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Posts Tagged ‘Big Bang

“I’m sure the universe is full of intelligent life. It’s just been too intelligent to come here.”*…

 

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The Fermi paradox, named for physicist Enrico Fermi, is the apparent contradiction between the lack of evidence for extraterrestrial civilizations and various high estimates for their probability (e.g., some of the optimistic estimates for the Drake equation).  Fermi wondered, “where are they?”

By way of context, Tim Urban in his wonderful Wait But Why?:

As many stars as there are in our galaxy (100 – 400 billion), there are roughly an equal number of galaxies in the observable universe—so for every star in the colossal Milky Way, there’s a whole galaxy out there. All together, that comes out to the typically quoted range of between 1022 and 1024 total stars, which means that for every grain of sand on every beach on Earth, there are 10,000 stars out there.

The science world isn’t in total agreement about what percentage of those stars are “sun-like” (similar in size, temperature, and luminosity)—opinions typically range from 5% to 20%. Going with the most conservative side of that (5%), and the lower end for the number of total stars (1022), gives us 500 quintillion, or 500 billion billion sun-like stars.

There’s also a debate over what percentage of those sun-like stars might be orbited by an Earth-like planet (one with similar temperature conditions that could have liquid water and potentially support life similar to that on Earth). Some say it’s as high as 50%, but let’s go with the more conservative 22% that came out of a recent PNAS study. That suggests that there’s a potentially-habitable Earth-like planet orbiting at least 1% of the total stars in the universe—a total of 100 billion billion Earth-like planets.

So there are 100 Earth-like planets for every grain of sand in the world. Think about that next time you’re on the beach.

Moving forward, we have no choice but to get completely speculative. Let’s imagine that after billions of years in existence, 1% of Earth-like planets develop life (if that’s true, every grain of sand would represent one planet with life on it). And imagine that on 1% of those planets, the life advances to an intelligent level like it did here on Earth. That would mean there were 10 quadrillion, or 10 million billion intelligent civilizations in the observable universe.

Moving back to just our galaxy, and doing the same math on the lowest estimate for stars in the Milky Way (100 billion), we’d estimate that there are 1 billion Earth-like planets and 100,000 intelligent civilizations in our galaxy.1

SETI (Search for Extraterrestrial Intelligence) is an organization dedicated to listening for signals from other intelligent life. If we’re right that there are 100,000 or more intelligent civilizations in our galaxy, and even a fraction of them are sending out radio waves or laser beams or other modes of attempting to contact others, shouldn’t SETI’s satellite dish array pick up all kinds of signals?

But it hasn’t. Not one. Ever…

Perhaps. as we’ve mused here at (R)D before, life is there, but we’re not seeing it because it isn’t a form of life that we recognize: c.f., “Two possibilities exist: Either we are alone in the Universe or we are not. Both are equally terrifying” and “That is a very Earthling question to ask, Mr. Pilgrim.”

But there are some who’ve refused to give up on the search for more traditionally-defined life; indeed, a new study quantifies the “fraction” (to which Urban alludes, above) of civilizations that could (should?) be communicating around our galaxy:

One of the biggest and longest-standing questions in the history of human thought is whether there are other intelligent life forms within our Universe. Obtaining good estimates of the number of possible extraterrestrial civilizations has however been very challenging.

A new study led by the University of Nottingham and published [earlier this month] in The Astrophysical Journal has taken a new approach to this problem. Using the assumption that intelligent life forms on other planets in a similar way as it does on Earth, researchers have obtained an estimate for the number of intelligent communicating civilizations within our own galaxy -the Milky Way. They calculate that there could be over 30 active communicating intelligent civilizations in our home Galaxy…

Details at (the slightly misleadingly-titled): “Research sheds new light on intelligent life existing across the galaxy.”

* Arthur C. Clarke

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As we stay tuned, we might send far-seeing birthday greeting to Fred Hoyle; he was born on this date in 1915.  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 “Big Bang” theory (a term he coined, derisively, in one 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.

