If intelligent aliens visit the Earth, it would be one of the most profound events in human history.

Surveys show that nearly half of Americans believe that aliens have visited the Earth, either in the ancient past or recently. That percentage has been increasing. Belief in alien visitation is greater than belief that Bigfoot is a real creature, but less than belief that places can be haunted by spirits.

In our daily life, we unfortunately have become used to seeing images of tumors and melanomas. You may have noticed that they’re are not entirely symmetric. This asymmetry is useful to doctors in their diagnoses, but why are they asymmetric?

The three recent appearances (and two subsequent removals) of “monoliths” in Romania, Utah and California are intriguing examples of what can capture the public’s imagination.

These constructions are metallic-looking structures about three or four metres tall, with a simple geometric design and reflective surface.

Early in the pandemic, many researchers feared people who contracted COVID could be reinfected very quickly. This was because several early studies showed antibodies seemed to wane after the first few months post-infection.

It was also partly because normal human coronaviruses, which are one cause of common colds and are cousins of SARS-CoV-2, do not generate long-lasting immunity, so we can get reinfected with them after 12 months.

Over recent weeks and months, we’ve heard of several COVID cases in which people have tested positive after previously clearing the virus.

Scientists are hopeful being infected with COVID-19 confers immunity for a length of time. But some of these instances have raised concerns about reinfection. Although rare, it seems to be possible.

The other thing which could be at play in many of these cases is “prolonged viral shedding”.

Tab, the Coca-Cola company’s original diet soda brand, is headed to the soda graveyard, joining retired brands such as Like, Leed and Limette.

Coca-Cola has announced that it is discontinuing Tab after 57 years on the market, and fans of the drink will have until the end of December to purchase their last can of nostalgia.

From the beginning, Tab’s story has been one of perseverance. The brand survived initial low sales, the artificial sweetener scares of the 1960s and 1970s, lukewarm enthusiasm for the product at the corporate level and intermittent consumer availability to become – for a brief period – the most popular diet soda in America. Then, of course, Diet Coke came along.