Mathblogging.orgRecent Postshttp://www.mathblogging.org/scripts/feed.php2014-09-16T00:53:55-04:00No copyright asserted over individual posts; see original posts for copyright and/or licensing.Mathblogging.org Atom serializerA proposition about complete funcoids and reloidshttp://www.mathblogging.org/post/988082014-09-15T17:13:41-04:00Victor PortonIn this recent blog post I have formulated the conjecture: Conjecture A funcoid is complete iff for a complete reloid . This conjecture has not been living long, I have quickly proved it in this note.A Solved Problem in Ornithologyhttp://www.mathblogging.org/post/988062014-09-15T17:09:00-04:00metooMarbled Murrelets are cute birds, for long time, with a mystery. This article starts with "The nest and nesting habits of the Marbled Murrelet remain unknown. This is the more remarkable when it is remembered that the bird is common throughout the summer season from Alaska and Kodiak Islands south to Washington, and that many able field naturalists have sought to penetrate the mystery of its home life.'' and ends with, ``Which Ornithological detective will solve the
[…]El testalegohttp://www.mathblogging.org/post/988112014-09-15T16:59:37-04:00ricardosLos lectores de este blog recordarán nuestra serie “domingo bíblico“, donde cada domingo publicamos una bonita cita de la biblia. Ahora les recomiendo la página The Brick Testament, con las mismas citas (y muchas otras más) del mismo librito, pero ilustradas con legos."La matematica dei Pink Floyd" al Festival "Frontiere letterarie"http://www.mathblogging.org/post/988022014-09-15T16:58:00-04:00Paolo AlessandriniDa tarthiev.deviantart.comL'autunno 2014 si preannuncia molto interessante per gli appassionati dei Pink Floyd. A parte la grande mostra "The Pink Floyd Exhibition", che doveva essere inaugurata il 19 settembre e invece è stata rinviata a tempo indeterminato, i fan sono in ansia per l'uscita del nuovo disco "The endless river", prevista per il mese di ottobre.<br />Gli esperti sono divisi tra chi sostiene che si tratterà di una raccolta di scarti e chi giura che il nuovo album non potrà che essere […]Correction on the recent theoremshttp://www.mathblogging.org/post/988092014-09-15T16:45:10-04:00Victor PortonAbout new theorems in in this my blog post: I’ve simplified this theorem: Theorem A reloid is complete iff . into Theorem A reloid is complete iff for a complete funcoid . For a proof see this note. The next theorem: Theorem A funcoid is complete iff . collapses into Theorem , what I proved […]La Sunmobile della General Motorshttp://www.mathblogging.org/post/988042014-09-15T16:44:02-04:00UnknownSu Corrierino e Giornalino, qualche giorno fa, è stata pubblicata la scannerizzazione di una pagina con due trafiletti di Mauro Janni del 17 gennaio 1965 in cui quello superiore è dedicato all'automobile solare della General Motors. In effetti l'automobile solare, la Sunmobile, è un modellino di poco meno di 40 cm costruito da William Cobb e presentato il 31 agosto del 1955 a un motor show a Chicago. Il modello, in legno di balsa, presentava 12 piccoli pannelli solari su tutta la parte […]Welding Math and Metal – Day 2http://www.mathblogging.org/post/988102014-09-15T16:13:49-04:00Megan SchmidtIf I needed to choose the most productive portion of most students’ week, Monday morning, first hour would be pretty low on the hierarchy of engagement. I was undeterred because making sure we had the correct solution was important. We discussed that the radius of the spool would decrease every time a layer of wire […]Typical 2nd Gr Assessment Questions and Your Thoughts...http://www.mathblogging.org/post/988012014-09-15T16:06:00-04:00Dave MarainImagine that. I'm not promoting my problems/solutions! As posted on my twitter account (twitter.com/dmarain) today... Here are a couple of typical questions your 2nd grade child/student may be working on... 1.<br> (Clock shows 1:00)<br> In 1/2 hour, it will be ___. Mathematical Practices Reflections...<br> Why do you believe some children would struggle with this? <br> Possible teacher/parent interventions? 2.<br> Write arrow rule. Fill in missing frames..<br> 5---?---15---?---25---? Mathematical
