Archive for Universe

Hawking and the Mind of God

Posted in Books, Talks and Reviews, Science Politics, The Universe and Stuff with tags , , , , , on March 3, 2021 by telescoper

There’s a new book out about Stephen Hawking which has triggered a certain amount of reaction (see, e.g., here) so I thought I’d mention a book I wrote, largely in response to the pseudo-religious nature of some of Hawking’s later writings.

I have in the past gone on record, both on television and in print, as being not entirely positive about the “cult” that surrounds Stephen Hawking. I think a number of my colleagues have found some of my comments disrespectful and/or churlish. I do nevertheless stand by everything I’ve said. I have enormous respect for Hawking the physicist, as well as deep admiration for his tenacity and fortitude, and have never said otherwise. I don’t, however, agree that Hawking is in the same category of revolutionary thinkers as Newton or Einstein, which is how he is often portrayed.

In fact a poll of 100 theoretical physicists in 1999 came to exactly the same conclusion. The top ten in that list were:

  1. Albert Einstein
  2. Isaac Newton
  3. James Clerk Maxwell
  4. Niels Bohr
  5. Werner Heisenberg
  6. Galileo Galilei
  7. Richard Feynman
  8. Paul Dirac
  9. Erwin Schrödinger
  10. Ernest Rutherford

The idea of a league table like this is of course a bit silly, but it does at least give some insight into the way physicists regard prominent figures in their subject. Hawking came way down the list, in fact, in 300th (equal) place. I don’t think it is disrespectful to Hawking to point this out. I’m not saying he isn’t a brilliant physicist. I’m just saying that there are a great many other brilliant physicists that no one outside physics has ever heard of.

It is interesting to speculate what would have happened if the list had been restricted to living physicists. I’d guess Hawking would be in the top ten, but I’m not at all sure where…

And before I get accused of jealousy about Stephen Hawking’s fame, let me make it absolutely clear that if Hawking was like a top Premiership footballer (which I think is an appropriate analogy), then I am definitely like someone kicking a ball around for a pub team on a Sunday morning (with a hangover). This gulf does not make me envious; it just makes me admire his ability all the more, just as trying to play football makes one realise exactly how good the top players really are.

I am not myself religious but I do think that there are many things that science does not – and probably will never – explain, such as why there is something rather than nothing. I also believe that science and religious belief are not in principle incompatible – although whether there is a conflict in practice does depend of course on the form of religious belief and how it is observed. God and physics are in my view pretty much orthogonal. To put it another way, if I were religious, there’s nothing in theoretical physics that would change make me want to change my mind. However, I’ll leave it to those many physicists who are learned in matters of theology to take up the (metaphorical) cudgels with Professor Hawking.

Anyway, this is the book I wrote:.

And here is the jacket blurb:

Stephen Hawking has achieved a unique position in contemporary culture, combining eminence in the rarefied world of theoretical physics with the popular fame usually reserved for film stars and rock musicians. Yet Hawking’s technical work is so challenging, both in its conceptual scope and in its mathematical detail, that proper understanding of its significance lies beyond the grasp of all but a few specialists. How, then, did Hawking-the-scientist become Hawking-the-icon? Hawking’s theories often take him into the intellectual territory that has traditionally been the province of religion rather than science. He acknowledges this explicitly in the closing sentence of his bestseller, A Brief History of Time , where he says that his ultimate aim is to know the Mind of God . Hawking and the Mind of God examines the pseudo-religious connotations of some of the key themes in Hawking’s work, and how these shed light not only on the Hawking cult itself, but also on the wider issue of how scientists represent themselves in the media.

I’m sure you’ll understand that there isn’t a hint of opportunism in the way I’m drawing this to your attention because my book is long out of print so you can’t buy it unless you get a copy second-hand…

Fine-tuning in Cosmology

Posted in The Universe and Stuff with tags , , , , , on March 25, 2019 by telescoper

I forgot to post a link to a paper by Fred Adams that appeared on the arXiv last month on the topic of the fine-tuning of the Universe which I had bookmarked for a blog a while ago.

My heart always sinks when the arXiv informs me that the abstract of a paper is `abridged’ so here’s the full version from the PDF you can download for yourself here. Please be aware, though, that it’s a lengthy paper running to over two hundred pages:

My own view on this topic is that it is indeed remarkable that the Universe is finely-tuned to exactly the extent required to allow authors to write such long papers about the fine-tuning of the Universe…

 

What is a Galaxy?

Posted in The Universe and Stuff with tags , , , , , , on January 19, 2011 by telescoper

An interesting little paper by Duncan Forbes and  Pavel Kroupa appeared today on the arXiv today. It asks what you would have thought was the rather basic question “What is a Galaxy?”. Like many basic questions, however, it turns out to be much  more complicated than you imagined.

Ask most people what they think a galaxy is and they’ll think of something like Andromeda (or M31), shown on the left, with its lovely spiral arms. But galaxies exist in many different types, which have quite different morphologies, dynamical properties and stellar populations.

The paper by Forbes and Kroupa lists examples of definitions from technical articles and elsewhere. The Oxford English Dictionary, for instance, gives

Any of the numerous large groups of stars and other
matter that exist in space as independent systems.

