Jim Al-Khalili's Website http://www.jimal-khalili.com The Website of Professor Jim Al-Khalili Mon, 06 Sep 2010 21:03:53 +0000 en hourly 1 New blog post: Do we have free will? http://www.jimal-khalili.com/news/new-blog-post-do-we-have-free-will.html http://www.jimal-khalili.com/news/new-blog-post-do-we-have-free-will.html#comments Mon, 06 Sep 2010 20:29:26 +0000 Jim Al-Khalili http://www.jimal-khalili.com/?p=826 Continue reading →]]> Here is the transcript of the second of my ‘Series 2′ sci-pods (which you can, if you prefer, download from this website or subscribe to for free via iTunes). In this blog I use physics rather than philosophy, metaphysics or theology to argue the case for free will.

[Read more..]

]]> http://www.jimal-khalili.com/news/new-blog-post-do-we-have-free-will.html/feed 0 Do we have free will? http://www.jimal-khalili.com/blog/free-will.html http://www.jimal-khalili.com/blog/free-will.html#comments Mon, 06 Sep 2010 20:05:23 +0000 Jim Al-Khalili http://www.jimal-khalili.com/?p=806 Continue reading →]]> Here is the transcript of the second of my ‘Series 2′ sci-pods (which you can, if you prefer, download from this website or subscribe to for free via iTunes). In this blog I use physics rather than philosophy, metaphysics or theology to argue the case for free will.

Well, it’s rather ambitious to cover adequately the whole subject of the nature of free in a blog, especially since we don’t yet have a clear consensus on whether we even HAVE free will. Scientists, philosophers and theologians, and for that matter, loads of other people too, have debated this subject for thousands of years. I’m going to focus here on some certain aspects of the nature of free will and its connection with my area of physics. I certainly won’t be straying into the realm of what’s called the mind-body problem or the nature of consciousness or the human soul.

Let’s start with the idea of determinism. Basically, a deterministic system is one for which, if you knew everything about it at a given moment in time, then you could, in principle compute what it will be doing at any time in the future. That is, the way it evolves in time is fully determined (hence ‘deterministic’). Isaac Newton showed with his laws of motion and gravity that our whole universe is deterministic – and this has been dubbed the Newtonian clockwork universe.

What has this got to do with free will? Well, since our physical brains are all ultimately made up of atoms and we are nothing more than the software of our brain (if you don’t like this last statement, tough, I stand by it) then those atoms obey the same laws of physics as the rest of the universe. So if we could, in principle, know the position of each atom in our brains and what it was doing at any given moment and we understood fully the rules that govern how they all interact and fit together to make up our brian cells, then we should (IN PRINICPLE – I am not saying this is ever going to be possible in practice) know the state of our brains at any time in the future. That is, I could predict what you will do, or think, next – provided of course you are not interacting with the outside world, otherwise I will need to know everything about that too.

So, basically, if we are part of Newton’s clockwork, deterministic universe, then all our actions are preordained and fixed in advance and we do not seem to have the freedom to choose.

So was Newton right? Well it sort of got worse when Einstein came along. His theory of relativity tells us that time and space are connected in a deep way and that time should really be considered as another dimension along with space to form 4-D spacetime. In this overall picture, called the block universe, time is just another axis, like the side of a box (only this box is one we cannot imagine as our brains cannot cope with that extra dimension. Basically, just as we can imagine a volume of space with all points in that volume coexisting, now we have to imagine all times (past, present moment and future) all frozen together. So it’s worse than Newton thought: it’s not just that the future is in principle ‘knowable’, but that it is already there waiting for our ‘now’ to move along the time axis to reach it. Bugger.

OK, so now along comes quantum physics, seemingly to the rescue. This is the theory of the subatomic world, where the rules of the game are fundamentally different to those in our everyday world. In fact, in the quantum domain, we discover real INDETERMINISM. That is, an atom might radioactively decay by spitting out an alpha particle, say. It turns out that we cannot, even in principle, predict when this might happen. Not because we have inadequate knowledge about that atom, but because the atom itself doesn’t know when this might happen. It’s not quite random of course, because we find that with a large number of identical atoms there is a statistical average that emerges. This is the half-life (the time it takes for exactly half the atoms in a sample to radioactively decay). So basically, the subatomic world is ruled not by certainties but by chance and probability.

