Posts Tagged ‘Universe’
“The question of whether a computer can think is no more interesting than the question of whether a submarine can swim”*…
Anil Dash, with a grounded view of artificial intelligence…
Even though AI has been the most-talked-about topic in tech for a few years now, we’re in an unusual situation where the most common opinion about AI within the tech industry is barely ever mentioned.
Most people who actually have technical roles within the tech industry, like engineers, product managers, and others who actually make the technologies we all use, are fluent in the latest technologies like LLMs. They aren’t the big, loud billionaires that usually get treated as the spokespeople for all of tech.
And what they all share is an extraordinary degree of consistency in their feelings about AI, which can be pretty succinctly summed up:
Technologies like LLMs have utility, but the absurd way they’ve been over-hyped, the fact they’re being forced on everyone, and the insistence on ignoring the many valid critiques about them make it very difficult to focus on legitimate uses where they might add value.
What’s amazing is the reality that virtually 100% of tech experts I talk to in the industry feel this way, yet nobody outside of that cohort will mention this reality. What we all want is for people to just treat AI as a “normal technology“, as Arvind Naryanan and Sayash Kapoor so perfectly put it. I might be a little more angry and a little less eloquent: stop being so goddamn creepy and weird about the technology! It’s just tech, everything doesn’t have to become some weird religion that you beat people over the head with, or gamble the entire stock market on…
Eminently worth reading in full: “The Majority AI View,” from @anildash.com.
Pair with: “Artificial Intelligences, So Far,” from @kevinkelly.bsky.social.
For an explanation of (some of) the dangers of over-hyping, see: “America’s future could hinge on whether AI slightly disappoints,” from @noahpinion.blog.web.brid.gy.
And for a peek at what lies behind each GenAI query: “Cartography of generative AI,” from @tallerestampa.bsky.social via @flowingdata.com.
While the arguments above are practical, note that a plethora of tech experts have weighed in with a a note of existential caution: “Statement on Superintelligence.”
Further to which (and finally), a piece from the Federal Reserve Bank of Dallas, projecting the economic impact of AI. It suggests that AI could provide a modest but meaningful boost to GDP over the next 25 years… if The Fed’s “Goldilocks Scenario” (in which, per Dash’s and Kelly’s comments, AI makes consistent incremental contributions to “keep living standards improving at their historical rate”) plays out. You’ll note that they also considered two other scenarios: a “benign singularity” scenario in which “AI eventually surpasses human intelligence, leading to rapid and unpredictable changes to the economy and society” and an “extinction singularity” in which “machine intelligence overtakes human intelligence at some finite point in the near future, the machines become malevolent, and this eventually leads to human extinction.”
Interesting times in which we live…
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As we parse pumped prognostication, we might recall that it was on this date in 4004 BCE that the Universe was created… as per calculations by Archbishop James Ussher in the mid-17th century. Ussher, the head of the Anglican Church of Ireland at the time, attempted to calculate the dates of many important events described in the Old Testament. His calculations, which he published in 1650, were not that far off from many other estimates made at the time. Isaac Newton, for example, believed that the world was created in 4000 BC.
When Clarence Darrow prepared his famous examination of William Jennings Bryan in the Scopes trial [see here], he chose to focus primarily on a chronology of Biblical events prepared by a seventeenth-century Irish bishop, James Ussher. American fundamentalists in 1925 found—and generally accepted as accurate—Ussher’s careful calculation of dates, going all the way back to Creation, in the margins of their family Bibles. (In fact, until the 1970s, the Bibles placed in nearly every hotel room by the Gideon Society carried his chronology.) The King James Version of the Bible introduced into evidence by the prosecution in Dayton contained Ussher’s famous chronology, and Bryan more than once would be forced to resort to the bishop’s dates as he tried to respond to Darrow’s questions.
