Saturday, April 29, 2017
Friday, April 28, 2017
I had never heard of Lego Grad Student before, but this brilliantly fills a gap in the online world. I'll include one of LGS's tweets in this blog entry.
Running into a paywall for yet another article, the grad student is pummeled anew by the academic-industrial complex. pic.twitter.com/QnvFhjszPk— Lego Grad Student (@legogradstudent) April 18, 2017
Title: Persistent Homology of Time-Dependent Functional Networks Constructed from Coupled Time Series
Authors: Bernadette J. Stolz, Heather A. Harrington, and Mason A. Porter
Abstract: We use topological data analysis to study "functional networks" that we construct from time-series data from both experimental and synthetic sources. We use persistent homology with a weight rank clique filtration to gain insights into these functional networks, and we use persistence landscapes to interpret our results. Our first example uses time-series output from networks of coupled Kuramoto oscillators. Our second example consists of biological data in the form of functional magnetic resonance imaging data that were acquired from human subjects during a simple motor-learning task in which subjects were monitored for three days during a five-day period. With these examples, we demonstrate that (1) using persistent homology to study functional networks provides fascinating insights into their properties and (2) the position of the features in a filtration can sometimes play a more vital role than persistence in the interpretation of topological features, even though conventionally the latter is used to distinguish between signal and noise. We find that persistent homology can detect differences in synchronization patterns in our data sets over time, giving insight both on changes in community structure in the networks and on increased synchronization between brain regions that form loops in a functional network during motor learning. For the motor-learning data, persistence landscapes also reveal that on average the majority of changes in the network loops take place on the second of the three days of the learning process.
Thursday, April 27, 2017
Tuesday, April 25, 2017
(More seriously, I really like this visualization.)
Here is the blurb on the Facebook post that goes with the Physics Today article (though I added the hyperlink): The ocellated lizard develops an intricate, ever-changing pattern of black and green spots when it matures. Now researchers have determined that the patterns on the animals' backs update according to a well-defined algorithm: Over a period of a month or so, a given scale will change color—from green to black or black to green—with a probability that depends on the colors of the scales around it. In essence, the reptile is the embodiment of a cellular automaton, a type of discretized model made popular by John Conway’s Game of Life and used to simulate the spread of wildfires, the firing of neurons, and other phenomena.
Physics Today's article is about a recent article in Nature called "A living mesoscopic cellular automaton made of skin scales".
Monday, April 24, 2017
As one of my friends pointed out on Facebook, I should perhaps be careful about using the terms "quick trip" and "Berkeley" in the same sentence. :)
Sunday, April 23, 2017
We gave away tons of AMS Mathematical Moments, in particular. We brought English, Spanish, and Korean versions of the Mathematical Moments. We also gave away a bunch of SIAM's Math Matters, Apply It!. We also had copies of our networks literacy handbook in each of the 19 languages in which it is available, and we brought copies of our networks outreach materials for school students and talked to a lot of teachers about it. We mostly discussed the outreach efforts themselves, but we also brought copies of the teaching materials with us.
I wonder how much mathematics ending up photobombing the pictures from the LA March?
Also, several people came and took pictures of a differential equation that I wrote down on a flip chart to explain to someone the difference between linear and nonlinear equations.
At different times, our booth also had a comedian and a Fields Medalist show up.
I was really exhausted after the event. An almost-8-hour teaching marathon in the heat is very tiring. (Having a tent and some shade was very helpful, though. Paying for a booth was a very good idea.)
An amusing incident: Yesterday morning, the first person who came to our booth asked us about buying our tangerine juice. Math, damnit! Not tangerine juice. That's for us!
Another amusing incident: One person I know recognized my handwriting on our flip chart before he saw me at our booth.
And some pictures of the action at our booth: one, another one, setting up, and setting up (and a view of one of our neighboring booths)
Update (4/25/17): And here are some pictures from the LA March from Los Angeles Magazine.
(Tip of the cap to Craig Montuori.)
Saturday, April 22, 2017
I'll try to post some more links later. I have been seeing fantastic signs on the March for Science Facebook page for the past several weeks (and I saw some great signs in LA today).
(Tip of the cap to Maria Satterwhite.)
P.S. Some Thomas Dolby got played at the LA March, of course. :) This was the first song blasted as the gathering started on their march after a series of short speeches. Allusions to Thomas Dolby also showed up yesterday on signs, of course.
Update (4/23/17): Here are some more signs. (Tip of the cap to Peter Mucha.)