OK, so does this quantum indeterminism rescue us from the bleak and fatalistic fixed future universe of Newton and Einstein? Some philosophers think so. They are wrong in my humble view. Quantum fuzziness, chance and probability all leak away very quickly before we can build up complex systems involving trillions of atoms. Of course there may be some features of the quantum world that have an effect in our macro world, after all, the reason the Sun shines is down to what’s called the quantum tunnelling effect whereby nuclei can fuse together to release energy. But on the whole, I still think that OUR world, the world of us, our brains and our free will is a deterministic one.

So, I ask again, do we have free will? The answer, despite what I have said about determinism, is yes, I believe we do. And it seems to have a lot to do with what is known as chaos theory. This is the idea that very tiny changes to the initial conditions of a system will quickly grow and lead to completely different outcomes – the famous butterfly effect. We see this most clearly in weather prediction. While we can now know with confidence what tomorrow’s weather will be, the further we try to look into the future, the more uncertain things become. More accurately, chaos theory states that, under certain conditions, applying the simple rules that govern how a completely deterministic system evolves, along with some feedback, can lead to chaotic behaviour. What is important is that such behaviour is not random, but just utterly unpredictable.

[As an aside, what is for me much more interesting is the flip side of chaos: that these same simple rules, applied repeatedly, can sometimes lead to beautiful and complex patterns emerging. Basically we can get order and structure where there was none before. You start with something without any structure, allow it to evolve and you spontaneously, without any external designer having a hand in it, start to see structure and patterns appearing.

In a way, this is how Darwinian evolution works. Nature starts with a basic life form or rudimentary organ, like the eye, applies simple rules (that it makes copies of itself but with the odd rare mutation that makes tiny changes) and repeats this over and over again. There is feedback in the form of the action of the environment that selects those mutations best suited to it. And what happens? Over billions of years we see complexity emerging spontaneously, without thought or design. Even human consciousness I think can be explained from an evolutionary perspective.]

Anyway, what has chaos theory and the butterfly effect have to do with free will? Well, it doesn’t matter that we live in a deterministic universe in which the future is, in principle, fixed. That future is only knowable if we were able to view the whole of space and time from the outside. Now you might be of the view, if you follow a monotheistic faith, that this is the perspective that God has. But, for us and our consciousnesses imbedded WITHIN spacetime, that future is NEVER knowable. For us, the future is open, the choices we make are real choices, and because of the butterfly effect, tiny changes brought about by different decisions we make, can lead to different outcomes – different futures.

So, thanks to chaos theory our future is never knowable to us. You might prefer to say that the future is preordained and that our free will is just an illusion, but the point is our actions still determine which of the infinite number of possible futures is the one that gets played out. God (if She’s out there) knows what we are going to do next, if you insist on Her necessary existence, but WE don’t and can never know. So we do have free will. QED.

]]> http://www.jimal-khalili.com/blog/free-will.html/feed 5 Blog post: nuclear physics funding http://www.jimal-khalili.com/news/new-blog-post-nuclear-physics-research.html http://www.jimal-khalili.com/news/new-blog-post-nuclear-physics-research.html#comments Tue, 31 Aug 2010 21:11:02 +0000 Jim Al-Khalili http://www.jimal-khalili.com/?p=797 Continue reading →]]> Next August, a large international conference will be held to celebrate the centenary of Lord Rutherford’s discovery of the atomic nucleus. It will take place in Manchester, the spiritual home of nuclear physics, where Rutherford carried out his pioneering work that marked the birth of the atomic age, and in doing so defined the course of the 20th century. [Read more..]

]]> http://www.jimal-khalili.com/news/new-blog-post-nuclear-physics-research.html/feed 0 A Nuclear Renaissance needs Nuclear Physicists http://www.jimal-khalili.com/blog/a-nuclear-renaissance-needs-nuclear-physicists.html http://www.jimal-khalili.com/blog/a-nuclear-renaissance-needs-nuclear-physicists.html#comments Tue, 31 Aug 2010 21:00:07 +0000 Jim Al-Khalili http://www.jimal-khalili.com/?p=782 Continue reading →]]> Next August, a large international conference will be held to celebrate the centenary of Lord Rutherford’s discovery of the atomic nucleus. It will take place in Manchester, the spiritual home of nuclear physics, where Rutherford carried out his pioneering work that marked the birth of the atomic age, and in doing so defined the course of the 20th century.

