Dork Scratchings

  I picked up this fantastic little book in Cambridge market a few days ago.  Published in 1908 by the Society for the Promotion of Christian Knowledge , it summarizes a lecture performed by Professor J Perry in 1890 in Leeds. The theme of the Romance of Science series is that remarkable and unexpected things can be discovered from the study of the apparently mundane.  In this lecture Professor Perry performs a series of experiments on various designs of spinning top and shows i.) What causes the precessional motion of a spinning top ii.) That a subterranean race could determine that we live on a spinning planet without ever seeing the stars iii.) Why the precessional motion of a top is in the same orientation as the spin, but the precessional motion of the Earth is in the opposite orientation iv.) Why some spinning tops stand up when you spin them on their side and even v.) A model of how a magnetic field might cause the observed rotation of plane polarized light The q...

Lockdown reading My lockdown reading list consists of just one book. This might last a long time I thought, so it's my opportunity to make a 2nd stab at understanding Quantum Field Theory. Last time, I bought "Quantum Field Theory for the gifted Amateur" and I learned a lot from it. Mainly that I am not gifted! I got three chapters through it and then gave up on the book, and on quantum field theory. This time round I did my research better and found a much more gentle book: Student Friendly Quantum Field Theory, by Robert D. Klauber . It covers the same material, but takes pains not to lose the reader, by spelling out every ambiguity and subtlety. I'm half way through and feeling quite chuffed with myself. Here I am studying hard, on a sunny day in Lockdown Britain: No, the weights are not mine In this book, and every other in the QFT literature there is a concept of some particles being virtual. What's this about?  Why are some virtual and o...

COBE CMB fluctuations. Original Source: NASA All tortoiseshell cats are female.  Males can be black, or ginger, but never tortoiseshell.  The reason for this is that the mechanism by which tortoiseshell cats get the patterns on their coats depends on having two X chromosomes.  This is all described beautifully in Chapter 7 of "Junk DNA", by Nessa Carey . Females have twice as many X chromosomes as males, which on the face of it should result in 100% more expression for the genes on that chromosome.  This should lead to much greater differences between males and females than we actually see.  To put this in perspective, Down's syndrome is caused by individuals having 3 copies of chromosome 21 instead of 2.  But this is a far smaller chromosome than X and the difference is only 50%, rather than 100%.  (The fact that chromosome 21 is so small is the reason Down's syndrome is more common than syndromes in which there are too many copies of more impo...

  Original Image: Mariuswalter CC BY-SA 4.0 I've just finished reading "A Crack In Creation" by Jennifer Doudna and Samuel Sternberg.  Doudna is the co-creator of CRISPR, the gene editing tool that genuinely is a Cracking Creation.  (I don't think the pun was intended since the word Cracking is not used much outside of and Wallace and Grommit appreciation societies, however, it would have been incredibly apt if it were!) If you are interested in How-Things-Work then this is a book for you.  I knew next to nothing about cell biology before starting it and now I feel like a pro.  The authors' writing style is incredibly clear, but what really saves you from the sense of drowning in acronym soup are the excellent illustrations throughout the book.  So, if you have heard the terms: DNA, RNA, base pair, ribosome, amino acid, protein, phage, virus, prokaryote, ... and so on, but aren't really sure what these things are or how they relate to each other th...

A review of Our Mathematical Universe (Max Tegmark) Our Mathematical Universe was my summer holiday reading this year.  But it turned out to be much more than just something to keep me occupied while lounging on the beach.  This book has changed my conception of reality.  The themes in the book are similar in nature to those in The Fabric of Reality by David Deutch - another one of my favourite books.  However, instead of restricting the argument to the parallel universes predicted by Everett's Universal Wavefunction, Tegmark takes us on a tour of four levels of multiverse.  More than this, he provides an overarching theoretical framework for understanding them based on what he calls "the A-word" (because using its full name is guaranteed to get your paper rejected). The argument goes like this.  Whenever we find Nature appears finely tuned to make self-aware life possible, then there are 3 possible explanations It's a fluke! It's design! (by a...

The Theoretical Minimum series by Leonard Susskind et al. My favourite books by a long way.  They do exactly what it says on the tin: Provide the minimum level of theory to start doing Physics properly. Prior to reading these books I had read a lot of pop-science and was always left with an uneasy feeling that I'd been duped. Having chosen to keep the audience broad the authors of most pop science struggle to communicate the concepts, and usually fall back on analogy - or wonder! - creating ambiguity and misunderstanding. (There is one notable exception - Feynman's QED: The Strange Theory of Light and Matter .) The Theoretical Minimum series side steps the problems faced by most science communicators by assuming the readers do have some tools under their belt.  Specifically basic calculus.   It's then able to take the quickest possible route to the edge of science .  (Okay, maybe not the edge, but it feels like it.)  Just don't skip any bits because t...

If you know me, you'll know I am positively obsessed with quantum physics and the whole Many Worlds Interpretation business.  No day goes by without me thinking about it, and my overriding obsession is to try to find a way to explain it to the less obsessed.  And, that's not easy - as my many mad ramblings at friends in the pub have proved to me. You think you have it simmered down to a perfect elevator pitch, and then, an opportunity! a potential convert! and the words get all jumbled.  Because it is only then that the mathematical knowledge assumed becomes apparent. About a year ago I read The Fabric Of Reality , and I realized that, thankfully, there exists a far, far smarter person with the same obsession as me.  Chapter 2 - Shadows - consists of the most perfect explanation - derivation even - of the reality of parallel worlds.  I wish I'd thought of it. The author David Deutsch starts off with the standard double slit experiment.  Then, li...

I ended up buying the book for the Tensor Calculus course.  Almost all the material is available for free in the youtube series, but I wanted to own a trophy.  I was also partly motivated by a sense of guilt - having gatecrashed a complete university course for free I felt I should at least leave the host a bottle of wine.... Having said that, I have delved into it a couple of times since.  The first time was because I was left with a slight sense of incompleteness by the course after it stated but did not prove Gauss' Divergence Theorem in general coordinates.  (The proof is in one of the final chapters.)  The second time was much later. I was preparing to learn GR and I needed a refresher in TC to boost my confidence.