“The universe is under no obligation to make sense to you”*…
Still, we try… In a consideration of three new books, the estimable Sean Carroll brings us up to date on the state of play…
Should scientists be embarrassed that they can’t settle on a definition for the Big Bang? The cosmologist Will Kinney describes it as the “physical theory of the hot infant universe,” while Wikipedia goes for the more elaborate “a physical theory that describes how the universe expanded from an initial state of high density and temperature.” The first refers only to early times, while the latter seems to extend to subsequent times as well. The physicist and science writer Tony Rothman offers the pithier “the universe’s origin,” the theoretical physicist Thomas Hertog suggests that it is the “primeval state” of cosmic history, and a NASA website gives us “the idea that the universe began as just a single point.” These seem to refer to one moment at the start of things, rather than the universe’s life since then.
All of these sources (except NASA, unfortunately) capture something correct. The confusion stems both from the inherent ambiguity of using ordinary language to describe novel scientific concepts and from the state of modern cosmology itself. Cosmology is the study of the universe on the largest scales. So it ignores details of stars and planets, focusing on galaxies and even bigger structures, up to the universe as a whole. Modern cosmology is only about a century old, as it wasn’t until the 1920s that astronomers determined that our own Milky Way is just one of a large number of galaxies and the origin and evolution of them all could be studied together. And it wasn’t until the 1990s that the field matured into the one that exists today, featuring precision measurements and ultralarge datasets.
Dealing as it does with some of the most profound questions about the nature of the cosmos, cosmological research has always involved a vigorous give-and-take between rampant speculation and unanticipated discoveries. Its practitioners have long been fond of spinning purportedly inviolate physical principles from their personal intuitions about how reality should work. But cosmology remains an empirical science—a cherished belief can be quickly swept away by a solid measurement.
The present moment in the science of cosmology is one of consolidation, as we have successfully incorporated the lessons of some impressive discoveries made near the turn of the twenty-first century. Yet crucially important questions remain unanswered, especially about what exactly happened at the onset of the expanding space that evolved into our contemporary universe. It is therefore a good time for books that take stock of where we are and what might come next, and that illustrate which puzzles modern physicists choose to take seriously.
This much we know: we live in a galaxy, the Milky Way, containing around 200 billion stars. There are something like a trillion galaxies in our observable universe, distributed almost uniformly through space. Stars and galaxies condensed out of an originally nearly smooth distribution of matter. Distant galaxies are moving apart from one another. Extrapolating backward, we reach a hot, densely packed configuration about 13.8 billion years ago. We can observe the remnants of this early period in nearly uniform cosmic background radiation coming from every direction in the sky.
The Big Bang model is precisely this general picture, of a universe that expands and cools out of a smooth, hot primordial state. It is well understood and almost universally accepted among modern cosmologists. The Big Bang event is a hypothetical moment when the whole thing might have started, at which the temperature and density are supposed to have been literally infinite—a “singularity,” in physics parlance. This is why the NASA definition above is unambiguously wrong: the Big Bang event has nothing to do with “a single point” in space—it refers to a moment in time.
Nobody knows whether there actually was such an event. To be honest, there probably wasn’t. Einstein’s theory of general relativity predicts that such a singularity would have happened, but most physicists think this signals a breakdown in the theory rather than being an accurate description of the physical world. A prediction of infinitely big physical quantities is apt to be a sign that we don’t have the right theoretical understanding…
[Starting with Einstein’s unification of space-time in 1905, Carroll explains the implications of quantum theory, in particular on the question of the expansion of the universe. Using the three (very different, but complementary) books under consideration, he unpacks the issues and demonstrates the way in which scientific theories about the origin of the universe often involve a vigorous give-and-take between speculation and discovery…]
… Taken together, these three books provide an illuminating view of the state of modern cosmology. There are established results, laudable efforts to connect promising hypotheses to a flood of incoming data, and brave speculations about the physical and metaphysical unknown. They are all notably well written for the genre and will keep readers entertained as they are educated. We can marvel at both how much scientists have learned about the universe and how much we have yet to understand.