It is ironic that now, 100 years on, this still vibrant research discipline is in danger of being wiped out in the UK as the axe falls on public spending later this year. Of course, every Tom, Dick and Professor will be arguing loudly that their research field is exciting, important and hence deserving of continued funding. Why then should nuclear scientists’ cautionary warning over possible budget cuts be heard above anyone else’s?

Nuclear physics is not difficult to sell as a ‘sexy’ area of science. For at the forefront of research in the UK and around the world today are many exciting and challenging questions. One major goal of the subject is to synthesise and study all possible types of nuclei in what is being referred to as the nuclear genome project. This will help us better understand the nature of the ‘glue’ holding together over 99% of everything we see around us.

Another goal of nuclear physics is to understand the fundamental processes that take place in space. Every star shines because of the energy provided by nuclear reactions taking place inside it. It is also nuclear reactions that drive the spectacular stellar explosions seen as supernovas, which create nearly all of the chemical elements. It is a humbling thought that every one of us is literally made up of stardust.

However, nuclear physics is not just about curiosity driven research. Unlike many other disciplines, the work has direct societal benefits and applications, in healthcare, radiological protection and the nuclear industry; all require skilled scientists trained to a large extent by academic nuclear physicists. It is therefore a mystery why the UK funds nuclear physics research at the level of just 5% of that of France and Germany.

Maintaining a nuclear-skilled workforce means there is a great potential for the UK, since the current nuclear renaissance brought about by the need to curb the use of fossil fuels is a worldwide activity. Just look at France: their leading position as a provider and exporter of nuclear fission-generated electrical power has without doubt been underpinned by their funding of academic nuclear research.

The UK already has too small a group of academic nuclear physicists and further loss of active academic researchers will mean that the discipline, and the expertise, is lost from universities. From studying how stars shine to applying that knowledge to the development of new treatments for cancer, UK nuclear physics funding as a discipline – one that costs less than a tenth of the UK’s annual CERN subscription – cannot be allowed to disappear.

]]> http://www.jimal-khalili.com/blog/a-nuclear-renaissance-needs-nuclear-physicists.html/feed 1 More Quantum Musings and Olbers’ Paradox http://www.jimal-khalili.com/blog/more-quantum-musings-and-olbers-paradox.html http://www.jimal-khalili.com/blog/more-quantum-musings-and-olbers-paradox.html#comments Sat, 28 Aug 2010 12:39:20 +0000 Jim Al-Khalili http://www.jimal-khalili.com/?p=753 Continue reading →]]> After a longer break than planned, here’s more stream of consciousness. Firstly, I should say a big thank you to those who left comments or emailed me about my blog on quantum biology. Actually since writing it I have heard that one of my recently graduated students at Surrey has been successful in being awarded a Doctoral Training Centre studentship, which basically means he has funding for a PhD and gets to choose from a pool of research projects available in the Faculty. He has expressed interest in my project to study genetic mutations by modelling them as quantum systems undergoing quantum tunnelling.

I have been asked whether I think that quantum mechanics might be important in genetic mutations (that lead to the proliferation of cancer cells) because of an idea called quantum Darwinism, whereby a microscopic biological system (say the genome) can evolve quantum mechanically into a superposition of different states that all co-exist and where some states are more successful at replicating than others. Well, that’s one possibility, but you might think that within the warm, ‘noisy’ confines of the living cell nothing can behave quantum mechanically for long enough for such superpositions to persist, and that decoherence takes place too quickly – that is, the genome couples to its external environment and so the quantum weirdness leaks out a bit like the way heat leaks away from a warm object in a colder environment. But maybe, as Schroedinger suggested over 60 years ago, this happens more slowly than we might think – something to do with the special order brought about the low entropy state that is life.

