The standard model of cosmology is a remarkably powerful and accurate description of the universe, tracing its evolution from the big bang to its current state, but it is not without mysteries. One of the biggest unsolved questions of the standard model is known as early cosmic inflation.Continue reading “Primordial Gravitational Waves Continue to Elude Astronomers”
Since the beginning of the Digital Age (ca. the 1970s), theoretical physicists have speculated about the possible connection between information and the physical Universe. Considering that all matter is made up of information that describes the state of a quantum system (aka. quantum information), and genetic information is coded in our DNA, it’s not farfetched at all to think that physical reality can be expressed in terms of data.
This has led to many thought experiments and paradoxes, where researchers have attempted to estimate the information capacity of the cosmos. In a recent study, Dr. Melvin M. Vopson – a Mathematician and Senior Lecturer at Portsmouth University – offered new estimates of how much information is encoded in all the baryonic matter (aka. ordinary or “luminous” matter) in the Universe.Continue reading “There are 6×10^80 Bits of Information in the Observable Universe”
Thanks to the most advanced telescopes, astronomers today can see what objects looked like 13 billion years ago, roughly 800 million years after the Big Bang. Unfortunately, they are still unable to pierce the veil of the cosmic Dark Ages, a period that lasted from 370,000 to 1 billion years after the Big Bang, where the Universe was shrowded with light-obscuring neutral hydrogen. Because of this, our telescopes cannot see when the first stars and galaxies formed – ca., 100 to 500 million years after the Big Bang.
This period is known as the Cosmic Dawn and represents the “final frontier” of cosmological surveys to astronomers. This November, NASA’s next-generation James Webb Space Telescope (JWST) will finally launch to space. Thanks to its sensitivity and advanced infrared optics, Webb will be the first observatory capable of witnessing the birth of galaxies. According to a new study from the Université de Genève, Switzerland, the ability to see the Cosmic Dawn will provide answers to today’s greatest cosmological mysteries.Continue reading “Cosmic Dawn Holds the Answers to Many of Astronomy’s Greatest Questions”
At the heart of most massive galaxies in our Universe, there are supermassive black holes (SMBH) on the order of millions to billions of times the mass of the Sun. As these behemoths consume gas and dust that’s slowly fed into their maws, they release tremendous amounts of energy. This leads to what is known as an Active Galactic Nucleus (AGN) – aka. a quasar – which can sometimes send hypervelocity jets of material for light-years.
Since they were first discovered, astrophysicists have suspected that SMBHs play an important role in the formation and evolution of galaxies. However, as a result, there has also been considerable research dedicated to how these massive objects form and evolve themselves. Recently, a team of astrophysicists conducted a high-powered simulation that showed exactly how SMBHs feed and determined that a galaxy’s arms play a vital role.Continue reading “This is How a Supermassive Black Hole Feeds”
We find examples of fractals everywhere in nature. Tree branches, snowflakes, river deltas, cloud formations, and more. So it’s natural to ask the ultimate question: is the entire universe one giant fractal? The answer is…no, but sorta yes.Continue reading “Is the Universe a Fractal?”
We’ve known for a while about the large-scale structure of the Universe. Galaxies reside in filaments hundreds of millions of light-years long, on a backbone of dark matter. And, where those filaments meet, there are galaxy clusters. Between them are massive voids, where galaxies are sparse. Now a team of astronomers in Germany and their colleagues in China and Estonia have made an intriguing discovery.
These massive filaments are rotating, and this kind of rotation on such a massive scale has never been seen before.Continue reading “The Largest Rotating Objects in the Universe: Galactic Filaments Hundreds of Millions of Light-Years Long”
Cosmologists have been struggling to understand an apparent tension in their measurements of the present-day expansion rate of the universe, known as the Hubble constant. Observations of the early cosmos – mostly the cosmic microwave background – point to a significantly lower Hubble constant than the value obtained through observations of the late universe, primarily from supernovae. A team of astronomers have dug into the data to find that one possible way to relieve this tension is to allow for the Hubble constant to paradoxically evolve with time. This result could point to either new physics…or just a misunderstanding of the data.
“The point is that there seems to be a tension between the larger values for late universe observations and lower values for early universe observation,” said Enrico Rinaldi, a research fellow in the University of Michigan Department of Physics and coauthor on the study. “The question we asked in this paper is: What if the Hubble constant is not constant? What if it actually changes?”Continue reading “Is the Hubble constant not…Constant?”
Since it was first theorized in the 1970s, astrophysicists and cosmologists have done their best to resolve the mystery that is Dark Matter. This invisible mass is believed to make up 85% of the matter in the Universe and accounts for 27% of its mass-energy density. But more than that, it also provides the large-scale skeletal structure of the Universe (the cosmic web), which dictates the motions of galaxies and material because of its gravitational influence.
Unfortunately, the mysterious nature of Dark Matter means that astronomers cannot study it directly, thus prevented them from measuring its distribution. However, it is possible to infer its distribution based on the observable influence its gravity has on local galaxies and other celestial objects. Using cutting-edge machine-learning techniques, a team of Korean-American astrophysicists was able to produce the most detailed map yet of the local Universe that shows what the “cosmic web” looks like.Continue reading “A Dark Matter map of our Local Cosmic Neighborhood”
It’s often said that in its earliest moments the universe was in a hot, dense state. While that’s a reasonably accurate description, it’s also quite vague. What exactly was it that was hot and dense, and what state was it in? Answering that question takes both complex theoretical modeling and high-energy experiments in particle physics. But as a recent study shows, we are learning quite a bit.Continue reading “What Happened Moments After the Big Bang?”
Cosmologists love universe simulations. Even models covering hundreds of millions of light years can be useful for understanding fundamental aspects of cosmology and the early universe. There’s just one problem – they’re extremely computationally intensive. A 500 million light year swath of the universe could take more than 3 weeks to simulate.. Now, scientists led by Yin Li at the Flatiron Institute have developed a way to run these cosmically huge models 1000 times faster. That 500 million year light year swath could then be simulated in 36 minutes.Continue reading “A new Method Simulates the Universe 1000 Times Faster”