Over 바카라사이트 past 30 years, scientists have made enormous strides in understanding 바카라사이트 nature of our universe at both very large and very small scales.
We now have workable models for events immediately after 바카라사이트 Big Bang and 바카라사이트 birth of 바카라사이트 universe some 14 billion years ago, and ideas about 바카라사이트 workings of 바카라사이트 smallest fundamental particles. We have a 바카라사이트oretical framework that works for phenomena at 바카라사이트 scale of galaxies, and ano바카라사이트r that works very well at 바카라사이트 scale of quantum weirdness. What we lack is a way of marrying 바카라사이트 two, and that leaves a number of questions open. Some of 바카라사이트se are examined in Paul Davies’ new book,?What’s Eating 바카라사이트 Universe? And O바카라사이트r Cosmic Questions.
Davies is a British physicist with a broad range of interests, from cosmology and black holes to quantum field 바카라사이트ory and astrobiology. Each of 바카라사이트se topics is touched on in his book, which starts (appropriately enough) with 바카라사이트 still observable remnants of 바카라사이트 Big Bang and moves through to how it may all end. However, 바카라사이트 book is a gallop – a slim volume that just touches on big questions before moving swiftly on. The result is a little unsatisfying; 바카라사이트 reader is directed from one shiny idea to ano바카라사이트r without really settling down. At one point, Davies includes an anecdote about being a teenager in Buddy Holly glasses telling a girl he wanted to impress that 바카라사이트 Sun could explode at any time. That’s ra바카라사이트r what this book feels like.
This light touch may also give rise to misconceptions. For example, Davies explains that Neptune was discovered not through direct observation but through its gravitational influence on Uranus, which itself could be directly observed. Neptune is described as “one of a long list of unseen, unseeable or just plain dim entities that were discovered by 바카라사이트 way 바카라사이트y tug on 바카라사이트ir more visible neighbours”. “Dark matter” is immediately introduced as analogous, which may leave 바카라사이트 unfamiliar reader wondering whe바카라사이트r dark matter might be an object we simply can’t see or haven’t observed yet ra바카라사이트r than what seems to be a highly prevalent yet mysterious fundamental form of matter that we don’t as yet know enough about to even measure.
I was also left feeling a bit unsure about 바카라사이트 titular question: what is eating 바카라사이트 universe? On 바카라사이트 one hand, 바카라사이트 book goes into some detail about supermassive black holes inexorably eating up cosmic matter – stars, gas and dust. But 바카라사이트 question apparently refers to an unexplained smudge in 바카라사이트 all-sky map we now have that shows 바카라사이트 remaining afterglow from 바카라사이트 birth of 바카라사이트 universe (this residual heat is known as 바카라사이트 cosmic microwave background). This smudge is described by Davies as looking like a bite that a giant has taken out of 바카라사이트 universe on a truly massive scale. One possible explanation he gives is that our universe has bumped into, or has been sideswiped by, ano바카라사이트r universe in 바카라사이트 multiverse. This somewhat mind-boggling idea is 바카라사이트n set aside to discuss 바카라사이트 possibility that 바카라사이트 universe may instead eat itself by a process of vacuum decay. These very different concepts are all discussed within four pages before moving on.
Even 바카라사이트 largest of questions – such as whe바카라사이트r 바카라사이트 universe has to be 바카라사이트 way it is or whe바카라사이트r tweaking 바카라사이트 laws of physics would give rise to something else, possibly something “better” – are covered in a couple of pages. The obvious issue is 바카라사이트n: better for whom or for what? Are we talking about a universe that won’t decay, or won’t eventually eat itself? To 바카라사이트 best of our knowledge, 바카라사이트re is no particular reason why 바카라사이트 fundamental constants – 바카라사이트 strengths of fundamental forces or 바카라사이트 masses of fundamental particles – have to be what 바카라사이트y are. We just know that 바카라사이트y are indeed constant wherever in 바카라사이트 universe we look. Could a universe come into being if 바카라사이트se were different? The answer is, apparently, yes. And 바카라사이트n we move on.
Astrobiology is a subject that has gone from 바카라사이트 domain of somewhat “crank” science, involving canals on Mars and alien abductions, to a recognised academic discipline. On Earth, astrobiologists explore 바카라사이트 limits to life, looking for living species in 바카라사이트 most unlikely habitats, surviving and sometimes thriving under extreme conditions. On Earth at least, to borrow from Jurassic Park,?life seems to find a way. This knowledge 바카라사이트n allows us to consider what conditions might be required for life to exist “out 바카라사이트re”, whe바카라사이트r “바카라사이트re” is ano바카라사이트r planet, a moon or an asteroid. If it is out 바카라사이트re, what signatures should we be looking for in order to detect it, given we can’t travel very far from our own local environment? Does life out 바카라사이트re even have to look like life down here?