Update (4/23/17): Naturally, and as expected, people nerded out quite a bit yesterday (just like we people do in venues like Dragon*Con). In some ways, it was also like Coachella for scientists and friends. You can see some more signs in this Motherboard article and this Vox article. (The so-called "Laplace equation" in one of the pictures actually shows a Laplace transform.) Spock, Data, Beaker, and other scientifically-themed fictional characters were also very well represented.
Update (4/23/17): According to this Washington post article, the March for Science was unprecedented. (Tip of the cap to Karen Daniels.)
Update (4/23/17): Here are some signs from the New York march. I am partial to the Oregon Trail one, of course. (I have seen variants of it posted on the Facebook page for March for Science.)
Update (4/25/17): Here are some pictures from the LA March.
Update (4/26/17): Linda Hall Library is developing a digital archive of the March for Science. Very cool! (Tip of the cap to Laci Gerhart-Barley.)
Friday, April 21, 2017
We'll be drawing from materials here (and hence here) and will also have booklets on essential concepts and core ideas about networks.
Thursday, April 20, 2017
Graph Alignment is a major open problem in mathematics and computer science. pic.twitter.com/Q8EJDSYLge— Mason Porter (@masonporter) April 20, 2017
Wednesday, April 19, 2017
In case you don't remember and don't want to follow a chain of links on Wikipedia, go to this page.
Tuesday, April 18, 2017
Sunday, April 16, 2017
A must for every library: eighteenth-century rotating table allowing readers to view multiple volumes at once. pic.twitter.com/p18X8LRpPo— NSCM (@LitteraCarolina) April 14, 2017
(Tip of the cap to Gabrielle Birkman.)
Saturday, April 15, 2017
The article includes a reprint of a cartoon from The New Yorker that reminds me of this song. (The song is relevant to the whole article, actually.)
(Tip of the cap to Ben Rogers.)
Friday, April 14, 2017
This is the first time in Major League Baseball history that a team started an outfield where all three outfielders have the same last name. Nice! (The Alous were in an outfield together, but they didn't all start a game together.)
My favorite starting outfield, however, is when the Cincinnati Reds started an outfield of Young, Frank, and Stynes. (It consisted of Dmitri Young in left field, Mike Frank in center field, and Chris Stynes in right field.)
Also see this recent blog entry.
(Tip of the cap to Sam Scarpino.O
Tuesday, April 11, 2017
I gave up on shoelaces very early in life (important life hack!). Of course, I never could tie the damn things in the first place, and I still can't.
The authors of this research may well have Ig Nobel prizes in their future (perhaps awarded jointly in physics and in fashion).
Quoting Steve from this article: "So many of the things that we do in math education—and maybe more generally in education—are giving students answers to questions that they would never think of asking. By definition, that's what it is to be boring."
Conversely, this also speaks to why so many students find networks exciting from the start. They're already asking many of these questions! They just need the words and concepts to make the questions more precise to be able to answer them in a better way.
Saturday, April 08, 2017
(I got this from a post on the Dragon*Con Facebook page.)
Friday, April 07, 2017
At first, I accidentally, introduced the typo "rouge", but I managed to change the tweet before anybody could reply with "What's a rouge wave?" Naturally, this inspired the title of this post.
Rogue Wave Hunters: Wind-generated waves in ring-shaped water tanks can spontaneously yield behemoth waves: https://t.co/4QSaR0MsSl— DynamicalSystemsSIAM (@DynamicsSIAM) April 7, 2017
I have an important question, though: What does "The Ride of the Valkyries" look like?
(Tip of the cap to Chris Gong.)
Thursday, April 06, 2017
(And, apropos, I received an e-mail called "What is Reality?", from a group of people working on a crazy idea, while I was reading this article.)
P.S. David Stevenson is a great classroom lecturer. I had him for half of AMa 95 at Caltech.
Tuesday, April 04, 2017
Monday, April 03, 2017
I wasn't aware of the historical path. I can't wait to see what results from some of the grades I give! Also, never underestimate the power of being bloody-minded...
(Tip of the cap to Nicholas Christakis and others.)
Sunday, April 02, 2017
Saturday, April 01, 2017
Rock 'n' Roll Physics Sing-Along. Thanks to Walter Smith for contacting me about doing this after he found my blog entry with my lyrics. Take a look at his physics-song webpage.
Friday, March 31, 2017
(And I am looking forward to the stories on ESPN and other venues.)
I got the news from Greg Fricke's post:
BEAVERS WIN! BEAVERS WIN! BEAVERS WIN! BEAVERS WIN! BEAVERS WIN! BEAVERS WIN! BEAVERS WIN! BEAVERS WIN! BEAVERS WIN! BEAVERS WIN!
After 586 (est, including 83 I played in) straight losses in SCIAC, dating back to 1988:
Caltech Beavers DEFEAT Pomona-Pitzer 4-3 on WALKOFF single.
