Posts Tagged ‘Black hole’
“Nothing can better cure the anthropocentrism that is the author of all our ills than to cast ourselves into the physics of the infinitely large (or the infinitely small)”*…
And very eye-opening it can be. Jason Kottke reports on an article in the most recent issue of the American Journal of Physics with the understated title of “All objects and some questions.”
You just have to admire a chart that casually purports to show every single thing in the Universe in one simple 2D plot. [As the article’s author explain:]
In Fig. 2 [above], we plot all the composite objects in the Universe: protons, atoms, life forms, asteroids, moons, planets, stars, galaxies, galaxy clusters, giant voids, and the Universe itself. Humans are represented by a mass of 70 kg and a radius of 50 cm (we assume sphericity), while whales are represented by a mass of 10^5 kg and a radius of 7 m.
The “sub-Planckian unknown” and “forbidden by gravity” sections of the chart makes the “quantum uncertainty” section seem downright normal — the paper collectively calls these “unphysical regions.” Lovely turns of phrase all.
But what does it all mean? My physics is too rusty to say, but I thought one of the authors’ conjectures was particularly intriguing: “Our plot of all objects also seems to suggest that the Universe is a black hole.”…
Is the universe a black hole? (and other provocative propositions): @kottke on a recent scientific paper: “The Plot of All Objects in the Universe.”
* Julio Cortázar, Around the Day in Eighty Worlds
###
As we size up scale, we might recall that it was on this date in 451 that a different kind of attempt to reconcile the finite and the infinite began: the first session of the Council of Chalcedon (in modern-day Turkey) was opened. The fourth ecumenical council of the Christian church, it was attended by over 520 bishops or their representatives (making it the largest and best documented of the first seven ecumenical councils). It was convened by the Roman emperor Marcian to re-assert the teachings of the ecumenical Council of Ephesus against the heresies of Eutyches and Nestorius— whose teachings attempted to dismantle and separate Christ’s divine nature from his humanity (Nestorianism) and further, to limit Christ as solely divine in nature (Monophysitism).
The Council succeeded in that task. As Jaroslav Pelikan characterized their findings:
We all teach harmoniously [that he is] the same perfect in godhead, the same perfect in manhood, truly God and truly man, the same of a reasonable soul and body; homoousios with the Father in godhead, and the same homoousios with us in manhood … acknowledged in two natures without confusion, without change, without division, without separation.
… which marked a turning point in the Christological debates. But it also generated heated disagreements between the council and the Oriental Orthodox Church, which saw things differently– a contention that informed the separation of the Oriental Orthodox Churches from the rest of Christianity… and led to the Council being remembered as “Chalcedon, the Ominous.”
“The history of astronomy is a history of receding horizons”*…
The closest astronomers have come to directly “seeing” a black hole happened last year, when the LIGO observatory detected the spacetime-warping gravitational waves radiating from a pair of black holes that collided some 1.3 billion years ago.
That’s cool. But for astronomers, it’s not enough. What’s eluded them is a view of the event horizon, the boundary of the black hole from which, when crossed, there is no return. After the event horizon, gravity is so intense that not even light can escape.
We’ve never seen a direct image of a black hole. But if an audacious experiment called the Event Horizon Telescope is successful, we’ll see one for the first time…
Find out how at “Astronomers just turned on a planet-size telescope to take a picture of a black hole.”
* Edwin Hubble
###
As we look into it, we might recall that it was on this date in 1006 CE that observers across China, Japan, Iraq, Egypt, and Europe recorded their observation of a supernova (now known as SN 1006). Likely the brightest observed stellar event in recorded history, it reached an estimated −7.5 visual magnitude (more than sixteen times the brightness of Venus). Many experts believe that it was also recorded in the Native American petroglyphs in White Tank Mountain Regional Park, Arizona, making them the first North American record of a supernova sighting.
SN 1006 supernova remnant
“I used to think information was destroyed in black holes. This was my biggest blunder, or at least my biggest blunder in science”*…
email readers click here for video
Gravitational waves sent out from a pair of colliding black holes have been converted to sound waves, as heard in this animation. On September 14, 2015, LIGO [the Laser Interferometer Gravitational-wave Observatory] observed gravitational waves from the merger of two black holes, each about 30 times the mass of our sun. The incredibly powerful event, which released 50 times more energy than all the stars in the observable universe, lasted only fractions of a second.
In the first two runs of the animation, the sound-wave frequencies exactly match the frequencies of the gravitational waves. The second two runs of the animation play the sounds again at higher frequencies that better fit the human hearing range. The animation ends by playing the original frequencies again twice.
