"ตรวจสายต่อต่างๆก่อน"

วันนี้ผมได้ข่าวว่าผลที่นักวิทยาศาสตร์จับเวลาแล้วพบว่านิวตริโนวิ่งเร็วกว่าแสงอาจเกิดจากข้อผิดพลาดที่สายต่อแบบเส้นใยนำแสงต่อกับการ์ดในคอมพิวเตอร์ไม่แน่น พอไขให้แน่นแล้วพบว่าเวลาที่บอกว่านิวตริโนวิ่งมาถึงก่อนแสงจะหายไป จึงน่าจะเป็นสาเหตุที่ทำให้ผลการทดลองออกมาเป็นอย่างนั้น

พอผมได้ยินข่าวนี้ปุ๊บ ผมก็คิดถึงคำแนะนำที่มีประโยชน์กับผมมากมากว่า 25 ปีแล้ว คือถ้ามีปัญหาอะไรเกี่ยวกับคอมพิวเตอร์หรืออิเลคทรอนิคส์ทั้งหลาย ให้ตรวจดูก่อนว่าสายไฟและสายสัญญาณต่างๆต่ออยู่แน่นดีไหม ผมเห็นคำแนะนำนี้เป็นครั้งแรกในบทความของ Jerry Pournelle ตอนที่เขายังเขียนบทความให้นิตยสาร Byte อยู่ ผมจำคำแนะนำนี้ได้ขึ้นใจและใช้มันเสมอๆเมื่อต้องแก้ปัญหาเกี่ยวกับเครื่องไฟฟ้าอิเลคทรอนิคส์ทั้งหลาย

หวังว่าท่านผู้อ่านจะนำเอาไปใช้นะครับ ชีวิตท่านน่าจะดีขึ้นบ้าง :-)

Monkeynomics! :-D

This is super interesting. The talk suggests that our irrational decisions are hardwired in the brain, since monkeys (whose most recent common ancestors we share lived about 35 million years ago), make the same kind of irrational decisions.

(If you have trouble listening to English, there's a transcript on the linked page too.)

Interesting Warnings About Power Law Distributions

I've wondered about some data that might be distributed according to a certain power law and I found these two links to be informative: So You Think You Have a Power Law — Well Isn't That Special? and Power-law distributions in empirical data.

The abstract of the paper in the second link reads:

Power-law distributions occur in many situations of scientific interest and have significant consequences for our understanding of natural and man-made phenomena. Unfortunately, the detection and characterization of power laws is complicated by the large fluctuations that occur in the tail of the distribution -- the part of the distribution representing large but rare events -- and by the difficulty of identifying the range over which power-law behavior holds. Commonly used methods for analyzing power-law data, such as least-squares fitting, can produce substantially inaccurate estimates of parameters for power-law distributions, and even in cases where such methods return accurate answers they are still unsatisfactory because they give no indication of whether the data obey a power law at all. Here we present a principled statistical framework for discerning and quantifying power-law behavior in empirical data. Our approach combines maximum-likelihood fitting methods with goodness-of-fit tests based on the Kolmogorov-Smirnov statistic and likelihood ratios. We evaluate the effectiveness of the approach with tests on synthetic data and give critical comparisons to previous approaches. We also apply the proposed methods to twenty-four real-world data sets from a range of different disciplines, each of which has been conjectured to follow a power-law distribution. In some cases we find these conjectures to be consistent with the data while in others the power law is ruled out.

A Research I Really Want To Be True

Someone pointed this research summary to me. It says that if we restrict our food to 20-50% of normal calories on one day and we eat till we are full the next day, we gain a lot of health benefits.

The excerpt:

"Since May 2003 we have experimented with alternate day calorie restriction, one day consuming 20-50% of estimated daily caloric requirement and the next day ad lib eating, and have observed health benefits starting in as little as two weeks, in insulin resistance, asthma, seasonal allergies, infectious diseases of viral, bacterial and fungal origin (viral URI, recurrent bacterial tonsillitis, chronic sinusitis, periodontal disease), autoimmune disorder (rheumatoid arthritis), osteoarthritis, symptoms due to CNS inflammatory lesions (Tourette's, Meniere's) cardiac arrhythmias (PVCs, atrial fibrillation), menopause related hot flashes."

If this is true, I will starve one day and go to a buffet the next day and live longer! I'm sure that after the one starving day, the food at the buffet will taste even better :-D

"Semantic Associations Between Signs And Numerical Categories In The Prefrontal Cortex" or MONKEYS CAN COUNT!

Read the full paper describing how Ilka Diester and Andreas Nieder performed experiments suggesting that monkeys can count integers.

Next, we should teach them number theory so they can work on prime numbers. For some adventurous monkeys, we might try calculus, set theory, or differential geometry! Oh wait, we already have such monkeys, they are called math and physics grad students! :-D

Here is the Author Summary:

We use symbols, such as numbers, as mental tools for abstract and precise representations. Humans share with animals a language-independent system for representing numerical quantity, but number symbols are learned during childhood. A first step in the acquisition of number symbols constitutes an association of signs with specific numerical values of sets. To investigate the single-neuron mechanisms of semantic association, we simulated such a mapping process in rhesus monkeys by training them to associate the visual shapes of Arabic numerals with the numerosity of multiple-dot displays. We found that many individual neurons in the prefrontal cortex, but only a few in the posterior parietal cortex, responded in a tuned fashion to the same numerical values of dot sets and associated shapes. We called these neurons association neurons since they establish an associational link between shapes and numerical categories. The distribution of these association neurons across prefrontal and parietal areas resembles activation patterns in children and suggests a precursor of our symbol system in monkeys.

Bizarre Experiments

See how far people were willing to go in the name of science! Here are twenty very surprising/strange/horrifying/or just plain cool experiments collected by Alex Boese, the author of Elephants on Acid: And Other Bizarre Experiments.

I especially like #2, #7, #12, #16, #17, and #19.