Prof Muller talks about time

By THOMAS HUKAHU
IN March, I did a review on a book written by two theoretical physicists, one of whom was the late Stephen Hawking.
This week, I am reviewing a book by another theoretical physicist and his discussion about time and related concepts.

Ways of getting books
Before I get into the actual review, let me share a bit about how we can look for good books.
The privilege of passing through a western nation, like Australia, is that you will get the chance to visit bookshops, where books you know about are on the shelves, those that are not available in Papua New Guinea.
The only place where you can find such books in PNG would be at second-hand shops, but then you cannot get all the books that you want. It depends on what was shipped to PNG. (I bought a copy of the first book by Hawking in a second-hand shop in Port Moresby a few years ago.)
When I got here to Adelaide in January, I made sure I first went to the library shelves and checked for popular books that I knew would be available, like the one I am currently discussing.
I also visited the public libraries and bookshops.
After borrowing Hawking’s book from the university library (which I had previously reviewed), I went to a bookshop to look for the book that I will be reviewing in this article.
I asked the assistant there and she said they did not have the title in stock but I could place an order with them, if I wanted to.
I placed the order and after a fortnight they contacted me and said I could go and buy the book.
Although, this may not work for bookshops in PNG, I am sure you can order books online too.
I am aware that some people order items from overseas retailers for their personal use by using their visa cards. (You may have to check with your bank if you can get such a card which can allow you to purchase items online. I got my visa card with Westpac early this year and I am sure it will be very handy for me in ordering things wherever I am.)

About the author and book
The book that I am reviewing this week is Now: The Physics of Time.
It is written by Richard A Muller, who is professor of physics at University of California at Berkeley. He is also a senior scientist at the Lawrence Berkeley National Laboratory.
(The laboratory was founded by Ernest Lawrence who also invented the cyclotron, which is a particle accelerator and a very useful instrument for particle physicists studying the speed and collision of subatomic particles, as part of investigating the laws of physics. Lawrence won the 1939 Nobel Prize in Physics for his invention of the cyclotron.)
So, Muller is actually a particle physicist. In the book though he calls himself an experimental physicist.
The book has 25 chapters.

What is experimental physics?
Muller is an experimental physicist. But, what does that mean?
Let me make something clear here before we go on with the review.
Let me go over a bit of history in physics, some things that I often mention to high school physics students, to hopefully get them to appreciate the work and sacrifice of scientists over the ages.
Galileo Galilei (1564-1642), the Italian physicist, mathematician and astronomer was said to be the first experimental scientist.
Among other things, he was the scientist who got into trouble with the top people in the Catholic Church (of which he was a member) and the government leaders of his time because he supported the view that the earth revolved around the sun (as in the sun-centred model) and not the sun and other planets revolving around the earth (as in the earth-centred model).
The earth-centred model was the one that Aristotle (384 BC-322 BC) promoted, and that became part of the Church’s accepted teachings.
That is to say, the Church and the authorities (including other scientists) supported the Aristotelian view for almost 2,000 years and persecuted people who thought otherwise.
(The bit about Aristotle and how unscientific but popular that view was then is also briefly discussed by Muller in his book.)
Galilei’s support of the sun-centred model was due to him observing the moons of Jupiter through his telescope. He noted that the moons, which were smaller than Jupiter, revolved around the planet, which was more massive.
From that observation, he drew the conclusion that the earth is also orbiting the sun, the more massive of the two. Galilei was imprisoned by the Church for disputing what they held onto erroneously for almost 2,000 years. (He was a brave man and never changed his view though he was treated harshly for what was the truth.)
It was Galilei who used observation or experimentation as a key element in the scientific method, which is: Unless you have data from an observation of, or experimentation about, a phenomenon, you cannot support a theory or hypothesis.
Mere talking or debating would not validate a theory that you are proposing. You must utilise the scientific method, which may at times include a mathematical model that can be proved mathematically.
Incidentally, in the year that Galileo died, another great mathematician, physicist and astronomer was born in England. He was Isaac Newton (1642-1727) and he built on some of the work that Galileo did to further advance science and mathematics in a big way.

A brief review
My review of Muller’s book will be shorter, in that many of the concepts he discussed are a bit scientific.
That is not to say, you should not try reading it if you are interested in the challenges that physicists are facing at the moment, as in what sort of concepts are puzzling them.
Muller states in the opening chapter that as absurd as it may seem to the common person, “time is flexible, stretchable, and even reversible”.
He said this comes from Albert Einstein’s discovery that the rate of time depends on both the velocity (or speed) and gravity of the body an observer is on, whether it is a planet or a star.
He also discusses the twin paradox (as Stephen Hawking mentioned in his book, which I reviewed in March).
In the twin paradox, twin A goes on a trip in a very fast spacecraft around our Solar System while twin B remains on earth.
Upon twin A’s return, it would be observed that twin B would have aged more than twin A. It is as if time had slowed down for twin A, or it has sped up for twin B.
These concepts come from Einstein’s theory of relativity and these have been validated by experiments that Muller himself has conducted.
He said in the book that he studied rapidly moving pions (subatomic particles) which travel at speeds closer to the speed of light (0.9999988 lightspeed). He was measuring the half-life (a certain measurement of time) of pions and found that a faster-moving pion had a speed that was 634 times longer than the value for stationary pions.
Such bits shared by Muller inform people that some of the absurd ideas accepted in the physics world have been tested by experiments and found to be correct, as otherworldly they may seem to be.
The book has a good number of appendices that add more to what the book itself has.
Interestingly, Muller also provides something for mathematically-minded people with “the math of relativity” in appendix 1, something that should be of interest even to senior physics or maths students in university.

Philosophy or knowledge of God may help
Towards the end of the book, Muller brings in some ideas from philosophers in regards to time, as a concept.
(Philosophers and even theologians have also been fascinated by the concept of time over the ages. St Augustine is someone who has also marvelled at the concept of time.)
Muller thinks that some of the ideas proposed by philosophers about time seem reasonable while others are not supported by scientific data.
He also asks the question about God and where his place may be in the universe. (Hawking asks similar questions in his books, even though he had claimed to be an atheist.)
You can read the book to see what Muller believes in.
In appendix 6, which is titled “Physics and God”, Muller takes note of some physicists and what they say about God. (Of the five that he quotes, four of them mention God as vital in life.)
In a future article, I will inform you about a discussion between a physicist and two philosophers about their thoughts regarding the universe.
Next week: Hoax, or conspiracy theory or truth?

• Thomas Hukahu is an Australia Awards students in Adelaide.