[ExI] Alien Civilizations May Only Be Detectable For A Cosmic Blink Of An Eye

[Keith Henson]

On Mon, Oct 20, 2025 at 8:36 PM <spike at rainier66.com> wrote:
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> -----Original Message-----
> From: Keith Henson <hkeithhenson at gmail.com>
>
> On Mon, Oct 20, 2025 at 5:35 AM John Clark <johnkclark at gmail.com> wrote:
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> snip
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> >>... Yes a Dyson sphere or swarm will radiate heat from both the inside and the outside.
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> >...A heat sink facing the sun or a hot surface is not useful as a heat sink.  They have to be facing solar north and south and be shaded from the sun...   Keith
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> There is work to be done yet on thermal modeling.

I have worked on radiators for use in space since 1979.  The most
recent can be found in the animation beamed energy bootstrapping.  The
sunshade is missing soyou can see the inner working.

> It is far too easy to assume away or wish away any kind of problems, but I keep coming up with designs that let most of the star's energy go right on past, with no clumps of nodes for the most advanced Dyson swarms.

That's pointless if you need the energy to do something.

> This leads me back to the notion that Dyson swarms could be very common but we can't see them in most cases.  Perhaps an early swarm hasn't worked out its optimal configuration and is still clumpy.

Why should a Dyson object ever be anything but a flat surface facing
the star and a backside radiator? Nothing else makes engineering
sense.

Keith
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> Or perhaps it is wishful thinking, because it would explain why we don't see Dyson swarms blocking most of a star's energy.  Explanation: it cannot.  The innermost nodes overheat, since they get radiation from all directions.  So... Dyson swarms get as small as they can (for speed and materials reasons) but most of the energy still goes right on thru.
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> So much for Kardashev's Kardashians: that notion is busted by old fashioned thermodynamics.
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> spike
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