Atomic Theory

‘[…] when atomic theory was first proposed, it sounded pretty crazy. And yes, we call it ‘Atomic Theory’, using the scientific definition of theory, which is “a well-tested set of ideas that explains many disparate observations”, not the colloquial definition of theory, which is “a guess.” But luckily there’s no-one running around any more saying “atoms are just a theory.”

But it wasn’t that long ago that people were running around saying that. You want to know who settled it for good? Einstein! Atoms had been postulated for a long time by the 20th century, but it wasn’t until Einstein mathematically proved the existence of atoms and molecules in 1905 that the matter was truly settled. And you thought Einstein was all about relativity and E=mc², he also proved atoms exist!

Question My Findings, Please?

‘Science is all about not fooling ourselves. A good scientist wants other scientists to try to poke holes in their ideas. It’s disappointing to be wrong, but if we are, we want to know!’

– Plait. P. (2015, August 6) Exoplanets: Crash Course Astronomy #27

Herding versus Agriculture

‘Herding is a really good and interesting alternative to foraging and agriculture. You domesticate some animals and then you take them on the road with you. The advantages of herding are obvious. First, you get to be a cowboy. Also, animals provide meat and milk, but they also help out with shelter because they can provide wool and leather.

The downside is that you have to move around a lot because your herd always needs new grass, which makes it hard to build cities, unless you are the Mongols.

But anyway, one of the main reasons herding only caught on in certain parts of the world is that there aren’t that many animals that lend themselves to domestication. Like, you have sheep, goats, cattle, pigs, horses, camels, donkeys, reindeer, water buffalo, yaks, all of which have something in common. They aren’t native to the Americas. The only halfway useful herding animal native to the Americas is the llama. […]

Most animals just don’t work for domestication. Like hippos are large, which means they provide lots of meat, but unfortunately, they like to eat people. Zebras are too ornery. Grizzlies have wild hearts that can’t be broken. Elephants are awesome, but they take way too long to breed.’

– Green. J. (2012, January 26) The Agricultural Revolution: Crash Course World History #1

Why did Agriculture Happen?

‘So why did agriculture happen? […]

Historians don’t know for sure, of course, because there are no written records. But, they love to make guesses. Maybe population pressure necessitated agriculture even though it was more work, or abundance gave people leisure to experiment with domestication, or planting originated as a fertility rite – or as some historians have argued – people needed to domesticate grains in order to produce more alcohol.

Charles Darwin, like most 19th century scientists, believed agriculture was an accident, saying, “a wild and unusually good variety of native plant might attract the attention of some wise old savage.”‘

– Green. J. (2012, January 26) The Agricultural Revolution: Crash Course World History #1

Advantages and Disadvantages of Agriculture

‘All right, […] let’s take a look at the advantages and disadvantages of agriculture.

Advantage: Controllable food supply. You might have droughts or floods, but if you’re growing the crops and breeding them to be hardier, you have a better chance of not starving.

Disadvantage: In order to keep feeding people as the population grows you have to radically change the environment of the planet.

Advantage: Especially if you grow grain, you can create a food surplus, which makes cities possible and also the specialization of labour. Like, in the days before agriculture, everybody’s job was foraging, and it took about a thousand calories of work to create a thousand calories of food, and it was impossible to create large population centres.

But, if you have a surplus, agriculture can support people not directly involved in the production of food. Like, for instance, tradespeople, who can devote their lives to better farming equipment, which in turn makes it easier to produce more food more efficiently, which in time makes it possible for a corporation to turn a profit on this ninety-nine cent double cheeseburger. […]

Some would say that large and complex agricultural communities that can support cities and eventually inexpensive meat sandwiches are not necessarily beneficial to the planet or even to its human inhabitants. […]

Advantage: Agriculture can be practised all over the world, although in some cases it takes extensive manipulation of the environment, […] irrigation, controlled flooding, terracing, that kind of thing.

Disadvantage: Farming is hard. So hard, in fact, that one is tempted to claim ownership over other humans and then have them till the land on your behalf, which is the kind of non-ideal social order that tends to be associated with agricultural communities.’

– Green. J. (2012, January 26) The Agricultural Revolution: Crash Course World History #1

Evolution 101

‘Consider Darwin’s original phrase natural selection: everything from Cuckoo Birds that lay their eggs in the nest of other birds, to giraffes whose long necks are good for reaching food in high trees, to humans whose brains make up for their fragile bodies, are selected for, naturally.

An even better phrase would be non-random selection or maybe even non-random elimination. While all genetic mutations are generated by a random copying error or random variation completely beyond the animal’s control, the selection of those traits is not random.

Successful variations that allow you to survive and reproduce are determined by the very specific circumstances of your environment, where elimination – death – might not be far away.

So, the selection of your traits is done by a very specific and sometimes brutal list of criteria. This is why people who say that they don’t understand how all animals could have “evolved by chance” don’t really understand how evolution works.

Here’s another phrase that doesn’t get it right: “evolution is just a theory”. In everyday speech, theory means guess; but in science, a theory is something that was tested time and time again, explains many different observations and is backed up by a mountain of evidence.

Evolution is a theory like gravity is a theory, and you don’t go jumping out your window because gravity is “just a theory”.

Why are we so certain? Emily knows:

Evolution is one of the most tested, most utilised and most widely accepted theories in science. It’s backed up by literally tonnes of fossil evidence which can show us shared traits with species that no longer exist, and help us map out lines of descent for creatures that are around today.

DNA sequencing further tells us about lines of descent and you can measure the commonality of the DNA possessed by two animals to tell how closely related they are, and when they may have split off from a common ancestor.

Radiometric dating allows us to assign dates to various fossils, further helping us map out lines of descent.

Then there’s the simple fact that extinct species are always found in the same rock layers you’d expect to find them. Which is why you don’t see a bunny skeleton in Cambrian rock layers from half a billion years ago. That’s also how we know that Dimetrodon is not a dinosaur.

Closely related species are often geographically distributed near one another. That’s not to mention that we can see evolution happening before our very eyes: whether it be the discovery of a new species that recently moved into a different environment, the development of newly adapted bacteria into superbugs, the evolution of new breeds of rapidly reproducing insects, or the almost constant changes in gene distribution in animal populations all over the world.’

– Green. H., Graslie. E. (2014, October 29) The Evolutionary Epic: Crash Course Big History #5

Definition of Science

‘There are lots of definitions of science, but I’ll say it’s is a body of knowledge and a method of how we learn that knowledge.

Science tells us that the stuff we think we know may not be perfectly known; it may be partly or entirely wrong. We need to watch the universe, see how it behaves, make guesses about why it’s doing what it’s doing and try to think of ways to support or disprove those ideas.

That last part is important.

Science must be – above all else – honest, if we really want to get to the bottom of things. Understanding that our understanding might be wrong is essential, and trying to figure out the ways we may be mistaken is the only way that science can help us find our way to the Truth.

Or at least, the nearest approximation to it.

Science learns. We meander a bit as we use it, but in the long run we get closer and closer to understanding reality. And that is the strength of science. And it’s all around us.’

– Plait. P. (2015, January 15) Introduction to Astronomy: Crash Course Astronomy #1