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[…]Class Opener – Day 10 – the Venn Menuhttp://www.mathblogging.org/post/988052014-09-15T16:00:51-04:00Bob LochelAfter a probability quiz on Friday, students were given a problem to tackle and finish for homework. The problem, Come Fly With Me (shared below), features many overlapping events which students need to process. Ideally, the problem is best summarized … Continue reading →Linear Equation from 2 points P2- Cutting out what you don’t needhttp://www.mathblogging.org/post/987922014-09-15T15:58:21-04:00banderson02So I am really looking over problems I have posted and am trying to see if I have fallen into the Teacher trap of being “too helpful” with directions. Looking at this problem: Using the numbers 1 to 4, using each only once, create 2 points that lie on a line with the following conditions: […]Calculus Going Viral?… Could It Behttp://www.mathblogging.org/post/987902014-09-15T15:30:00-04:00"Shecky Riemann"<br />Forbes Magazine reports on Ohio State professor Jim Fowler taking calculus to the Web via Coursera (and getting rave reviews):<br />http://tinyurl.com/lz2smt2<br /><br />And he's on YouTube, if you don't want to sign up for Coursera without getting a sampling first:<br />https://www.youtube.com/user/kisonecat<br /><br />here's his intro to the course:<br /><br /><br /><br /><br />Launching Today: Mathematica Online!http://www.mathblogging.org/post/987862014-09-15T15:20:44-04:00Stephen WolframIt’s been many years in the making, and today I’m excited to announce the launch of Mathematica Online: a version of Mathematica that operates completely in the cloud—and is accessible just through any modern web browser. In the past, using Mathematica has always involved first installing software on your computer. But as of today that’s [...]Launching Today: Mathematica Online!http://www.mathblogging.org/post/987872014-09-15T15:12:24-04:00Stephen WolframIt’s been many years in the making, and today I’m excited to announce the launch of Mathematica Online: a version of Mathematica that operates completely in the cloud—and is accessible just through any modern web browser. In the past, using Mathematica has always involved first installing software on your computer. But as of today that’s [...]Launching Today: Mathematica Online!http://www.mathblogging.org/post/987972014-09-15T15:12:21-04:00Stephen WolframIt’s been many years in the making, and today I’m excited to announce the launch of Mathematica Online: a version of Mathematica that operates completely in the cloud—and is accessible just through any modern web browser. In the past, using Mathematica has always involved first installing software on your computer. But as of today that’s [...]Awefullhttp://www.mathblogging.org/post/988032014-09-15T14:57:00-04:00Vlad AlexeevImages by Jordan Bettcher (Dream--Awake)
http://im-possible.info/english/art/pencil/jordan-bettcher.html
Author - http://dream--awake.deviantart.com/
Maple Leafs' math whiz Patrick Watling embraces hockey analyticshttp://www.mathblogging.org/post/987982014-09-15T14:29:42-04:00UnknownMaple Leafs' math whiz Patrick Watling embraces hockey analytics: Kevin McGran:
Watling, a member of the Toronto Marlies and at his first Leaf rookie camp trying to raise a few eyebrows, is the rare player who gets Corsi and Fenwick and other advanced stats that are bringing a new way to look at hockey.
[source: mme rss]Imitation Game wins Toronto top prizehttp://www.mathblogging.org/post/987992014-09-15T14:27:13-04:00UnknownImitation Game wins Toronto top prize: Genevieve Hassan:
Alan Turing biopic The Imitation Game has won the People’s Choice award at the Toronto Film Festival.
[source: mme rss]Bagchi’s thesishttp://www.mathblogging.org/post/987842014-09-15T14:24:53-04:00KowalskiDespite everything, there is something to be said for the internet. Just a few days ago, I wanted to reference the work of Bagchi, who provided the probabilistic interpretation of Voronin’s Universality Theorem for the Riemann zeta function. However, the original was unpublished, and one of the few papers of Bagchi on this topic pointedly […]The Mathematics of Ebola Trigger Stark Warnings: Act Now or Regret Ithttp://www.mathblogging.org/post/988002014-09-15T14:24:24-04:00UnknownThe Mathematics of Ebola Trigger Stark Warnings: Act Now or Regret It: Maryn McKenna:
The most arresting is a piece published last week in the journal Eurosurveillance, which is the peer-reviewed publication of the European Centre for Disease Prevention and Control (the EU’s Stockholm-based version of the US CDC). The piece is an attempt to assess mathematically how the epidemic is growing, by using case reports to determine the “reproductive number.” (Note for non-epidemiology geeks: The
[…]Alex en el país de los númeroshttp://www.mathblogging.org/post/987822014-09-15T14:23:06-04:00Rafalillo86Hola a todos!
