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Archive for the ‘cosmology’ category: Page 3

Aug 29, 2022

Cosmologist Laura Mersini-Houghton: ‘Our universe is one tiny grain of dust in a beautiful cosmos’

Posted by in category: cosmology

As her new book on the origins of the universe is published, the Albanian-American scientist explains how her work on multiverse theory influenced Stephen Hawking.

Aug 28, 2022

How the Physics of Nothing Underlies Everything

Posted by in categories: cosmology, physics

Then a mere scientist pulled it off. Otto von Guericke invented a pump to suck the air from within a hollow copper sphere, establishing perhaps the first high-quality vacuum on Earth. In a theatrical demonstration in 1,654, he showed that not even two teams of horses straining to rip apart the watermelon-size ball could overcome the suction of nothing.

Since then, the vacuum has become a bedrock concept in physics, the foundation of any theory of something. Von Guericke’s vacuum was an absence of air. The electromagnetic vacuum is the absence of a medium that can slow down light. And a gravitational vacuum lacks any matter or energy capable of bending space. In each case the specific variety of nothing depends on what sort of something physicists intend to describe. “Sometimes, it’s the way we define a theory,” said Patrick Draper, a theoretical physicist at the University of Illinois.

As modern physicists have grappled with more sophisticated candidates for the ultimate theory of nature, they have encountered a growing multitude of types of nothing. Each has its own behavior, as if it’s a different phase of a substance. Increasingly, it seems that the key to understanding the origin and fate of the universe may be a careful accounting of these proliferating varieties of absence.

Aug 28, 2022

What is on the other side of a black hole?

Posted by in category: cosmology

On the other side of a black hole is the other side. It’s not two dimensional like the artists renderings. The question is… what’s inside of it?

Aug 28, 2022

Artemis I Payloads Moon an Asteroid and Beyond

Posted by in category: cosmology

Experiments from Artemis I are headed to the moon an asteroid and beyond. See this mission overview which delves into the ten cubesat secondary payloads and the manikin experiments flying on Artemis I.

Worm-hole generators by the pound mass: https://greengregs.com/

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Aug 28, 2022

Did the Big Bang happen?

Posted by in categories: cosmology, mathematics, open access, physics

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Physicists have many theories for the beginning of our universe: A big bang, a big bounce, a black hole, a network, a collision of membranes, a gas of strings, and the list goes on. What does this mean? It means we don’t know how the universe began. And the reason isn’t just that we’re lacking data, the reason is that science is reaching its limits when we try to understand the initial condition of the entire universe.

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Aug 28, 2022

The Latest Webb Observations Don’t Disprove The Big Bang, But They Are Interesting

Posted by in category: cosmology

This isn’t what we see. What we observe is that more distant galaxies have a dimmer surface brightness than closer ones. The amount of dimming is proportional to the amount of redshift the galaxy has. You might think this proves that all those distant galaxies are speeding away from us, but it actually doesn’t. If those distant galaxies were speeding away, you’d have two dimming effects. The red shift and the ever-increasing distance. The Tolman test predicts that in a simple expanding universe, the surface brightness of galaxies should diminish proportional to both redshift and distance. We only see the effects of redshift.

This fact has led some to propose a static universe where light spontaneously loses energy over time. It’s the so-called tired light hypothesis, and it’s very popular among big bang opponents. If the universe is static and light is tired, then the Tolman test predicts exactly what we observe. Hence no big bang.

Back in 2014, Eric Lerner et al. published a paper making exactly this point. It caused a flurry of “Big Bang Dead!” articles in the popular media. The latest claims about Webb killing the big bang began with a popular article by the same Eric Lerner. So here we are. In fairness, back in 2014, the Hubble observations supported Lerner’s claim, and so do the latest Webb observations. But what Lerner conveniently omitted from his paper is that the Hubble and Webb observations also support the LCDM model.

Continue reading “The Latest Webb Observations Don’t Disprove The Big Bang, But They Are Interesting” »

Aug 28, 2022

New Black Hole Math Closes Cosmic Blind Spot

Posted by in categories: cosmology, mathematics

A mathematical shortcut for analyzing black hole collisions works even in cases where it shouldn’t. As astronomers use it to search for new classes of hidden black holes, others wonder: Why?

Aug 27, 2022

The Oldest Fossil Radio Galaxy Discovered Yet Has Been Found Hiding in a Cluster

Posted by in category: cosmology

The oldest radio galaxy yet discovered is hidden in a cluster.

Astronomers claim to have found the oldest fossil radio galaxy yet discovered, hiding in a cluster. The brightest galaxy in the cluster erupted as a result of supermassive black hole activity, blowing massive bubbles of radio light into space, according to a report published by ScienceAlert.

“These newly discovered bubbles — known as radio lobes, or a radio galaxy — are the oldest of their kind we’ve ever seen,” claimed the astronomers’ team led by Surajit Paul and Savitribai Phule from Pune University in India.

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Aug 27, 2022

What is a wormhole?

Posted by in category: cosmology

Are you curious?

Imagine two towns on two opposite sides of a mountain. People from these towns would probably have to travel all the way around the mountain to visit one another. But, if they wanted to get there faster, they could dig a tunnel straight through the mountain to create a shortcut. That’s the idea behind a wormhole.

A wormhole is like a tunnel between two distant points in our universe that cuts the travel time from one point to the other. Instead of traveling for many millions of years from one galaxy to another, under the right conditions, one could theoretically use a wormhole to cut the travel time down to hours or minutes.

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Aug 27, 2022

Wormholes explained: How these space-time shortcuts act like time machines

Posted by in categories: cosmology, time travel

Imagine two towns on two opposite sides of a mountain. People from these towns would probably have to travel all the way around the mountain to visit one another. But, if they wanted to get there faster, they could dig a tunnel straight through the mountain to create a shortcut. That’s the idea behind a wormhole.

A wormhole is like a tunnel between two distant points in our universe that cuts the travel time from one point to the other. Instead of traveling for many millions of years from one galaxy to another, under the right conditions, one could theoretically use a wormhole to cut the travel time down to hours or minutes.

Because wormholes represent shortcuts through space-time, they could even act like time machines. You might emerge from one end of a wormhole at a time earlier than when you entered its other end.

Continue reading “Wormholes explained: How these space-time shortcuts act like time machines” »

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