The Kardashev Scale

Siena Woolf UVI-8

The Kardashev scale is a method of measuring a civilisation’s level of technological advancement based on the amount of energy it can use. It is a scale which classifies hypothetical extraterrestrial civilisations and generally, it divides into three types of civilisations. The method of measuring was proposed in 1964 by a Soviet astronomer called Nikolai Kardashev, but as time progressed, physicists such as Carl Sagan and Michio Kaku have adopted this idea and brought forth their own interpretations. The scale was originally published in a five-page paper called “Transmission of information by extraterrestrial civilisations.” It strongly focused on calculating how powerful a light signal from any point of the universe would need to be for radio scientists at the time to detect it.

Nikolai Kardashev

Kardashev was born into a family of professional revolutionaries who worked with the Bolsheviks in 1932, just after what many would call the golden age of physics. In 1978, he started a project called the Space Very-Long-Baseline-interferometry (VLBI) mission Radio Astron. This mission covered more than thirty years and was finally launched in 2011. It uses a global network of radio dishes as one radio telescope the size of the earth. The VLBI method was used in 2019 and 2022 by the Event Horizon Telescope to capture the black hole images. The main goal of the mission was originally to study astronomical objects with an angular resolution of up to a few millionths of an arc second. On top of this, Kardashev is thought to have predicted the existence of pulsars1 in his papers before they were originally discovered.

On the Kardashev scale, there are three main categories simply typed I, II, and III. The overall status of a given civilisation is the product of two things: energy and technology. The better the technology, the more energy a civilisation can harness.

1. Type I is described as a “technological level close to the level presently attained on the Earth.”

2. Type II as “a civilization capable of harnessing the energy radiated by its own star.”

3. Type III as “a civilisation in possession of energy on the scale of its own galaxy”

The Earth’s current status is a Type I civilisation on the Kardashev sphere, whereas a civilisation with a working Dyson Sphere2 a structure harvesting its

1 A pulsar is a highly magnetised neutron star that emits beams of electromagnetic radiation out of its magnetic poles

2 A Dyson Sphere is a hypothetical megastructure that completely encompasses a star's light would qualify as type II. The scale is only concerned with energy consumption on a cosmic scale and since the 1960s, the scale has had a few extensions proposed beyond the three originally defined by Kardashev. Scientists such as Carl Sagan believe our civilization has a rank more like 0.7 since we have not harnessed the equivalent of the entire energy of the Earth.

Energy development for Type I, as defined by Kardashev, is limited to one planet and the civilisation has to be able to harness all the energy available. Energy sources such as Nuclear Fusion, geothermal power, and other renewables are a given. The energy required to be at a Type I civilisation implies the conversion of about 2kg of matter to energy per second. An equivalent energy release could theoretically be achieved by fusing around 280kg of hydrogen into helium per second. As well as this, antimatter in large quantities would prove a mechanism to produce power on a scale several magnitudes above the current level of technology. The collisions would release four orders of magnitude greater than fission and two orders greater than fusion. Renewable energy would have to be through solar power, wind, biofuel, or hydroelectricity; star and captures a large percentage of its power output but, there is no feasible way with Earth’s current technology to use the equivalent of the Earth’s total absorbed solar energy as this could only be done by completely coating the surface with man-made structures.

The energy development for Type II is that the civilisation has managed to harness the power of their local sun. An example strategy for this is to construct a Dyson Sphere or a Swarm around it. The civilisation is y to have colonised multiple planets in their solar system and use the same constructions created by a Type I civilization but applied to a large number of planets in multiple planetary systems. Another means of harnessing energy would be to feed a stellar mass into a black hole and collect photons (light particles) emitted by the accretion disk, reducing a black hole’s angular momentum known as the Penrose Process, this process, may however only be possible for a Type III civilization to achieve.

Energy development for a Type III civilisation would use the same techniques employed by a Type II civilisation but applied to all possible stars of one or more galaxies and they would be able to gather the energy released from a supermassive black hole which exists at the centre of most galaxies. Another method of capturing energy would be through gamma-ray bursts or quasars3 , if a civilisation could capture this energy, they would have an energy source comparable to small active galaxies.

As mentioned earlier, Michio Kaku is a theoretical physicist who speaks on the Kardashev scale. Alongside this, he works on string field theory and is currently pursuing Einstein's research to unite the four fundamental forces. Kaku estimates that we may be anywhere from 100 to 200 years away from graduating into a type I civilization on the Kardashev scale.

Furthermore, Carl Sagan was a pioneer in physics history, understanding that if the countless stars in the universe are suns, they will have their own planets. He also considered how planets may have habitable moons such as Titan and Europa and that Venus has an atmosphere which enhances the greenhouse effect, making it the hottest planet in the solar system. He was also a pioneering scientist in SETI (Search for ExtraTerrestrial Intelligence). Sagan’s main argument to do with the Kardashev scale was that the categories represented too vast of leaps in energy consumption and so he proposed dividing each Type into smaller categories (Type 1.1, 1.2, etc).

