Brian Koberlein, Author at Universe Today

January 3, 2021January 3, 2021 by Brian Koberlein

Astronomers Improve Their Distance Scale for the Universe. Unfortunately, it Doesn't Resolve the Crisis in Cosmology

The accuracy of Gaia distance measurements. Credit: ESA

Measuring the expansion of the universe is hard. For one thing, because the universe is expanding, the scale of your distance measurements affects the scale of the expansion. And since light from distant galaxies takes time to reach us, you can’t measure what the universe is, but rather what it was. Then there is the challenge of the cosmic distance ladder.

December 28, 2020December 28, 2020 by Brian Koberlein

New Data Supports the Modified Gravity Explanation for Dark Matter, Much to the Surprise of the Researchers

A falling apple. Credit: Bithin raj / Unsplash

Dark matter is an extremely good theory. It’s supported by a wealth of observational and computational data, which is why it’s part of the standard model of cosmology. But dark matter hasn’t been directly observed, so sometimes even strong supporters of dark matter are motivated to look at the alternatives.

December 22, 2020December 22, 2020 by Brian Koberlein

If Axions Explain Dark Matter, it Could be Possible to Detect Them Nearby Neutron Stars

The Robert C. Byrd Green Bank Telescope. Credit: Green Bank Observatory/NRAO

As we continue to search for dark matter particles, one thing is very clear: they cannot be any of the elementary particles we’ve discovered so far. The particles would need to have mass, but interact with light only weakly. Of the known particles, neutrinos fit that description, but neutrinos have a tiny mass, and aren’t nearly enough to explain dark matter. Some other kind of particle must make up the majority of dark matter.

December 18, 2020December 18, 2020 by Brian Koberlein

A new Type of Atomic Clock Uses Entangled Atoms. At Most, it Would be off by 100 Milliseconds Since the Beginning of the Universe

Lasers are used to squeeze atoms and entangle them. Credit: MIT

Measuring time is about counting steps. Whether it’s the drip-drip of a water clock, the tic-toc of a mechanical clock, or the oscillating crystal of a quartz watch. Any accurate timepiece is built around counting the steps of something regular and periodic. Nothing is perfectly regular, so no clock keeps perfect time, but our timepieces are getting very, very accurate.

December 16, 2020December 16, 2020 by Brian Koberlein

Next Generation Gravitational Wave Detectors Should be Able to see the Primordial Waves From the Big Bang

An artist view of primordial gravitational waves. Credit: Carl Knox, OzGrav/Swinburne University of Technology

Gravitational-wave astronomy is still in its youth. Because of this, the gravitational waves we can observe come from powerful cataclysmic events. Black holes consuming each other in a violent chirp of spacetime, or neutron stars colliding in a tremendous explosion. Soon we might be able to observe the gravitational waves of supernovae, or supermassive black holes merging billions of light-years away. But underneath the cacophony is a very different gravitational wave. But if we can detect them, they will help us solve one of the deepest cosmological mysteries.

December 12, 2020December 12, 2020 by Brian Koberlein

Is There a way to Detect Strange Quark Stars, Even Though They Look Almost Exactly Like White Dwarfs?

A neutron star (~25km across) next to a quark star (~16km across). Original Image Credit: NASA's Goddard Space Flight Center

The world we see around us is built around quarks. They form the nuclei of the atoms and molecules that comprise us and our world. While there are six types of quarks, regular matter contains only two: up quarks and down quarks. Protons contain two ups and a down, while neutrons contain two downs and an up. On Earth, the other four types are only seen when created in particle accelerators. But some of them could also appear naturally in dense objects such as neutron stars.

December 10, 2020December 10, 2020 by Brian Koberlein

Black Holes Gain new Powers When They Spin Fast Enough

Computer simulation of plasma near a black hole. Credit: Hotaka Shiokawa / EHT

General relativity is a profoundly complex mathematical theory, but its description of black holes is amazingly simple. A stable black hole can be described by just three properties: its mass, its electric charge, and its rotation or spin. Since black holes aren’t likely to have much charge, it really takes just two properties. If you know a black hole’s mass and spin, you know all there is to know about the black hole.

December 9, 2020December 9, 2020 by Brian Koberlein

Heard of Mini-Neptunes and gas-Dwarfs? Here's a new one: sub-Earths

Several types of exoplanets. Credit: PHL @ UPR Arecibo

The planets in our solar system are broadly divided into two groups: small, rocky worlds like Earth, and large gas giants. Before the discovery of exoplanets, it was thought that our solar system was very typical. The light and heat of a star push the gas to the outer solar system, while heavier dust remains closer to the star. Thus a solar system has close rocky planets and distant gas giants. But we now know that planets and star systems have much more diversity.

December 4, 2020December 4, 2020 by Brian Koberlein

An Astronomer Checked to see if There’s a Secret Message in the Cosmic Microwave Background Radiation

The Cold Spot area resides in the constellation Eridanus in the southern galactic hemisphere. The insets show the environment of this anomalous patch of the sky as mapped by Szapudi’s team using PS1 and WISE data and as observed in the cosmic microwave background temperature data taken by the Planck satellite. The angular diameter of the vast supervoid aligned with the Cold Spot, which exceeds 30 degrees, is marked by the white circles. Credit: ESA Planck Collaboration/ Gerg? Kránicz

In the New Testament, the book of John opens with In the beginning was the Word. Whether a poetic musing of philosophy or a declaration of faith, it encapsulates an idea that has been around a long time. If the cosmos was made, either by advanced aliens or a divine creator, might this architect have buried a message within the universe? Some absolute proof of intentional design.

December 3, 2020December 3, 2020 by Brian Koberlein

Australian Radio Telescopes Just Completed a map of the Universe

An ASKAP antenna views the southern sky. Credit: CSIRO

Although radio astronomy has been around since the 1930s, it is only in recent years that astronomers have been able to make high-resolution maps of the radio sky. Sky maps are difficult for radio telescopes because radio antennas need to be focused on an extremely small patch of sky to capture images in high resolution. But with modern antennas and computer processing, we can now scan the sky quickly enough to map the heavens in a reasonable amount of time.