Half a century of Christmases ago, the NASA space mission Apollo 8 became the first manned craft to leave low Earth orbit, atop the unprecedentedly powerful Saturn V rocket, and head out to circumnavigate another celestial body, making 11 orbits of the moon before its return. The mission is often cast in a supporting role – a sort of warm up for the first moon landing. Yet for me, the voyage of Borman, Lovell and Anders six months before Neil Armstrong’s “small step for a man” will always be the great leap for humankind.

From the Neolithic to present times, the amount of sunlight we see in a day has had a profound impact on human culture. We are fast approaching the winter solstice for the Northern hemisphere, which takes place on December 21. This is the longest night of the year – once celebrated as “Yule” by the pagan people of Northern Europe before it became Christmas.

Christmas and the holidays are a time to relax and celebrate with family and friends. But the festive season can also be a time of unwanted weight gain that won’t budge once the holidays are over.

Research (mostly from the United States) has found adults typically gain 400 to 900 grams over the holidays.

No-one wants to miss out on the celebrations. But knowing more about the kilojoule content of your favourite Christmas treats can help you make conscious decisions about which foods and drinks to have and enjoy, and what portion sizes to choose.

This year, I served on the judging panel for The Royal Statistical Society’s International Statistic of the Year.

On Dec. 18, we announced the winner: 90.5 percent, the amount of plastic that has never been recycled. Okay – but why is that such a big deal?

This is an article from Head to Head, a series in which academics from different disciplines chew over current debates. Let us know what else you’d like covered – all questions are welcome..

Sharon George: Plastics are ingrained in our everyday lives. Since 1950, it’s estimated that we have produced billions of tons of plastic, and most of this is not recycled.

Plastics have spread around the world through oceans, rivers and the air to every part of the planet. In rivers and oceans, plastic moves vast distances and is now found right through the water column of the oceans, from the surface to the deepest trenches.

One of the most baffling puzzles of modern astrophysics is the nature of Fast Radio Bursts, which were discovered in 2007. These are seemingly rare, extremely bright flashes of light with radio wavelengths. They last only milliseconds; originate outside our galaxy, the Milky Way; come from regions with enormously strong magnetic fields; and pass through a significant amount of gas or dust before reaching Earth.