Another Gravitational Wave detection

June 16, 2016

Another gravitational wave detection by LIGO has been announced!

See https://www.ligo.caltech.edu/news/ligo20160615

The June 15 announcement page points out that while the signal was weaker than the first detection due to the black hole masses being smaller (14 and 8 solar masses vs 36 and 29):

…when these lighter black holes merged, their signal shifted into higher frequencies bringing it into LIGO’s sensitive band earlier in the merger than we observed in the September event. This allowed us to observe more orbits than the first detection–some 27 orbits over about one second (this compares with just two tenths of a second of observation in the first detection). Combined, these two factors (smaller masses and more observed orbits) were the keys to enabling LIGO to detect a weaker signal. They also allowed us to make more precise comparisons with General Relativity. Spoiler: the signal agrees, again, perfectly with Einstein’s theory.

The news release continues:

Our next observing interval – Observing Run #2, or “O2” – will start in the Fall of 2016. With improved sensitivity, we expect to see more black hole coalescences, and possibly detect gravitational waves from other sources, like binary neutron-star mergers. We are also looking forward to the Virgo detector joining us later in the O2 run. Virgo will be enormously helpful in locating sources on the sky, collapsing that ring down to a patch, but also helping us understand the sources of gravitational waves.

Gravitational Wave astronomy does seem to have arrived!

 

Commentary on Q&A’s church and politics

May 16, 2016

ABC’s Q&A on April 25 2016 discussed the relationship between the (Christian) church and politics and I’d like to make some observations from watching this. The panel consisted of:

  • John Haldane, Visiting Professor and Catholic intellectual
  • Julie McCrossin, (Uniting) Church elder and journalist
  • Ray Minniecon, Indigenous Anglican Pastor
  • Rev. Tiffany Sparks, Anglican Priest and representative for A Progressive Christian Voice;
  • Lyle Shelton, Managing Director, Australian Christian Lobby.

So, there was a Catholic, a representative of the Uniting Church (UC), two Anglicans, and a person of undeclared denomination. No Church of Christ, Lutherans, Baptists, Seven Day Adventists, Christian Scientists, Jehovah’s Witnesses. At least protestants and catholics of some sort were broadly represented I suppose.

I suppose it was an interesting discussion, albeit within the narrow confines of the Christian church. John Haldane was easiest to listen and seemed the most lucid, ironic, given the evils of the Catholic church.

Julie McCrossin suggested that people of other faiths (e.g. Muslim people) should have been included on the panel and mentioned that her particular UC encouraged columns from other religions in their newsletter. I wonder whether pastafarians, adherents of Jainism (a gentler, saner religion than most), Hindus, Buddhists, Satanists, or Scientologists are also welcome to speak in such a column? Or aren’t they “serious” religions?

This inclusiveness struck me as both positive and odd at the same time. Positive because dialogue of any sort is better than none. Odd because it seems to suggest unitarian leanings. Just as I was once encouraged not to be a fence sitter, an agnostic at the time, and so found my way to atheism, I would have thought that people of faith should make up their mind what counts as valid belief and what does not.

How can inter-faith dialogue even at the highest level recognise world views that are fundamentally incompatible and in principle, immune to revision? The truth is it really matters what billions of human beings believe and why they believe it.
(Sam Harris, Letter to a Christian Nation)

What bothers me about such talk of inter-faith dialogue, and certainly as expressed on Q&A, is that secularists including atheists are often not mentioned at all or only in passing, as if they couldn’t be moral agents. True, secular humanists, atheists and agnostics are the odd ones out here. Still, inter-faith dialogue just seems too much like the blind leading the blind or at least, the biased leading the biased.

John Haldane challenged Ray Minniecon about the claim that aboriginal people owned the land before white settlers arrived. A sensitive topic. There is of course, a need to acknowledge the awful details of our white settler history far more than we do, not just the romantic versions of it, the ANZAC spirit, and so on. But honestly, we really all need to get a grip. The idea that any human owns a country, an area of land, is very odd, and arguably just an artefact of the world we have constructed.

I have great sympathy with the idea that generations of aboriginal or other can live on a landscape and develop a  deep attachment to it; even a few days spent bushwalking can deeply affect you. But such experiences do not imply ownership.

