A team of scientists, including Chief Investigator Ilya Mandel from the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) at Monash University, recently studied what happens to rotating massive stars when they reach the end of their lives.
Stars produce energy by fusing lighter elements into heavier ones in their core: hydrogen into helium, then helium into carbon, oxygen, and so on, up to iron. The energy produced by this nuclear fusion also provides pressure support inside the star, which balances the force of gravity and allows the star to remain in equilibrium.
This process stops at iron. Beyond iron, energy is required to sustain fusion rather than being released by fusion. A heavy iron star core contracts under gravity, creating a neutron star, or if it is heavy enough, a black hole. Meanwhile, the outer layers of the star explode in a brilliant flash, observable as a supernova. However, some massive stars seem to completely disappear without any explosion. Theories suggest that these massive stars completely collapse into black holes, but is that possible?
Black holes are the dark remnants of collapsed stars, regions of space cut off from the rest of the universe. If something falls into a black hole, it can never come back out. Not even light can escape, meaning black holes are invisible even with powerful telescopes. Yet physicists know black holes exist because they’re consistent with time-tested theories, and because astronomers have observed how matter behaves just outside a black hole.
Naturally, science fiction loves such an enigmatic entity. Black holes have played starring roles in popular books, movies and television shows, from “Star Trek” and “Doctor Who” to the 2014 blockbuster “Interstellar.”
But black holes aren’t quite as menacing as they are commonly portrayed. “They definitely do not suck,” says Daryl Haggard, an astrophysicist at McGill University in Montreal. “A black hole just sits there, passively. Things can fall onto it, just as meteors can fall to Earth, but it doesn’t pull stuff in.”
This corresponds to a certain symmetry of nature: T-symmetry, or time-reversal invariance. Our everyday experience indicates to us, quite strongly, that the laws of physics must violate this symmetry, but for decades, we couldn’t demonstrate it. But a few years ago, we experimentally proved the laws of physics are different depending on which direction time runs. Here’s how we know.
Although planets, stars, and galaxies all spin along an axis of rotation, new research suggests that the universe itself might also revolve around an axis, or several, but on a cosmic scale challenging one of the fundamental assumptions of astrophysics, the cosmological principle, which holds that the same physical laws are homogeneous and uniform, isotropic, everywhere in the universe. This exotic new theory paints a picture of a spinning universe that creates structural anisotropies and asymmetries on cosmic scales of hundreds of millions of light years.
Enter one Lior Shamir, a computational astronomer at Kansas State University, who presented evidence that has yet to be peer reviewed at the recent virtual Zoom meeting of the American Astronomical Society that the early universe rotated like an enormous, complex galaxy, and continued this momentum through the galaxies we see today, hinting that the early universe had a more uniform structure that it has been steadily losing through time, resulting in an increasingly chaotic cosmos.
Pleased to have been the guest on this most recent episode of Javier Ideami’s Beyond podcast. We discuss everything from #spaceexploration to #astrobiology!
In this episode, we travel from Ferdinand Magellan’s voyage to the first mission to Mars with Bruce Dorminey. Bruce is a science journalist and author who primarily covers aerospace, astronomy and astrophysics. He is a regular contributor to Astronomy magazine and since 2012, he has written a regular tech column for Forbes magazine. He is also a correspondent for Renewable Energy World. Writer of “Distant Wanderers: The Search for Planets Beyond the Solar System”, he was a 1998 winner in the Royal Aeronautical Society’s Aerospace Journalist of the Year Awards (AJOYA) as well as a founding team member of the NASA Astrobiology Institute’s Science Communication Focus Group.
