The Fermi paradox revisited: Technosignatures and the contact era
Focusing on radio communications for SETI purposes and as a solution to the Fermi Paradox I find to be incredibly outdated thinking. Let me summarize:<p>1. Planets are incredibly inefficient in creating living area per unit mass;<p>2. Orbitals are incredibly efficient at creating living area per unit mass. IIRC 1% of Mercury&#x27;s mass could create a full Dyson Swarm around the sun and have billions of times of the living area of Earth;<p>3. Space orbitals as typified by an O&#x27;Neil Cylinder (being 2-4 miles wide and 20-40 miles long) don&#x27;t require new physics or new materials. Stainless steel has sufficient tensile strength;<p>4. Orbitals easily allow energy generation from solar power collection, which in space would be much more efficient than on Earth. So this idea isn&#x27;t even predicated on nuclear fusion power generation becoming commercially viable. If that does happen, this becomes even more likely. The point is it&#x27;s not required;<p>5. Dyson Swarms (being a collection of orbitals that would capture the energy output of the Sun in the same way that water droplets in a fog would obscure something) can be built incrementally. We use the term &quot;Dyson Swarm&quot; instead of the original &quot;Dyson Sphere&quot; because of the misconception that a Dyson Sphere is a rigid sphere. There is no known of theorized material with sufficient strength for that. Same for ringworlds;<p>6. Such a Dyson Swarm built between the orbits of Venus and Mars would not be that crowded. The mean distance between orbitals would still be hundreds of thousands of kilometers;<p>7. Orbitals will generate heat. That heat needs to be vented. The only way to do that in space is by expelling mass, which isn&#x27;t really sustainable, or by radiating it away. Physics tells us that the wavelength of light radiated away is basically just a function of temperature of the radiating object. At any reasonable temperature, that means largely infrared (&quot;IR&quot;) radiation;<p>8. The amount of energy such a megastructure would have available is beyond comprehension. We use an estimated 10^11 Watts of power. Capturing Solar output would mean ~10^26 Watts of power. That means if the population of humans was a quadrillion people (ie 10^15), the average power each person has would be the same as the entire Earth currently uses. Think about that;<p>9. This is likely the most practical way to travel between star systems, as in imparting momentum from light onto a spaceship. People who have looked at this see it as quite practical to get to ~0.86c this way. Beyond this, believe it or not, the aerodynamic drag of interstellar gas slows you down too much; and<p>10. The timeline from going from this to coloizing the entire galaxy is pessimistically 10 million years (assuming 0.01c and 100k LY across the galaxy).<p>If you accept these premises, such a structure would stick out. There&#x27;s no hiding something like this. The signature would be heavy on the IR spectrum and would be visible from thousands of LY away. A galaxy that had been fully colonized this way would be obvious from <i>millions</i> of LY away.<p>I find this idea attractive because it is incremental and requires no new physics or theoretical materials (unlike, say, the many attempts to come up with a mathematical basis for warp drives).<p>Radio band usage in this scenario is completely irrelevant.