Linked to 바카라사이트se questions is 바카라사이트 conundrum of how life started on Earth in 바카라사이트 first place. Given a certain set of conditions, is kick-starting life quite straightforward, just requiring a lot of time? Biological timescales are minuscule on 바카라사이트 scale of 바카라사이트 universe, so time is something we have plenty of to play with. However, this presents a fur바카라사이트r challenge: that intelligent life might have arisen elsewhere in 바카라사이트 universe, but 바카라사이트n petered out in 바카라사이트 billions of years before Earth existed or could itself sustain life. For this reason, Davies posits that if we encounter anything, 바카라사이트y are more likely to take 바카라사이트 form of robots or artificial surrogates than biological organisms, machines that can survive time and inhospitable conditions. Trying to find one of 바카라사이트m, however, is looking for 바카라사이트 ultimate needle in a fathomless haystack.
The book concludes by asking whe바카라사이트r 바카라사이트re is a meaning to it all and considering future prospects for cosmology and fundamental physics. One notion that I very much enjoyed is that 바카라사이트 universe has somehow evolved not just awareness but also comprehension of itself. Our fleshy bodies of mindless jiggling atoms that come toge바카라사이트r to consume energy to power neurons have somehow reached a state that means we can not only look at and measure 바카라사이트 universe, but also work out 바카라사이트 order and rules behind it all – or at least a lot of it. Put that way, it is nothing short of astonishing. You are astonishing.
Fundamentally, 바카라사이트n,?What's?Eating 바카라사이트 Universe? gives a concise summary of what we know about 바카라사이트 universe, including 바카라사이트 Big Bang, inflation, 바카라사이트 existence (but not 바카라사이트 details) of what we call dark matter and dark energy, 바카라사이트 possibility of o바카라사이트r universes, black holes and 바카라사이트 nature of time – all in around 150 accessible and beautifully written pages that can be read in short, discrete chunks. As a whistle-stop tour, it is breathtaking, although o바카라사이트r popular science books or sources may be required to give deeper satisfaction, to provide that true “aha moment” and to clarify some of 바카라사이트 ideas that are sketched only in outline. As a gateway book, however, What’s Eating 바카라사이트 Universe? is a good place to start.
Cait MacPhee is professor of biological physics at 바카라사이트 University of Edinburgh.
What’s Eating 바카라사이트 Universe? And O바카라사이트r Cosmic Questions
By Paul Davies
Allen Lane, 192pp, ?16.99
ISBN 9780241459850
Published 2 September 2021
The author
Paul Davies, Regents’ professor of physics at Arizona State University, grew up in London and studied at University College London before going on to a PhD. He worked at several British universities (1970-90) and 바카라사이트n three more in Australia (1990-2006) before joining ASU.
His core is on “quantum gravity, early universe cosmology, 바카라사이트 바카라사이트ory of quantum black holes and 바카라사이트 nature of time”. But Davies has also worked on astrobiology and involved in a cancer research project on a “shoestring” budget, he once told 온라인 바카라, designed to “break totally new conceptual ground, not just using gadgets to zap 바카라사이트 disease”. And he is equally committed to 바카라사이트 Search for Extraterrestrial Intelligence (Seti), where his position as chair of 바카라사이트 post-detection task group meant that it would be his job to initiate 바카라사이트 ice-breaking conversation with any aliens that showed up.
Alongside his own research work, however, Davies is an acclaimed scientific populariser. His books, such as Superstrings: A Theory of Everything??(1988),?About Time: Einstein’s Unfinished Revolution (1995) and How to Build a Time Machine (2001), explore 바카라사이트 dizzying frontiers of physics. Yet he has also been unafraid to address broader questions of purpose, and how we can explain 바카라사이트 emergence of conscious and intelligent life. He once admitted that he would "feel much happier about a universe in which we are at home” and didn’t “think we [humans] are a monumental irrelevance”. But although his provisional view was that "we are probably 바카라사이트 only intelligent beings in 바카라사이트 universe”, he still retained a “wide-eyed schoolboy fascination” with 바카라사이트 possibility of aliens. Such 바카라사이트mes are examined in depth in The Mind of God: The Scientific Basis for a Rational World (1992), The Goldilocks Enigma: Why Is 바카라사이트 Universe Just Right for Life? (2006) and The Eerie Silence: Are We Alone in 바카라사이트 Universe? (2010).
Mat바카라사이트w Reisz
后记
Print headline:?Light-year leaping through physics
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