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kottke.org posts about Kurzgesagt

Black holes could delete the Universe

posted by Jason Kottke   Aug 25, 2017

In their latest video, Kurzgesagt takes a look at black holes, specifically how they deal with information. According to the currently accepted theories, one of the fundamental laws of the Universe is that information can never be lost, but black holes destroy information. This is the information paradox…so one or both of our theories must be wrong.

The paradox arose after Hawking showed, in 1974-1975, that black holes surrounded by quantum fields actually will radiate particles (“Hawking radiation”) and shrink in size (Figure 4), eventually evaporating completely. Compare with Figure 2, where the information about the two shells gets stuck inside the black hole. In Figure 4, the black hole is gone. Where did the information go? If it disappeared along with the black hole, that violates quantum theory.

Maybe the information came back out with the Hawking radiation? The problem is that the information in the black hole can’t get out. So the only way it can be in the Hawking radiation (naively) is if what is inside is copied. Having two copies of the information, one inside, one outside, also violates quantum theory.

So maybe black holes holographically encode their information on the surface?

The size of life: the differing scales of living things

posted by Jason Kottke   Aug 10, 2017

In the first in a series of videos, Kurzgesagt tackles one of my favorite scientific subjects: how the sizes of animals governs their behaviors, appearance, and abilities. For instance, because the volume (and therefore mass) of an organism increases according to the cube of the increase in length (e.g. if you double the length/height of a dog, its mass roughly increases by 8 times), when you drop differently sized animals from high up, the outcomes are vastly different (a mouse lands safely, an elephant splatters everywhere).

The bit in the video about how insects can breathe underwater because of the interplay between the surface tension of water and their water-repellant outer layers is fascinating. The effect of scale also comes into play when considering the longevity of NBA big men, how fast animals move, how much animals’ hearts beat, the question of fighting 100 duck-sized horses or 1 horse-sized duck, and shrinking people down to conserve resources.

When humans get smaller, the world and its resources get bigger. We’d live in smaller houses, drive smaller cars that use less gas, eat less food, etc. It wouldn’t even take much to realize gains from a Honey, I Shrunk Humanity scheme: because of scaling laws, a height/weight proportional human maxing out at 3 feet tall would not use half the resources of a 6-foot human but would use somewhere between 1/4 and 1/8 of the resources, depending on whether the resource varied with volume or surface area. Six-inch-tall humans would potentially use 1728 times fewer resources.

See also The Biology of B-Movie Monsters, which is perhaps the most-linked article in the history of kottke.org.

Information Age automation is coming for your job

posted by Jason Kottke   Jun 09, 2017

This new video by Kurzgesagt examines automation in the past (“big stupid machines doing repetitive work in factories”) and argues that automation in the information age is fundamentally different. In a nutshell,1 whereas past automation resulted in higher productivity and created new and better jobs for a growing population, automation in the future will happen at a much quicker pace, outpacing the creation of new types of jobs for humans.

Their two main sources for the video are Martin Ford’s Rise of the Robots and The Second Machine Age by Erik Brynjolfsson and Andrew McAfee.

  1. The German phrase “kurz gesagt” means roughly “in a nutshell”, so this is a pun. Laugh now!