Ray Minniecon made a reasonable yet familiar remark about white settlement having happened only a short time ago compared to the aboriginal settlement of Australia. I found myself puzzled by a follow-on comment from him about Christianity also being a blip in time compared to aboriginal settlement. It left me wondering why he was a Christian minister, given his apparently disinterested view of the importance of the appearance of Christ on Earth.

Of course, all human events are a blip in time compared to the age of the Universe. Again, we need to get over our pompous self-importance. In approximate terms, we have in reverse chronological order (and gap-riddled):

  • White settlement of Australia: 200 years ago
  • Birth of Christianity: 2000 years ago
  • Aboriginal occupation of Australia: 50,000 years ago
  • End of the reign of dinosaurs: 65 million years ago
  • Formation of Earth: 4.5 billion years ago
  • Big Bang: 13.8 billion years ago

I’ve always found the Cosmic Calendar quite compelling. Popularised by Carl Sagan on Cosmos, the whole timescale of the universe is compressed into 12 months. Nothing remotely human begins until late morning on December 31. The original settlement of Australia by seafarers didn’t happen until 11:58pm and the last few thousand years of human history occupies the last 30 seconds of the day!

cosmos-04-hulu

source: http://k1017fm.com/files/2014/03/Cosmos-04-Hulu.jpg

The totality of human civilisation on Earth is indeed a blip on the cosmic timescale. Arguably the most important thing to have happened in that final 30 seconds of December 31 was the invention of the Scientific Method, the only reliable way to understand the world. Not faith.

One of the greatest challenges facing civilisation in the 21st century is for human beings to learn to speak about their deepest personal concerns, about ethics, spiritual experience, and the inevitability of human suffering, in ways that are not flagrantly irrational. We desperately need a public discourse that encourages critical thinking and intellectual honesty. Nothing stands in the way of this project more than the respect we accord religious faith.

(Sam Harris, Letter to a Christian Nation)

Another early morning rainbow

February 23, 2016

About to ride to the bus station this morning; greeted by another nice rainbow:

 

Brought to us by the laws of physics. No pot of gold evident. Pity.

LIGO Gravitational Wave detection: the work of many…

February 13, 2016
I think it’s worth noting that 3 of the authors of the LIGO Gravitational Wave detection paper are listed as deceased (two in 2015 and 1 in 2012) and humbling to realise that, especially in a field like cosmology or particle physics, a scientist could spend his or her working life on something like this and never see the sought-after result.
binary-wave
It also emphasises that Science is usually not about a single person working in isolation, but about the work of many people collaborating and competing over a long period of time.
An ABC post about David Blair’s work on this for 40 years further underscores the point.
Congratulations to the hundreds (from the author list alone!) of scientists, engineers, and support people who contributed in some way to the first direct detection of gravitational values 100 years after their prediction from general relativity by Einstein.

It’s Darwin Day (actually)

February 11, 2016

Happy Darwin Day 2016!

charles-darwin-evolved-marketing-leader1

Freedom of thought is best promoted by the gradual illumination of men’s minds which follows from the advance of science. (Charles Darwin)

The darwinday.org website has lots of resources about the life and work of Charles Darwin (1809 to 1882) and the Richard Dawkins Foundation has recently added teacher materials.

From so simple a beginning endless forms most beautiful and most wonderful have been, and are being, evolved. (Charles Darwin, Origin of Species)

Meanwhile, let creationism talk itself into oblivion.

It has often and confidently been asserted, that man’s origin can never be known; but ignorance more frequently begets confidence than does knowledge; it is those who know little, and not those who know much, who so positively assert that this or that problem will never be solved by science. (Charles Darwin, The Descent of Man)

 

Marvin Minsky (1927 to 2016)

January 31, 2016

MIT Artificial Intelligence (AI) pioneer Marvin Minsky died at the age of 88 on January 24th in Boston.

2006_marvin_minsky1

See this EE Times blog post for a good summary.

Marvin Minsky’s participation in the 1956 Dartmouth Conference along with John McCarthy, Nathaniel Rochester, and Claude Shannon gave rise to the term artificial intelligence. While considerable progress has been made in the domain of machine intelligence, Minsky’s book The Emotion Machine deals with some of the more recalcitrant aspects of human-level intelligence.

His work ranged widely, including early work in neural networks (perceptrons) or connectionism and symbolic or classical AI including expert systems. I took university classes in classical AI and enjoyed experimenting with neural networks in the 90s, but my knowledge representation Master’s thesis was very much in the symbolic camp.

