Components of components of components…

By the end of my last post, science had reached the level of GCSE physics/chemistry; the world is made of atoms, atoms consist of electrons orbiting a nucleus, and a nucleus consists of a mixture of positively charged protons and neutrally charged neutrons. Some thought that this was the deepest level things could go; that everything was made simply of these three things and that they were the fundamental particles of the universe. However, others pointed out the enormous size difference between an electron and proton, suggesting that the proton and neutron were not as fundamental as the electron, and that we could look even deeper.

In any case, by this point our model of the inside of a nucleus was incomplete anyway; in 1932 James Chadwick had discovered (and named) the neutron, first theorised about by Ernest Rutherford to act as a ‘glue’ preventing the protons of a nucleus from repelling one another and causing the whole thing to break into pieces. However, nobody actually had any idea exactly how this worked, so in 1934 a concept known as the nuclear force was suggested. This theory, proposed by Hideki Yukawa,¬†held that nucleons (then still considered fundamental particles) emitted particles he called mesons; smaller than nucleons, they acted as carriers of the nuclear force. The physics behind this is almost unintelligible to anyone who isn’t a career academic (as I am not), but this is because there is no equivalent to the nuclear force that we encounter during the day-to-day. We find it very easy to understand electromagnetism because we have all seen magnets attracting and repelling one another and see the effects of electricity everyday, but the nuclear force was something more fundamental; a side effect of the constant exchange of mesons between nucleons*. The meson was finally found (proving Yukawa’s theory) in 1947, and Yukawa won the 1949 Nobel Prize for it. Mesons are now understood to belong to a family of particles called gluons, which all act as the intermediary for the nuclear strong force between various different particles; the name gluon hints at this purpose, coming from the word ‘glue’.

*This, I am told, becomes a lot easier to understand once electromagnetism has been studied from the point of view of two particles exchanging photons, but I’m getting out of my depth here; time to move on.

At this point, the physics world decided to take stock; the list of all the different subatomic particles that had been discovered became known as ‘the particle zoo’, but our understanding of them was still patchy. We knew nothing of what the various nucleons and mesons consisted of, how they were joined together, or what allowed the strong nuclear force to even exist; where did mesons come from? How could these particles, 2/3 the size of a proton, be emitted from one without tearing the thing to pieces?

Nobody really had the answers to these, but when investigating them people began to discover other new particles, of a similar size and mass to the nucleons. Most of these particles were unstable and extremely short-lived, decaying into the undetectable in trillionths of trillionths of a second, but whilst they did exist they could be detected using incredibly sophisticated machinery and their existence, whilst not ostensibly meaning anything, was a tantalising clue for physicists. This family of nucleon-like particles was later called baryons, and in 1961 American physicist Murray Gell-Mann organised the various baryons and mesons that had been discovered into groups of eight, a system that became known as the eightfold way. There were two octets to be considered; one contained the mesons, and all the baryons with a ‘spin’ (a quantum property of subatomic particles that I won’t even try to explain) of 1/2. Other baryons had a spin of 3/2 (or one and a half), and they formed another octet; except that only seven of them had been discovered. Gell-Mann realised that each member of the ‘spin 1/2’ group had a corresponding member in the ‘spin 3/2’ group, and so by extrapolating this principle he was able to theorise about the existence of an eighth ‘spin 3/2’ baryon, which he called the omega baryon. This particle, with properties matching almost exactly those he predicted, was discovered in 1964 by a group experimenting with a particle accelerator (a wonderful device that takes two very small things and throws them at one another in the hope that they will collide and smash to pieces; particle physics is a surprisingly crude business, and few other methods have ever been devised for ‘looking inside’ these weird and wonderful particles), and Gell-Mann took the Nobel prize five years later.

But, before any of this, the principle of the eightfold way had been extrapolated a stage further. Gell-Mann collaborated with George Zweig on a theory concerning entirely theoretical particles known as quarks; they imagined three ‘flavours’ of quark (which they called, completely arbitrarily, the up, down and strange quarks), each with their own properties of spin, electrical charge and such. They theorised that each of the properties of the different hadrons (as mesons and baryons are collectively known) could be explained by the fact that each was made up of a different combination of these quarks, and that the overall properties of ¬†each particle were due, basically, to the properties of their constituent quarks added together. At the time, this was considered somewhat airy-fairy; Zweig and Gell-Mann had absolutely no physical evidence, and their theory was essentially little more than a mathematical construct to explain the properties of the different particles people had discovered. Within a year, supporters of the theory Sheldon Lee Glashow and James Bjorken suggested that a fourth quark, which they called the ‘charm’ quark, should be added to the theory, in order to better explain radioactivity (ask me about the weak nuclear force, go on, I dare you). It was also later realised that the charm quark might explain the existence of the kaon and pion, two particles discovered in cosmic rays 15 years earlier that nobody properly understood. Support for the quark theory grew; and then, in 1968, a team studying deep inelastic scattering (another wonderfully blunt technique that involves firing an electron at a nucleus and studying how it bounces off in minute detail) revealed a proton to consist of three point-like objects, rather than being the solid, fundamental blob of matter it had previously been thought of. Three point-like objects matched exactly Zweig and Gell-Mann’s prediction for the existence of quarks; they had finally moved from the mathematical theory to the physical reality.