I suppose that is OK, but isn’t very  precise. How do you define “independent”, for example? Two galaxies orbiting in a binary system aren’t independent, but you would still want to count them as two galaxies rather than one. A group or cluster of galaxies is likewise not a single large galaxy, at least not by any useful definition. At the other extreme, what about a cluster of stars or even a binary star system? Why aren’t they regarded as gaaxies too? They are (or can be) gravitationally bound..

Clearly we have a particular size in mind, but even if we restrict ourselves to “galaxy-sized” objects we still have problems. Why is a globular cluster not a small galaxy while a dwarf galaxy is?

To be perfectly honest, I don’t really care very much about nomenclature. A rose by any other name would smell as sweet, and a galaxy by any other name would be just as luminous. What really counts are the physical properties of the various astronomical systems we find because these are what have to be explained by astrophysicists.

Perhaps it would be better to adopt Judge Potter Stewart‘s approach. Asked to rule on an obscenity case, he wrote that hard-core pornography was difficult to define, but ” I know it when I see it”….

As a cosmologist I tend to think that there’s only one system that really counts – the Universe, and galaxies are just bits of the Universe where stars seemed to have formed and organised themselves into interesting shapes. Galaxies may be photogenic, nice showy things for impressing people, but they aren’t really in themselves all that important in the cosmic scheme of things. They’re just the Big Bang’s bits of bling.

I’m not saying that galaxies aren’t extremely useful for telling us about the Universe; they clearly are. They shed light (literally) on a great many things that we wouldn’t otherwise have any clue about. Without them we couldn’t even have begun to do cosmology, and they still provide some of the most important evidence in the ongoing investigation of the the nature of the Universe. However, I think what goes on in between the shiny bits is actually much more interesting from the point of view of fundamental physics than the shiny things themselves.

Anyway, I’m rambling again and I can hear the observational astronomers swearing at me through their screens, so let me move on to the fun bit of the paper I was discussing, which is that the authors list a number of possible definitions of a galaxy and invite readers to vote.

For your information, the options (discussed in more detail in the paper) for the minimum criteria to define a galaxy are:

  • The relaxation time is greater than the age of the Universe
  • The half-light radius is greater than 10 parsecs
  • The presence of complex stellar systems
  • The presence of dark matter
  • Hosts a satellite stellar system

I won’t comment on the grammatical inconsistency of these statements. Or perhaps I just did. I’m not sure these would have been my choices either, but there you are. There’s an option to add your own criteria anyway.

The poll can be found here.

Get voting!

UPDATE: In view of the reaction some of my comments have generated from galactic astronomers I’ve decided to add a poll of my own, so that readers of this blog can express their opinions in a completely fair and unbiased way:


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Hawking and the Mind of God

Posted in Books, Talks and Reviews, Science Politics, The Universe and Stuff with tags , , , , , on September 2, 2010 by telescoper

I woke up this morning to the news that, according to Stephen Hawking, God did not create the Universe but it was instead an “inevitable consequence of the Law of Physics”. By sheer coincidence this daft pronouncement has come out at the same time as the publication of Professor Hawking’s new book, an extract of which appears in todays Times.

It’s interesting that such a fatuous statement managed to become a lead item on the radio news and a headline in all the national newspapers despite being so obviously devoid of any meaning whatsoever. How can the Universe be  “a consequence” of the theories that we invented to describe it? To me that’s just like saying that the Lake District is a consequence of an Ordnance Survey map. And where did the Laws of Physics come from, if not from God?

Stephen Hawking is undoubtedly a very brilliant theoretical physicist. However, something I’ve noticed about theoretical physicists over the years is that if you get them talking on subjects outside physics they are generally likely to say things just as daft as some drunk bloke  down the pub. I’m afraid this is a case in point.

Part of me just wants to laugh this story off, but another part is alarmed at what must appear to many to be an example of an arrogant scientist presuming to pass judgement on subjects that are really none of his business. When scientists complain about the lack of enthusiasm shown by sections of the public towards their subject, perhaps they should take seriously the alienating effect that such statements can have. This kind of thing isn’t what I’d call public engagement. Quite the opposite, in fact.

In case anyone is interested, I am not religious but I do think that there are many things that science does not – and probably will never –  explain, such as why there is  something rather than nothing. I also believe that science and religious belief are not in principle incompatible – although whether there is a conflict in practice does depend of course on the form of religious belief and how it is observed. God and physics are in my view pretty much orthogonal. To put it another way,  if I were religious, there’s nothing in theoretical physics that would change make me want to change my mind. However, I’ll leave it to those many physicists who are learned in matters of theology to take up the (metaphorical) cudgels with Professor Hawking.

No doubt this bit of publicity will increase the sales of the new book, so I’ve decided  to point out that I have  written a book myself on precisely this question, which is available from all good airports bookshops. I’m sure you’ll understand that there isn’t a hint of opportunism in the way I’m drawing this to your attention. If you think this is a cynical attempt to cash in then all I can say is

BUY MY BOOK!

I also noticed that today’s Grauniad is offering a poll on the existence or non-existence of God. I noticed some time ago that there’s a poll facility on WordPress, so this gives me an excuse to try repeating it here. Anything dumb the Guardian can do, I can do dumber. However, owing to funding cuts I’ve decided to do a single poll encompassing several topical news stories at the same time.


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