Brian Koberlein, Author at Universe Today

February 19, 2021February 19, 2021 by Brian Koberlein

A new Approach Could Tease out the Connection Between Gravity and Quantum Mechanics

In physics, there are two main ways to model the universe. The first is the classical way. Classical models such as Newton’s laws of motion and Einstein’s theory of relativity assume that the properties of an object such as its position and motion are absolute. There are practical limits to how accurately we can measure an object’s path through space and time, but that’s on us. Nature knows their motion with infinite precision. Quantum models such as atomic physics assume that objects are governed by interactions. These interactions are probabilistic and indefinite. Even if we constrain an interaction to limited outcomes, we can never know the motion of an object with infinite precision, because nature doesn’t allow it.

February 15, 2021February 15, 2021 by Brian Koberlein

A Cluster of Black Holes Found Inside a Globular Cluster of Stars

This image from the NASA/ESA Hubble Space Telescope shows the central region of the rich globular star cluster NGC 3201 in the southern constellation of Vela (The Sails). A star that has been found to be orbiting a black hole with four times the mass of the Sun is indicated with blue circle. Credit: ESA/NASA

Black holes come in at least two sizes: small and large. Small black holes are formed from stars. When a large star reaches the end of its life, it typically ends in a supernova. The remnant core then collapses under its own weight, forming a black hole or neutron star. Small stellar-mass black holes are typically tens of solar masses. Large black holes lurk in the centers of galaxies. These supermassive black holes can be millions or billions of solar masses. They formed during the early universe and triggered the formation and evolution of galaxies around them.

February 11, 2021February 11, 2021 by Brian Koberlein

It's Starting to Look Like Super-Earths Really are Just Great big Terrestrial Planets

Artists’s impression of the rocky super-Earth HD 85512 b. Credit: ESO/M. Kornmesser

We’ve learned a thing or two about exoplanets in the past several years. One of the more surprising discoveries is that our solar system is rather unusual. The Sun’s worlds are easily divided into small rocky planets and large gas giants. Exoplanets are much more diverse, both in size and composition.

February 9, 2021February 9, 2021 by Brian Koberlein

If Dark Matter is Made of Sterile Neutrinos, a new Survey has Narrowed Down What to Look for

We don’t know what dark matter is. We do know what it isn’t, and that’s a problem. Matter is made of elementary particles, from the quarks and electrons that make up atoms and molecules, to primordial neutrinos spread throughout the cosmos. But none of the known elementary particles can comprise dark matter, so what is it?

February 3, 2021February 3, 2021 by Brian Koberlein

Black Holes Simulated in a Tank of Water Reveals “Backreaction” for the First Time

This artist's concept shows the most distant supermassive black hole ever discovered. It is part of a quasar from just 690 million years after the Big Bang. Credit: Robin Dienel/Carnegie Institution for Science

It’s hard to make a black hole in the lab. You have to gather up a bunch of mass, squeeze it until it gravitationally collapses on itself, work, work, work. It’s so hard to do that we’ve never done it. We can, however, make a simulated black hole using a tank of water, and it can tell us interesting things about how black holes work.

January 23, 2021January 23, 2021 by Brian Koberlein

In Theory, Supermassive Black Holes Could get Even More Supermassive

Artist view of a stupendously large black hole. Credit: NASA, ESA, and D. Coe, J. Anders

Our universe contains some enormous black holes. The supermassive black hole in the center of our galaxy has a mass of 4 million Suns, but it’s rather small as galactic black holes go. Many galactic black holes have a billion solar masses, and the most massive known black hole is estimated to have a mass of nearly 70 billion Suns. But just how big can a black hole get?

January 21, 2021January 21, 2021 by Brian Koberlein

Strange Green Star is the Result of a Merger Between two White Dwarfs

Artist view of a binary white dwarf. Credit: University of Sheffield

A white dwarf isn’t your typical kind of star. While main sequence stars such as our Sun fuse nuclear material in their cores to keep themselves from collapsing under their own weight, white dwarfs use an effect known as quantum degeneracy. The quantum nature of electrons means that no two electrons can have the same quantum state. When you try to squeeze electrons into the same state, they exert a degeneracy pressure that keeps the white dwarf from collapsing.

January 18, 2021January 18, 2021 by Brian Koberlein

Planets are Finally Being Discovered Orbiting Farther From Their Stars

An artistic view of the Jovian exoplanet GJ 504b. Credit: NASA's Goddard Space Flight Center/S. Wiessinger

Discovering exoplanets is a difficult job. Given the challenges, it’s amazing that we’ve found any at all. But astronomers are clever, so there are currently more than 4,300 confirmed exoplanets. They range from small Mercury-sized worlds to planets larger than Jupiter, but most of them have one thing in common: they orbit close to their home star.

January 14, 2021January 14, 2021 by Brian Koberlein

Astronomers see a Hint of the Gravitational Wave Background to the Universe

Artist view of orbiting black holes. Credit: Caltech/R. Hurt (IPAC)

Gravitational-wave astronomy is still in its infancy. LIGO and other observatories have opened a new window on the universe, but their gravitational view of the cosmos is limited. To widen our view, we have the North American Nanohertz Observatory for Gravitational Waves (NANOGrav).

January 13, 2021January 13, 2021 by Brian Koberlein

Astronomers can use Pulsars to Measure Tiny Changes of Acceleration Within the Milky Way, Scanning Internally for Dark Matter and Dark Energy

Using pulsars to measure mass distribution in the Milky Way. Credit: Dana Berry, IAS

As our Sun moves along its orbit in the Milky Way, it is gravitationally tugged by nearby stars, nebulae, and other masses. Our galaxy is not a uniform distribution of mass, and our Sun experiences small accelerations in addition to its overall orbital motion. Measuring those small tugs has been nearly impossible, but a new study shows how it can be done.