Archive for the ‘cosmology’ category: Page 8

Apr 21, 2022

Small explosions called micronovae discovered on dead stars

Posted by in category: cosmology

Micronovae are about 1 million times less bright than a classical nova, says Scaringi, lasting just half a day, compared with several weeks for novae.

The brevity of the events meant they had previously been missed, but TESS was able to spot them during its around-the-clock observations of the galaxy in search of exoplanets. Three were seen up to 5,000 light years from Earth, with the white dwarfs brightening temporarily before dimming again.

The exact mechanism behind the explosions isn’t clear, but it is thought they may be caused by hydrogen accumulating at the poles of the star – perhaps as much as the mass of an asteroid in just 100 days. Eventually, the hydrogen reaches sufficient temperatures and pressures to ignite fusion and cause a localised thermonuclear explosion that releases as much energy as the sun would in a day.

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Apr 19, 2022

Giant space telescopes could be made out of liquid

Posted by in category: cosmology

The Hubble space telescope has a primary mirror of 2.4 meters. The Nancy Grace Roman telescope also has a mirror measuring 2.4 meters, and the James Webb Space Telescope has a whopping 6.5 meter primary mirror. They get the job done that they were designed to do, but what if… we could have even bigger mirrors?

The larger the mirror, the more light is collected. This means that we can see farther back in time with bigger mirrors to observe star and galaxy formation, image exoplanets directly, and work out just what dark matter is.

But the process for creating a mirror is involved and takes time. There is casting the mirror blank to get the basic shape. Then you have to toughen the glass by heating and slow cooling. Grinding the glass down and polishing it into its perfect shape comes next followed by testing and coating the . This isn’t so bad for smaller lenses, but we want bigger. Much bigger.

Apr 18, 2022

The Solar Energy Multiverse Keeps Expanding: Perovskites, Shape-Shifting Molecules, & More

Posted by in categories: cosmology, economics, solar power, sustainability

Solar energy has barely scratched the surface of its potential to decarbonize the global economy in time to avert catastrophic warming.

For all the activity in the solar energy marketplace, PV technology has barely even begun to hit the global economy in full force. Huge solar arrays filled with rows of super-efficient silicon solar panels are just one piece of an expanding universe. With that in mind, here are 4 new developments that could kick the slow pace of change into high gear.

1. Distributed Solar Energy

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Apr 18, 2022

What’s Really Going on Inside a Neutron Star

Posted by in categories: chemistry, cosmology

Scientists are finally getting closer to figuring out the puzzle of the structure of neutron stars and revealing the nature of their ultra-dense interiors.

In theories of stellar evolution, neutron stars are considered one of the end states of stars, along with white dwarfs and black holes. As a star evolves it will enter stages of expansion as hydrogen is fused into helium and so on through the periodic table of elements. Depending on the mass of the star, a limit will be reached whereby nuclear fusion can no longer take place and the star is no longer able to overcome the immense gravitational force which it has been holding back for all these years. As a result, the star implodes, ejecting its outer layers as a planetary nova or a supernova, leaving only a mere remnant of its former self behind – or so the story goes.

For massive stars, the implosion is so great that it crushes its stellar matter to such high densities that the oppositely charged electrons and protons are forced so close together that they fuse to become neutrons, hence creating a neutron star. This neutron star is so dense that a single teaspoonful could weigh a billion tonnes! For stars massive enough, it is further theorised that the gravitational collapse would be so great that it would instead crush the neutron star down to the size of an infinitesimal point, creating a black hole.

Apr 16, 2022

You Can See What Hubble is Photographing in Real Time

Posted by in category: cosmology

Keep tabs on the storied space telescope.

The Hubble Space Telescope has been responsible for some of the most exciting astronomical finds in history and while research time with Hubble is highly sought after, anyone can check what the storied telescope is currently pointed at whenever they like.

Most of the time, casual observers only hear about select Hubble observations when NASA or the European Space Agency (ESA) shares them, whether that be through blogs or on Twitter. For example, the photo above is of spiral galaxy M91, which was observe by Hubble and shared on the NASA blog today. This galaxy is of interest because it hides a gigantic supermassive black hole at its core. In a 2009 study, astronomers found that it weighs somewhere between 9.6 and 38 million times as much as the Sun.

