# Posts

### July 24, 2014

+

9:51 AM | Gödel's Vienna: Finding Café Reichsrat

The Café Reichsrat in Vienna is notable as the place where Gödel, on August 26, 1930, first announced the incompleteness theorem to Carnap, Feigl, and Weismann. The members of the Vienna Circle had met there to prepare for the trip to the "Zweite Tagung für Erkenntnislehre der Exakten Wissenschaften," a satellite meeting to the congress of the German Society of Mathematicians organized by the Vienna Circle. This was where the famous symposium on the foundations of mathematics took place,
[…]

+

9:47 AM | Mathematicians' intuitions - a survey

I'm passing this on from Mark Zelcer (CUNY): A group of researchers in philosophy, psychology and mathematics are requesting the assistance of the mathematical community by participating in a survey about mathematicians' philosophical intuitions. The survey is here: http://goo.gl/Gu5S4E. It would really help them if many mathematicians participated. Thanks!

+

9:43 AM | Zeno’s Paradox - Numberphile

How can an infinite process end?
An explanation helpful for geometric series and limiting sums

+

9:30 AM | Student Created Slope Pages

This year, I was feeling a little uninspired when it came to creating notebook pages over finding slope in Algebra 1. We'd done lots of practice. And, most students seemed to grasp the concept. Since my students had watched me make notebook pages for an entire semester, I decided it was their turn. I split each class up into 3 groups and assigned them each a different way of finding slope - from a graph, from a table, and from two points. I told each group to […]

+

[We apologize if you receive multiple copies of this CFP.]
16th International Conference on Distributed Computing and Networking
January 4-7 2015, Goa, India http://www.icdcn.org
Important Dates
Due date for submission: July 25th 2014
Date for notification: September 26th 2014
Date for camera-ready submission: October 15th 2014
ICDCN is a premier international conference dedicated to addressing
advances in Distributed Computing and Communication Networks, which over
the years, has become
[…]

+

9:02 AM | Kissing the curve

Rachel Thomas
From a smile to a line drawing by Picasso, curves bring great beauty to our world. But how curvy is a curve?
From a smile to a line drawing by Picasso, curves bring great beauty to our world. Curves are also a beautiful and important part of mathematics and understanding curvature can shed light not just on
[…]

+

9:02 AM | Large-ish data packages in R

If you've played around with R enough, there comes a time when you just need some data to mess around …

+

7:48 AM | No uniform ultrafilters

Earlier this morning I received an email question from Yair Hayut. Is it consistent without the axiom of choice, of course, that there are free ultrafilters on the natural numbers but none on the real numbers? Well, of course that the answer is negative. If $\cal U$ is a free ultrafilter on $\omega$ then $\{X\subseteq\mathcal […]

+

7:47 AM | [DMANET] Last Week, July 26 || SENSORDEVICES 2014 || November 16 - 20, 2014 - Lisbon, Portugal

INVITATION:
=================
Please consider to contribute to and/or forward to the appropriate groups the following opportunity to submit and publish original scientific results to SENSORDEVICES 2014.
The submission deadline is extended to July 26, 2014.
Authors of selected papers will be invited to submit extended article versions to one of the IARIA Journals: http://www.iariajournals.org
=================
============== SENSORDEVICES 2014 | Call for Papers ===============
CALL FOR
[…]

+

This is a work in progress so we should cut the Khan Academy some slack. Even with that in mind, though, I'm seriously underwhelmed by the SAT prep materials up so far. I know their heart is in the right place, but from the skimpy selection to the low wattage instruction, there's just not that much here.I address the subject in more detail at the teaching site, You Do the Math, but I don't hit the bigger concern that I keep running into with these online learning ventures. As far as I can […]

+

trigonometry-is-my-bitch:
Geometrical visualisation of a 4D shape from a 3D Perspective - The Tesseract
Hypercubes are shapes with n dimensions where n is greater than the 3 dimensions of a normal cube. The Tesseract, or the 4-cube, is a 4 dimensional hypercube.
where n is the dimensional number, in any hypercube:
vertices = 2^n
edges = n(2^n-1 )
faces = 2^n-3(n-1)n

+

6:30 AM | 1809

1809 = 3 x 3 x 3 x 67.1809 is the sum of the first 26 palindromes (A046489).1809 is the sum of the first 17 primes whose indices are primes (A083186).1809 is a non-palindromic balanced number; the first and last half of its digits have the same sum (A145808).1809 is a multiple of 9 that contains 9 in its decimal representation (A121029).1809 is 3421 in base 8. It is 809 in base 15.1809 divides 373 - 1.Source: OEIS

+

5:47 AM | Completamento del quadrato

Completamento del quadrato. Parabola e circonferenza. Spiegazione :lol: © 2014, Angelo Stella. All rights reserved.

+

5:00 AM | Euclid in a Taxicab: Sparse Blind Deconvolution with Smoothed $\ell_1/ell_2$ Regularization

Laurent Duval just sent me the following:Dear IgorNuit Blanche is a nest of choice for many sparsities. The ones of concern here are those approximated by an $l_1/l_2$, or Taxicab/Euclidean norm ratio, which was already covered in some of your posts: http://nuit-blanche.blogspot.fr/2012/04/compressive-sensing-this-week.htmlhttp://nuit-blanche.blogspot.fr/2012/03/old-and-new-algorithm-for-blind.htmlhttp://nuit-blanche.blogspot.fr/2008/05/cs-kgg-explanation-of-l0-and-l1.html We propose
[…]

+

3:07 AM | Decimal Mistake in the News

Decimal points are small, and so easy to lose. And it appears that many of them were lost on FAFSA (Free Application for Federal Student Aid) forms, which is NOT a place that you would want incorrect data. According to an official document from July 18, people filling out the form were supposed to round monetary […]