The state of cosmology (and a look at science at work): “A First Time for Everything,” from @seanmcarroll.bsky.social in @nybooks.com.
* Neil deGrasse Tyson
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As we wrestle with reality, we might spare a thought for a major (if, in the end, incorrect) character in tale that Carroll tells: Fred Hoyle; he died on this date in 2001. A prominent astronomer, he formulated the theory of stellar nucleosynthesis. But he is rather better remembered for his controversial stances on other scientific matters—in particular his rejection of the (as Carroll observes, now widely-accepted) “Big Bang” theory– a term he coined, derisively, in an episode of his immensely-popular series The Nature of the Universe on BBC radio– and his promotion of panspermia as the source of life on Earth (or maybe the traffic was in the other direction?).
“In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move.”*…
In the face of cosmologists who are trying to combine string theory with the theory of cosmic inflation to understand the universe-as-we-find-it, Neil Turok suggests a much simpler explanation. Frank Landymore reports…
Our understanding of the universe, as advanced as it is, remains riddled with paradoxes and huge question marks. Physicists have come up with some pretty heady ideas to explain them — we’ll get to those later — but there just might be a far “simpler” solution to all those holes in cosmology.
As Higgs Chair of Theoretical Physics at the University of Edinburgh Neil Turok explains in an essay for The Conversation, there could be a “mirror” universe that existed before the Big Bang and is a reflection of our own, moving backward in time.
It’s a trippy concept to wrap your head around, but simpler on the physics side of things. It would neatly balance out some of the asymmetries we observe in the universe, provide an answer to dark matter, and supplant some of what Turok would characterize as clumsier leading theories in cosmology, like cosmic inflation and string theory.
“Picturing the big bang as a mirror neatly explains many features of the universe which might otherwise appear to conflict with the most basic laws of physics,” wrote Turok, who published his team’s findings in the journal Annals of Physics. “The progress we have already made convinces me that, in all likelihood, there are alternatives to the standard orthodoxy — which has become a straitjacket we need to break out of.”
The physical laws of the universe should exhibit charge, parity, and time reversal — collectively known as CPT — symmetry, which essentially means every physical interaction can be mirrored. So to break down its implications: every particle should have an anti-particle of the opposite charge, every space has its inversion, and time can be reversed.
Except that’s not what we actually observe. Time only goes forward, and there are more particles than anti-matter particles. As far as we can tell, our universe is not symmetrical.
But: “Our mirror hypothesis restores the symmetry of the universe,” Turok argued. He compared it to looking at your reflection: “The combination of you and your mirror image are more symmetrical than you are alone.”
Extrapolating our universe backward in time through the Big Bang, “we found its mirror image, a pre-bang universe in which (relative to us) time runs backward and antiparticles outnumber particles,” Turok wrote.
This could also solve the mystery of dark matter, an invisible substance thought to make up 85 percent of all matter in the universe. Under the mirror hypothesis, weak, subatomic particles called neutrinos would be the ideal candidate to explain it.
Since we’ve only observed left-handed neutrinos, perhaps yet-unseen right-handed could even exist in the mirror universe.
What’s more, this could also tidily explain why the universe appears to be so uniform and flat. The prevailing theory is that a period of accelerated, faster-than-light expansion called cosmic inflation was responsible for shaping how the universe is today — but we’re yet to observe the large gravitational waves this would have produced.
With a handy mirror universe, however, “statistical arguments explain why the universe is flat and smooth and has a small positive accelerated expansion, with no need for cosmic inflation,” Turok wrote.
Of course, there’s a lot more needed to bear out this intriguing hypothesis. But Turok argues that, even if disproven, it demonstrates that there could be more straightforward explanations than what the Standard Model offers…
A mirror of our own, going backwards in time: “Physicist Says There’s Another Universe Hiding Behind the Big Bang,” from @futurism.
