Posts Tagged ‘Isaac Newton’

Physics Textbook on Cosmology and Gravitation

March 15, 2018

M.V. Berry, Principles of Cosmology and Gravitation (Bristol: Institute of Physics Publishing 1989).

Yesterday came the news of the death of the great British physicist and cosmologist, Stephen Hawking at the age of 76. Hawking had suffered for most of his adult life from motor neurone disease, since he was diagnosed with it in his early 20s. He was given only three years to live, but instead managed to live out a very full lifespan working on his theories of the origin of the universe and Black Holes. He was a great ambassador for science. His book, A Brief History of Time, was a bestseller when it appeared in 1980s, although he admitted that it was probably a book few finished. And he showed that it was still possible for a disabled person to do cutting edge research, provided they had the necessary technical and medical support. In his case, it was his wheelchair and the machine that allowed him to speak, first of all by keying in the words, then by twitching just a single muscle. Some of the praise seemed a bit too fulsome to me. Like when they started saying that he was the greatest scientist since Newton and Einstein. I don’t think he was. And Hawking on his own didn’t unlock the secrets of universe or Black Holes, as the Beeb’s presenters also claimed. As for his great sense of humour, well, it existed, as his appearance on shows like The Simpsons demonstrated, but my memory of it is marred by him turning up with the TV critic, Victor Lewis Smith, telling fart jokes and laughing on the 1990s series, Inside Victor Lewis Smith. But it really was inspiring to see how he was a great hero to the ‘A’ level students at a science fair yesterday, and how he had inspired them to become interested in science.

One of the complaints Richard Dawkins has made about popular science programmes is that they’re too ‘dumbed-down’. He points out that they have to have lots of explosions, and they mustn’t include equations, in case that scares people off. There’s a lot with which I don’t agree with Dawkins. I’m not an atheist, and have argued on this blog against him and the other militant atheists. But he is right here. Scientists writing the popular science books have said that they’ve been told by their publishers to leave equations out, because every equation in a book damages sales.

I think this is the wrong attitude to have. It’s why I’ve put up this piece about the above book by M.V. Berry. It’s an undergraduate physics textbook, which does contain the fundamental mathematical equations for this area of physics. Its contents include

1. Introduction

2. Cosmography
2.1 What the universe contains
2.2 The cosmic distance hierarchy and the determination of galactic densities
2.2.1 Parallax
2.2.2 Distance from velocity measurements
2.2.3 Distance from apparent luminosity
2.2.4 Weighing galaxies
2.3 The red shift and the expansion of the universe.

3. Physical base of general relativity
3.1 The need for relativistic ideas and a theory of gravitation.
3.2 Difficulties with Newtonian mechanics: gravity
3.3. Difficulties with Newtonian mechanics: inertial frames and absolute space.
3.4 Inadequacy of special relativity.
3.5 Mach’s principle, and gravitational waves.
3.6 Einstein’s principle of equivalence.

4 Curved spacetime and the physical mathematics of general relativity.
4.1 Particle Paths and the separation between events
4.2 Geodesics
4.3 Curved spaces
4.4 Curvature and gravitation.

5 General relativity near massive objects
5.1 Spacetime near an isolated mass.
5.2 Around the world with clocks.
5.3 Precession of the perihelion of Mercury
5.4 Deflection of light
5.5 Radar echoes from planets
5.6 Black Holes

6 Cosmic Kinematics
6.1 Spacetime for the smoothed-out universe
6.2 Red shifts and horizons
6.3 Apparent luminosity
6.4 Galactic densities and the darkness of the night sky.
6.5 Number counts

7 Cosmic dynamics
7.1 Gravitation and the cosmic fluid
7.2 Histories of model universes
7.3 The steady state theory
7.4 Cosmologies in which the strength of gravity varies

8 In the beginning
8.1 Cosmic black-body radiation.
8.2 Condensation of galaxies
8.3 Ylem.

Appendix A: Labelling astronomical objects
Appendix B: Theorema Egregium
Problems
Solutions to odd-numbered problems
Useful numbers.

there’s also a bibliography and index.

