Showing all posts tagged: astronomy
Extraterrestrials may arrive in 500 years, but not in flying saucers
30 April 2024
In the late 1960’s, former United States President Jimmy Carter, reported seeing an Unidentified Flying Object (UFO). Today unexplained objects, or phenomena, seen in the skies, are referred to as Unidentified Anomalous Phenomenon (UAP). Carter, however, was not expecting to participate in any historic close encounter of the third kind:
While puzzled by the object and its origins, Carter himself later said that, while he had considered the object to be a UFO — on the grounds it was unexplained — his knowledge of physics had meant he had not believed himself to be witnessing an alien spacecraft.
Some people may be unhappy that Carter allowed physics to get in the way of a good story. Because wouldn’t it be great if we could whiz about the galaxy in a vessel the size of the average suburban house, which every other intelligence in the galactic neighbourhood seems capable of, except us.
House-size flying saucers defy the laws of physics, because, you know, their builders seemingly are able to defy the laws of physics. It would however be awesome to zap back and forth to say the nearest star system, Alpha Centauri, in a house-size vessel that could travel (presumably/somehow) faster than the speed of light. At least I’m not breaking the laws of dreaming there.
But if close-to-light-speed interstellar travel, together with the possibly of extraterrestrials visiting Earth (from the far side of the Milky Way, no less) intrigues you, read this Twitter/X post, by American physicist Casey Handmer. Visitors from civilisations, from maybe fifty thousand light years across the galaxy, may be mere centuries away from reaching our solar system:
Let’s say that any civilization that can figure out interstellar travel can develop from slow to 99% of the speed of light in 500 years, and they’re coming from the other side of the galaxy — 50,000 years ago. By the time the light of their first (presumably highly energetic, fireworksy) relativistic travel reaches us, they’re already 99% of the way here – just 500 years to roll out the welcome mat.
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Extra-terrestrials may not want Earth as part of their galactic empire
19 April 2024
A conquering interstellar civilisation could bring the entire galaxy under its yoke in about a million years, assuming said civilisation could traverse the Milky Way at about ten percent the speed of light. I expect it’d be a multi-generational undertaking.
It’d also be up to those who conceived of the original vision to conquer the galaxy, to find a way to keep their descendants motivated. A million years is a long time.
This might be one reason why we’ve not encountered any extra-terrestrial lifeforms so far. No one has the energy to invade the whole galaxy, so they’ve stayed in their corner, undetected. But there is another possibility. The all-powerful invaders are being picky.
They’re only acquiring sections of the Milky Way, and the planets in those regions, that are of some sort of value to them. Perhaps Earth is not in that category.
This is the upshot of the latest Kurzgesagt video presentation. An interesting theory. We are not alone, but we are not wanted.
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Is the Sun conscious? Can a great ball of fire think for itself?
5 April 2024
Maybe I’ve been watching too much of Universe, the Brian Cox made documentary about, well, the universe, and am way too willing to take in all manner of ideas, no matter how outlandish they may seem. So when this article (PDF), exploring the possibility the Sun is a conscious entity (of some sort), written in 2020 by Rupert Sheldrake, appeared on my news feed recently, my curiosity was piqued.
Meanwhile, field theories of consciousness propose that some electromagnetic fields actually are conscious, and that these fields are by their very nature integrative. When applied to the sun, such field theories suggest a possible physical basis for the solar mind, both within the body of the sun itself and also throughout the solar system. If the sun is conscious, it may be concerned with the regulation of its own body and the entire solar system through its electromagnetic activity, including solar flares and coronal mass ejections. It may also communicate with other star systems within the galaxy.
If the Sun could talk, what might it say to us? Maybe, “do something about climate change before it’s too late.” Or, “always wear sunscreen when in my presence.”
It’s a fun idea, solar consciousness, but I’m not sure we’d ever hear Brian Cox going along with the notion. I’ll defer to Star Trekin’! in the meantime: it’s consciousness; but not as we know it…
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astronomy, humour, philosophy, science
An app that points to centre of the Milky Way galaxy
26 March 2024
Image courtesy of Pexels.
Tangentially related to my previous post… product designer and technologist Matt Webb has created an app, named Galactic Compass (link to Apple app store), that points to the centre of the galaxy.
When on the (far less light polluted) NSW Central Coast, I can kind of look down from the tail of the constellation Scorpius (the scorpion), and be observing the right patch of the night sky.
When back amongst the super bright lights of Sydney though, that can be a little trickier. Like, find a star, any star, let alone the Scorpius constellation.
Read also Galactic Compass’ origin/development story, the app was built with help from ChatGPT.
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artificial intelligence, astronomy, science, technology
A patch for computer software one light-day away on Voyager 1
25 March 2024
One of the computers on NASA’s deep space probe Voyager 1 is experiencing some sort of malfunction, with recent signals from the probe containing no usable data. Mission engineers are apparently confident the problem can be resolved, even though Voyager 1 is almost a light-day distant, meaning it’ll take time to apply a fix:
Because Voyager 1 is more than 15 billion miles (24 billion kilometers) from Earth, it takes 22.5 hours for a radio signal to reach the spacecraft and another 22.5 hours for the probe’s response to reach antennas on the ground. So the team received the results of the command on March 3. On March 7, engineers began working to decode the data, and on March 10, they determined that it contains a memory readout.
