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Tackling the Universe’s Big Questions - Dr Stuart Clark

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I have enormous pleasure in announcing the release of my book The Big Questions: The Universe in the United States of America.   Published by Metro Books it is available exclusively through Barnes and Noble.  They are initially offering the book in hardback for $8.98, a discount of 10%.

Click on the ‘read more’ link below the tags to read an in-depth interview with my about tackling the big questions in astronomy.


Transcript of the Interview between Spanish magazine Redes para la Ciencia  and Dr Stuart Clark, talking about The Big Questions: The Universe.

REDES] Some ancient people thought that the universe was a flat surface, others that it was a sphere... What is your mental picture of the Universe, taking into account what we know about it now? What image comes at your mind when you think about the Cosmos?

DR STU] I find it as hard as anyone to imagine the vastness of space.  Years ago I was using United Kingdom Infrared Telescope on Hawaii; I was reading about the ancient Polynesians and the way they navigated vast stretches of the Pacific in little boats.  The voyages were so long and so dangerous that tiny miscalculations could mean they missed the islands altogether. I remember thinking that’s what the vastness of space must be like: huge tracts of nothing and tiny little islands of stars.  The image has stayed with me ever since.

REDES] Give me some orders of magnitudes (or metaphors) to picture myself what the Universe is: How big is the Universe? How old is it? How many things does it contain?

DR STU] Imagine that the distance between the Sun and Pluto is the length of a soccer pitch. The Sun would be a globe just 2 centimetres in diameter. The Earth would be 2.3 metres away from the Sun and just 2 millimetres across. At the other end of the pitch, Pluto would be nothing more than a speck of dust. Where would the nearest star be? − in the crowd? – in the car park? − in the next street? All wrong. The nearest star would be 645 kilometres (401 miles) away. And that is nothing on the cosmic scale.  The Galaxy is 100,000 times larger still, and the next large galaxy is twenty times that distance away.  The Universe is at least ten thousand times larger still: maybe a lot more.  It’s very big out there; too big for me to imagine, certainly.

REDES] What is the strangest object or place in the Universe, in your opinion? I mean the one that is more radically different from what we are used to in our environment.

DR STU] Without doubt the strangest places in the Universe are the black holes.  These are celestial objects that have become so dense they generate a gravitational field from which nothing can escape.  Einstein's General Relativity breaks down inside a black hole, so we can understand nothing about what takes places inside them.  Interestingly, this also happens at the moment of the Big Bang, the supposed moment of creation for the Universe, and it implies that if we ever develop a theory to understand black holes we will understand how the Universe came into being as well.

REDES] How far can we travel in the universe? Will we ever get close to strange, enormous and faraway objects, like black holes or pulsars, for example?

DR STU] It is almost impossible to overstate the difficulty of travelling to the stars.  Space is a dangerous environment full of harmful radiation that we are protected from on the Earth.  Just to get to Mars would take about 9 months, during which time the astronaut must be shielded from solar flares and cosmic rays. To reach the stars would require some form of ‘warp drive’ that allows us to travel faster than the speed of light.  Although a Mexican physicist, Miguel Alcubierre, has designed a warp drive, to make it work requires a type of energy that we have never encountered before: so-called negative energy.  There are some hints that this may exist in the Universe but no one has detected it in a lab yet.

REDES] Is the Universe eternal? Has it always been as it is and will it always be as it is?

 

DR STU] Scientists have often wondered whether the Universe is eternal but since the 1960s and the apparent confirmation of the Big Bang, we now think that it had a moment of formation about 13.7 billion years ago.  Certainly the Universe is constantly changing because it is expanding.  Celestial objects are forming and dying all the time, and the chemical composition of the Universe is changing because the stars are perpetually transforming hydrogen gas into helium and other chemicals. As time goes on, the Universe will continue to evolve.  There are various possibilities for its demise.  It could expand forever with all the celestial objects becoming black holes, or it could stop expanding and then collapse back on itself, with everything being destroyed in a gigantic collision called the Big Crunch.

REDES] Is this the only possible Universe? Will our Universe give way to a different one? Or are there many Universes at the same time?

DR STU] If the physicists are right and their string theories are the way to unify the two opposing theories of General Relativity and Quantum Mechanics, then it seems inevitable that there is an infinite number of alternative universes.  These will be coexisting with us at the moment; some will be very similar to our Universe, others will be greatly different.  We are at the beginning of investigating these questions in a scientific manner, so the most honest answer at the moment is “We don’t know”.