Minsky provided advice for the movie 2001: A Space Odessey regarding the delusional HAL 9000 computer. He made this remark about the film:

Kubrick’s vision seemed to be that humans are doomed, whereas Clarke’s is that humans are moving on to a better stage of evolution.

I’ll end with more Minsky quotes that provide some insight into this influential man’s thought processes. I particularly like the final tongue-in-cheek comment.

No computer has ever been designed that is ever aware of what it’s doing; but most of the time, we aren’t either.

If you just have a single problem to solve, then fine, go ahead and use a neural network. But if you want to do science and understand how to choose architectures, or how to go to a new problem, you have to understand what different architectures can and cannot do.

I believed in realism, as summarized by John McCarthy’s comment to the effect that if we worked really hard, we’d have an intelligent system in from four to four hundred years.

Peter Naur’s passing

January 21, 2016

Danish computer science pioneer, Peter Naur, died on January 3 2016 after a short illness, aged 87.

peter_naur sourcehttp://www.naur.com

 

Peter Naur received the ACM Turing award in 2005 for “…fundamental contributions to programming language design and the definition of Algol 60, to compiler design, and to the art and practice of computer programming”.

He is best known as the original editor of the Algol 60 Report, and as the “N” in BNF or Backus-Naur Form (with John Backus of Fortran, and other, fame), first used to describe the syntax of Algol 60. He objected to this and thought BNF should denote Backus-Normal Form instead. Nevertheless, MacLennan (1983), in Principles of Programming Languages: Evaluation and Implementation), notes the following about the connection between BNF and Naur:

Peter Naur, then the editor of the Algol Bulletin, was surprised because Backus’s definition of Algol-58 did not agree with his interpretation of the Algol-58 report. He took this as an indication that a more precise method of describing syntax was required and prepared some samples of a variant of the Backus notation. As a result, this notation was adopted for the Algol-60 report…

I gave examples of BNF from the Report along with Algol code fragments in a talk I gave to the Australian Computer Society about the 50th anniversary of Algol 60. Compiler construction tools like lex & yacc arose from the creation of BNF and variations such as EBNF (with which I have spent more time) led to more expressive and concise programming language grammars and still more powerful tools.

Alan Perlis commented in 1978, with a pun on the begin and end keywords used to delimit code blocks, that:

Algol’s is the linguistic form most widely used in describing the new exotic algorithms…Where important new linguistic inventions have occurred, they have been imbedded usually within an Algol framework, e.g. records, classes, definitions of types and their operations,…, modules. Algol has become so ingrained in our thinking about programming that we almost automatically base investigations in abstract programming on an Algol representation to isolate, define, and explicate our ideas…It was a noble begin but never intended to be a satisfactory end.

Others have remarked upon the contribution of Algol:

Here is a language so far ahead of its time that it was not only an improvement on its predecessors but also on nearly all its successors. (1980 Turing Award Lecture, C.A.R. Hoare)

Lisp and Algol, are built around a kernel that  seems as natural as a branch of mathematics. (Metamagical Themas, Douglas Hofstadter)

Algol 60 lives on in the genes of Scheme and Pascal. (SICP, Abelson & Sussman)

Block structure, lexical scope, and recursion are just a few features that no Pascal, C/C++, Python, Java, C# or  programmer would find surprising. Naur and his collaborators played a large part in shaping the programming languages we think and code in today. Scheme is a dialect of Lisp — Lisp predating Algol — that was ultimately influenced by it, e.g. lexical scope and by the “language report” document approach (see Revised Report on the Algorithmic language Scheme).

As Perlis alludes to above, many of the beneficiaries of the descendants of Algol are unaware of how their language constrains the way in which they think about programs and programming, the Sapir-Whorf hypothesis in action.

The late Dutch computer scientist, Edsger Dijkstra remarked:

Several friends of mine, when asked to suggest a date of birth for Computing Science, came up with January 1960, precisely because it was Algol 60 that showed the first ways in which automatic computing could and should and did become a topic of academic concern.

Naur started his career as an astronomer, but changed his profession after encountering computers. He was not fond of the idea of programming as a branch of mathematics and saw it as very much a human activity, the sub-title of a 1992 book (Computing: A Human Activity) by Naur. Section 1.4 entitled Programming as Theory Building challenges the simplistic Agile mantra that source code is all that matters, whereas in fact, like JPEG image files, it can be seen as a lossy format, a distillation of a programmer’s thoughts with lost context, mitigated only in part by appropriate comments (an art form in itself).