Turok’s full essay– longer and more detailed, but very accessible– is here.
* Douglas Adams, The Restaurant at the End of the Universe
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As we size up symmetry, we might send lofty birthday greetings to another ponderer of the cosmos, Carl Edward Sagan; he was born on this date in 1934. An astronomer, cosmologist, astrophysicist, astrobiologist (his contributions were central to the discovery of the high surface temperatures of Venus), he is best remembered as a popularizer of science– via books like The Dragons of Eden, Broca’s Brain and Pale Blue Dot, and the award-winning 1980 television series Cosmos: A Personal Voyage (which he narrated and co-wrote), the most widely-watched series in the history of American public television (seen by at least 500 million people across 60 different countries).
He is also remembered for his contributions to the scientific research of extraterrestrial life, including experimental demonstration of the production of amino acids from basic chemicals by radiation.
(Readers can enjoy a loving riff on Cosmos here.)
“It is clear that there is no classification of the Universe that is not arbitrary and full of conjectures. The reason for this is very simple: we do not know what kind of thing the universe is.”*…
… Still, scientists try. Ethan Siegel on the current state of play– with special attention to whether or not our cosmic landscape is endless or not, and why the Universe is so uniform on large scales, but so non-uniform on smaller scales…
13.8 billion years ago, our Universe as we know it began with the hot Big Bang, which gave rise to a primordial soup of particles and antiparticles that led to the planets, stars, and galaxies we know today. The hot Big Bang itself was set up by a preceding phase known as cosmic inflation, but only the final tiny fraction-of-a-second gets imprinted onto our observable Universe. What we can observe about the Universe is finite, but what about the unobservable parts that lie beyond it: are they finite or infinite? What the data can tell us is limited, but here’s what we think and why…
Read on to find out: “Is the Universe finite or infinite?” from @StartsWithABang in @bigthink.
* Jorge Luis Borges, in “The Analytical Language of John Wilkins”
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As we stargaze, we might send sunny birthday greetings to Herbert Friedman; he was born on this date in 1916. A physicist and astronomer, he made seminal contributions to the study of solar radiation. Friedman joined the Naval Research Laboratory in 1940 and developed defense-related radiation detection devices during WW II. In 1949, he obtained the first scientific proof that X rays emanate from the sun, when he directed the firing into space of a V-2 rocket carrying a detecting instrument. Through subsequent rocket astronomy, he also produced the first ultraviolet map of celestial bodies, and gathered information for the theory that stars are being continuously formed, on space radiation affecting Earth, and on the nature of gases in space. Friedman also made fundamental advances in the application of x rays to material analysis.
“A time will come when men will stretch out their eyes. They should see planets like our Earth.”*…
Not long ago the search for extraterrestrials was considered laughable nonsense. Today, as Adam Frank explains, it’s serious and scientific…
Suddenly, everyone is talking about aliens. After decades on the cultural margins, the question of life in the Universe beyond Earth is having its day in the sun. The next big multibillion-dollar space telescope (the successor to the James Webb) will be tuned to search for signatures of alien life on alien planets and NASA has a robust, well-funded programme in astrobiology. Meanwhile, from breathless newspaper articles about unexplained navy pilot sightings to United States congressional testimony with wild claims of government programmes hiding crashed saucers, UFOs and UAPs (unidentified anomalous phenomena) seem to be making their own journey from the fringes.
What are we to make of these twin movements, the scientific search for life on one hand, and the endlessly murky waters of UFO/UAP claims on the other? Looking at history shows that these two very different approaches to the question of extraterrestrial life are, in fact, linked, but not in a good way. For decades, scientists wanting to think seriously about life in the Universe faced what’s been called the ‘giggle factor’, which was directly related to UFOs and their culture. More than once, the giggle factor came close to killing off the field known as SETI (the search for extraterrestrial intelligence). Now, with new discoveries and new technologies making astrobiology a mainstream frontier of astrophysics, understanding this history has become important for anyone trying to understand what comes next. But for me, as a researcher in the field of technosignatures (signs of advanced alien tech) – the new face of SETI – getting past the giggle factor poses an existential challenge.