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Apr 15, 2022

These Supermassive Black Holes are About to Collide

Posted by in category: cosmology

Scientists have discovered two supermassive black holes, locked together in a final, terrible spiral. They’re about to collide. And when they do, it will shake the fabric of spacetime itself.

Combing through decades of radio telescope observation data, a team of Caltech astronomers discovered a radio pattern from the deep sky unlike anything ever observed before. It was a flickering point of light, a blazar some nine billion light-years away. Every five years, it waxed and waned in brightness in a perfect sine wave, like clockwork. But that’s not what made it special. What made it special is where the signal diverged from the pattern. Over nearly fifty years, this point of light had obeyed a clockwork cycle of five-year pulses — except for the twenty years where it didn’t.

Five other observatories confirmed the readings, including the University of Michigan Radio Astronomy Observatory, MIT’s Haystack Observatory, the National Radio Astronomy Observatory (NRAO), Metsähovi Radio Observatory in Finland, and NASA’s Wide-field Infrared Survey Explorer (WISE) space satellite. This was no error.

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Apr 14, 2022

“Probing the Dark Universe” — A Lecture

Posted by in categories: cosmology, particle physics

In this one-hour public lecture Josh Frieman, director of the Dark Energy Survey, presents an overview of our current knowledge of the universe and describe new experiments and observatories. Over the last two decades cosmologists have made remarkable discoveries: Only 4 percent of our universe is made of ordinary matter — atoms, molecules, etc. The other 96 percent is dark, in forms unlike anything with which we are familiar. About 25 percent is dark matter, which holds galaxies and larger-scale structures together and may be a new elementary particle. And 70 percent is thought to be dark energy, an even more mysterious entity which speeds up the expansion of the universe. Josh Frieman is senior staff scientist at the Fermilab and Professor of Astronomy and Astrophysics and member of the Kavli Institute for Cosmological Physics at the University of Chicago. The Dark Energy Survey is a collaboration of 300 scientists from 25 institutions on 3 continents, which built and uses a powerful 570-Megapixel camera on a telescope in Chile to carry out a 5-year survey of 300 million galaxies and thousands of supernovae to probe dark energy and the origin of cosmic acceleration.

Apr 14, 2022

Hubble Uncovers Bizarre, Evolutionary Missing Link From the Dawn of the Universe

Posted by in category: cosmology

Bizarre, Evolutionary Missing Link Uncovered in Hubble Deep Survey of Galaxies The universe is so saturated with galaxies that even the weirdest things can go unnoticed for years after Hubble Space Telescope “deep-exposure” observations are taken. In sort of an intergalactic Where’s Waldo, an international team of astronomers uncovered in Hubble archival data a mysterious red dot nearly in the middle of the Great Observatories Origins Deep Survey-North (GOODS-North). As innocuous as it looks, it could be a rare missing link between some of the very earliest galaxies and the birth of supermassive black holes. The object, referred to as GNz7q, existed when the universe was just a toddler, only 750 million years after the big bang. The mixture of radiation from the object cannot be attributed to star formation alone. The best explanation is that it is a growing black hole shrouded in dust. Given time, the black hole will emerge from its dusty cocoon as a brilliant quasar, an intense beacon of light at the heart of an early galaxy. The pioneering Hubble telescope has provided a unique target for NASA ’s James Webb Space Telescope to use its spectroscopic instruments to study objects like GNz7q in unprecedented detail.

Apr 12, 2022

When It Comes to Science We Need to Understand the Past to Divine the Future

Posted by in categories: cosmology, science

How we came to exist is best stated in the Barenaked Ladies’ lyric “It All Started with the Big Bang,” the moment that space-time began.

Inflatons, gravitons, and Dark Matter are the story that is emerging immediately following The Big Bang.

Apr 11, 2022

On using the multiverse to avoid the paradoxes of time travel

Posted by in categories: cosmology, time travel

John Abbruzzese, On using the multiverse to avoid the paradoxes of time travel, Analysis, Volume 61, Issue 1, January 2001, Pages 36–38, https://doi.org/10.1093/analys/61.1.36.

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