Os dejo con mi aportación al Carnaval de Matemáticas:
http://elmundoderafalillo.blogspot.com.es/2014/09/alex-en-el-pais-de-los-numeros.html
Espero que os guste ;)Teacher Reflection 180: Day 4http://www.mathblogging.org/post/987932014-09-15T14:22:44-04:00banderson02What did I learn about my Math Class this week?   What did my students struggle with this week?   What did I do well this week?   Where do I need to begin with this class next week?Filed under: Reflections Tagged: Teacher Reflection 180Disquisitiones Arithmeticaehttp://www.mathblogging.org/post/987912014-09-15T14:22:00-04:00nilo de roockIt's time to read Gauss's original work. More later. Reflective Teaching: Day 3http://www.mathblogging.org/post/987942014-09-15T14:18:33-04:00banderson02Discuss one “observation” area that you would like to improve on for your teacher evaluation.   The biggest observation area I need to improve on is transitions. This is an area that changes every year with each student group that walks through your door. Time is always fighting me in my class, and I need […]An analytic formula for the median.http://www.mathblogging.org/post/987812014-09-15T14:18:00-04:00UnknownThree observations get you there:
min { a,b,c} = − max {−a, −b, −c}
second from top {a,b,c,d,e} = max ( {a,b,c,d,e} without max({a,b,c,d,e}) )
max {a,b,c} ~ log_t (t^a + t^b + t^c ), t→∞
Putting these three together you can make a continuous formula approximating the median. Just subtract off the ends until you get to the middle.
It’s an ugly expression. But, now you also have a way to view the sort operation—which is discontinuous—in a “continuous”
[…]The Follow-up puzzle to the Unexpected LS-C Nt.http://www.mathblogging.org/post/987852014-09-15T14:09:35-04:00UnknownSo, agreeing to read “colimit of a (terminal-truncated) commuting cube” as the homotopical replacement for “finite open cover”, argue the converse of last note’s implication; i.e., given a colimit $k$-cube s.t. the (last) colimit structure maps are separately trivial, construct a factorization of the diagonal $ X \to X^k $ through $ W^k X \to X^k $.
(I’ve worked it out already, but there’s no need to put everything up here, is there? !)Math Reflection 180: Day 11http://www.mathblogging.org/post/987952014-09-15T14:00:18-04:00banderson02Something I learned today was ________________________ (be specific! An answer of math is too general)   An example of this is ____________________   If I made a problem for a test using this concept it would be:Filed under: Math Reflection 180Math Reflection 180: Day 10http://www.mathblogging.org/post/987962014-09-15T13:56:02-04:00banderson02Something I learned today was ________________________ (be specific! An answer of math is too general)     _____________________ was similar to the lesson yesterday because ____________________ (write a couple of sentences explaining how they are)        Filed under: Math Reflection 180Unhappy Truckers and Other Algorithmic Problemshttp://www.mathblogging.org/post/987782014-09-15T13:39:00-04:00UnknownUnhappy Truckers and Other Algorithmic Problems: Tom Vanderbilt:
Her comment reflects a basic truth about the math that runs underneath the surface of nearly every modern transportation system, from bike-share rebalancing to airline crew scheduling to grocery delivery services. Modeling a simplified version of a transportation problem presents one set of challenges (and they can be significant). But modeling the real world, with constraints like melting ice cream and idiosyncratic human
[…]Let’s go fly a kite!http://www.mathblogging.org/post/987672014-09-15T12:56:46-04:00TJToday my Euclidean Geometry class discussed the construction of a kite with a compass and straightedge. They had four different constructions, all of them different from the one I had in mind. And these constructions led us to interesting discussions and new questions. It was a truly glorious day. I love teaching this class so […]Math Problem Solvinghttp://www.mathblogging.org/post/987792014-09-15T12:46:41-04:00Steven MillerThe purpose of this column is to talk about the weekly math puzzle night dinners run by myself and Professor Palsson, and to invite you to join us for this and other related activities. Here’s a quick summary of problem solving activities here; for more information or to be added to the email lists, contact me