I am the principal investigator of NASA’s first ever grant to study signatures of intelligent life from distant exoplanets. My colleagues and I are tasked with developing a library of technosignatures or evidence of technology-wielding life forms on distant planets. Taking on that role has been the culmination of a lifetime fascination with the question of life and the Universe, a fascination that formed when I was a kid in the 1970s, drinking deep from the well of science fiction novels, UFO documentaries and Star Trek reruns. Early on, as a teenager reading both Carl Sagan and Erich von Däniken (the author of Chariots of the Gods), I had to figure out how to separate the wheat from the chaff. This served as a kind of training ground for dealing with questions facing me and my colleagues about proper standards of evidence in astrobiology. It’s also why, as a public-facing scientist, I must work to understand how people not trained in science come to questions surrounding UFOs as aliens. That is what drove me, writing a recent popular-level account of astrobiology’s frontiers called The Little Book of Aliens (2023), to stare hard into the entangled history of UFOs, the scientific search for life beyond Earth, and the all-important question of standards of evidence…
[Frank explains the efforts underway, their history, and the rigor being applied in sifting for credible evidence…]
… With the giggle factor receding for the scientific search for life, where does that leave UFOs and UAPs? There, the waters remain muddied. It is a good thing that pilots feel they can report sightings without fear of reprisal as a matter of air safety and national defence. And an open, transparent and agnostic investigation of UAPs could offer a masterclass in how science goes about its business of knowing rather than just believing. In The Little Book of Aliens, I even explained how such an investigation might be conducted (the recent NASA UAP panel and the Galileo Project are exploring these kinds of options). But if my colleagues and I claimed we’d found life on another world, we’d be required to provide evidence that meets the highest scientific standards. While we should let future studies lead us where they may, there is simply no such evidence surrounding UFOs and UAPs that meets these standards today. In fact, at a recent hearing conducted by NASA’s UAP panel, it was revealed that government studies show only a small percentage of reported sightings failed to find a reasonable explanation. Many of the remaining cases did not have enough data to even begin an attempt at identification. The sky is simply not awash in unexplained phenomena.
In the end, what matters is that, after thousands of years of arguing over opinions about life in the Universe, our collective scientific efforts have taken us to the point where we can finally begin a true scientific study of the question. The next big space telescope NASA is planning will be called the Habitable Worlds Observatory. The name tells you all you need to know. We’re going all in on the search for life in the Universe because we finally have the capabilities to search for life in the Universe. The giggle factor is finally history.
How UFOs almost killed the search for life in the universe: “Alien life is no joke,” from @AdamFrank4 in @aeonmag.
For more on a related field, see Astrobiology (@carnegiescience)
Also apposite (and typically for him, both informative and very amusing): John Oliver on UFOs
* the foresightful Christopher Wren
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As we look up, we might recall that it was on this date in 1930 that Pluto was announced to be the name chosen for the newly-discovered ninth planet (previously known as Planet X) by Roger Lowell Putnam, trustee of Lowell Observatory, Flagstaff, Arizona, (and nephew of the late Percival Lowell who had established the observatory and initiated the search there for the ninth planet). Pluto had been located there on in February of that year at that institution by Clyde Tombaugh.
Putnam was quoted on the front page of the New York Times, saying, “We felt in making our choice of a name for Planet X, that the line of Roman gods for whom the other planets are named should not be broken, and we believe that Dr. Lowell, whose researches led directly to its discovery, would have felt the same way.” Pluto in mythology was the ruler of the underworld, regions of darkness. “P.L.” is also Lowell’s monogram.
While it’s still known as Pluto, in 2006 the International Astrophysical Union demoted it from a “planet” to a “dwarf planet.”
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