220px-Fred_Hoyle source

 

Written by LW

June 24, 2020 at 1:01 am

“Nothing happens until something moves”*…

 

Universe

 

What determines our fate? To the Stoic Greek philosophers, fate is the external product of divine will, ‘the thread of your destiny’. To transcendentalists such as Henry David Thoreau, it is an inward matter of self-determination, of ‘what a man thinks of himself’. To modern cosmologists, fate is something else entirely: a sweeping, impersonal physical process that can be boiled down into a single, momentous number known as the Hubble Constant.

The Hubble Constant can be defined simply as the rate at which the Universe is expanding, a measure of how quickly the space between galaxies is stretching apart. The slightest interpretation exposes a web of complexity encased within that seeming simplicity, however. Extrapolating the expansion process backward implies that all the galaxies we can observe originated together at some point in the past – emerging from a Big Bang – and that the Universe has a finite age. Extrapolating forward presents two starkly opposed futures, either an endless era of expansion and dissipation or an eventual turnabout that will wipe out the current order and begin the process anew.

That’s a lot of emotional and intellectual weight resting on one small number…

How scientists pinned a single number on all of existence: “Fate of the Universe.”

[Readers might remember that the Big Bang wasn’t always an accepted paradigm— and that on-going research continues to surface challenges.]

* Albert Einstein

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As we center ourselves, we might spare a thought for Kurt Friedrich Gödel; he died on this date in 1978.  A  logician, mathematician, and philosopher, he is considered (along with Aristotle, Alfred Tarski— whose birthday this also is– and Gottlob Frege) to be one of the most important logicians in history.  Gödel had an immense impact upon scientific and philosophical thinking in the 20th century.  He is, perhaps, best remembered for his Incompleteness Theorems, which led to (among other important results) Alan Turing’s insights into computational theory.

Kurt Gödel’s achievement in modern logic is singular and monumental – indeed it is more than a monument, it is a landmark which will remain visible far in space and time. … The subject of logic has certainly completely changed its nature and possibilities with Gödel’s achievement.                  — John von Neumann

kurt_gödel source

 

“Life can only be understood backwards; but it must be lived forwards”*…

 

If you wanted to hear the future in late May, 1968, you might have gone to Abbey Road to hear the Beatles record a new song of John Lennon’s—something called “Revolution.” Or you could have gone to the decidedly less fab midtown Hilton in Manhattan, where a thousand “leaders and future leaders,” ranging from the economist John Kenneth Galbraith to the peace activist Arthur Waskow, were invited to a conference by the Foreign Policy Association. For its fiftieth anniversary, the F.P.A. scheduled a three-day gathering of experts, asking them to gaze fifty years ahead. An accompanying book shared the conference’s far-off title: “Toward the Year 2018”…

More amazing than science fiction,” proclaims the cover, with jacket copy envisioning how “on a summer day in the year 2018, the three-dimensional television screen in your living room” flashes news of “anti-gravity belts,” “a man-made hurricane, launched at an enemy fleet, [that] devastates a neutral country,” and a “citizen’s pocket computer” that averts an air crash. “Will our children in 2018 still be wrestling,” it asks, “with racial problems, economic depressions, other Vietnams?”

Much of “Toward the Year 2018” might as well be science fiction today. With fourteen contributors, ranging from the weapons theorist Herman Kahn to the I.B.M. automation director Charles DeCarlo, penning essays on everything from “Space” to “Behavioral Technologies,” it’s not hard to find wild misses. The Stanford wonk Charles Scarlott predicts, exactly incorrectly, that nuclear breeder reactors will move to the fore of U.S. energy production while natural gas fades. (He concedes that natural gas might make a comeback—through atom-bomb-powered fracking.) The M.I.T. professor Ithiel de Sola Pool foresees an era of outright control of economies by nations—“They will select their levels of employment, of industrialization, of increase in GNP”—and then, for good measure, predicts “a massive loosening of inhibitions on all human impulses save that toward violence.” From the influential meteorologist Thomas F. Malone, we get the intriguing forecast of “the suppression of lightning”—most likely, he figures, “by the late 1980s.”

