A universe turned inward
"Imagine the energy crisis of a really advanced planetary civilization. They've used up all their fuels, they depend on solar power. An enormous
amount of energy is generated by the local star, but most of the star's light doesn't fall on their planet. So perhaps, they would build a shell, to
surround their star, and harvest every photon of sunlight. Such beings, such civilizations, would bear little resemblance to anything we know."
Back in 1960 Freeman Dyson
began to consider the facts of death on a planetary scale. Like a candle, our
beautiful Sun will run down and the energy we need to keep living will fade away with it. In dramatic terms we’ll be in the cold against the silence
of space and alone in our little backwash of the galactic arm. At such a time, alone or not, life on Earth will experience a long, drawn-out
extinction event that will span millennia. Will we let it?
Based on our current knowledge, this is the fate of all planetary systems – all stars
and their civilisations with them. Say hello to entropy!
Dyson scratched his head and he ummed and ahhhed for a while before coming up with the concept of Dyson
. There are many variations on this concept although it’s essentially about closing the windows and doors to keep the heat in. He
imagined a civilisation constructing a sphere, or cloud of stations, around
their sun to trap as much of its diminishing energy as they could.
Clever enough and possibly something that’s unavoidable for civilisations to endure? I guess that depends on a million other events such as access
to space travel, exotic energy or visits from the ‘neighbours.’
Speaking of neighbours, we’ve been pressing our ears to the walls
for years now and
spying through the gaps
of our metaphorical curtains. So far, nothing. Space seems mighty
quiet right now. Well, if we had a civilisation within our galactic neighbourhood, what if they
are already behind something like a Dyson
Sphere? What if they are hunkered around the embers of their sun and we can’t see their ‘light’ or hear their ‘chatter?’
In science, we have that PITA called the 1st Law of Thermodynamics
and its apocalyptic
sister, the 2nd Law of Thermodynamics.
. We could say it’s part of the reason why
the Universe is *probably* doomed to a fading, cold death. It simply means that energy cannot be created or destroyed just converted into other forms.
For our purposes, this means that our potential Dyson-dwellers can’t keep all the energy in a closed system…some has to escape by conversion in
the mid infrared range.
Beginning last month, this is just what some scientists have set out to do. They’re looking for the signature of energy escaping from Dyson Spheres.
The Best Way to Find
Aliens: Look for Their Solar Power Plants
That's because if Dyson Spheres exist, they promise to give off a very particular kind of heat signature, a signature that we should be able to
see through our infrared telescopes. The solar energy collected by a Dyson Sphere would heat it, the same way that your computer heats up when it uses
electricity. That heat would radiate off the sphere as infrared light rather than visible light. "A Dyson Sphere would appear very bright in the
mid-infrared," Wright explained to me. "Just like your body, which is invisible in the dark, but shines brightly in mid-infrared goggles."
The search is intended to last for two years and might have more chance of success than SETI’s approach. Radio signals disperse and civilisations
might only have brief windows (in galactic terms) where they generate the types of signals SETI are listening for. However, something like a Dyson
solution would presumably be a stable system with a steady output of mid infrared radiation. Also, in theory, these potential systems could have
life-spans of millions of years which would offer us much greater windows of opportunity.
Wright's group will have access to data that Fermilab's researchers could only dream of. They'll be scanning three different infrared sky
surveys, including NASA's Wide-field Infrared Survey Explorer (WISE) (pictured up top) which is hundreds of times more sensitive than IRAS. They'll
be looking for Dyson Spheres in our galaxy, but also for whole galaxies with excess waste heat -- galaxies that may contain a large number of stars
enshrouded in technological megastructures.
Success for us would be a world-changing event. It’d be a joyous occasion to actually know that LIFE is out there and the Universe isn’t as quiet
as we thought. However, spare a thought for what existence within a Dyson environment could be like. Psychologically, you’d live within a universe
turned inwards and you’d be poking at the embers of a dying fire as the cold gets ever nearer. As much as we'll celebrate such an awesome
discovery, it'd be like looking at our own inevitable death and that of our Sun.