Welcome to the new year, and the new decade. I’m sure many of you are glad to see 2020 go, though we aren’t out of the tunnel yet. The best way we can make 2021 a better year is to look after our friends, family, and neighbors. As Kurt Vonnegut once wrote, in this harsh world, you’ve got to be kind.
More Science, Less Fiction
There were no fiction posts this month. With the holiday and a couple of other big projects I needed to finish, I didn’t have time to be very creative. But there have been plenty of science news.
Research on dark matter has delivered several surprises. Neutrinos are a form of dark matter since they have mass and don’t interact strongly with light. We’ve long known that dark matter can’t be neutrinos alone, but a new study shows how neutrinos play a significant role in the structure and evolution of galaxy clusters. The biggest mystery of dark matter stems from the fact that we haven’t been able to detect dark matter particles. A team of scientists thinks they can overcome that challenge by looking for radio signals from dark matter in neutron stars. Because there is plenty of indirect evidence for dark matter, most astronomers think it exists. One reason for this is that the main alternative to dark matter, modified gravity, hasn’t had much evidence to support it. But in a surprising study, astronomers found evidence for modified gravity in the rotation of galaxies in some clusters. The study doesn’t disprove dark matter, but it does show that aspects of general relativity might be wrong.
Speaking of relativity, several new ways to study it have been proposed. Fast rotating black holes could reveal whether alternatives to general relativity are valid, and this could solve one of the big mysteries about black holes, known as the no-hair theorem. Gravitational waves are extremely faint and difficult to observe. A new way of filtering the signal from the noise could greatly improve the sensitivity of gravitational wave telescopes, and might help us detect primordial gravitational waves from the big bang. Since relativity is a theory of time, measuring time accurately is an important aspect of testing it. Recently a team of engineers has built a clock so accurate it would be off by no more than 100 milliseconds in the entire age of the cosmos. It could become a new standard for time measurement…in time.
One of the revolutions in astronomy of recent years has been the rise of detailed sky surveys. We now have a new radio map of the Southern sky, which will be an excellent complement to the radio surveys we have of the Northern hemisphere. Data from the Gaia spacecraft has given us data from more than a billion stars in the Milky Way. A new study of Gaia data has shown we’re a bit closer to the center of our galaxy than we had thought. Surveys of exoplanets have allowed us to study the formation and evolution of planetary bodies. New work suggests that exoplanets form in two stages, rather than all at once. If valid, it could explain why Earth-like planets are relatively rare. Another team looked at data from the Montreal White Dwarf Database, which has the mass and surface gravity from more than 40,000 white dwarfs. They found some interesting results that point to the existence of strange matter within some white dwarfs.
Finally, there was a very speculative study looking for evidence of a signal in the cosmic microwave background. It’s an idea straight out of science fiction. Could super-advanced aliens bury a message within the first light of the big bang itself? Alas, the study didn’t find an alien message.
I hope you are enjoying the regular posts here. Unfortunately, Google continues to de-emphasize my website, preferring to favor copy-pasta sites filled with Google Ads. So if you like the site, please share it with your friends, and encourage them to subscribe to the newsletter. Word of mouth is still the best way to grow the site.
There will plenty of posts in 2021, so until next time I wish you well.