My curiosity about white dwarfs continues to be piqued by the occasional journal article, like a recent study from Caldon Whyte and colleagues reviewing the possibilities for living worlds around such stars. Aimed at Astrophysical Journal Letters, the paper takes note of the expansion of the search space from stars like the Sun (i.e., G-class) in early thinking about astrobiology to red dwarfs and even the smaller and cooler brown dwarf categories. Taking us into white dwarf territory is exciting indeed. How lucky to live in a time when our technologies are evolving fast enough to start produc ..read more

The idea of moving stars as a way of concentrating mass for use by an advanced civilization – the topic of recent posts here – forces the question of whether such an effort wouldn’t be observable even by our far less advanced astronomy. In his paper on life’s response to dark energy and the need to offset the accelerating expansion of the cosmos, Dan Hooper analyzed the possibilities, pointing out that cultures billions of years older than our own may already be engaged in such activities. Can we see them? I like Centauri Dreams reader Andrew Palfreyman’s comment that what astronomers know as ..read more

Living a long time forces decisions that could otherwise be ignored. This is true of individuals as well as societies, but let’s think in terms of the individual human being. Getting older creates survival scenarios as simple as ensuring safety and nutrition for the elderly. But let’s extend lifetimes to centuries and beyond. In this thought experiment, we create a society of people so long-lived that their personal planning takes in events like a possible asteroid strike in 200 years. A person who could live for a billion years has to think in terms of surviving a dying Sun engulfing his or h ..read more

If life can organize into sentient beings around stars other than our own, there are few assumptions we can make about the civilizations that would emerge. We’ve long ago given up on the idea that such creatures would look like us, just as we abandoned the concept of life on every conceivable astronomical object. William Herschel, among others, thought life might exist on the Sun, a notion that in different form may be coming back around, as witness the growing interest in panpsychism and stellar consciousness. But let’s talk about physical life forms rather than energy fields. Since we have t ..read more

While working on a piece about interstellar migration as a response to the accelerating expansion of the universe for next week, I want to pause a moment on a just announced observation. I’ve always had a fascination with the Magellanics, those satellite galaxies that are so useful to astronomers because their gravitational interactions with the Milky Way render both of them irregular in shape. That triggers waves of star formation and tells us something about how galaxies assemble themselves. The Small Magellanic Cloud (SMC), about 200,000 light years away, shows little structure, while the L ..read more

I’ve played around a bit with Bluesky in the past, but have now decided it’s time to make a move. Those of you who have been following the site on X will want to know about the change, as posted in my first new Bluesky ‘skeet’ in some time. The change in user experience is striking, a bit like walking in an alpine meadow after spending years in a subway car. Not that I have anything against subways… Have decided to move to BlueSky for good, having left X for obvious reasons. Future posts from my Centauri Dreams site will be linked here. Current post considers Clément Vidal's striking concept ..read more

Suppose you want to migrate to another star, taking your entire civilization with you. Not an easy task given our technology today, but let’s remember that in the 13 billion year-plus history of the Milky Way, countless stars and their planets have emerged that are far older than our 4.6-billion year old Sun. If we imagine an intelligence that survives for a billion years or more, we can hardly put constraints on what it might accomplish. The idea of moving a star with its planetary system intact is out there on the edge of what science fiction can accomplish, if not yet science. There have ev ..read more

Given our intense scrutiny of planets around other stars, I find it interesting how little we know even now about the history of our own Sun, and its varying effects on habitability. A chapter in an upcoming (wildly overpriced) Elsevier title called The Archean Earth is informative on the matter, especially insofar as it illuminates which issues most affect habitability and how the values for these vary over time. It’s also a fascinating look at changing conditions on Venus, Earth and Mars. We know a great deal about the three worlds from our local and planetary explorations, but all too littl ..read more

Over the weekend I learned about Joseph Haydn’s Symphony No. 47, unusual in that it offers up some of its treasures in perfect symmetry. Dubbed ‘The Palindrome,’ the symphony’s third movement, Minuetto e Trio, is crafted to play identically whether attacked normally – moving forward through the score – or backwards. You can check this out for yourself in this YouTube video, or on this non-auditory reference. The pleasure of unexpected symmetry is profound, and when seen through the eyes of our spacecraft, can be startling. Consider the storied star Vega. We see this system from our perspective ..read more

Bear with me today while I explore the pleasures of the Infinite Monkey Theorem. We’re all familiar with it: Set a monkey typing for an infinite amount of time and eventually the works of Shakespeare emerge. It’s a pleasing thought experiment because it’s so visual and involves animals that are like us in many ways. Now we learn from a new paper that the amount of time involved to reproduce the Bard is actually longer than the age of the universe. About which more in a moment, but indulge me again as I explore infinite monkeys as they appear in fictional form in the mid-20th Century. In “Infle ..read more