Peternaur

sourcehttps://en.wikipedia.org/wiki/Peter_Naur

In Programming as Theory Building, Naur outlines scenarios relating to writing a compiler for similar languages and the development of a large real-time industrial monitoring system. In his words:

The conclusion seems inescapable that at least with certain kinds of large programs, the continued adaption, modification, and correction of errors in them, is essentially dependent on a certain kind of knowledge possessed by a group of programmers who are closely and continuously connected with them.

Naur was offered a professorship in computer science at the University of Copenhagen in 1969. He thought that computer science was fundamentally about the nature and use of data, didn’t much like the phrase and coined the term datology, which he thought had a more human orientation, giving rise to what has been called the Copenhagen interpretation of computer science (as opposed to quantum physics).

Later in his career, Peter Naur was critical of contemporary conceptions of science and philosophy, developed a theory of human thinking called Synapse-State Theory of Mental Life, contrasted human vs computer thinking (see this video) and rejected the possibility of strong AI. I may not agree with all of Naur’s ideas in this area, but consider them worth hearing.

As an aside, this Y-Combinator post about Naur’s passing makes the interesting observation that a number of widely used programming languages other than Algol 60 have Danish origins, e.g.

  • PHP (Rasmus Lerdorrf)
  • Turbo Pascal, Delphi, C# (Anders Hejlsberg)
  • C++ (Bjarne Stroustrup)

It has occurred to me increasingly in the last few years that many of our field’s pioneers are reaching the end of their lives. Even confining oneself to those associated with programming language design and implementation, since 2010, at least the following have died:

  • Denis Ritchie: C
  • John McCarthy: Lisp
  • Robin Milner: ML
  • Peter Naur: Algol

Before I started writing this post, I knew about Naur’s association with Algol 60 and BNF, but that’s about all. Now I’ve discovered that, like so many pioneers, he had depths I have only just started to explore, even if confining myself to his work Computing: A Human Activity.

 

Critique of a Christian pamphlet

December 14, 2015

Most Friday nights, Christian street preachers and pamphleteers inhabit Adelaide’s Rundle Mall. One pamphlet offered to me recently had the title The Final Flicker.

candle_flame_light_214001

In summary, the pamphlet makes the following assertions:

  1. Everyone will die.
  2. The time of our death is unknown.
  3. The sudden death of a loved one shocks and distresses.
  4. The Bible can provide answers to the questions about life, but Science cannot. Neither can friends or doctors.
  5. Our time here and now is only a space in which to prepare for after death, according to the Bible.
  6. The Bible is clear that after death we go to one of two places, Heaven or Hell, and it’s your choice.
  7. God never created man for Hell, but…
  8. God is holy and just and cannot live in the presence of sin, so…
  9. Heaven is only for those who have had their sins forgiven, those who have been made righteous.
  10. Hell is the sad and necessary place of those who refuse God’s mercy.
  11. The Bible says that whoever believes in God’s son will not perish but have everlasting life.
  12. God is just, so must punish sins.
  13. God loves each of us, despite of our sin.
  14. All have sinned and fallen short of God’s glory.
  15. Jesus was the son of God, holy, pure, and sinless.
  16. The sacrificial death of Jesus on the cross took away our sins.
  17. He was the only one who was able to do this.
  18. Death could not hold him. On the third day he rose.
  19. He now sits at the right hand of God.
  20. All you have to do is repent, turn from your sin, trust Him as your Saviour and you will be saved.

The first two are self-evident: we’re going to die but we don’t know when. For anyone who has lost someone close, the third is not hard to fathom either. Actually, it’s patronising and pedantic. Everyone dies. Welcome to Life.

Point 4 says that the Bible has all the answers about life and that friends and scientists don’t. This is a bold claim indeed and needs to be justified.

That which can be asserted without evidence can be dismissed without evidence. (Christopher Hitchens)

The fifth point declares that the purpose of life is only to prepare for death. Really? How depressing. Another unjustified claim unworthy of further attention. Nothing to see here. Move along…

Hmm. Wait. If these people really believed what they said, namely that the purpose of life is only to prepare for death, then why wait? Why not just end their lives now? I suppose the counter claim will be that suicide is a sin. Phew!

EDIT: After reading this post, a friend pointed out that since all sins should be forgiven, even this is not really an objection.