Another possibility is that this decoherence, which can essentially be thought of as the environment ‘measuring’ the quantum system by interacting with it (coupling to it) can bring about what is known as a Zeno effect. That is, slowing down the quantum tunnelling process, or more speculatively, an anti-Zeno effect, which speeds up the quantum tunnelling process. My colleague in the Department, Paul Stevenson, and I published a paper a few years ago in which we show that this does indeed take place for the case of a one-dimensional wavepacket tunnelling through a square potential barrier (see left). Well, in certain genetic mutation what we have is a hydrogen bond breaking across one site and reforming somewhere else. In other words, a proton sitting in a potential well, quantum tunnels to a neighbouring one. This stuff is not new and there have been a number of papers in the past decade or two that have studied this.

Anyway, all very speculative at the moment, but the possibilities are so exciting that it is well worth the effort to investigate, and an ideal PhD project.

But, at the risk of making this a very long blog, what I really planned to do was transcribe my audio podcasts (“Jim Al-Khalili’s Sci-Pods” on iTunes) as blogs for those who would rather not listen to my voice droning on and prefer the written word. So, here goes. The following is the first of my ‘Series 2′ Sci-Pods and is a discussion of Olbers’ paradox and how it connects to a proof of the Big Bang itself. Enjoy.

Why is it dark at night?

I am often asked about what proof we have that the Big Bang actually happened; that 13.7 billion years ago the whole Universe suddenly came into existence out of absolutely nothing. In fact space and time themselves didn’t exist before the Big Bang. Well there are several pieces of compelling evidence that tell us this idea is correct. The first is the most convincing: that when we look out through our telescopes at distant galaxies, far beyond our own Milky Way, we see they are all rushing apart. And the further we look out the faster they seem to be moving away from us in every direction. This expansion of the Universe suggests it must have all started when everything was much closer together, in fact all squeezed into a single point.

The second piece of evidence is that outer space has a very specific temperature of around minus 270 degrees Centigrade. This is exactly the temperature it should be by now if it began with a Big Bang 13.7 billion years ago and has been cooling down ever since.

The third piece of evidence is proportion of the different chemical elements. Most of atoms in the Universe are hydrogen (the simplest atom), followed by helium. Between them they make up about 98% of all the stuff we can see. All other elements make up the remaining couple of percent. This can only really be explained with the Big Bang idea that in the early universe these two simplest elements were cooked but once it expanded and cooled the temperature dropped below what was needed for nuclear fusion to take place and all the other 90 elements in the periodic table had to wait to be synthesised inside stars.

But there is another often overlooked proof of the Big Bang that relies on simple logic – OK and a few calculations you will have to trust me on. It is sometimes referred to as Olbers’ paradox. Put simply: just ask the question: ‘why does it get dark at night?’

You might think that this is a rather trivial, even silly question to ask. After all, even a child ‘knows’ that this is because the Sun sets below the horizon, and since there is nothing else in the sky anywhere near as bright as the Sun we have to make do with the feeble reflected light from the Moon and even more feeble light from the distant stars. Well, guess what? It’s not as simple as that!

Olbers

We have good reason to believe that even if the Universe is not infinite in size (and it might be), it is so enormous that, for all intents and purposes, it does go on for ever. And so we come up against Olbers’ paradox. This states that the night sky has no right being dark at all. It should be even brighter than it normally gets during the day. In fact, the sky should be so bright, all the time, that it should not even matter whether the Sun is up in the sky or not.


Imagine you are standing in the middle of a very large forest. So large in fact that you can assume it is infinite in extent. Now try shooting an arrow horizontally such that it does not hit a tree trunk. In this idealised situation the arrow must be allowed to keep on going in a straight line without ever dipping down to the ground. You find, of course that it is impossible. Even if the arrow misses all the closer trees, it will eventually always hit one. Since the forest is infinite, there will always be a tree in the flight path of the arrow, however far away that tree is. It doesn’t matter how dense the forest is either. If you were to chop down ninety percent of all the trees, this would simply mean that the arrow will, on average, travel ten times as far before it encounters a tree trunk.

Now consider a simple model universe that is infinite, that is static (by which I mean not expanding) and with stars evenly spread out. The light that reaches us from the stars is like the example of the arrow. It does not matter where we look in the sky, if the Universe is infinite we should always see a star in our line of sight. So there would not be any gaps in the sky where we do not see a star and the whole sky should be as bright as the surface of the Sun, all the time!