No one on this team had yet been born the last time Caltech registered a SCIAC win in baseball.
1988... such a magical year for baseball...
Update: And here are some details: Caltech baseball has just won its first SCIAC game since 1988! Trailing 3-2 headed to the 9th inning, the Beavers got a two-out single from David Watson, who was replaced on the base paths by Schaffer Reed. Senior Kai Kirk then smacked a double to left center to tie the game, bringing freshman Alex Corado came up to bat. The rookie got ahead 3-0 before facing a full count and slashed a single to left field to plate the historic walk-off run.
Update: Also take a look at the video and the ensuing victory celebration.
Update (4/01/17): This is not an April Fool's Day joke. (I know it sounds like one.)
Thursday, March 30, 2017
(The arXiv doesn't have 1 April as a mailing day this year, so we get it early.)
The last sentence of the abstract is amusing: "Over-training is also discussed, although the linear algebra teacher assures us that in Barry’s case this is not possible."
As things catch my eye, I will post links to more April Fool's Day shenanigans.
Here are various past posts related to April Fool's Day (and a couple of other posts that show up in the search but aren't particularly related).
Update: Here is another joke arXiv paper. It is called: Schrodinger's Cat and World History: The Many Worlds Interpretation of Alternative Facts
Update: This article seems to purposely be dated April 1st, but it has a rather different flavor from the other two.
Update: According to an April 1st article in The Guardian, former British chancellor (more formally, "Chancellor of the Exchequer") George Osborne has become a fashion designer. (Tip of the cap to Dominic Vella.)
Update (4/01/17) Here is a screenshot of my April Fool's Day prank of 2006, for which I was able to convince a member of Caltech's public-relations department to post my article (actual fake news, which of course is an April 1st tradition) on the Caltech web page and include a link to it in an e-mail circular.
Update (4/01/17): Cherwell, a student publication from University of Oxford, published an interesting story about possible cancellation of the Cancer Research UK Boat Races. Here is another one from Cherwell.
Update (4/01/17): There's also the matter of the Spaced X rocket launch out of Santa Monica, California. (Tip of the cap to Andrea Bertozzi.)
Update (4/01/17): In other news, an ancient particle accelerator was discovered on Mars. (Tip of the cap to Jean Bellissard.)
Update (4/01/17): George Takei played an amusing prank.
Update (4/01/17): Also, the American Physical Society is launching a new journal called Physical Review Tweets. Awesome!
Update (4/02/17): Google remixed an old (but awesome) prank by letting people play Ms. Pac-Man on Google Maps. (Tip of the cap to Myah Evers.) Google also played a few other pranks.
Update (4/02/17): And here are various other pranks that you may have encountered yesterday.
Update (4/08/17): Well, the Reddit prank appears to have resulted in a rather interesting example of self-organization (and of astounding art, with some "This is why we can't have nice things." thrown in). (Tip of the cap to Kevin Hickerson, Maria Satterwhite, and others.)
Wednesday, March 29, 2017
Here's a nice (and topical) one to start us off: "Get your facts first, and then you can distort them as much as you please."
Update (3/30/17): Here is another, of many, great quotes that you can find on the above page: "Whenever you find that you are on the side of the majority, it is time to reform."
I recently saw this awesome license plate that does so as well.
I really enjoy alluding to the characters Boris and Natasha. I did that recently in my winning entry in a caption content, and I did it in 2006 in an Aprils Fool's Day prank.
This is my first ever trip to Missouri.
A little while ago, after I went through the x-ray machine, the TSA agents wanted to check my hair to make sure I wasn't hiding something in there. (This happens a couple of times every year.)
Monday, March 27, 2017
Update: This is an episode of a mathematics show called "Infinite Series". The above episode refers to an episode about Markov chains. Take a look at their YouTube channel and Twitter feed.
