Tag: cosmology
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The mystery of the lopsided Universe
On the largest scales — far bigger than any galaxy or galaxy cluster — the Universe is remarkably smooth and regular. Tiny irregularities in the early cosmos are what gave rise to all the structures we see today, including us, but there’s another irregularity covering the whole sky. The Universe appears to be ever-so-slightly lopsided,…
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My dysfunctional relationship with dark energy
“Dark energy” is one of the more unfortunate names in science. You’d think it has something to do with dark matter (itself a misnomer), but it has the opposite effect: while dark matter drives the clumping-up of material that makes galaxies, dark energy pushes the expansion of the Universe to greater and greater rates. Though…
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Ionizing the Universe with black holes and neutron stars
About 380,000 years after the Big Bang, the Universe cooled off enough for stable atoms to form out of the primordial plasma. However, sometime in the billion years or so after that, something happened to heat the gas up again, returning it to plasma form. Though we know reionization (as it is called) happened, that…
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Sinners in the hands of an angry GLaDOS
It’s one of those nagging thoughts many of us have had: is our existence a reality or an illusion? Philosophers and scientists have grappled with the question, though today much of the discussion focuses on a related question: do we live in a computer simulation? In my (first hopefully of multiple) essays for Aeon magazine,…
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A glowing filament shows us where the dark matter hides
Astronomers have identified a filament in the cosmic web, which is the pattern formed by dark matter. That web in turn dictates the distribution of galaxies, since the dark matter attracts ordinary matter — atoms — through its gravity. However, it’s hard to spot the filaments connecting the different halos of dark matter, because…
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The week in review (October 20-26)
I had a wonderful time at GeekGirlCon; thanks again to Dr. Rubidium, AKA Nick Fury, for putting together the DIY Science Zone, and to everyone who made it a great event. I have a more formal wrap-up post in the works, but in the meantime, have some science writing. The river of spacetime (Galileo’s Pendulum):…
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The week in review (September 22-28)
I spent much of the week sick, but that doesn’t stop me. I care about you, people. All black holes, great and small (Galileo’s Pendulum): As my regular readers have probably figured out, I love black holes. I could probably find an excuse to write about them most days. So, why not take an online…
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On the multiverse, metaphysics, and meaning
I don’t spent a lot of time thinking about the multiverse: the possible existence of regions of the cosmos that have never been connected to ours at any time, and may never be in the future. That’s because those parallel pocket universes aren’t directly detectable, and may never be even indirectly detectable, putting them into…
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Early galaxies: live large, die big, burn bright
How did the biggest galaxies form? Based on the ages of stars inhabiting them, the largest elliptical galaxies — those kind of boring egg-shaped clouds of stars with no pretty spiral arms — formed fairly early in the history of the Universe. While smaller elliptical galaxies likely are the modern version of submillimeter bright galaxies…
Bowler Hat Science 