Archive for the ‘Sentence(s) of the day’ Category

Police and politics

April 27, 2013

‘Police business,’ he said almost gently, ‘is a hell of  a problem. It’s a good deal like politics. It asks for the highest type of men, and there’s nothing in it to attract the highest type of men. So we have to work with what we get …

That is from Raymond Chandler’s The lady in the lake. An enjoyable read if you are into mysteries.

Fault-tolerant discovery!

November 28, 2011

Michael Nielsen’s piece (Some) garbage in, gold out is the must-read of the day; to give you a flavour, here are some excerpts from the piece:

How many people have truly mastered quantum field theory, statistical inference, detector physics, and distributed computing?What, then, should we make of any paper announcing that the Higgs boson has been found?

Standard pre-publication peer review will mean little. Yes, it’ll be useful as an independent sanity check of the work. But all it will show is that there’s no glaringly obvious holes. It certainly won’t involve more than a cursory inspection of the evidence.

When discoveries rely on hundreds of pieces of evidence or steps of reasoning, we can be pretty sure of our conclusions, provided our error rate is low, say one part in a hundred thousand. But when we start to use a million or a billion (or a trillion or more) pieces of evidence or steps of reasoning, an error rate of one part in a million
becomes a guarantee of failure, unless we develop systems that can tolerate those errors.

It seems to me that one of the core questions the scientific community will wrestle with over the next few decades is what principles and practices we use to judge whether or not a conclusion drawn from a large body of networked knowledge is correct? To put it another way, how can we ensure that we reliably come to correct conclusions, despite the fact that some of our evidence or reasoning is almost certainly wrong?

Or think of the loss of the Mars Climate Orbiter. That’s often described as a failure to convert between metric and imperial units, which makes it sound trivial, like the people at NASA are fools. The real problem was deeper. As a NASA official said:

People sometimes make errors. The problem here was not the error [of unit conversion], it was the failure of NASA’s systems engineering, and the checks and balances in our processes to detect the error. That’s why we lost the spacecraft.

In other words, when you’re working at NASA scale, problems that are unlikely at small scale, like failing to do a unit conversion, are certain to occur. It’s foolish to act as though they won’t happen. Instead, you need to develop systems which limit the impact of such errors.

In the context of science, what this means is that we need new methods of fault-tolerant discovery.

… one useful source of ideas may be systems and safety engineering, which are responsible for the reliable performance of complex systems such as modern aircraft. According to Boeing, a 747-400 has six million parts, and the first 747 required 75,000 engineering drawings. Not to mention all the fallible human “components” in a modern aircraft. Yet aircraft systems and safety engineers have developed checks and balances that let us draw with very high probability the conclusion “The plane will get safely from point A to B”. Sounds like a promising source of insights to me!

Have fun!

Sentence of the day

August 30, 2011

Every generation gets the self-help guru that it deserves.

From here; via Abi.

Growth and ways of knowing

June 18, 2011

Growth involves movement through five progressively more complex ways of knowing, which Kegan referred to as stages of development in 1982, orders of consciousness in 1994, and forms of mind in 2000.

From here.

The two senses of normal

July 30, 2010

Paul Graham:

The world is more addictive than it was 40 years ago. And unless the forms of technological progress that produced these things are subject to different laws than technological progress in general, the world will get more addictive in the next 40 years than it did in the last 40.

The next 40 years will bring us some wonderful things. I don’t mean to imply they’re all to be avoided. Alcohol is a dangerous drug, but I’d rather live in a world with wine than one without. Most people can coexist with alcohol; but you have to be careful. More things we like will mean more things we have to be careful about.

Most people won’t, unfortunately. Which means that as the world becomes more addictive, the two senses in which one can live a normal life will be driven ever further apart. One sense of “normal” is statistically normal: what everyone else does. The other is the sense we mean when we talk about the normal operating range of a piece of machinery: what works best.

These two senses are already quite far apart. Already someone trying to live well would seem eccentrically abstemious in most of the US. That phenomenon is only going to become more pronounced. You can probably take it as a rule of thumb from now on that if people don’t think you’re weird, you’re living badly.

Take a look!

Protecting yourself against modern perils

July 8, 2010

With time, as with money, avoiding pleasure is no longer enough to protect you. It probably was enough to protect hunter-gatherers, and perhaps all pre-industrial societies. So nature and nurture combine to make us avoid self-indulgence. But the world has gotten more complicated: the most dangerous traps now are new behaviors that bypass our alarms about self-indulgence by mimicking more virtuous types. And the worst thing is, they’re not even fun.

Paul Graham in his latest piece.

Experiments and theory

July 2, 2010

I want to emphasize, however, that the role of numerical simulation at best is not essentially different from that of carefully controlled experimentation, especially in situations like this where the underlying physical model seems well understood. Experiments, both real and numerical, can test existing theoretical ideas and inspire new ones, but cannot substitute for fundamental theory.

J S Langer, Models of pattern formation in first-order phase transitions, in Directions in condensed matter physics: memorial volume in honor of Shang-keng Ma, Edited by G Grinstein and G Mazenko, World Scientific, 1986.

Argumentational skills for different contexts

January 21, 2010

Winston Churchill once praised the argumentational skills of the celebrated barrister and politician F. E. Smith, 1st Earl of Birkenhead, by stressing their suitability to context: ‘The bludgeon for the platform; the rapier for a personal dispute; the entangling net and unexpected trident for the Courts of Law; and a jug of clear spring water for an anxious perplexed conclave’.

Andrew Aberdain in his enjoyable The informal logic of mathematical proof (in 18 unconventional essays on the nature of mathematics).

Resorting to the indignity of …

August 24, 2009

Numerical simulations!!! P W Anderson as quoted here (via ZapperZ):

Very few believed [localization] at the time, and even fewer saw its importance; among those who failed to fully understand it at first was certainly its author. It has yet to receive adequate mathematical treatment, and one has to resort to the indignity of numerical simulations to settle even the simplest questions about it.

—Philip W. Anderson, Nobel lecture, 8 December 1977

Captions for photographs

June 5, 2009

Yes! Sometimes, they make a very interesting reading too; like this one for example, which reads, partly:

… the technology awareness workshop on “Sorting of Mangoes based on internal defects using soft X-Ray imaging” at CEERI Centre

Internal defects? Soft X-ray imaging? And, who would have thought mangoes and sorting can be used in the same sentence with those other two phrases? Not me, at least!