Brian Koberlein, Author at Universe Today

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.

January 10, 2021January 15, 2021 by Brian Koberlein

There's no way to Measure the Speed of Light in a Single Direction

Special relativity is one of the most strongly validated theories humanity has ever devised. It is central to everything from space travel and GPS to our electrical power grid. Central to relativity is the fact that the speed of light in a vacuum is an absolute constant. The problem is, that fact has never been proven.

January 7, 2021January 7, 2021 by Brian Koberlein

New Observations Agree That the Universe is 13.77 Billion Years old

Cosmic Microwave Background. Scientists compared this to modern galaxy distributions to track dark matter. Copyright: ESA/Planck Collaboration

The oldest light in the universe is that of the cosmic microwave background (CMB). This light was formed when the dense matter at the beginning of the universe finally cooled enough to become transparent. It has traveled for billions of years to reach us, stretched from a bright orange glow to cool, invisible microwaves. Naturally, it is an excellent source for understanding the history and expansion of the cosmos.

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.