REDES] What is the most difficult open question about the Universe, in your opinion?

 

DR STU] Without a doubt it is the nature of gravity.  Newton in the 17th century described gravity as a force; Einstein in the 20th century explained it as a consequence of the fabric of space.  But what is that fabric?  Is it just a convenient mathematical image?  Our attempts to explain gravity in the same way we explain other forces of nature, with quantum theory, are struggling.Physicists perform heroic mathematical efforts with string theories and other ideas but I often wonder if perhaps gravity cannot be explained like that.  I wonder whether it is completely different and only when we learn what gravity really is will we be able to understand black holes, the Big Bang, whether warp drives are possible and whether there are alternative universes.

REDES] What is the most important experiment for the understanding of the Universe that is being carried out, or is currently programmed?

 

DR STU] There are three that I can think of immediately.  The Large Hadron Collider in Switzerland will provide a massive boost to particle physics whatever it finds.  It is working at completely uncharted energies, so the potential for discovery is enormous.  It may even show us if the hypothetical dark matter that is supposed to pervade the universe exists. Secondly, there is a 40-year experiment that has been running on the Moon.  The Apollo astronauts left mirrors up there, and, using lasers on Earth, teams of astronomers chart the movement of the Moon to astonishing accuracies.  So far, they have found no deviation from what Einstein’s theory predicts and that is providing tight constraints on string theory. Thirdly, The European Space Agency’s Planck mission is mapping the leftover radiation from the Big Bang and has the potential to tell us about the very origin of our Universe. I cannot wait for those results.

REDES] In a time of satellites and complex measuring instruments, is it still important to have clean skies to explore the Universe?

 

DR STU] Yes, it is.  Spain is one of the world’s leading exponents of ground-based astronomy.  It has observatories on La Palma and Tenerife, not to mention the major role it plays in the European Southern Observatory.  Spanish astronomers clearly recognise the value of clear skies.  Telescopes can be built on Earth far larger than anything that can be launched into space, but they cannot see all the different types of radiations. So, both approaches are needed to achieve the full picture. Even if we forget the science for a moment, the beautiful night sky is jewel that all of us can enjoy.  It’s so inspiring to look up at the starry dome and just gaze.  I still do that, after decades in astronomy.

REDES] In principle, it is impossible to perform experiments with the Universe: we can only make measures and observations. Provided that this is true, are our cosmological theories as well founded as other scientific models? How are they better than traditional cosmologies?

 

DR STU] Scientific theories must always be testable.  Although we cannot go out into the Universe to create experiments, or create a star in the lab to test our ideas, science allows us to make predictions of what may happen.  We can then look for these events to test our theories. Light and the other radiations such as infrared, ultraviolet and radio waves are our messengers.  They come to us on Earth and mean that we do not have to travel to them in space. The return of Halley’s comet was the first bold prediction to come from Newton’s law of gravity.  Newton’s theory was testable because it could predict future events, not just provide a framework to understand existing phenomena.

REDES] Some cosmological models, like string theory, have been criticised because it is impossible to take measurements to check for their validity. What is your opinion about these models?

DR STU] The power of science is that it is testable.  It is the only route to knowledge that has an objective way of testing its validity.  If we abandon that we wind the clock back over 400 years to the time before Isaac Newton, when scientific enquiry consisted of making observations and then arguing for a hypothesis.

I’m sure that the string theorists would agree with that and that the major focus of their work is to find something new and testable about their work.  By that I mean to use their theory to make a prediction about something we should find in nature. Having said that, I wonder whether string theories are too complicated at present.  I hope someone will spot some faulty assumption, correct it, and suddenly everything will become clear.

REDES] The study of the Universe is a contemplative, curiosity-driven science, and a field that has yielded lots of technologies. What is the respective role of curiosity and economic interest in the development of this research? Do you think the balance is correct nowadays?

 

DR STU] The only thing that should drive research is curiosity.  As soon as you start asking what benefit comes out of it, you weaken it because the scientist has to make compromises.  It is like an artist who constantly checks his inspiration by asking whether what he is doing is commercially viable. The fact is that most research does not lead to financial rewards, but some breakthroughs change the world by creating whole new industries and commercial opportunities.  Lasers are a good example, as are medical X-rays.  The latter developed out of curiosity driven research into the structure of the atom.  If someone had been attempting to improve medicine, they would not have studied physics. My point is that you don’t know what you’re going to get out of science, but you will always get something.  I know that sounds idealistic and that in reality there are limited funds so scientists have to demonstrate some form of value to what they do but in my perfect world, people would follow only their curiosity.

