What is the Kardashev scale?
The scale was originally designed in 1964 by the Russian astrophysicist Nikolai Kardashev. He was looking for signs of extraterrestrial life within cosmic signals. The Kardashev scale has 3 base classes, each with an energy disposal level: Type I (10¹⁶W), Type II (10²⁶W), and Type III (10³⁶W).
Other astronomers have extended the scale to Type IV (10⁴⁶W) and Type V. The energy available to this kind of civilisation would equal that of all energy available in not just our universe, but in all universes and in all time-lines. These additions consider both energy access as well as the amount of knowledge the civilisations have access to.
This video by Isaac Arthur offers an in-depth look at the Kardashev Scale, a system of classifying advanced civilisations. Isaac will talk about what it is, and what some of the capabilities of such civilisations would be.
What are the three types of civilisations?
A Type I civilisation can manage the entire energy and material resources of a planet. A Type II civilisation is capable of harnessing the energy and material resources of a star and its planetary system. A Type III civilisation is able to marshal the energy and material resources of an entire galaxy.
Theoretical physicist Freeman Dyson proposed in the 1960s that such advanced civilisations could be detected by the telltale evidence of their mid-infrared (IR) emissions.
What is the Dyson sphere?
Proponents of solar power know that only a tiny fraction of the sun’s total energy strikes the Earth. What if we, as a civilisation, could collect all of the sun’s energy? If so, we would use some form of Dyson sphere, sometimes referred to as a Dyson shell or megastructure.
Physicist and astronomer Freeman J. Dyson first explored this idea as a thought experiment in 1960. Dyson’s two-page paper in the journal Science was titled Search for Artificial Stellar Sources of Infrared Radiation because he was imagining a solar-system-sized solar power collection system not as a power source for us earthlings, but as a technology that other advanced civilisations in our galaxy would, inevitably, use.
Dyson proposed that searching for evidence of the existence of such structures might lead to the discovery of advanced civilisations elsewhere in the galaxy, and indeed, since late 2015, astronomers have been arguing about a bizarre and now-controversial star, known to astronomers as KIC 8462852, whose light may indicate telltale signs of a Dyson sphere under construction around it.
What is KIC 8462852 or Tabby’s Star?
The more scientists learn about “Tabby’s Star,” the more mysterious the bizarre object gets.
Newly analysed observations by NASA’s planet-hunting Kepler space telescope show that the star KIC 8462852 — whose occasional, dramatic dips in brightness still have astronomers scratching their heads — has also dimmed overall during the last few years.
KIC 8462852 hit the headlines last September, when a team of astronomers led by Tabetha Boyajian of Yale University announced that the star had dimmed dramatically several times over the past few years — in one case, by a whopping 22 percent.
These brightness dips are too significant to be caused by an orbiting planet, so scientists began suggesting alternative explanations. Perhaps a planet or a family of orbiting comets broke up, for example, and the ensuing cloud of dust and fragments periodically blocks the star’s light. Or maybe some unknown object in the depths of space between the star and Earth is causing the dimming.
Could Humanity Ever Really Build a Dyson Sphere?
As the latest episode of PBS Space Time explains, making a single vast mega-structure encapsulating the Sun is structurally impossible.
We’d be faced with gravitational stresses, structural in-habitability, and location instability. Moreover, we currently don’t have the engineering capabilities nor the materials to pull this off.
But collecting the entire output of our home star may still be the smart choice. What we do instead is to build a Dyson “swarm,” and not a Dyson “sphere.” The Dyson Swarm is made up of one-kilometer (0.6 mi) solar panels that orbit the Sun in hundreds of stable criss-cross patterns.
To accomplish the same objective, we’d first have to cannibalise Mercury and blow it up to harvest the materials we need to build the swarm. Learn more in the video below:
Republished by Blog Post Promoter