We are a worldwide social network of freethinkers, atheists, agnostics and secular humanists.

Latest Activity

Michel replied to Marc's discussion Mexican Toilets
24 minutes ago
Michel left a comment for Bishop Verde
29 minutes ago
Michel left a comment for Arthur Sawilejskij
30 minutes ago
Profile IconBishop Verde and Arthur Sawilejskij joined Atheist Universe
32 minutes ago
Mohamed updated their profile
37 minutes ago
Don commented on Adriana's group A World of Words
44 minutes ago
Mohamed added a discussion to the group Imagine No Religion
52 minutes ago
doone commented on Hope's group Imagine No Religion
2 hours ago
Marianne replied to Marc's discussion Dernières nouvelles in the group QUEBEC PUNCH
2 hours ago
Mohamed posted a blog post
2 hours ago
doone replied to Dallas Gaytheist's discussion The AVM Video Thread in the group Animal | Vegetable | Mineral
2 hours ago
Neal commented on doone's group USA & WORLD NEWS
4 hours ago
Neal commented on Michel's group FoxNews Watch
4 hours ago
Neal commented on Chris's group Right Wing Whackos
5 hours ago
Chris commented on Mark Strange's blog post The Eleven Satanic Rules of the Earth
5 hours ago
Davy replied to Marianne's discussion Are there superstitious atheists ?
5 hours ago

Birthdays

Birthdays Today

Birthdays Tomorrow

Information

Mathematics

"Mathematics is the gate and key of the sciences." (Roger Bacon)

Location: #science
Members: 28
Latest Activity: yesterday

Free and open online Mathematics course materials from MIT. Lecture notes, exams , audio video lectures, textbooks by MIT professors.

Discussion Forum

A mathematical model of obesity

Started by Adriana. Last reply by Hope May 16. 1 Reply

The New York Times published today a fascinating interview with mathematician Carson Chow from the National Institute of Diabetes, Digestive and Kidney Diseases (NIDDK), who has developed an equation that describes the problem of obesity and how American became so overweight in such a short period of time. He explains that a mathematical model may give an answer to the question much faster than experimental work or field work. He openly admits that the food industry lobby will not like his conclusions. According to Chow, it's the overproduction of food and the fact that it became so inexpensive that is causing this epidemics. Among the many surprising things his model predicts, is that if you're already obese, even an increase of 10 calories per day over long periods will cause you to gain more weight than if you are of normal weight and consume an extra 10 calories, every day. His model also predicts that humans are slow to respond to calorie intake changes, and that what counts is the # of calories consumed over the course of a year, not really daily variations in the food intake. I recommend reading the whole interview, is very interesting.A CONVERSATION WITH CARSON CHOWA Mathematical Challenge to ObesityMichael Temchine for The New York TimesFIGHTING OBESITY Carson Chow at a supermarket. Dr. Chow, a mathematician, has found that a food glut is behind America’s weight problem.By CLAUDIA DREIFUSPublished: May 14, 2012Carson C. Chow deploys mathematics to solve the everyday problems of real life. As an investigator at the National Institute of Diabetes and Digestive and Kidney Diseases, he tries to figure out why 1 in 3 Americans are overweight.We spoke at the recent annual meeting of the …Continue

Tags: science, model, health, obesity, mathematics

Predicting the distribution of Sasquatch in western North America - Starts With a Bang

Started by doone. Last reply by Michel Apr 16. 5 Replies

Weekend Diversion: Where Bigfoot DwellsCategory: Random Stuff • biology"You never need think you can turn over any old falsehoods without a terrible squirming of the horrid little population that dwells under it." -Oliver Wendell HolmesAs an astrophysicist, I get sent all sorts of (unsolicited) novel ideas and theories claiming to overturn everything from special relativity to quantum theory to the Big Bang. But the biologists get one very special type that I don't, that I was fortunate enough to have shared with me. This is not a case of physicists vs. biologists; on the contrary -- as the Be Good Tanyas might tell you -- this is what it sounds likeWhen Doves Cry.Because biologists get emails like this:I have been researching bigfoot in Washington and have 3 hours of video and castings of 2 different foot prints in the snow. I now have a chunk of hair I found on a broken tree branch. I need to find out what kind of animal it came from. It is about 3 inches long and like dry fishing line and there is some hair that is like a under coat or winter coat. You my think I'm crazy but that's ok because I know what I have and some day the world will know too.Now, the only evidence for bigfoot I've ever seen comes courtesy of …Continue

Tags: western, North, America, in, Sasquatch

Endre Szemerédi Wins Math's Biggest Prize

Started by Adriana Mar 22. 0 Replies

Endre Szemerédi Wins Math's Biggest Prizeby Barry Cipra on 21 March 2012, 6:35 PM | 0 CommentsEmail Print | MorePrevious Article…Continue

