A pervasive myth in Australia is that hot weather is the greatest danger to our health. In reality, it’s more likely cold weather will kill you.

For all our concern about the dangers of heatwaves, simple analysis of mortality data suggests the cold months present a much greater health risk. Almost 7% of deaths in Australia from 1988 to 2009 were attributable to cold weather. Less than 1% of deaths were attributable to heat.

The heads of more than 100 of the world’s top artificial intelligence companies are very alarmed about the development of “killer robots”. In an open letter to the UN, these business leaders – including Tesla’s Elon Musk and the founders of Google’s DeepMind AI firm – warned that autonomous weapon technology could be misused by terrorists and despots or hacked to perform in undesirable ways.

A cold beer on a hot day or a whisky nightcap beside a coal fire. A well earned glass can loosen your thinking until you feel able to pierce the mysteries of life, death, love and identity. In moments like these, alcohol and the cosmic can seem intimately entwined.

So perhaps it should come as no surprise that the universe is awash with alcohol. In the gas that occupies the space between the stars, the hard stuff is almost all-pervasive. What is it doing there? Is it time to send out some big rockets to start collecting it?

Neurological and psychiatric conditions both involve the brain, but are treated very differently. Put simply, neurologists are trained to deal with the “brain” and psychiatrists to deal with the “mind”. Neurologists and psychiatrists formally parted company in the late 19th century.

Ever since the days of Sigmund Freud – who was originally a neurologist but is also the father of psychoanalysis – the way we think about brain disorders has been coloured by this artificial divide.

If you’ve ever needed a blood transfusion, or donated blood, you probably would have been asked your blood type. While it was once thought all blood was the same, we now know there are different types of blood, called blood groups. Transfusions between blood groups can be catastrophic, even deadly, so knowing the blood type of donors and recipients is of the utmost importance.

Our bodies contain trillions of red blood cells. Each is covered in an array of proteins and sugars, inherited from our parents, which determine our blood group. We can all be classified into group A, B, AB or O, based on which sugars coat our red blood cells.

Here are some surprising facts about humans’ effect on planet Earth. We have made enough concrete to create an exact replica of Earth 2mm thick. We have produced enough plastic to wrap Earth in clingfilm. We are creating “technofossils”, a new term for congealed human-made materials – plastics and concretes – that will be around for tens of millions of years.

But it is the scale that humans have altered Earth’s life support system that is the most concerning.