Space Stories: Black Holes & Dark Energy, New Forms of Ice, and Dark Dwarf Galaxies

Posted on by onespaceman2000
Image (Credit): Ship from the Disney film The Black Hole. (Disney)

Here are some recent stories of interest.

—University of Hawaii: “First Observational Evidence Linking Black Holes to Dark Energy“

Searching through existing data spanning 9 billion years, a team of researchers led by scientists at University of Hawaiʻi at Mānoa has uncovered the first evidence of “cosmological coupling” –a newly predicted phenomenon in Einstein’s theory of gravity, possible only when black holes are placed inside an evolving universe.

UH Mānoa astrophysicists Duncan Farrah, a faculty member at the Institute for Astronomy and the Department of Physics and Astronomy, and Kevin Croker, a professor of physics and astronomy led this ambitious study, combining Hawaiʻi’s expertise in galaxy evolution and gravity theory with the observation and analysis experience of researchers across nine countries to provide the first insight into what might exist inside real black holes.

—Astronomy.com: “Scientists Create New Form of Ice that Might Exist on Ocean Moons“

Chemists have discovered a new form of ice, and their work may have major consequences for our understanding of the outer solar system. We usually encounter three forms of water on the surface of Earth: solid, liquid, and vapor. On our planet, solid ice mainly comes in one variety, where water molecules arrange themselves into an orderly and repeated crystalline structure. But scientists have discovered 19 other varieties of water-ice that may appear throughout the universe.

—Phys.org: “Chinese Astronomers Discover an Isolated Dark Dwarf Galaxy“

Using the Five-hundred-meter Aperture Spherical radio Telescope (FAST), Chinese astronomers have detected a new galaxy, which received designation FAST J0139+4328. The newfound galaxy is isolated, has a relatively low stellar mass, and is dominated by dark matter. The discovery was detailed in a paper published February 6 on the arXiv pre-print server.

Astronomy and ChatGPT: Do Your Own Homework

Posted on by onespaceman2000
Credit: OpenAI

While I recently used the new AI software ChatGPT (created by OpenAI, which was founded by Elon Musk and others) to draft up a poem, I did not use it to learn more about astronomy. Others have already attempted this and came back with mixed results.

Last month, the website Astronomy reported back on its results testing ChatGPT on a few questions. Some of these questsions included:

  • On average, how many stars are formed each year in the Milky Way?
  • What would happen if two supermassive black holes merged?
  • Why do the giant planets rotate so much faster than the terrestrial planets in our solar system?

The verdict? Astronomy was not impressed, reporting:

…once you start asking questions whose answers are not so obvious and dig into the subtleties of astrophysics — the types of informed, discerning questions that our readers regularly send us — ChatGPT becomes prone to giving answers that seem plausible, but are very wrong. To make things worse, ChatGPT is also very bad at knowing when it is making things up, and it can’t cite any sources.

Cloudy Nights users found ChatGPT to be a little more useful when listing out clear facts when answering questions such as “What are the best objects to observe in the night sky during January from the Northern Hemisphere?” It was also helpful answering this question – “What is the forum on the site Cloudy Nights about?”:

Cloudy Nights is a forum-based website that is focused on the hobby of astronomy. The site features a wide range of forums where members can discuss various topics related to astronomy, including telescopes, astrophotography, observing techniques, and more. In addition to the forums, the site also features reviews, articles, and other resources to help people learn more about astronomy and enjoy the hobby. Whether you are a beginner or an experienced astronomer, there is likely to be something of interest on the Cloudy Nights forum.

As with using Wikipedia as your main source, use ChatGPT at your own risk. I have more faith in Wikipedia because it represents the interaction of humans and therefore is based on more context for the answers. It also provides source material, unlike ChatGPT. If you use them as tools you should be okay. If you use them as oracles (in the original sense), then you are on your own.

Video: Brian Cox on Multiverses and More

Posted on by onespaceman2000
Image (Credit): Dr. Brian Cox in an interview discussing multiverses. (LADbible TV)

About a month ago, English physicist Brian Cox was discussing a variety of topics in an interview on LADbible TV titled Brian Cox On The Multiverse And Life On Other Planets. You can hear Dr. Cox respond to a number of questions about the infinite universe, multiverses, finding intelligent life off planet, black holes, the end of the Earth, and even the recent DART mission. It is worth spending 23 minutes of your time listening to his answers.

For instance, he notes that it is his reasonable guess that there are no other worlds in the galaxy like ours in terms of harboring intelligent life. He points out that it took anywhere from 3.5 to 4 billion years for intelligent life to form on the Earth, which is about 1/3 the age of the universe. If we do find other life in the galaxy, he expects it to be slime and not much more. Later on, he states that not even the intelligent life on this planet would have been possible without a planet-killer asteroid taking out the dinosaurs, so it was a fluke that made way for intelligent life.