EPISODE LINKS: Bruce web: https://www.forbes.com/sites/brucedorminey/#47e297264d03 Distant Wanderers Book: https://www.amazon.es/Distant-Wanderers-Search-Planets-Beyond/dp/1441928723 Renewable Energy World: https://www.renewableenergyworld.com/author/bruce-dorminey/#gref Bruce’s Twitter: https://twitter.com/bdorminey
INFO: Podcast website: https://volandino.com Spotify: https://open.spotify.com/show/3O74ctu6Hv5zZdHYT9Ox3Z Apple Podcasts: https://podcasts.apple.com/us/podcast/beyond/id1509949724 RSS: https://volandino.com/feed/podcast Full episodes playlist:
OUTLINE: 01:21 — Magellan’s journey to the indies; first circumnavigation of the earth — Risk: today vs previous centuries. 02:15 — On route to the Spice Islands — Moluccas — Treaty of Tordesillas. 03:07 — Spain and Portugal on top of the world. 03:41 — Reaching philippines and the wrong side of things. 05:20 — Killed in the Philippines. 06:08 — The reasons behind the expedition: trade and religion. 07:23 — Casualties — Magellan’s expedition vs today. 07:58 — Early astronauts, challenging missions — minimal computing power. 08:40 — Mission to Mars and tolerance to risk today. 10:03 — First Mars mission attempt — the odds. 10:37 — Watching the Apollo launches live. 11:23 — The uniqueness of the moment — Apollo 8. 12:12 — Putting risk in perspective: astronauts of the Apollo program vs today. 13:05 — Psychological risks of space missions — Harrison Hagan “Jack” Schmitt (last person that walked on the moon) — the impact of being on the moon. 15:54 — Psychological factors on a trip to Mars — can we predict them? — Experiences on the International Space Station. 17:03 — Shortening the trip to Mars. 19:02 — The drive to do these missions today vs the Apollo times. 20:00 — The lost time in the moon — natural resources, astronomy, practicing for future missions to mars. 20:37 — Terraforming Mars 22:33 — Second homes, platforms in space (example: at Lagrange points). 23:43 — Exoplanets — detecting signs of life. 26:18 — Methods of detection & verification vs going there (detecting microbial life through analysis of color, surface reflectivity and other means) 27:50 — Enceladus: plumes of gas and liquid — potential insitu analysis by probes. 28:43 — microfossils on Mars. 29:00 — Impact of finding life in another planet of our solar system, even if microbial. 29:54 — Intelligent life — David Kipping, Columbia University — 3:2 odds that intelligence is rare. 30:31 — Probability of finding life — 400 billion stars in our galaxy. 33:24 — Facing the discovery of new forms of intelligent life. 35:50 — People’s resilience and attention spans / Inter-species communication. 38:26 — Could we miss new kinds of lifeforms due to them having different structures, chemical arrangements, etc? 40:30 — What is life — lack of agreement. 41:48 — Scratching the surface on any topic — a neverending search for an ultimate truth. 43:50 — ALH 84001 Allan Hills meteorite 47:26 — Asteroid mining — natural resources — Planetary Resources startup (acquired by ConsenSys). 48:52 — Commercializing space travel — trips to go around the moon — translunar flights. 51:22 — Progress since the Apollo era and next steps. 52:55 — Spending a weekend on the moon. 54:00 — Next decade in Space — putting a crew on mars, robotic sample return missions, permanent or semi-permanet settlements on the lunar surface, optical and radio-based astronomy on the far side of the moon, space tourism, space based interferometers, etc 56:22 — will other intelligent life forms want to communicate? gregarious vs non-gregarious civilizations. 57:35 — Consequences of the pandemic. 59:06 — conclusion — “Distant Wanderers — search for planets beyond the solar system”
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Astronomers announced the discovery of a ghostly, almost perfectly circular, arc of ultraviolet emission centered on the handle of the Big Dipper and stretching 30 degrees across the Northern sky. If the arc were extended, it would completely encircle the Big Dipper with a diameter of 60 degrees.
This unique object was discovered by Andrea Bracco, an astronomer at the Ruđer Bošković Institute in Zagreb, Croatia, Marta Alves, an astronomer at Radboud University in the Netherlands, and Robert Benjamin, a professor of physics and astronomy at the University of Wisconsin-Whitewater in the United States. Benjamin, who contributed to the analysis of the structure, presented the team’s newest results at an on-line meeting of American Astronomical Society on June 2. A report on the discovery has been published in the April volume of Astronomy & Astrophysics Letters.
The arc, stretching beyond the constellation Ursa Major, is 30 degrees long, a fraction of a degree thick, and made of compressed, energized interstellar gas. The source of the energy and the arc shape indicate an advancing shock wave from a stellar explosion or supernova which occurred 60 degrees above the plane of the Milky Way Galaxy. The distance and age of the explosion which created the shock wave is highly uncertain. The team estimates that the explosion occurred more than 100,000 years ago at a distance of approximately 600 light years.
Skateboarding legend Rodney Mullen teams up with Physics Girl to explain the unusual physics behind skateboard tricks. Filmed with a phantom high speed camera at 1000fps, see Mullen’s tricks like never before.
If you liked this video check out these: How SMOOTHNESS of a SOCCER BALL affects curve!
Crazy tic tac bounce!?
Created by: dianna cowern editing: jabril ashe animations: kyle norby props: kyle kitzmiller science advisor: dan walsh
Check out Beyond Slow Motion: https://www.youtube.com/beyondslowmotion and Kuma Films: https://www.youtube.com/channel/UC497r18hyShx1ffsYcgK_kg
A million thanks to Rodney Mullen! https://www.instagram.com/rodneymullen/?hl=en
Thanks to Kyle Kitzmiller twitter.com/kylekengineering
Physicists are figuring out how close you can get to a black hole before you are unlikely to escape. That threshold is called the innermost stable circular orbit (ISCO).