But for every amusingly wrong prediction, there’s one unnervingly close to the mark…

Those uncannily-accurate predictions, and their backstories, at “The 1968 book that tried to predict the world of 2018.”

* Søren Kierkegaard

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As we ponder posterity, we might send static-y birthday greetings to Robert Woodrow Wilson; he was born on this date in 1936.  An astronomer, he detected– with Bell Labs colleague Arno Penzias– cosmic microwave background radiation: “relic radiation”– that’s to say. the “sound “– of the Big Bang.  Their 1964 discovery earned them the 1978 Nobel Prize in Physics.

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“When physicists say ‘we don’t understand what’s going on here,’ they really, really mean it”*…

 

Theoretical physicists and cosmologists deal with the biggest questions, like “Why are we here?” “When did the universe begin?” and “How?” Another questions that bugs them, and likely has bugged you, is “What happened before the Big Bang?”

To be perfectly clear, we can’t definitively answer this question—but we can speculate wildly, with the help of theoretical physicist Sean Carroll from the California Institute of Technology. Carroll gave a talk last month at the bi-annual meeting of the American Astronomical Society in Grapevine, Texas, where he walked through several pre-Bang possibilities that would result in a universe like ours…

Consider the options at: “What Was Our Universe Like Before the Big Bang?

* Theoretical physicist Peter Woit, Columbia University

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As we scrutinize the singularity, we might spare a thought for E. E. Barnard; he died on this date in 1923. Recognized as a gifted observational astronomer, he is probably best known for his discovery of the high proper motion of Barnard’s Star in 1916, which is named in his honor.  But, drawing on his experience as a photographer’s assistant in his adolescence (and building on the work of John William Draper), Barnard also contributed mightily to the development of celestial photography.

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Written by LW

February 6, 2017 at 1:01 am

“Widespread public access to knowledge, like public education, is one of the pillars of our democracy, a guarantee that we can maintain a well-informed citizenry”*…

 

Top Row (left to right): André Breton; Buster Keaton; László Moholy-Nagy   Middle Row (left to right): Gertrude Stein; H. G. Wells; Frank O’Hara; Alfred Stieglitz   Bottom Row (left to right): Evelyn Waugh; D. T. Suzuki; Paul Nash; Mina Loy

Via Public Domain Review

Pictured above is our top pick of those whose works will, on 1st January 2017, enter the public domain in many countries around the world. Of the eleven featured, five will be entering the public domain in countries with a “life plus 70 years” copyright term (e.g. most European Union members, Brazil, Israel, Nigeria, Russia, Turkey, etc.) and six in countries with a “life plus 50 years” copyright term (e.g. Canada, New Zealand, and many countries in Asia and Africa) — those that died in the year 1946 and 1966 respectively. As always it’s a varied gaggle who’ve assembled for our graduation photo, including the founder of the Surrealist movement, a star of the silent film era, the Japanese author behind the popularisation of Buddhism in the West, two female writers at the heart of the Modernist scene, and one of the “fathers of science fiction”…

More on each of the “graduates” at Class of 2017.

* Scott Turow, attorney, author, President of the Author’s Guild

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As we share and share alike, we might send foresightful birthday greetings to Erasmus Darwin; he was born on this date in 1731.  Erasmus was an accomplished doctor (he declined an offer to be personal physician to Charles III).  He was also a restless inventor, devising both a copying machine and a speaking machine to impress his friends (inventions he shared rather than patenting). But he is better remembered as a key thinker in the “Midlands Enlightenment”– a founder of the Lunar Society of Birmingham and author of (among other works) The Botanic Garden, a poem that anticipates the Big Bang theory in its description of an explosion, a “mass” which “starts into a million suns,” and Zoonomia, or, The Laws of Organic Life, which contained one of the first formal theories of evolution… one that foreshadowed the theories of Erasmus’ reader– and grandson– Charles… all of which are in the public domain.

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