I’m not claiming to understand the equations. I struggled at both my ‘O’ level maths and physics, and what I know about science and astronomy I learned mostly through popular science books. But in the mid-1990s I wanted to see at least some of the equations scientists used in their explorations and modelling of the universe. One of the popular science books I was reading said at the time that this book was at the level that people with ‘A’ level maths could understand, and this didn’t seem quite so much a jump from my basic maths skills. So I ordered it. I’m afraid I can’t say that I’ve read it properly, despite the fact that I keep meaning to. Some of the equations are just too much for me, but I can follow the explanations in the text. I’m putting this notice of the book up here, in case there are any budding Stephen or Stephanie Hawkingses out there, who want to go a bit further than the pop-sci explanations, and see for themselves what the maths behind it all is like.

The Beeb also said in their eulogy for the great man, that Hawking hoped that the people reading his A Brief History of Time would come away with one point, even if they hadn’t finished it: that the universe is governed by rational law. Actually, this ideas isn’t unique to Hawking by a very, very long way. It actually comes from the Middle Ages, and is the assumption that makes science possible. Hawking was an agnostic, I believe, and many scientists are atheists. But this assumption that the universe is governed by rational laws ultimately comes from Christian theology. The founds of modern science in the Renaissance pointed to the passages in the Bible, in which God’s Wisdom creates the universes and establishes the boundaries and courses of natural phenomena, like the tides and stars. And the anarchist of science, Feuerabend, pointed out that the assumption that the laws of the universe all form a consistent whole come from Christian doctrine, quoting the 13th century theologian and philosopher, Thomas Aquinas: ‘We must believe that the laws of the universe are one, because God is one.’

Hawking has passed away, but it’s clear that he has inspired many more people to become interested in this rather arcane branch of the sciences. I hope this continues, despite the Tories’ attack on education and science and research for its own sake.

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The French Astronomer Who Gave His Name to the Captain of the Enterprise?

December 28, 2016

More space/ SF stuff.

Looking through the 1982 Yearbook of Astronomy, edited by Patrick Moore, I found on the chapter for July a very brief biography of the 17th century French astronomer, Jean Picard. The piece ran

1982 is the anniversary of the death of Jean Picard, a celebrated French astronomer. He was born at La Fleche, in Anjou, on 21 July 1620; he studied for the priesthood, and was ordained, but his main interest was in astronomy. In 1645 he was appointed Professor at the College de France, and took a leading part in the establishment of the Paris Observatory. His most famous piece of research was undertaken in 1669-70, when he made a new and more accurate determination of the radius of the Earth. it has been said that it was this which allowed Isaac Newton to complete his work on the theory of gravitation, though in fact Newton’s earlier hesitation was due to the fact that one link in his chain of argument was incomplete. Jean Picard died as the result of an accident on 12 July 1682. (pp. 103-4).

Reading that, I wonder if he was the inspiration for Patrick Stewart’s character in Star Trek: The Next Generation, Captain Jean-Luc Picard. I’ve also got a feeling that another Francophone space scientist may also have inspired the name and character. Professor Calculus in the Tintin books by Herge is based on a real French scientist, who ascended to the edge of space in a high altitude balloon in the last century. I can’t remember the scientist’s name, but I’ve got a feeling it was also Picard.

Of course, it could all be coincidence. But considering the high standard of TV drama set by the series, it really wouldn’t surprise me if the creators and producers had done their historical research, and decided to create the Picard character partly as a tribute to these scientists.

Science Britannia and the Need for a Programme on Medieval Science

September 22, 2013

Last week, the Beeb started a new series on the history of science, Science Britannia, broadcast on BBC 2 on Wednesdays at 8.00 pm. Fronted by Professor Brian Cox, now Britain’s answer to Carl Sagan, the series traces the development of British science and the personalities of the scientists involved from the mid-18th century. The name, Science Britannia, seems to come from the various music documentary series the Beeb has screened over recent years, such as Jazz Britannia, and one on caricature, political satire, the Music Hall and burlesque, Rude Britannia. Now any series on the history of science is to be welcomed, though my problem with such series is that they are always set in the Renaissance or later. In this case, I suspect the series has been influenced in its selection of the date at which to begin by Jenny Uglow’s, The Lunar Men. This was about the 18th century society of natural philosophers – the term ‘scientist’ was not coined until the 19th century – of which Erasmus Darwin was a member. He published his own theory of evolution fifty years before that of his better-known grandson, Charles. On this Wednesday programme Cox does go back to Isaac Newton in the 17th century, to examine his psychology, as well as that of later pioneering British scientists.

