Everyone knows a 'day' - one rotation of Earth - is around 24 hours long and lengthening at a rate of some 1.7 milliseconds every century. Yet 2 billion years ago it was 19.5 hours and at that rate we should have days lasting 60 hours.

Yet we don't. Instead, the tidal pull of the moon was halted for over a billion years. For that, we can thank the pull of the sun. This tidal stalemate between the sun and moon has been linked to the atmosphere’s temperature and Earth’s rotational rate.

Epidemiologists looked at data from from 1999 to 2020 and noted that death rates due to poisonings, firearms, and all other injuries increased substantially in the U.S., many of them due to suicide attempts.

The demography analysis of 3,813,894 deaths collated by the National Center for Health Statistics due to non-natural causes was simplistic - age, sex, race, ethnicity, and belief about intent, then separating out criminal acts for things like gun deaths and if there was no clear intent of suicide, listing drug overdoses as accidental, while parsing motor vehicle injuries and falls as well.

Nearly 3 million years ago, early human ancestors used some of the oldest stone tools ever found to butcher hippos and pound plant material, and for half that time they were butchering each other - a new paper says 1.45 million years of killing each other for food.

The brain and the digestive tract are in constant communication, relaying signals that help to control feeding, and the implication that this communication network may also influence our mental state - as if "hangry" is science any more than a child getting hyperactive if they eat a piece of candy is - means it has been linked to everything from autism to Parkinson's disease.

Because there is very little science, it is mostly suggestion used to sell supplements and yogurt that makes you poop. A new technology hopes to introduce data to brain-gut mysticism. 

Stars die in lots of ways. Most low-mass stars like our Sun shed their outer layers and eventually fade to white dwarf stars. Larger ones prefer to burn out rather than fade away so they go supernova and create ultradense objects like neutron stars and black holes. When two stellar remnants form a binary system, they also can collide. 

Yet a new paper shows there may be a fourth way - a collision where non-binary stars in dense regions can be forced together. The work used a long-duration gamma-ray burst with the Gemini South telescope in Chile.

If you have traveled, you have seen someone who is a frequent traveler be offered an upgrade but decline because they are with someone else and want to stay together. This is rare in other species. 

Yet not all experiences get equal treatment - if a parent is traveling with a child they may take the upgrade to give it to the child - and a new paper sought to understand how consumers make trade-offs between experience quality and togetherness. The authors write that consumers prioritize physical togetherness with relationship partners over opportunities that would improve an experience in real time.