Another objection a Christian apologist may raise is: time is needed for such preparation. But how much preparation and of what kind? If it’s just a matter of believing something, well, anyone can do that, at anytime. If life is a moral training ground, and salvation comes from good works, then sure, that would take time. But, skipping to the end, point 20 says:

All you have to do is repent, turn from your sin, trust Him as your Saviour and you will be saved.

So no good works are required, just turning away from sin and having faith.

Higher up the list again: point 6 says that the Bible is clear that after death we go to Heaven or Hell.

Crystal clear?

What biblical verse declares this so unambiguously? The pamphlet is keen to point to specific verses to “back up” other points. Why not this one, given its obvious importance?

Perhaps it should quote Matthew 25:41. Want to see what that would mean in practice? Read points 7 to 10 again, view as much of  the The Thinking Atheist’s video Burn Victims as you can and then ask yourself whether any aspect of a god who would send one of its own creatures to such an unimaginably hideous place could ever be considered good, just or righteous in any meaningful sense.

Point 11 brings us to John 3:16, the idea that if we just believe in God, we won’t be punished for our sins eternally but will have, a better, eternal life. That brings us back to the question I raised above: how much preparation is necessary and of what kind? Well, if we just have to believe, then we can end it all at any time! Right?

Surely this is all just too much like a game…

God could simply declare that everyone can come to the eternal party. Apparently this god requires the attention and adoration of its creatures. But an all powerful god should want for nothing. Right?

Point 12 declares that “God is just, so must punish sins”. That’s like me saying that I have a strong sense of morality, so I should punish those who don’t, or at least those who do “wrong”. Oh, I forgot. I’m not a god… Apparently, you need to have created a universe to be able to call yourself “just”.

All other points (12 to 17) are in need of evidence, not the least of which:

  • that Jesus was the only one who could atone for our sins;
    • including weak “supporting” Old Testament prophecy fulfilment claims such as referred to in the pamphlet: Isaiah 53:5;
    • that there were any sins in need of atonement in the first place;
  • that Jesus rose from the dead and…
  • now lives with God;
  • that salvation (if necessary at all), is attained by faith alone and not by works;
    • i.e. that in order to be saved, you don’t have to be good, just gullible.
The person who is certain, and who claims divine warrant for his certainty, belongs now to the infancy of our species.
(Christopher Hitchens)

In the end, the essence of the pamphlet is this:

  • We will all die.
  • All of us have sinned and fallen short of God (Romans 3:23).
  • Jesus sacrificed himself for our sins.
  • Belief in Jesus leads to eternal life rather than eternal punishment.

The only positive thing I can say about any of this is that at least the pamphleteers are being consistent regarding core Christian claims, rather than adhering to some watered down theology consisting of only a vague notion of god, like many liberal denominations. That’s not to say anything about the veracity of the fundamentalist’s claims of course.

One particularly obnoxious idea that emerged in antiquity is Pascal’s wager, the “argument” that it is in our best interest to assume that God (but which?; there are so many to choose from) exists, to avoid the possibility of eternal punishment.

If God does not exist, the thinking goes, nothing has been lost, right?

Wrong! A life of pointless servitude can been avoided if a person recognises the distinct possibility that monotheism is an off-by-one error, i.e. that there is no evidence that any god exists, some version of the Judaeo-Christian god or any other, so that the correct number of gods is not one but zero.

Based upon the available evidence, this is all an atheist claims. My son noted this short animation recently, which makes a pretty compelling case for the off-by-one error.

In fact, “atheism” is a term that should not even exist. No one ever needs to identify himself as a “non-astrologer” or a “non-alchemist.”… Atheism is nothing more than the noises reasonable people make in the presence of unjustified religious beliefs.
(Sam Harris, Letter to a Christian Nation)

The Universe revealed by Science is rich enough. We don’t need to add our own unfounded complexity. Science and engineering have created the modern world that so many of us are fortunate to live in and is, along with critical thinking more generally, the only hope for solving our biggest problems.

If religious instruction were not allowed until the child had attained the age of reason, we would be living in a quite different world.
(Christopher Hitchens)

I get that people are afraid to die and find the idea of losing those they care about difficult to bear. The deep-felt desire for an afterlife is, I think, at the heart of most religions, whether openly acknowledged or not.

However, given the challenges to our way of life from climate change and dogmatic thinking, it’s not okay to retreat into The Dark like frightened children.

