can actually do this it would be, to use the favorite word of a
certain orange politician, *HUGE*.

http://www.sciencemag.org/news/2016/12/scientists-are-close-building-quantum-computer-can-beat-conventional-one

Interesting quote from the above:

​"*​*
*We like to joke that once we have a quantum computer, we're going to use
it to design the next quantum computer.*
​"​

​If anyone thinks Google has a chance of really pulling this off
you'd better sell your Bitcoins!​


  John K Clark
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