Just picked mine up today. Gotta love Nintendo’s innovation eh? You Xboxers and PS3ers can have your gun-thumbs; I’m going to start training for the Auckland Half Marathon in my lounge!
(and, no, that’s not me with the bowl haircut although I once sported a monstrosity similar to that but that was the 70s and it was, like, far out and almost choice)
In any given group of people, how many people do you think there need to be in order for there to be a 50% chance of at least two people sharing the same birthday?
365 / 2 = ~183 people?
Nope. Think again. This is not a trick question, just plain old mathematical probability.
The answer, which I found very counter-intuitive at first, is 23. It’s called the Birthday Paradox. The mistake I was making (and that most people would probably make) is that I was picking a single birthday and thinking of the probability of any given birthday matching it rather than moving on and testing for every other birthday possibility in the group.
I still struggle with it however, when I think back to school days where there should have been a 100% chance of two kids sharing a birthday in any two classes. I can’t remember anyone sharing a birthday at all.
(Or have I done the math wrong here by assuming that two classes of 23 students will give a 100% chance? Perhaps this equates to 75% instead or remains at 50%? Gaaah! I knew I should have listened in school!).
Jack, if you are reading this perhaps you could test this to see if it really works in a class situation?
Last month I signed up with New Scientist and ended up automatically sponsoring an orangutan in Borneo. We received the pack with photos of “Roy” (who’s very cute and undoubtedly adorning the fridges of many other people) and I never thought all that much else about it.
For my last post I was scavenging around for photos of apes and came across this and thought it worthy of a post of its own:
Ever wanted to know what blog posts you write require the least effort and get the most comments? No? Well I did and I threw together a bit of SQL to help me identify the areas I can improve upon if I’m to become a serious challenger for the title of the Laziest Blogger Ever™:
SELECT p.post_title, ROUND((SUM(LENGTH(w.comment_content))/LENGTH(p.post_content))*100) AS roi, LENGTH(p.post_content) AS post_length, SUM(LENGTH(w.comment_content)) AS comment_length FROM blog.wp_posts p INNER JOIN blog.wp_comments w ON w.comment_post_ID = p.ID GROUP BY p.ID ORDER BY roi DESC LIMIT 10
It returns the top 10 blog posts ranked by the percentage return on a post measured by the number of characters invested in the opening post compared to the number of characters returned in the comments.
My top 3:
(From chick.com)
Last year a study was performed by Sam Harris, Sameer A. Sheth and Mark S. Cohen where they used fMRI to observe the physical responses of the brain when a person was provided with statements that were taken to be true, false or otherwise. They found that different areas of the brain showed activity depending on how the subject perceived the statement.
Here is the abstract of the original study:
Objective: The difference between believing and disbelieving a proposition is one of the most potent regulators of human behavior and emotion. When one accepts a statement as true, it becomes the basis for further thought and action; rejected as false, it remains a string of words. The purpose of this study was to differentiate belief, disbelief, and uncertainty at the level of the brain.
Methods: We used functional magnetic resonance imaging (fMRI) to study the brains of 14 adults while they judged written statements to be “true” (belief), “false” (disbelief), or “undecidable” (uncertainty). To characterize belief, disbelief, and uncertainty in a content-independent manner, we included statements from a wide range of categories: autobiographical, mathematical, geographical, religious, ethical, semantic, and factual.
Results: The states of belief, disbelief, and uncertainty differentially activated distinct regions of the prefrontal and parietal cortices, as well as the basal ganglia.
Interpretation: Belief and disbelief differ from uncertainty in that both provide information that can subsequently inform behavior and emotion. The mechanism underlying this difference appears to involve the anterior cingulate cortex and the caudate. Although many areas of higher cognition are likely involved in assessing the truth-value of linguistic propositions, the final acceptance of a statement as “true” or its rejection as “false” appears to rely on more primitive, hedonic processing in the medial prefrontal cortex and the anterior insula. Truth may be beauty, and beauty truth, in more than a metaphorical sense, and false propositions may actually disgust us.
Oliver Sacks, in a review of the study said,
Harris et al. note that reactions of assent are significantly prompter than those of dissent or uncertainty. This they take to support “Spinoza’s conjecture that the mere comprehension of a statement entails the tacit acceptance of its being true,” an almost reflexive, if provisional, assent, to be followed by a more deliberate weighing and assessment. Human beings, in other words, are wired to “accept appearances as reality until they prove otherwise.” This seems to us to ring true.
The most provocative suggestion made by Harris et al. relates to their finding that all reactions of assent or acceptance (or belief, if one prefers) are neurophysiologically identical, whether propositional judgments are made in the highly charged realm of ethical or religious issues or the seemingly neutral realm of arithmetical statements. If such results can be duplicated, Harris et al. will have made a fascinating discovery.
The results of this original study have led to questions of whether religious faith ‘looks’ different than belief at the level of the brain and Harris is preparing for another study that will also use fMRI to observe the physical aspects of belief and faith.
In an attempt to find questions that will best suit the upcomming study Harris has set up four surveys and is looking for people who have opinions either way regarding Christianity to participate. If you are a Christian or an atheist/agnostic and you want to help them identify the most appropriate stimuli for the study you can complete one or more of the following surveys:
Each one has around 100 questions. I did C and it didn’t take too long.
A couple of weeks ago I purchased Carl Sagan’s 1979 TV series, Cosmos on DVD. Actually, it aired in 1980 but was filmed in 1979 and 1979 sounds way cooler than 1980.
It totally rocks!
Sure, he’s wearing beige and, sure, there has been progress in astronomy since the series was produced but I found myself learning plenty of new stuff with every episode. (Did you know that Eratosthenes calculated the earth’s circumference to within a margin of 5-10% back in 240BCE?).
What I love about the scientific method is that when done properly you present the facts as best you know them but remain open to future discoveries and you also disclose known weaknesses. In this series at the end of many of the episodes Sagan appears (looking greyer) with a “10 years later update” and very little of the original content needed revision. The only bit that stands out is that in one of the episodes he presents some of the experiments showing the creation of organic molecules in the laboratory and 10 years later added that they now believe it’s likely that the organic molecules may have formed in the icy bodies of comets.
Also, this was produced at a very uncertain time when the threat of all-out nuclear war seemed quite possible and many of his comments about the future of the human race are bracketed with “if we don’t destroy ourselves first”.
This series is a brilliant way to get an excellent perspective on our place in history and in the universe. It’s factual, balanced and remarkably well-produced. They even managed to avoid the temptation to use the snazzy synthesised music of the era (or is that ‘error’?) and instead opted for tasteful classical music.
Sagan had a very broad understanding of our universe and had a knack for presenting it in an extremely digestible way. With that understanding came an enthusiasm that remains contagious even after his death.
If you come across this series in your video store or for sale in a shop I’d encourage you to do yourself a favour and pick it up. And if you know me (this includes Dale, Ken, Frank and Jack), give me a yell if you want to borrow it and I’ll get it to you.
