The Great Oxidation Event


Breathable air
2.4 billion years ago

For the first half of Earth’s history, there was hardly any oxygen in the air. But then some bacteria began harnessing sunlight to make sugar from carbon dioxide and water, just like green plants today. These microbes pumped out oxygen as a waste product, creating the oxygen-rich atmosphere we have today. But the first oxygen may have caused the entire planet to freeze over into a ‘Snowball Earth’, by stripping the greenhouse gas methane from the air.

See other: History of Life

Earth is Born


Birth of a planet
4.5 billion years ago

Earth grew from a cloud of dust and rocks surrounding the young Sun. Earth formed when some of these rocks collided. Eventually they were massive enough to attract other rocks with the force of gravity, and vacuumed up all the nearby junk, becoming the Earth. The Moon probably formed soon after, when a planet-sized chunk of rock smashed into the Earth and threw up a huge cloud of debris. This condensed into the Moon.

See other: History of Life

Language and Scientific Understanding


Osiatynski: Would this extrahuman observer think the same way about our symbols, ideas, needs, and values?

Chomsky: Absolutely. I think he would be struck by the uniformity of human societies in every aspect. And there is more than that. Let’s imagine again an observer looking at us without any preconceptions. I think he would be struck by the fact that although human beings have the capacity to develop scientific knowledge, it must be a very limited capacity because it is only done in very narrow and specific domains. There are huge areas where the human mind is apparently incapable of forming sciences, or at least has not done so. There are other areas — so far, in fact, one area only — in which we have demonstrated the capacity for true scientific progress.

Osiatynski: Physics?

Chomsky: Physics and those parts of other fields that grow out of physics — chemistry, the structure of big molecules — in those domains, there is a lot of progress. In many other domains, there is very little progress in developing real scientific understanding.

Osiatynski: Isn’t it because man wants to exercise control over the physical world?

Chomsky: I don’t think so. I think it probably reflects something very special about the nature of our minds. There is no evolutionary pressure to create minds capable of forming sciences; it just happened. Evolutionary pressure has not led to higher rates of reproduction for people capable of solving scientific problems or creating new scientific ideas. So if, in fact, the science-forming capacities evolved for other reasons, it would not be too surprising if those particular structures that have developed proved to be rather special in their nature, reflecting the contingencies of their evolution or the working of physical law.

– Wiktor Osiatynski (ed.), Contrasts: Soviet and American Thinkers Discuss the Future (MacMillan, 1984), pp. 95-101

Spaghettification


Spaghettification is the process by which any object would be stretched and ripped apart by gravitational forces on falling into a black hole. Essentially, when a particle draws too close to the source of the powerful gravitational field, it is stretched into long thin shapes, like pasta.

The term was coined by Stephen Hawking in his book, A Brief History of Time, where he likened this process to spaghetti. Much like other aspects of the black hole theory and model, this effect of drawing too close to a black hole remains untested, unobserved and unproven, and relates to areas of physics that remain largely unexplored, namely the concept of a force so powerful that no matter what components make up a piece of matter, it will be stretched further than is deemed by many to be within the realms of physical plausibility.

“Sure, black holes can kill us, and in a variety of interesting and gruesome ways. But, all in all, we may owe our very existence to them.” ― Phil Plait

On Two Outcomes


“There are two possible outcomes: if the result confirms the hypothesis, then you’ve made a discovery. If the result is contrary to the hypothesis, then you’ve made a discovery.”

– Enrico Fermi

Shooting In The Air


A typical 7.62mm round fired vertically normally climbs about 2,400 metres in 17 seconds, and then take another 40 seconds or so to return to the ground. It falls at a speed of about 70 metres per second (falling base first, because it’s more stable that way round).

The bullet velocity required for skin penetration is between 45 and 60 metres per second, but a blow to the head doesn’t need to penetrate the skin in order to be fatal, and this is the key: the reason fatalities are disproportionate is that any injuries which do occur are likely to be cranial. So while it’s less likely that you’ll be hit than if somebody is aiming at you, if you are hit it’s more likely to be fatal – about five times as likely as in normal firing.

“A lot of the people who keep a gun at home for safety are the same ones who refuse to wear a seat belt.” – George Carlin

Even if it’s launched vertically the bullet is likely to move sideways quite significantly – when it slows down towards its highest point it is particularly susceptible to sideways movement by the smallest gust of wind.

Experiments in Florida just after the First World War involved a machine gun set up on a ten-foot-square platform positioned over water so that the returning bullets could be seen to splash down. The gun was adjusted to centre the returning bullets onto the stage, but, of more than 500 bullets fired into the air, only four hit the stage at the end of their return journey. Unfortunately, the size of the stage is at present not known.

“You don’t need no gun control, you know what you need? We need some bullet control. Men, we need to control the bullets, that’s right. I think all bullets should cost five thousand dollars! Five thousand dollars per bullet! You know why? Because if a bullet cost five thousand dollars there would be no more innocent bystanders.” – Chris Rock