I do have one criticism of these series, however. They largely ignore the amazing scientific and technological advances that went on during the Middle Ages. Historians of medieval science, such as James Hallam in his book, God’s Philosophers, and A.C. Crombie in his two volume history of medieval science, have demonstrated that there was no Scientific Revolution in the 16th and 17th centuries in the sense that these ideas were a radical break with medieval science. They weren’t. Instead, they had their roots very much in the investigations and examination of nature of medieval natural philosophers even as they rejected their Aristotelianism. Roger Bartlet, in his programme on the medieval worldview, has demonstrated that the Middle Ages were not anti-science and that the mixture of science and faith made perfect sense to them, even if it now seems irrational to us. For example, I made a list of about 20 innovations that appeared in Europe during the Middle Ages. They were
Adoption for the purpose of preventing the deaths of unwanted children, Council of Vaison, 442.

Linguistics: Priscian, 6th century.

Floating Mills, Belisarius, 537.

Orphanage, St. Maguebodus, c. 581.

Electrotherapy, Paul of Aegina, 7th century.

Tide Mills, Adriatic and England, 11th century.

Armour plated warships, Scandinavia, 11th century.

Lottery, Italy, 12th century

Harness, Europe, c. 1150.

Spectacles, Armati or Spina, c. 1280.

Pencil – silver or black lead used for drawing, 14th century.

High Explosive Marine Shell, Netherlands, c. 1370, or Venice 1376.

Movable type, Laurens Janszoon, alias Coster, 1423,

Oil painting, H and J Van Eyck, 1420,

Diving Suit, Kyeser, c. 1400.

Double crane, Konrad Kyeser, early 15th century.

Screw, 15th century Europe.

Arquebus, Spain, c. 1450, first used at Battle of Moret, 1476.

Hypothermia, France, c. 1495.

Air gun, Marin Bourgeois, 1498.

Source

Great Inventions Through History (Edinburgh: W&R Chambers 1991).

This is only a short list. There have been whole encyclopaedias written on medieval science and technology.

I think one reason why such as programme has not been broadcast is because it conflicts with the received wisdom about the Middle Ages, and the aggressively atheist views of some of the media own scientific darlings. Since the Renaissance, and particularly since the 19th century, the Middle Ages have been viewed as an age of superstition, in which the Church actively discouraged and persecuted science and scientists. This wasn’t the case, but the idea is still promoted very strongly. One of those, who continues to do this, is Richard Dawkins, who is now known as an atheist propagandist almost as much for his work as a biologists and science writer. Very many of the science programmes screened on British television, whether BBC or Channel 4, included Dawkins as an expert. He is a popular speaker at literary and science festivals, even though his views on the relationship between science and faith and the history of science are completely wrong. Nevertheless, it agrees with the historical prejudices of his audience and the media. James Hallam said that he found it difficult to find a publisher for his book, God’s Philosophers, but its demonstration that people of faith – Christian priests, monks and laymen – could do great science in the Age of Faith – directly contradicted the popular view of the period. One publisher explicitly told him that they weren’t going to be publish the book because they were an atheist. Censorship and bigotry is by no means the sole province of the religious.

Unfortunately, the current institutional structure of the BBC and its commissioning process appears to make this extremely difficult to correct, at least for those outside of the television industry. A year or so ago I was so incensed at the repeat of the media’s prejudice against medieval science, that I considered writing to the BBC to propose a series on it to correct it. I ended up giving up altogether. If you go to the relevant pages on this, you’ll find that while the BBC will accept scripts and suggestions from outside the industry for drama, fiction and comedy, all factual content must be developed with a production company before they will consider it. What this means is that unless you are already a media insider, you have absolutely no chance of getting your idea for a factual series developed for TV.

I hope, however, that the Beeb’s view of medieval science will change, and that we can expect a series on it sometime soon. In the meantime, if anyone has any suggestions, how I can approach the Beeb or another TV channel or production company to get such a series made, please let me know. It’s about time we did something to challenge this fashionable atheist myth.