All in all, he said it is a “big ask” to expect to find other planets with intelligent life in this violent universe with a 4 billion-year chain of life uncut by events, making our civilization quite unique. Of course, earlier in the interview he also points out that there are about 2 trillion galaxies in our “small patch” of the universe, so even one intelligent planet per galaxy can amount to a lot of civilizations. Yet ever seeing or even knowing about these civilizations is something else. Add in the idea of multiverses created by endless big bangs, and the odds of intelligent life increase again within these other unknowable universes.

It’s a lot to get your heard around, though Dr. Cox has a way of making it all sound so reasonable. For that reason, I again ask you to spend 23 minutes with Dr. Cox to clear your head and make room for some new ideas.

Pic of the Week: Hickson Compact Group 40

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Image (Credit): The NASA/ESA Hubble Space Telescope view of five galaxies, called the Hickson Compact Group 40. (NASA/ESA Hubble)

This week’s image is from the NASA/ESA Hubble Space Telescope. It shows an amazing collection of five galaxies in close proximity to one another in what is known as the Hickson Compact Group 40. In about one billion years they are expected to coalesce into one large galaxy.

Here is the summary from the Hubble site:

This menagerie includes three spiral-shaped galaxies, an elliptical galaxy and a lenticular (lens-like) galaxy. Somehow, these different galaxies have crossed paths to create an exceptionally crowded and eclectic galaxy sampler.

Caught in a leisurely gravitational dance, the whole group is so crowded that it could fit within a region of space that is less than twice the diameter of our Milky Way’s stellar disc.

Though such galaxy groupings can be found in the heart of huge galaxy clusters, these galaxies are notably isolated in their own small patch of the Universe, in the direction of the constellation Hydra.

One possibility is that there’s a lot of dark matter (a poorly understood and invisible form of matter) associated with these galaxies. If they come close together the dark matter can form a big cloud within which the galaxies orbit. As the galaxies plough through the dark matter they feel a frictional force that results from its gravitational effects. This slows their motion and makes the galaxies lose energy, so they fall together. Therefore, this snapshot catches the galaxies at a very special moment in their lifetimes. In about 1 billion years they will eventually collide and merge to form a single giant elliptical galaxy.

Astronomers have studied this compact galaxy group not only in visible light, but in radio, infrared, and at X-ray wavelengths. Almost every one of the galaxies has a compact radio source at its core, which could be evidence for the presence of a supermassive black hole. X-ray observations show that the galaxies have been gravitationally interacting as witnessed by the presence of a lot of hot gas amongst them. Infrared observations reveal clues to the rate of formation of new stars.

Though over 100 such compact galaxy groups have been catalogued in sky surveys going back several decades, Hickson Compact Group 40 is one of the most densely packed. Observations suggest that such tight groups may have been more abundant in the early Universe and provided fuel for powering black holes, known as quasars, whose light from superheated inflating material blazed across space. Studying the details of galaxies in nearby groups like this helps astronomers sort out when and where galaxies assembled themselves, and what they are assembled from.

Space Stories: JWST, a Galaxy Catalog, and a Stellar Graveyard

Posted on by onespaceman2000
Image (Credit): JWST image of the Tarantula Nebula, which is about 160,000 light-years away. (NASA, ESA, CSA, STScI)

Here are some recent stories of interest.

—Nature.com: “‘Bit of Panic’: Astronomers Forced to Rethink Early Webb Telescope Findings“

Astronomers have been so keen to use the new James Webb Space Telescope (JWST) that some have got a little ahead of themselves. Many started analysing Webb data right after the first batch was released, on 14 July, and quickly posted their results on preprint servers — but are now having to revise them. The telescope’s detectors had not been calibrated thoroughly when the first data were made available, and that fact slipped past some astronomers in their excitement.

—DailyScience.com: “‘Astronomers Map Distances to 56,000 Galaxies, Largest-ever Catalog“

How old is our universe, and what is its size? A team of researchers led by University of Hawaii at Manoa astronomers Brent Tully and Ehsan Kourkchi from the Institute for Astronomy have assembled the largest-ever compilation of high-precision galaxy distances, called Cosmicflows-4. Using eight different methods, they measured the distances to a whopping 56,000 galaxies. The study has been published in the Astrophysical Journal.

—University of Sydney: “Milky Way’s Graveyard of Dead Stars Found“

The first map of the ‘galactic underworld’ – a chart of the corpses of once massive suns that have since collapsed into black holes and neutron stars – has revealed a graveyard that stretches three times the height of the Milky Way, and that almost a third of the objects have been flung out from the galaxy altogether.