Starlight Takes a Detour
Astronomers were treated to three views of the same supernova because of massive sources of gravity that sent the starlight on detours. The next replay, which may come in 2037, could help cosmologists nail down the universe's controversial expansion rate, Ken Croswell reports for Science News. Diverted light has become a major tool for studying the universe in recent years. Distortions of distant galaxies caused by dark matter have hinted at weaknesses in the leading theory of cosmology, Charlie Wood reported for Quanta last year.
Rebuilding Math With Infinity Categories
"Infinity categories" is a dizzying and novel new branch of mathematics. Emily Riehl, one of the mathematicians leading the development of this young field, has written an introduction to it for Scientific American. Infinity category theory takes on the ambitious task of rebuilding math from the ground up. As Kevin Hartnett reported for Quanta in 2019, it may encourage mathematicians to abandon the equals sign for the squishier but more comprehensive concept of "equivalence."
The Long Trek Toward Humanity
Where did we humans come from? Our evolution hasn't been a steady march from tree dwellers to tool users, Erin Wayman writes for Science News. Rather, we are the last twig of a surprisingly bushy hominin tree. Powerful new genetics tools have played a major role in revealing our ancestors' migrations out of Africa and the interactions they had with our hominin cousins along the way, Jordana Cepelewicz reported for Quanta in 2019. | |