Tags: number theory, combinatorics, prize, math

The definitive answer: gender disparity in math ability is NOT biological

Started by Adriana. Last reply by Michel Feb 14. 6 Replies

From the American Mathematical Society, in its publication Notices, an excellent, thorough, full-of-data article was published: Debunking Myths about Gender and Mathematics Performance. It can be read for free at the link. The conclusion is that it is socioeconomic factors. Here you have it:Conclusions In summary, we conclude that gender equity and  other sociocultural factors, not national income, school type, or religion per se, are the primary determinants of mathematics performance at all levels for both boys and girls. Our findings are consistent with the gender stratified hypothesis, but not with the greater male variability, gap due to inequity, single-gender classroom, or Muslim culture hypotheses. At the individual level, this conclusion suggests that well-educated women who earn a good income are much better positioned than are poorly educated women who earn little or no money to ensure that the educational needs of their children of either gender with regard to learning mathematics are well met.It is fully consistent with socioeconomic status of the home environment being a primary determinant for success of children in school. At the national level, the United States ranked only thirty-first in mean mathematics performance out of the sixty-five countries that participated in the 2009 PISA. Eliminating gender discrimination in pay and employment opportunities could be part of a win-win formula for producing an adequate supply of future workers with high-level competence in mathematics.Wealthy countries that fail to provide gender equity in employment are at risk of producing too few citizens of either gender with the skills necessary to compete successfully in a knowledge-based economy driven by science and technology.But please go to the article, they tested many hypotheses and there are lots of graphs and…Continue

Tags: gap, gender, mathematics

Built on Facts

Loading… Loading feed

Comment Wall

Comment

You need to be a member of Mathematics to add comments!

Comment by doone yesterday
Comment by Michel on Saturday
Comment by doone on May 17, 2012 at 3:37pm
Comment by Michel on May 17, 2012 at 3:05pm
Comment by doone on May 17, 2012 at 1:24pm

Tim Curtin's incompetence with basic statistics

Category: Global Warming
Posted on: May 17, 2012 2:05 AM, by Tim Lambert

Tim Curtin's incompetence with basic statistics is the stuff of legend. Curtin has now demonstrated incompetence at a fairly new journal called The Scientific World Journal. Consider his very first "result" (emphasis mine):

I first regress the global mean temperature (GMT) anomalies against the global annual values of the main climate variable evaluated by the IPCC Hegerl et al. [17] and Forster et al. [28] based on Myhre et al. [29], namely, the total radiative forcing of all the noncondensing greenhouse gases [RF]

Annual(Tmean) = a + b[RF] + u(x)

The results appear to confirm the findings of Hegerl et al. [17] with a fairly high R^2 and an excellent t-statistic (>2.0) and P-value (<0.01) but do not pass the Durbin-Watson test (>2.0) for spurious correlation (i.e., serial autocorrelation), see Table 1. This result validates the null hypothesisof no statistically significant influence of radiative forcing by noncondensing GHGs on global mean temperatures.

Any first year stats student or competent peer reviewer should be able to tell you that you a statistical test cannot prove the null hypothesis. But it's far worse than that as Tamino explains:

The DW statistic for his first regression is d = 1.749. For his sample size with one regressor, the critical values at 95% confidence are dL = 1.363 and dU = 1.496. Since d is greater than dU, we do not reject the null hypothesis of uncorrelated errors.

This test gives no evidence of autocorrelation for the residuals. But Tim Curtin concluded that it does. He further concluded that such a result means no statistically significant influence of greenhouse gas climate forcing (other than water vapor) on global temperature. Even if his DW test result were correct (which it isn't), that just doesn't follow. ...

In other words, the regression which Curtin said fails the DW test actually passes, while the regression which he said passes, actually fails.

And -- the presence of autocorrelation doesn't invalidate regression anyway.

I have to wonder what kind of "peer-reviewed" scientific journal would publish this. Who were the referees for this paper?

And do check out Curtin's responses in comments where he insists that he didn't get it wrong. Curtin's understanding of statistics is so poor that he can't recognize his own mistakes.

Comment by Neal on May 14, 2012 at 7:12pm

Definitely.

Comment by Michel on May 14, 2012 at 6:38pm

This collection of pancakes is a keeper!
So many uses... 

Comment by doone on May 14, 2012 at 5:20pm

Fractal Pancakes

Fraktale Pfannkuchen von Saipancakes, wo’s noch mehr von dem Quatsch gibt. (via JWZ)

Comment by Neal on May 9, 2012 at 5:13pm

Liking the visuals. =)

Comment by doone on May 9, 2012 at 4:51pm
 
 
 

© 2012   Created by Atheist Universe.   Powered by

Badges  |  Report an Issue  |  Terms of Service