+

2:03 AM | Coherent population forecasting using R

This is an example of how to use the demography package in R for stochastic population forecasting with coherent components. It is based on the papers by Hyndman and Booth (IJF 2008) and Hyndman, Booth and Yasmeen (Demography 2013). I will use Australian data from 1950 to 2009 and forecast the next 50 years. In demography, “coherent” forecasts are where male and females (or other sub-groups) do not diverge over time. (Essentially, we require the difference between the groups to be […]

+

1:50 AM | Large cardinals need not be large in HOD

[bibtex key=ChengFriedmanHamkins:LargeCardinalsNeedNotBeLargeInHOD] Continue reading →

+

I read an excellent article today ... Why Do Americans Stink at Math? Please, read it!Several years ago I read the book, Innumeracy: Mathematical Illiteracy and Its Consequences by John Allen Paulos. It was interesting to see documented the very thing I had heard too many times. Parents would say, "I was never good at math either. I can't even balance my checkbook." Not many people would admit to not being able to read the newspaper, but parent after parent […]

+

Another post from Tap Into Teen Minds. Enjoy!
Watch my Apple Distinguished Educator Showcase from the 2014 Global Institute in San Diego, California on Redefining Mathematics Education.
The post Redefining Mathematics Education #ADE2014 Showcase appeared first on Tap Into Teen Minds.

+

Last week there was an interesting twitter discussion on the nature of projects versus the nature of problems.@dandersod @samjshah @k8nowak @leslie_su76 How is Mega M&M a project rather than a problem?— Dan Meyer (@ddmeyer) July 17, 2014 It occurred with specific reference between the differences of PBL (project-based learning) and PrBL (problem-based learning). If you follow this blog or scan the provided tags you will find PBL does occupy some space here. There is also a large amount of
[…]

+

I was wondering whether the outerplanar strict confluent drawings I studied in a Graph Drawing paper last year had underlying diagrams whose treewidth is bounded, similarly to the treewidth bound for the usual outerplanar graphs. The confluent graphs themselves can't have low treewidth, because they include large complete bipartite graphs, but I was hoping that a treewidth bound for the diagram could be used to prove that the graphs themselves have low clique-width. Sadly, it turns out not to […]

+

trigonometry-is-my-bitch:
Geometrical visualisation of a 4D shape from a 3D Perspective - The Tesseract
Hypercubes are shapes with n dimensions where n is greater than the 3 dimensions of a normal cube. The Tesseract, or the 4-cube, is a 4 dimensional hypercube.
where n is the dimensional number, in any hypercube:
vertices = 2^n
edges = n(2^n-1 )
faces = 2^n-3(n-1)n

+

12:22 AM | Black Moon

I finished my masters a little more than a year ago and am starting a Ph.D. in two months. In the intervening year, I have done a little research, some teaching, and made the (very) occasional post here. I have … Continue reading →

+

12:11 AM | One quote that tells you everything you need to about Florida's culture of charter school oversight

From the Sun-Sentinel's previously mentioned profile of Steve Gallon III [emphasis added].The schools’ financial team began to caution the boards against overspending, flag certain payments, and raise concerns about Gallon’s seemingly unchecked authority.“I started warning board members,” said [Katrina] Lunsford, the financial manager.She also said: “He, from an overall standpoint, just started taking charge and taking over.”Records show the boards at times responded with
[…]

### July 23, 2014

+

11:10 PM | Discrete wiskunde

voorkennishet binomium van Newtonvolledige inductierecursieve formulesrekenkundige rijenmeetkundige rijenDat was nog een heel gedoe...

+

11:05 PM | #July2014Challenge: The other SBG

I had to work today, so I figured I would go for an easy blogpost. I am part of a blogging challenge to blog everyday in July, put together by druin. I figured an easy blogpost would be one where I am sharing one of the many amazing teaching resources or strategies that have been shared with me over the years. Enter SBG.No, I don't mean Standards Based Grading. When I first started reading blogs I saw SBG plastered all over blog links. This was really confusing,
[…]

+

11:00 PM | On This Day in Math - July 24

In mathematics the art of proposing a question must be held of higher value than solving it. ~Goerg CantorToday is the 205th day of the year; there are 205 pairs of twin primes less than ten thousand. *Number Gossip EVENTSIn 1673, Edmund Halley entered Queen's College, Oxford, as an undergraduate. Halley had attended the prestigious St. Paul's school, where in 1671, he was appointed captain, a position resembling today's student body president. He was an excellent student, and by the […]

+

A Democratic senator from Montana, John Walsh, is the latest high-profile politician to face plagiarism charges. The New York Times reports: …one of the highest-profile credentials of Mr. Walsh’s 33-year military career appears to have been improperly attained. An examination of the final paper required for Mr. Walsh’s master’s degree from the United States Army […]

+

10:36 PM | Flow

I have been doing a fair amount of yoga down here in NOLA. It was part of my commitment to myself that I would find a way to remain active during my stay here. (Especially with all the excellent fried cuisine and cocktails, it seemed a real priority to exercise.) I signed up for an unlimited introductory deal, and I have been doing an hour of fairly rigorous yoga every weekday without missing a beat. At first, because I had been away from the mat for so long (months, really), I had a hard time […]

+

10:19 PM | Wildcard Skepticism

Might there be excellent reasons to embrace radical skepticism, of which we are entirely unaware? You know brain-in-a-vat skepticism -- the view that maybe last night while I was sleeping, alien superscientists removed my brain, envatted it, and are now stimulating it to create the false impression that I'm still...