Although Voyager 1, and deep space counterpart Voyager 2, have left the solar system and are in interstellar space, it is estimated it will take Voyager 1 another three hundred years to reach the Oort cloud. The vastly scattered debris, rocky remnants of the formation of the solar system, that constitutes the Oort cloud, may extend more than two light years from the Sun. That’s about half way to the nearest star system, Alpha Centauri.
So to be truly beyond the solar system, I imagine the Voyager probes will need to clear the Oort cloud first. We might be waiting sometime for that to happen. It’s incredible the way mission controllers can keep tabs on deep space missions though, and trouble shoot, and perhaps remedy problems, despite their distance from the Sun.
About twenty years ago, scientists were puzzled by changes in the trajectories of deep space probes Pioneers 10 and 11. Somehow both craft, then located in the Kuiper belt, which is situated beyond the orbit of Neptune, appeared to have slowed down slightly. All sorts of theories were advanced to account for the anomaly, including the idea that gravity may be behaving in ways not seen before.
After analysing gargantuan quantities of data, mission engineers determined that heat loss was having a subtle influence on the movements of the probes, in that it was acting a little like a brake. Contact with both vessels had been lost by that stage, so even if a fix could have been devised, it unfortunately could not have been applied.
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astronomy, science, technology
To go where no one has gone before, the limit of the universe
22 March 2024
German animation and design studio Kurzgesagt have been producing excellent informative and educational videos for what seems like half the lifespan of the universe. Let’s hope Peak-Kurzgesagt is a situation that never comes to pass.
Their latest video, the Paradox of an Infinite Universe, covers some heady ground; the concept of a physical edge, or boundary, to the universe. If we could somehow reach such a region, could we press our hand against it, as we can a garden wall? Hmm…
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Noctalgia: when you miss seeing the light polluted night sky
25 September 2023
Noctalgia is the recently minted neologism for the phenomenon of missing dark skies at night. Noctalgia is something astronomers could tell you about. Dark, light pollution free, skies are essential for their work, but they’re not so commonplace anymore. And here we have a dilemma.
The source of this light pollution is the night lighting that keeps us safe and secure. But light pollution does not only originate from the surface of the planet. The growing number of satellites in Earth orbit, of which we likewise greatly depend, is also adding to the problem for astronomers:
More recently, the explosive growth in satellite communication “constellations,” like SpaceX’s Starlink system, has put orders of magnitude more satellites into orbit than even a decade ago, with even more on the way. Those satellites don’t just spoil deep-space astronomical observations when they cross a telescope’s field of view; they also scatter and reflect sunlight from their solar arrays. The abundance of satellites is causing the overall brightness of the sky to increase all around the globe.
Maybe noctalgia can be added to the list of contender words when dictionaries next update their lexicons, if that hasn’t already happened.
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The solar system has another planet, but where is it hiding?
20 September 2023
Astronomers are convinced the solar system hosts another planet, often dubbed Planet Nine, or Planet X, but are unable to agree on its size and mass, nor its location.
A few years ago speculation was rife a Neptune size body was orbiting the Sun well beyond Pluto, taking between ten to twenty thousand years to make a circuit. While mathematical evidence suggested the existence of the planet, observations turned up nothing.
Now astronomers think a planet similar in size to Earth may be lurking in the far reaches of the solar system, though nowhere as far out as the supposed Neptune size body:
According to planetary scientists Patryk Sofia Lykawka of Kindai University in Japan and Takashi Ito of the National Astronomical Observatory of Japan, this world, frozen and dark so far from the Sun, would be no greater than 3 times the mass of Earth, and no farther than 500 astronomical units from the Sun.
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The workings of the universe are my spirit animal
29 July 2023
The best way to understand the universe — to whatever extent that is possible — may be to see the cosmos as an animal. A fascinating, yet somewhat unpredictable animal, says Andrew Pontzen, a professor of cosmology at University College London, writing for The Guardian:
It once seemed that, for all its immensity, the cosmos could be understood through the application of a small number of rigid physical laws. Newton encapsulated this idea, showing how apples falling from trees and planetary orbits around our sun arise from the same force, gravity.
J. B. S. Haldane, a Scottish mathematical biologist, said it best, in an essay he wrote almost one-hundred years ago, in 1927, titled Possible Worlds: “Now, my own suspicion is that the universe is not only queerer than we suppose, but queerer than we can suppose.” Words of wisdom, them.
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Space-time being rippled by waves from supermassive black holes
29 June 2023
Scientists think low-frequency gravitational waves generated by super-massive black holes found at the centres of some galaxies may be sending ripples through the fabric of space-time. While astronomers still aren’t one-hundred percent sure these waves exist, they would help in the study of super-massive black holes, if they did.
The super-massive black hole, Sagittarius A — also known as Sag A — at the centre of our galaxy, the Milky Way, may not be a generator of these gravitational waves though. At a mere four point three million times the mass of the Sun, it’s considered to be a relatively small, er, super-massive black hole.
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