Emergence in the Game of Life

How do complex structures emerge from simple systems?
How do you define emergence?

Conway's Game of life is a popular and widely studied version of cellular automata. It is based on four simple rules for the evolution of a two-dimensional grid of squares that can either be dead or alive. What is amazing is that distinct patterns: still lifes, oscillators, and spaceships can emerge.

Gosper's glider gun is shown below.

What does this have to do with strongly correlated electron systems?
The similarity is that one starts with extremely simple "rules": a crystal structure plus Coloumb's law and the Schrodinger equation (Laughlin and Pines' Theory of Everything) and complex structures emerge: quasi-particles, broken symmetry states, topological order, non-Fermi liquids, ...

Recently, Sophia Kivelson and Steven Kivelson [daughter and father] proposed the following definition:

An emergent behavior of a physical system is a qualitative property that can only occur in the limit that the number of microscopic constituents tends to infinity.

I think this would mean the properties above would not be classified as emergent. I am not sure I agree. I think I still prefer older broader definitions such as that of Michael Berry in terms of singular expansions or that of P. Luisi.
The definition also disagrees with Michael Polanyi, who argued that language and grammar are emergent.

My ambivalence to anonymous blog comments

Although this blog has a wide readership one thing it struggles with is to attract many comments, and particularly much back and forth discussion. Sometimes people tell me that this is just because it is not provocative or controversial enough.

A while ago I changed the settings to allow anonymous comments and this has led to an increase in comments which is encouraging. However, I do have some ambivalence about this. 

Ideally, any comment and opinion should be judged on the merits of its content not based on who is giving it. We should beware of arguments from authority. On the other hand, that is not the way most of us think and act. We do give some weight to the author. For example, an anonymous commenter says "I am a physicist and I am a climate change skeptic" it does not have the same weight as the opinion of a respected physicist who has relevant expertise.

I am also concerned that people are not willing to take the risk of being publically identified with their views. This does not just reflect on the commenter but also reflects poorly on the scientific and academic community. Why are people so hesitant? Is the community so intolerant of controversial views? 

Here I should say I am very sympathetic to some peoples nervousness. At least twice, I suggested to younger colleagues who did not have permanent jobs that they delete specific comments they made on the blog that were critical of the "establishment".

I welcome discussion.

Nevertheless, please don't let my ambivalence stop you making comments.

An ode to long service leave

Australia has many unique things besides kangaroos and koalas. Long service leave (LSL) is a generous and egalitarian feature of the "welfare" state. After ten years working for the same employer [or the same sector such as government universities] an employee is granted three months fully paid vacation. (The exact terms and conditions vary slightly between states and employers). LSL is available to all full-time employees, regardless of whether they are janitor or CEO. This is in addition to four (plus) weeks of annual leave and for faculty in addition to "sabbaticals" [called Special Studies Program in my university]. If an employee resigns any unused balance is "cashed out".

University faculty work hard and some are workaholics. Many don't even take their allotted annual vacation, let alone LSL. Balances carry over each year and so some faculty have large balances. The "accountants" (who basically run the university) don't like this because LSL is a "liability" on their spreadsheets. If all of the faculty with large balances resigned at the same time the university would have to "cash" them out and there would be no money available to hire replacements for several months. Who would do the teaching, research, and admin? The university would grind to a halt....
However, this is pretty silly because the likelihood of massive simultaneous resignations of this particular group is extremely unlikely. When an individual does resign one can always wait a while to rehire and others absorb their "workload". Furthermore, this is likely to happen anyway, because replacing people, particularly senior ones, takes a while anyway.

Nevertheless, because the accountants rule, faculty are put under pressure to take LSL and recreation leave (vacation) if they have large balances. Specifically at UQ, when a staff member has a balance of more than 15 weeks of LSL they can be "directed" to take leave to reduce their balance. In fact, we now receive emails from the Executive Dean telling us that in our annual appraisal (performance review) we have to discuss the issue and come up with a written plan of how we will reduce our leave balance. On one level this is fine. However, on another level, this just reflects skewed priorities. We do not get explicit instructions and reminders (and threats) to discuss and plan how to engage better with students, set more challenging assessment, focus on research quality rather than quantity, be critical about metrics, ...

So what do people do with their LSL?
Is it actually in the best interests of the university for people to take it?

Here are some specific examples I am aware of.

1. Keep going to your office and doing research but no teaching or admin. The problem is that legally the university does not want this as they don't have liability insurance for you while on campus.

2. Treat it as a sabbatical and visit another institution. The problem is that you are on vacation as far as the university is concerned and so cannot use grant money for travel.

3. Have a long vacation and come back refreshed and motivated.

4. Have a great vacation and decide to retire early.

5. Spend the time looking for a new job. During this time many things and important decisions are left in limbo, before the employee eventually leaves.

Although most of these options may be good for the employee, they may not be the best thing for the employer. Thus, in the bigger scheme of things, forcing people to take LSL is debatable.
There is more to an institution than spreadsheets....

Having said all this I should say that I am really enjoying my LSL. The picture below is from a kayak trip in the San Juan Islands, near my mother-in-law's house, which also features sunsets such as above.

The rise of BS in science and academia

I never thought I would write a blog post with such a word in it.

In today’s Seattle Times there is an editorial about fake news and an opinion piece, How to fine-tune your BS meter, by Jevin West.
At the University of Washington, West and Carl Bergstrom, have started a course entitled, Calling BS: Data reasoning for the digital age.
West states:

Our philosophy is that you don’t need a Ph.D. in statistics or computer science to call BS on the vast majority of data bullshit. If you think clearly about what might be wrong with the data someone is using and what might be wrong about the interpretation of their results, you’ll catch a huge fraction of the bullshit without ever going into the mathematical details.  

Unfortunately, this applies to science as much as to Fake News. On his blog, Peter Woit discusses the rise of Fake Physics.

Science is in trouble when the word I most often hear associated with the name of a particular Ivy League science Professor is BS. Furthermore, in many contexts, I hear people dismiss specific papers,
particularly that appear in luxury journals, as “just BS”.

A good question is what criteria should we use to distinguish between uncritical enthusiasm, marketing, hype, and BS?

I first thought of writing a post on this subject when I encountered this video clip from CNN.
I thought, “Wow! Who is this commentator?” Maybe I should have known, but I learned that Fareek Zakaria has quite a following, a Ph.D. in Political Science from Harvard, and is rightly viewed as a serious commentator, regardless of whether you agree with his political leanings.
The commentary is based on a number one New York Times bestseller, On BS  by Harry Frankfurt, a distinguished Princeton philosopher.

Debating emergence and reductionism

As part of a TV documentary, Why are we here? produced by Ard Louis and David Malone there is a nice series of interviews where emergence is discussed by George Ellis, Peter Atkins, and Denis Noble.
I can't seem to embed the interviews here and so have put in links to short clips.

George Ellis discusses the difference between weak and strong emergence and his attitude to each.

In separate clips, Denis Noble discusses emergence  and reductionism in biology.

Peter Atkins, a hardcore reductionist, IMHO does not seem to seriously engage with the issue.