The real universe may also be infinite, but in other respects it is not quite like the above simple model. First of all, the stars are not spread out evenly but clumped together in galaxies. This doesn’t matter. It just means that the night sky should be as bright as an average galaxy, which is not quite as bright as the surface of an average star but still blinding. Secondly, our Universe is expanding. Does this make a difference? Physicists have carried out detailed calculations that have shown that this does not solve the problem; it just reduces it.

It was thought that maybe space is filled with interstellar dust and gas that would block the light from the more distant galaxies. But if the Universe has been around for long enough, then even this material would slowly heat up, due to the light it has absorbed, and will eventually shine with the same brightness as the galaxies it obscures.

The true answer, the one which finally lays Olbers’ paradox to rest, is that the Universe has not been around forever, so light from very distant galaxies has simply not had enough time to reach us. If the Big Bang happened 13.7 years ago, then galaxies that are further away from us than 13.7 billion lightyears (remember a lightyear is the distance covered by light in a year) are invisible to us because their light is still in transit and has yet to reach us. Admittedly, the discussion is complicated a little due to the expansion of the Universe – the very furthest galaxies we can see, because their light that has been travelling towards us for 13.7 billion years is only just reaching us today, are in fact over 40 billion lightyears away due to the expansion – but what we can see in the sky is just a tiny fraction of the whole Universe. We call this the ‘visible universe’ and we cannot, even with the most powerful telescopes, see beyond this horizon in space. So the amount of light reaching us from space, and hence the brightness (or darkness) of the night sky, depends on how far out we can see, and this tells us how old the Universe is.

Finally, we can turn Olbers’ paradox on its head and say that the real proof that the Big Bang happened is that it gets dark at night. Now isn’t that a cool argument to use when confronted by someone who is sceptical about evidence for the big bang!

]]> http://www.jimal-khalili.com/blog/more-quantum-musings-and-olbers-paradox.html/feed 3 Forthcoming book lectures http://www.jimal-khalili.com/news/forthcoming-book-lectures.html http://www.jimal-khalili.com/news/forthcoming-book-lectures.html#comments Fri, 27 Aug 2010 14:05:57 +0000 Jim Al-Khalili http://www.jimal-khalili.com/?p=732 Continue reading →]]> Here is an early list of lecture engagements to be given by Jim Al-Khalili coinciding with the publication of his new book:

29 September
Asia House Science Series: in association with the Royal Society
The House of Wisdom and the Golden Age of Arabic Science
6:45 PM

30 September
1.00 PM

10 October
4.00 PM

20 October
Chemists and Al-chemists in Medieval Islam
5.30 PM

31 October
Manchester Science Festival
3.00 PM
3 November
Advances in mathematics in medieval Islam.

3 november
Institute of Physics Merseyside Branch
On the Shoulders of Eastern Giants: the forgotten contribution of the medieval physicists
7:30 PM

]]> http://www.jimal-khalili.com/news/forthcoming-book-lectures.html/feed 0 STEPHEN HAWKING AT THE ROYAL ALBERT HALL http://www.jimal-khalili.com/news/stephen-hawking-at-the-royal-albert-hall.html http://www.jimal-khalili.com/news/stephen-hawking-at-the-royal-albert-hall.html#comments Thu, 26 Aug 2010 21:24:05 +0000 Jim Al-Khalili http://www.jimal-khalili.com/?p=713 Continue reading →]]> We each exist for but a short time, and in that time explore but a small part of the whole universe. But humans are a curious species. We wonder, we seek answers…

In an extremely rare public lecture, one of the world’s greatest thinkers, Professor Stephen Hawking will discuss his new book The Grand Design in which the most recent scientific thinking about the mysteries of the universe is presented in language marked by both brilliance and simplicity.

The lecture takes place at the Royal Albert Hall on Wednesday 20th October at 8.30pm and will be chaired by Theoretical Physicist, Author and Broadcaster, Professor Jim Al-Khalili.

Ticket prices include a copy of The Grand Design (Bantam Press – £18.99) to be collected on the night.

BOOK YOUR TICKETS HERE

Also look out for September edition of the September edition of Eureka, the monthly science magazine from The Times, which contains extracts from Hawking’s new book as well as contributions from Jim Al-Khalili and Frank Close who comment on Hawking’s views about M-theory.

