Condensed concepts

In 2016, when I saw the first results from the LIGO gravitational wave interferometer my natural caution and skepticism kicked in. They had just observed one signal in an incredibly sensitive measurement. A lot of data analysis was required to extract the signal from the background noise. That signal was then fitted the results of numerical simulations of the solutions to Einstein's gravitational field equations describing the merger of two black holes. Depending on how you count about 15 parameters are required to specify the parameters of the binary system [distance from earth, masses, relative orientations of orbits, .... The detection events involve displacement of the mirrors in the interferometer by about 30 picometres! What on earth could go wrong?! After all, this was only two years after the BICEP2 fiasco which claimed to have detected anisotropies in the cosmic microwave background due to gravitational waves associated with cosmic inflation. The observed signal turned ou

Someone told me that the day after your book is published you will start finding errors. They were correct. Here are the first errors I have become aware of. On Page 2 I erroneously state that diamond "conducts electricity and heat very poorly." However, the truth about conduction of heat is below, taken from the opening paragraph of this paper. Diamond has the highest thermal conductivity, L, of any known bulk material. Room-temperature values of L for isotopically enriched diamond exceed 3000 W/m-K, more than an order of magnitude higher than common semiconductors such as silicon and germanium. In diamond, the strong bond stiffness and light atomic mass produce extremely high phonon frequencies and acoustic velocities. In addition, the phonon-phonon umklapp scattering around room temperature is unusually weak. Figure 2 on page 4 has a typo. Diamond is "hard" not "hand". On page 82 I erroneously state that for the superfluid transition, the "critical

This is ultra-condensed matter physics! In 1931,  Subrahmanyan Chandrasekhar published a seminal paper, for which he was awarded the Nobel Prize in 1983. He showed that a white dwarf star must have a mass less than 1.4 solar masses, otherwise it will collapse under gravity. White dwarfs are compact stars for which the nuclear fuel is spent and electron degeneracy pressure prevents gravitational collapse.  The blog Galileo unbound has a nice post about the history and the essential physics behind the paper. There are a several things I find quite amazing about Chandrasekhar's derivation  and the expression for the maximum possible mass.  m_H is the mass of a proton. M_P is the Planck mass. The value of the mass limit is about 1.4 solar masses. Relativity matters If the electrons are treated non-relativistically then there is no mass limit. However, when the star becomes dense enough the Fermi velocity of the electrons approaches the speed of light. Then relativistic effects must b

 I am not sure I have seen this before. If you watched the movie Oppenheimer, you may have noticed that a one point a student excitedly showed Oppenheimer the latest issue of Physical Review and the following image flashed across the movie screen. On Continued Gravitational Contraction J. R. Oppenheimer and H. Snyder A beautiful blog post just appeared on 3 Quarks Daily,   September 1, 1939: A Tale Of Two Papers by Ashutosh Jogalekar The post describes the scientific and historical significance of the paper, including how it attracted no interest for twenty years, being eclipsed by a paper in the same issue of Physical Review. The Mechanism of Nuclear Fission Niels Bohr and John Archibald Wheeler Have you ever seen a Hollywood movie that explicitly showed the page of a scientific journal article.

My book has finally been released by Amazon  in the USA. I don't like Amazon but it is cheap and you can avoid shipping charges. In Australia Amazon has listed under "Engineering and Transportation" and is currently out of stock.