[tt] [megascale] Fwd: Re: [orions_arm] Re: Galaxy obliteration

Fri Nov 30 07:49:08 UTC 2007

----- Forwarded message from Bryan Bishop <kanzure at gmail.com> -----

From: Bryan Bishop <kanzure at gmail.com>
Date: Thu, 22 Nov 2007 07:29:02 -0600
To: megascale at heybryan.org
Subject: [megascale] Fwd: Re: [orions_arm] Re: Galaxy obliteration
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Subject: Re: [orions_arm] Re: Galaxy obliteration
Date: Wednesday 21 November 2007 23:17
From: Damien Sullivan <phoenix at mindstalk.net>
To: orions_arm at yahoogroups.com

On Wed, Nov 21, 2007 at 10:51:14PM -0000, drashner1 wrote:
> > This brings me back to the intergalactic Nicholles beam strategy I
> > mentioned earlier.

Aaaagh.  I thought I'd seen all the misspellings by now, but.  I don't
think that's even a valid name.

James Nicoll.  No h, no s.

> First, I wonder how wide the beam would be by the time it got to its

To recap: the original idea was of a Dyson-sized phased array beam, not
a mirror.  Not saying a mirror can't work, but he found a phase array
easier to imagine I guess, especially given where the star is relative
to easy concavity.  Of course the phase array has to be coordinated
among a Dyson swarm, not a sphere, but.

Then we can do the calcs.  Source aperture anywhere from a million
(solar diameter) to 100 million (1/3 AU radius) kilometers, target
aperture of 10000 km (Earth diameter, roughly), wavelength of 1e-9 km
 or less, range of 1e6*1e4/1e-9 = 1e19 km or 1e6 light years.  1e8
 light years if you use the larger source aperture.  So.  Only 1e4
 light years if you do planet to planet beams -- note, that's more than
 the OA expansion radius so far.  And that's using infrared beams, UV
 boosts range by 10, X-rays get ridiculous (but actually making the
 beam is probably also Really Hard; the smaller the wavelength, the
 harder the phase coordination problem, I think.)

http://groups.google.com/group/sci.space.tech/msg/7eaf8e000bcc0514
isn't the earliest source but it'll do for now.  Note he talks about
evaporating Earth mass worlds in a week.

> Second, and going back to the beam width, I wonder how effectively
> you could aim this thing.  True we have the Argus Array which is
> quite the

Deliberately hitting anything less than a planet with a known orbit is
probably impossible.  Ruining a planetary ecosystem is probably easy:
note that when you're focusing a star on a planet, you don't need a
 long beam time, or full focusing, to totally overwhelm the natural
insolation.  And boosting the atmosphere to escape velocity, or boiling
the oceans, will wreck things nicely.

But a lot of the initial idea was "huh, you *can* focus things at huge
ranges" rather than serious ideas about intergalactic warfare.

> efficiency it will still take over 150yrs to take Jupiter apart. 
> Much

That long?  But the Earth is a week... oh, binding energy of a uniform
sphere goes up as the square of the mass, and down as the linear of the
radius.  (300^2)/10 = 10,000; 10,000 weeks is 192 years, close enough.

> Which raises the question: We have generally treated N beams as a
> sort of 'instant' weapon sweeping through a solar system and flashing
> planets and megastructures and even Jupiter nodes to drifting ash in
> a fraction of a second.  But is this an accurate representation?

Well, no.  Don't know where you got that idea.  Actual blobs will still
take a while, even if you focus fully.

Surfaces, OTOH, should be toast, which will make counterattack or
escaping difficult.

Of course, the usual assumption is of a Sun-like star, 4e26 Joules. 
 Red dwarfs are common but dimmer, by 10-1000; enough to still fry an
 ecosystem, as you bear down with 10 million times the energy it
 normally receives, instead of 10 billion times.  OTOH, there's the
 occasional brighter star, up to 10,000 or even 1e6x.  Hit Jupiter with
 the output of a blue supergiant and that 200 years turns theoretically
 into one ten-thousandth of a year, or about an hour.

Huh.

What was that about the Panvirtuality concentrating about brighter
stars?

Of course, in light of things like the Turing construct
http://www.orionsarm.com/worlds/Turing.html
Dyson swarms around a mere fusion reactor seem kind of quaint.

-xx- Damien X-)

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