]]> http://www.jimal-khalili.com/news/stephen-hawking-at-the-royal-albert-hall.html/feed 1 Judging a book by its cover http://www.jimal-khalili.com/news/judging-a-book-by-its-cover.html http://www.jimal-khalili.com/news/judging-a-book-by-its-cover.html#comments Thu, 29 Jul 2010 06:07:00 +0000 Jim Al-Khalili http://www.jimal-khalili.com/?p=696 Blog post about the new title of my forthcoming book.

]]> http://www.jimal-khalili.com/news/judging-a-book-by-its-cover.html/feed 0 Judging a book by its cover http://www.jimal-khalili.com/blog/book-title.html http://www.jimal-khalili.com/blog/book-title.html#comments Wed, 28 Jul 2010 06:06:01 +0000 Jim Al-Khalili http://www.jimal-khalili.com/?p=672 Continue reading →]]> Firstly, thanks to everyone who has emailed or Tweeted me their comments about the possible alternative titles for my new book – and indeed thanks to Richard Wiseman who set up a vote on his blog page, and to everyone who voted or added a useful comment. So, here is an update.

Firstly, a quick recap: After three and a bit years in the writing, my new book on the scientific achievements during the golden age of the medieval Islamic empire is almost finished. It heads off to printers next week, to be in all good bookshops on 30 September! Hurrah.

It also now has the new title as shown on the left. This might not have been everyone’s first choice title, but there was a rationale for doing it – one that I concede is sensible and actually necessary.

The original working title has been “The House of Wisdom“, with the subtitle of “The Flourishing of A Glorious Civilisation and the Golden Age of Arabic Science“. This despite another book, by Jonathan Lyons, out a few years ago on the same subject with the same title “The House of Wisdom: How the Arabs Transformed Western Civilisation“.

Now, the marketing arm of the publishers have become rightly concerned about the likely confusion between the two books (same title, same subject, even book covers were looking similar!) and all parties have now settled on the alternative title of “Pathfinders: The Golden Age of Arabic Science” – a reference to a quote about Ibn Khaldun, the Arab scholar of the 14th century and father of the fields of economics and social science. Some people tweeted me about this saying they were not so sure about the new title, that it sounded like a travel guide or government initiative etc. I guess it is all about the context. Ibn Khaldun’s full quote (which will appear on the back cover of the book) reads:

    “He who finds a new path is a pathfinder, even if the trail has to be found again by others; and he who walks far ahead of his contemporaries is a leader, even though centuries pass before he is recognized as such.”
The book is part history, part science. It covers the period between the 8th and 15th centuries when the international language of science was Arabic, when on the whole Europe was in the Dark Ages before the Renaissance and scientific revolution. It fills the gap in the story of science and the remarkable scientists between the ancient Greeks and the European led modern science. Part of the blurb on the inside flap of the dust cover will read:
Few of these scientists, [who lived during this golden
age between 8th and 15th centuries], are now known in
the western world. Who has heard of Abu Rayhan
al-Biruni, a Persian polymath and genius to to rival
Leonardo da Vinci? Or the Syrian astronomer Ibn
al-Shatir, whose manuscripts would inspire
Copernicus’s heliocentric model of the solar system?
Or al-Khwarizmi, the father of algebra and the
greatest mathematician of the medieval world? Or
the Iraqi physicist Ibn al-Haytham who practised the
modern scientific method 600 years before Bacon and
Descartes and founded the field of modern optics long
before Newton? Or even ninth-century physician
al-Razi, who carried out some of the world’s earliest
clinical trials?
–
So, do I like the new title? Well, actually I think it is powerful, and sounds more grownup than the original “House of Wisdom” which, as several people have pointed out sounds more like fiction than non-fiction.
Anyway, I hope you will like the book.

]]> http://www.jimal-khalili.com/blog/book-title.html/feed 4 “Science and Islam” on BBC4 http://www.jimal-khalili.com/news/science-and-islam-on-bbc4.html http://www.jimal-khalili.com/news/science-and-islam-on-bbc4.html#comments Tue, 27 Jul 2010 16:08:52 +0000 Jim Al-Khalili http://jimal-khalili.com/wordpress/?p=406 My BBC4 series Science and Islam is being repeated. Episode Two (The Empire of Reason) was screened on Monday 26 July 2010 and is currently available on iPlayer.

Episode Three (The Power of Doubt) is on next Monday, 2 August. 2010.

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