As the black holes spiral closer and closer in together, the frequency of the gravitational waves increases. Scientists call these sounds “chirps,” because some events that generate gravitation waves would sound like a bird’s chirp.
More background from LIGO:
email readers click here for video
* Stephen Hawking
###
As we scan the event horizon, we might send difficult-to-detect birthday greetings to Lawrence Maxwell Krauss; he was born on this date in 1954. A theoretical physicist and cosmologist, Dr. Krauss was among the first to propose the existence of the enigmatic dark energy that makes up most of the mass and energy in the universe. He directs the Origins Project, and has written several books on science for the general public, including Fear of Physics (1993), The Physics of Star Trek (1995), Quantum Man: Richard Feynman’s Life in Science (2011), and A Universe from Nothing (2012).
“Black holes are the seductive dragons of the universe”*…
Just when the confirmation of gravity waves seemed conclusively to affirm Einstein’s theory of general relativity…
If you thought regular black holes were about as weird and mysterious as space gets, think again, because for the first time, physicists have successfully simulated what would happen to black holes in a five-dimensional world, and the way they behave could threaten our fundamental understanding of how the Universe works.
The simulation has suggested that if our Universe is made up of five or more dimensions – something that scientists have struggled to confirm or disprove – Einstein’s general theory of relativity, the foundation of modern physics, would be wrong. In other words, five-dimensional black holes would contain gravity so intense, the laws of physics as we know them would fall apart…
“If naked singularities exist, general relativity breaks down,” said one of the team, Saran Tunyasuvunakool. “And if general relativity breaks down, it would throw everything upside down, because it would no longer have any predictive power – it could no longer be considered as a standalone theory to explain the Universe.”
If our Universe only has four dimensions, everything is cool, and ring-shaped black holes and naked singularity are not a thing. But physicists have proposed that our Universe could be made up of as many as 11 dimensions. The problem is that because humans can only perceive three, the only way we can possibly confirm the existence of more dimensions is through high-energy experiments such as the Large Hadron Collider…
More at “A five-dimensional black hole could ‘break’ general relativity, say physicists.”
* Robert Coover, A Child Again
###
As we marvel at models, we might send very carefully-crafted birthday greetings to Jacques de Vaucanson; he was born on this date in 1709. A mechanical genius, de Vaucanson invented a number of machine tools still in use (e.g., the slide rest lathe) and created the first automated loom (the inspiration for Jacquard). But he is better remembered as the creator of extraordinary automata. Among his most famous creations: The Flute Player (with hands gloved in skin) and The Tambourine Player, life-sized mechanical figures that played their instruments impressively. But his masterpiece was The Digesting Duck; remarkably complex (it had 400 moving parts in each wing alone), it could flap its wings, drink water, eat grain– and defecate.
Sans…le canard de Vaucanson vous n’auriez rien qui fit ressouvenir de la gloire de la France. (Without…the duck of Vaucanson, you will have nothing to remind you of the glory of France)
– Voltaire
“If you think this Universe is bad, you should see some of the others”*…
In cosmology as in so many branches of the scientists, theorist tend to get most of the attention. But in the end, it’s experimentalists who covert hypothesis into knowledge. Current theories suggest that our universe– which could be “the universe” or could be one of many– could be a hologram, a computer program, a black hole or a bubble—and, experimentalists suggest, there are ways to check…
Ponder their proofs at “What Is the Universe? Real Physics Has Some Mind-Bending Answers.”
* Philip K. Dick
###
As we practice our pronunciation of “billions and billions,” we might spare a thought for Ron Toomer; he died on this date in 2011. Toomer began his career as an aeronautical engineer who contributed to the heat shields on NASA’s Apollo spacecraft. But in 1965, he joined Arrow Development, an amusement park ride design company, where he became a legendary creator of steel roller coasters. His first assignment was “The Run-Away Mine Train” (at Six Flags Over Texas), the first “mine train” ride, and the second steel roller coaster (after Arrow’s Matterhorn Ride at Disneyland). Toomer went on to design 93 coasters worldwide, and was especially known for his creation of the first “inversion” coasters (he built the first coasters with 1, 2, 3, 4, 5, 6, and 7, loops). In 2000, he was inducted in the International Association of Amusement Parks and Attractions (IAAPA) Hall of Fame as a “Living Legend.”
Toomer with his design model for “The Corkscrew,” the first three-inversion coaster
“The Corkscrew” at Cedar Point Amusement Park, Ohio
You must be logged in to post a comment.