Come on people, grow up! We are not at the centre of things.

I’ll end with another quote from Hitchens, who has said it all better than I ever could:

The only position that leaves me with no cognitive dissonance is atheism. It is not a creed. Death is certain, replacing both the siren-song of Paradise and the dread of Hell. Life on this earth, with all its mystery and beauty and pain, is then to be lived far more intensely: we stumble and get up, we are sad, confident, insecure, feel loneliness and joy and love. There is nothing more; but I want nothing more.

 

 

Back to Future with (g)vi(m)

October 24, 2015

In the 90s I was pretty happy if you sat me down with a C compiler and vi. Any programmer, at least if exposed to a Unix variant of some kind, will know about the sometimes quirky but very powerful editor, vi. At UTAS as a computer systems officer (“jack of all trades, master of none”: coding, soldering, networking, software/hardware installation), I taught vi and other Unix-related topics to academics in short courses; later, as a junior academic, I continued to use it whenever on a Unix system. It may sound a bit sad, but one of the happiest 2 weeks of employment was spent in a portable office (terrapin style) with a DEC VT220 terminal, SunOS (or it may have been Solaris by then) Unix, a C compiler and vi, with which I was tasked to write the core of a student enrolment system at UTAS, still in use for several years after I left.

I also occasionally used emacs and, on pre-OS X Macs, whatever editor the IDE (integrated development environments, although I suspect they weren’t called that at the time) provided, for example: THINK C.

On the Amiga I used an editor that came with AmigaDOS (ED or EDIT was, I think, the name), MicroEMACS, and at least one port of vi. These, especially the fairly minimalist MicroEMACS, were perfectly fine for developing my ACE Amiga BASIC compiler.

I’ve also had a go at writing a simple editor or two, including one for a PICK mainframe email system I developed as an undergraduate project.

Upon finding the need to leave UTAS (due to university funding cuts around 1996) I was offered work with a Tasmanian Internet Service Provider (ISP) as a programmer and sysadmin, when things were just getting started in that area. Being paid to code in C and learning Perl kept me happy for while, although I knew at the start that I’d want something more than to work for an ISP but it was a great opportunity. Best of all I was able to provide employment for one of my former UTAS students there after I left, giving him a start in the game. There, as always, was vi, this time on FreeBSD and BSDi Unix systems.

When I started working for Motorola (and later Freescale Semiconductor) in 1997, I found a fairly even split between use of vi and emacs there (under Solaris), along with a high degree of religious adherence to one or the other, the kind of zeal that still accompanies the adherents of particular programming languages. I’ve always had a fascination for the LISP programming language, so emacs with its in-built LISP interpreter won points on that front, along with specific modes of use in the Motorola/Freescale environment.

These days I’m a bit of a generalist when it comes to both editors and programming languages (C, C++, Java, Python, R etc), although I have my favourites and those less favoured. That’s the subject of another post, I think.

On any given day, I could find myself using vi, emacs, Eclipse, Visual Studio, PyCharm and various other IDEs. On Unix (okay, Linux systems now) or cygwin I have for many years tended to use vi (okay, vim, its now dominant incarnation) for quick editing when I want an editor now and emacs for more complex editing. Despite the power of modern IDEs, they are, like modern operating systems, often slow resource hogs, and tend to leave me a bit cold. At least some of these have emacs and vi modes for their editors. There are other newcomer editors under Windows and Unix that while fine, don’t compel me to want to use them. To be fair to IDEs though, if you need non-trivial source-level debug, they’re hard to beat. Having said that, I’ll still break out a command-line debugger when it’s appropriate.

Now, as a software engineer with CSIRO, especially in Linux high performance compute (HPC) cluster environments coding in C++, I find myself using vi or in particular gvim (“graphical vi improved”) in that context more and more again. Once more I’m really loving its power and simplicity, including tags for source code navigation, split windows, and all the keyboard shortcut goodness that have always made vi fast and productive to work with. Also better from a resource usage point of view on a HPC system.

Maybe this is partly motivated by a nostalgic streak, but mostly arises from a pragmatic approach.

Anyway, sometimes improving on the past is not so easy or at best only incremental.

Double rainbow

August 31, 2015

My wife Karen was in the front yard early this morning and called out to come have at look at this nicely defined (and double) rainbow:


  
As she remarked, the spectrum of colours was really obvious in parts.

Nice start to the day, followed by a quick ride and dash to the bus.


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