(The quarks discovered were of the up and down flavours; the charm quark wouldn’t be discovered until 1974, by which time two more quarks, the top and bottom, had been predicted to account for an incredibly obscure theory concerning the relationship between antimatter and normal matter. No, I’m not going to explain how that works. For the record, the bottom quark was discovered in 1977 and the top quark in 1995)

Nowadays, the six quarks form an integral part of the standard model; physics’ best attempt to explain how everything in the world works, or at least on the level of fundamental interactions. Many consider them, along with the six leptons and four bosons*, to be the fundamental particles that everything is made of; these particles exist, are fundamental, and that’s an end to it. But, the Standard Model is far from complete; it isn’t readily compatible with the theory of relativity and doesn’t explain either gravity or many observed effects in cosmology blamed on ‘dark matter’ or ‘dark energy’- plus it gives rise to a few paradoxical situations that we aren’t sure how to explain. Some say it just isn’t finished yet, and that we just need to think of another theory or two and discover another boson. Others say that we need to look deeper once again and find out what quarks themselves contain…

*A boson is anything, like a gluon, that ‘carries’ a fundamental force; the recently discovered Higgs boson is not really part of the list of fundamental particles since it exists solely to effect the behaviour of the W and Z bosons, giving them mass

Art vs. Science

All intellectual human activity can be divided into one of three categories; the arts, humanities, and sciences (although these terms are not exactly fully inclusive). Art here covers everything from the painted medium to music, everything that we humans do that is intended to be creative and make our world as a whole a more beautiful place to live in. The precise definition of ‘art’ is a major bone of contention among creative types and it’s not exactly clear where the boundary lies in some cases, but here we can categorise everything intended to be artistic as an art form. Science here covers every one of the STEM disciplines; science (physics, biology, chemistry and all the rest in its vast multitude of forms and subgenres), technology, engineering (strictly speaking those two come under the same branch, but technology is too satisfying a word to leave out of any self-respecting acronym) and mathematics. Certain portions of these fields too could be argued to be entirely self-fulfilling, and others are considered by some beautiful, but since the two rarely overlap the title of art is never truly appropriate. The humanities are an altogether trickier bunch to consider; on one hand they are, collectively, a set of sciences, since they purport to study how the world we live in behaves and functions. However, this particular set of sciences are deemed separate because they deal less with fundamental principles of nature but of human systems, and human interactions with the world around them; hence the title ‘humanities’. Fields as diverse as economics and geography are all blanketed under this title, and are in some ways the most interesting of sciences as they are the most subjective and accessible; the principles of the humanities can be and usually are encountered on a daily basis, so anyone with a keen mind and an eye for noticing the right things can usually form an opinion on them. And a good thing too, otherwise I would be frequently short of blogging ideas.

Each field has its own proponents, supporters and detractors, and all are quite prepared to defend their chosen field to the hilt. The scientists point to the huge advancements in our understanding of the universe and world around us that have been made in the last century, and link these to the immense breakthroughs in healthcare, infrastructure, technology, manufacturing and general innovation and awesomeness that have so increased our quality of life (and life expectancy) in recent years. And it’s not hard to see why; such advances have permanently changed the face of our earth (both for better and worse), and there is a truly vast body of evidence supporting the idea that these innovations have provided the greatest force for making our world a better place in recent times. The artists provide the counterpoint to this by saying that living longer, healthier lives with more stuff in it is all well and good, but without art and creativity there is no advantage to this better life, for there is no way for us to enjoy it. They can point to the developments in film, television, music and design, all the ideas of scientists and engineers tuned to perfection by artists of each field, and even the development in more classical artistic mediums such as poetry or dance, as key features of the 20th century that enabled us to enjoy our lives more than ever before. The humanities have advanced too during recent history, but their effects are far more subtle; innovative strategies in economics, new historical discoveries and perspectives and new analyses of the way we interact with our world have all come, and many have made news, but their effects tend to only be felt in the spheres of influence they directly concern- nobody remembers how a new use of critical path analysis made J. Bloggs Ltd. use materials 29% more efficiently (yes, I know CPA is technically mathematics; deal with it). As such, proponents of humanities tend to be less vocal than those in other fields, although this may have something to do with the fact that the people who go into humanities have a tendency to be more… normal than the kind of introverted nerd/suicidally artistic/stereotypical-in-some-other-way characters who would go into the other two fields.

This bickering between arts & sciences as to the worthiness/beauty/parentage of the other field has lead to something of a divide between them; some commentators have spoken of the ‘two cultures’ of arts and sciences, leaving us with a sect of sciences who find it impossible to appreciate the value of art and beauty, thinking it almost irrelevant compared what their field aims to achieve (to their loss, in my opinion). I’m not entirely sure that this picture is entirely true; what may be more so, however, is the other end of the stick, those artistic figures who dominate our media who simply cannot understand science beyond GCSE level, if that. It is true that quite a lot of modern science is very, very complex in the details, but Albert Einstein was famous for saying that if a scientific principle cannot be explained to a ten-year old then it is almost certainly wrong, and I tend to agree with him. Even the theory behind the existence of the Higgs Boson, right at the cutting edge of modern physics, can be explained by an analogy of a room full of fans and celebrities. Oh look it up, I don’t want to wander off topic here.

The truth is, of course, that no field can sustain a world without the other; a world devoid of STEM would die out in a matter of months, a world devoid of humanities would be hideously inefficient and appear monumentally stupid, and a world devoid of art would be the most incomprehensibly dull place imaginable. Not only that, but all three working in harmony will invariably produce the best results, as master engineer, inventor, craftsman and creator of some of the most famous paintings of all time Leonardo da Vinci so ably demonstrated. As such, any argument between fields as to which is ‘the best’ or ‘the most worthy’ will simply never be won, and will just end up a futile task. The world is an amazing place, but the real source of that awesomeness is the diversity it contains, both in terms of nature and in terms of people. The arts and sciences are not at war, nor should they ever be; for in tandem they can achieve so much more.