REDES] Who is the scientist you know that has surprised you most in your career?

 

DR STU] Wow, that’s a tough question.  I think I’m surprised most by the original thinkers.  The ones who were not afraid to cut across conventional thinking with new, even ‘heretical’ ideas.  The ones that have my deepest respect are those that backed up their new thinking with solid evidence, of course.  So I’m thinking about people like Johannes Kepler, Isaac Newton, and Albert Einstein. Currently, I have respect for Mordehai Milgrom of the Weizmann Institute in Israel.  I am intrigued by his work that hints at gravity being something more than we traditionally think it is.  Whether he’s right or wrong, his extension of Newton’s second law of motion requires some kind of explanation – it fits the data too well to be simply dismissed.

REDES] What is our role in the Universe? Are we just an irrelevant accident or is the Universe especially tuned for us?

 

DR STU] I’m not sure that science is equipped to answer this question yet.  We simply do not know enough about how the Universe works to know if it has a purpose and whether we have a role in that.  A key issue is whether there is other intelligent life in the Universe.  Are we just a fluke, or one in a number of other routes to intelligent reasoning? I am intrigued by the idea that information is the most fundamental quantity in the Universe, rather than matter or energy.  And, of course, human brains are the most powerful information processors that we know.  Perhaps that links us to the Universe in some fundamental way that we can only guess at presently.

REDES] In which moment of history has our vision of the Universe changed most radically?

 

DR STU] My latest project is a trilogy of novels that dramatise the key moments in astronomical history.  Called The Sky’s Dark Labyrinth the first part is being published in the UK this spring. I would choose three moments. The first is Kepler’s discovery of elliptical orbits, which made the Sun-centred Universe a workable solution.  I have no idea why we remember Copernicus more than Kepler.  Kepler was a genius, the first person in history since the ancient Greeks investigated music, to distil a natural phenomenon into mathematics. Then, comes Newton, the subject of the second novel.  He described almost all motion on Earth and in space as being the result of gravity.  He defined the chain of investigation that we call the scientific method and his work led to the modern world. Finally Einstein.  He made us think of gravity not as a force but as a kind of universal landscape.  His general relativity allowed us to calculate the past and future of the whole universe – but not even Einstein understood the true power of his work.

REDES] What concept about the Universe have you found most difficult to explain? How do you tackle the issue of explaining an idea when it is extremely difficult to do it?

DR STU] I try to distil everything into everyday language, with everyday ideas. The most difficult concepts to explain are the ones that haven’t been worked out properly yet.  For example: What is a black hole?  What came before the Big Bang?  What is gravity? All I can do in these situations is explain as clearly as possible what we do know, or the paths of enquiry that astronomers have walked down.  Once I have taken people as far as I can, then I have to say that we are waiting for the next Newton or Einstein. I have no fear of saying, “We don’t know.”  Some astronomers like to pretend that we have all the answers but we don’t, and the public appreciate that honesty.  I think actually that they are excited by it and the potential of what’s to come.

REDES] Why do you feel so attracted to studying and explaining the Universe?

DR STU] I cannot remember a time when I wasn’t fascinated by astronomy.  Even as a small child, I remember being in the back of my parents’ car and gazing at the stars during a long drive home and feeling somehow drawn to them. I read astronomy and science fiction constantly, and jumped when the chance came to go to University and study astronomy. I still get excited when I read new papers; my imagination lights up as some new piece of knowledge slots into place. There are new things being discovered all the time, new missions to be excited about.  I enjoy looking forward, and the potential of astronomy still inspires me. Most recently I have become fascinated by the history of the subject, particularly the way in which past astronomers related to the Universe.  All of them seemed concerned with finding the links between the vastness of space and the perceptions of humans.  It assures me that astronomy is a noble pursuit.



The Big Questions: The Universe is available in the US here.  In the UK, it is available from all leading booksellers, including at 42% discount from Amazon.co.uk.  Hang on, 42% – is someone at Amazon at Douglas Adams fan?

This interview was conducted with Michele Catanzaro for the Spanish magazine Redes para la Ciencia.  My thanks to both.  You can download the article in Spanish here.

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