3 A Quasi Stellar Object with an extremely luminous active nucleus powered by a supermassive black hole

Carl Sagan

Sagan's involvement in SETI was incredibly important. In this scientific search, scientists monitor electromagnetic radiation for signs of transmissions from civilisations on other planets. The first scientific meeting of the SETI institute had ten attendees including Frank Drake and Sagan who used the Drake equation to speculate that the number of civilisations was roughly between 1,000 to 100 million civilizations in the Milky Way galaxy This scientific investigation began shortly after the advent of the radio in the early 1900s, and efforts internationally have been going since the 1980s. The first telescope designed specifically for SETI use was the Allen Telescope Array, which is a radio telescope array of which the first 42 elements have been constructed and are capable of conducting searches every day.

Finally, the James Webb Space Telescope is most recent modern day telescope which has the purpose of “help[ing] scientists understand how we got herehow, from the tangle of molecules, stars, galaxies, black holes, and planets that populate the universe, the ingredients necessary for life emerged and combined to make this place called

Earth” (per National Geographic). The telescope cost $10 billion and is too big to fit inside one of the worlds biggest rockets, the Ariane 5, without being folded up and will see the universe primarily in infrared light. The sensitivity of the telescope will help it directly observe alien worlds, although this was not the primary purpose of the telescope. In 1989, when the concept of the James Webb was conceived, planets orbiting other stars (exoplanets) had not yet been discovered. John Grunsfeld, a former NASA astronaut and STScI (Space Telescope Science Institute) deputy director said that the “James Webb is sold as studying galaxies, but i think the greatest discovery may be a habitable Earth-like exoplanet That’s what’s going to blow everybody away. ”

With modern technology rapidly increasing, the capturing of two black holes, and the innovations in space

Oobleck: Solid, Liquid or Both?

Alexia Noirot UVI-5 travel from companies such as SpaceX, the amount of time for our civilization to grow to a type 1 civilization on the Kardashev Scale may be within the lifetime of a child born tomorrow

Oobleck is one of those things we would make and play with as kids. A simple mixture of water and cornstarch creates a liquid suspension but when a force is applied (i.e from one's hand pressing down or squeezing it) the liquid feels and behaves as a solid.

Oobleck is an example of a non-newtonian fluid. A Newtonian fluid is one which maintains a constant viscosity at any given temperature. Viscosity is a measure of a fluid's resistance to flow. A fluid that is highly viscous has a high resistance and flows slower than a low-viscosity fluid. An example of a high viscous fluid would be honey, whereas a low-viscosity fluid could be water. A non-newtonian fluid does not have a constant viscosity.

Stress and Strain:

In physics stress and strain are talked about a lot in regards to materials. Stress is the force that is applied to the body, and strain is the effect the body feels as a result of the stress. For example: hitting a hammer against a sheet of metal. The force applied by the hammer creates stress and the result of that is described as strain (possible deformation of the metal). Newtonian fluids don’t respond much to stress. Imagine hitting a pool of water with a hammer, the water simply goes around the hammer, it does not resist the stress applied and it is essentially unchanged. The water does not resist the force of the hammer and does not show any signs of strain.

Non-newtonian fluids change their viscosity or flow behaviour under stress. A sudden application of a force (stress) can cause the material to get thicker and act as a solid or in some cases become less viscous. Removing the stress will allow the material to return to its original state. In the case of oobleck, its viscosity or resistance to flow increases with an applied stress. This type of behaviour is called dilatant or shear thickening.

How come this happens with oobleck:

The explanation for this strange behaviour lies in the shape of the cornstarch molecule. Cornstarch can dissolve in hot water, as the heat disrupts the bonds and makes them soluble. Cornstarch consists of long chains of starch molecules that don’t dissolve in cold or room temperature water. As a suspension mixture, solid particles spread through the water without dissolving - this is key to its properties. When a sudden force is applied to oobleck, the starch grains rub against each other and lock into position. The phenomenon is when shear thickening occurs and it basically means particles in a dense suspension resist further compression in the direction of shear. When oobleck is at rest, the high surface tension (the tendency of liquid surfaces at rest to shrink into the minimum surface area possible. Surface tension is what allows objects with a higher density than water such as insects to float on a water surface without becoming even partly submerged) of water causes water droplets to surround the starch granules. Water acts as a liquid cushion or lubricant, allowing the grains to flow freely. The sudden force pushes the water out of the suspension and jams the starch grains against each other.

And so to conclude, oobleck can act as both liquid and solid depending on its environment. Kind of cool no?