The Giant's Shoulders #10

Every scientist stands on the shoulders of giants as they add just a little bit more to what their intellectual forbears had achieved in science. In the same vein and as the host for the April edition of The Giant's Shoulders, I stand on the shoulders of the previous giant (singular), The Evilutionary Biologist, where I link to blog posts talking about classic papers in science and important people or concepts in the history of science. And Curving Normality will be the next host in May.

Dijkstra's algorithm

Dijkstra's algorithm for finding the shortest paths in a graph is a classical one that most students of computer science get to learn about, although I suspect few have actually read the original paper. Published in the very first volume of the journal Numerische Mathematik in 1959, an official copy of the three-page paper A Note on Two Problems in Connexion with Graphs is available from SpringerLink, although you would have to be at an academic institution with a subscription or have a personal subscription to SpringerLink to download the paper.

Continue reading "Dijkstra's algorithm"

The not so perfectly smooth rings of Saturn

I have always been impressed by how smooth the rings of Saturn look like. But the rings are actually made up of small chunks of ice, and sharp-eyed users at the Unmanned forum noticed that thousands of small boulders and moonlets were casting shadows on the ring, reminding us that the ring is not just one huge solid thing. It helps that the Sun is now lower on the horizon from the viewpoint of the rings, which means that longer shadows are cast.

Shadows cast on the rings of Saturn
Shadows cast on the rings of Saturn

Repealing "right of conscience" excuses

Now that the Obama administration is about to repeal the "right of conscience" rule, which was a thinly veiled last-minute attempt by the Bush administration to withhold healthcare in abortion and birth control and so broadly worded so as to sidestep controversy over reproductive healthcare (not that it worked), I hope they don't get cold feet. Certain religious groups are now trying to convince the Obama administration not to repeal the rule.

If the rule doesn't get repealed, I fear we will see ridiculous cases like a doctor letting a woman in his care die for lack of CPR because "it's against his religious beliefs to touch women". This might be an extreme example, but it's not as if similar things are not already happening. And a broad right of conscience rule for healthcare means that there would be no consequences for withholding healthcare when it should be reasonably expected, even in life-threatening situations.

Conversion between theism and atheism

When a religious person encounters an atheist who used to be a devout follower of the same religion, a response that is all too commonly heard is that the current atheist never used to be a believer. Complete rubbish in almost every case, it's hardly impossible for a theist to become an atheist or vice versa.

Not that I always believe it when a theist claims to have been an atheist in the past. I would take it at their word if it was just that, but often enough the claim is accompanied by "I was angry at God", which completely demolishes the credibility: it is a little hard to be so angry at something one does not even think exists. I put slightly more credence to claims for someone to have converted to a religion out of intellectual reasons, except the claims almost invariably undermine themselves as the intellectual arguments put forward tend to be really bad, not even passing the "the same sort of reasoning would not apply to another contradictory religion" filter. There have been exceptions, although the religious concepts have been so watered down that they may as well not have been religions.

Without extraneous and dubious claims as the above, I would usually take a theist's claim that they used to be an atheist at their word. Oddly enough, it's much rarer to see a current atheist with a dubious claim to having previously been a theist. It might be because I'm biased ...