Saturday, March 25, 2017
Title: Eigenvector-Based Centrality Measures for Temporal Networks
Authors: Dane Taylor, Sean A. Myers, Aaron Clauset, Mason A. Porter, and Peter J. Mucha
Abstract: Numerous centrality measures have been developed to quantify the importances of nodes in time-independent networks, and many of them can be expressed as the leading eigenvector of some matrix. With the increasing availability of network data that changes in time, it is important to extend such eigenvector-based centrality measures to time-dependent networks. In this paper, we introduce a principled generalization of network centrality measures that is valid for any eigenvector-based centrality. We consider a temporal network with N nodes as a sequence of T layers that describe the network during diff erent time windows, and we couple centrality matrices for the layers into a supracentrality matrix of size NT x NT whose dominant eigenvector gives the centrality of each node i at each time t. We refer to this eigenvector and its components as a joint centrality, as it reflects the importances of both the node i and the time layer t. We also introduce the concepts of marginal and conditional centralities, which facilitate the study of centrality trajectories over time. We find that the strength of coupling between layers is important for determining multiscale properties of centrality, such as localization phenomena and the time scale of centrality changes. In the strong-coupling regime, we derive expressions for time-averaged centralities, which are given by the zeroth-order terms of a singular perturbation expansion. We also study first-order terms to obtain fi rst-order-mover scores, which concisely describe the magnitude of the nodes' centrality changes over time. As examples, we apply our method to three empirical temporal networks: the United States Ph.D. exchange in mathematics, costarring relationships among top-billed actors during the Golden Age of Hollywood, and citations of decisions from the United States Supreme Court.
"I have discovered a truly remarkable proof of this theorem which a Twitter post is too small to contain."— Mason Porter (@masonporter) March 25, 2017
In retrospect, I should have written "this tweet" instead of "a Twitter post" to make the parallel even stronger.
Thursday, March 23, 2017
(Tip of the cap to Rachael Rosenthal.)
Update (3/27/17): This article in The Washington Post includes several more spectacular examples of GOP D & D. By the way, the hashtag is #GOPDnD. (Tip of the cap to Mohi Kumar for this article.)
Title: The Multilayer Nature of Ecological Networks
Authors: Shai Pilosof, Mason A. Porter, Mercedes Pascual, and Sonia Kéfi
Abstract: Although networks provide a powerful approach to study a large variety of ecological systems, their formulation does not typically account for multiple interaction types, interactions that vary in space and time, and interconnected systems such as networks of networks. The emergent field of ‘multilayer networks’ provides a natural framework for extending analyses of ecological systems to include such multiple layers of complexity, as it specifically allows one to differentiate and model 'intralayer' and 'interlayer' connectivity. The framework provides a set of concepts and tools that can be adapted and applied to ecology, facilitating research on high-dimensional, heterogeneous systems in nature. Here, we formally define ecological multilayer networks based on a review of previous, related approaches; illustrate their application and potential with analyses of existing data; and discuss limitations, challenges, and future applications. The integration of multilayer network theory into ecology offers largely untapped potential to investigate ecological complexity and provide new theoretical and empirical insights into the architecture and dynamics of ecological systems.
Wednesday, March 22, 2017
I'm pretty sure that this is the official definition that you'll find in many mathematics books.
In case you're interested in these objects, see Todd Kapitula's primer. And here is a new article by Chris Jones that reminded me of the above definition.
Actually, I'm pretty sure I once heard someone — maybe even Chris? — joking call an Evans function "a Wronskian on steroids" during a seminar. I remember thinking that 'on steroids' probably wasn't doing justice to the function.
Tuesday, March 21, 2017
I am puzzled as to why Ingrid Daubechies didn't share this prize.
Update: Terry Tao has written a short blog post about the prize. Among other things (and I hadn't caught this), note the following text from Tao: Daubechies also made extremely important contributions to the theory of wavelets, but my understanding is that due to a conflict of interest arising from Daubechies’ presidency of the International Mathematical Union (which nominates members of the Abel prize committee) from 2011 to 2014, she was not eligible for the prize this year, and so I do not think this prize should be necessarily construed as a judgement on the relative contributions of Meyer and Daubechies to this field.
Wednesday, March 15, 2017
Also see previous blog entries of mine, such as this one, this one, and this one.
Vindication is mine!
(Tip of the cap to Jaideep Taggart Singh.)
Update: Aaron Clements pointed me to this Washington Post article.
Also see my Facebook post about this for witty repartee, other suggested names, and possible prequels (e.g., "The Vector").
(Tip of the cap to Sammy Kline for the information about the reboot.)
As a twist on this, I decided to look at the first sentence of the preface of one of my books. This yields the following sentence: "Traditionally, much of the study of networks has focused on structural features, and then the murders began."
Unfortunately, the tense of the sentence hurts things, so I am going to change one letter ("s" to "d" in the word "has") to produce the following sentence: "Traditionally, much of the study of networks had focused on structural features, and then the murders began."
Much better! (And highly amusing.)
(Tip of the cap to Keith Fraser.)
I would move "cherry" way over to the right.
I did recently have an experience with eating a pink Starburst and expecting strawberry but getting watermelon instead. It was unpleasant.
Even more unpleasant are past experiences of eating red with the hope that it's cherry but then getting cinnamon instead.
Tuesday, March 14, 2017
(Tip of the cap to Jeremy Stell.)
Update (3/19/17): I forgot to mention that I found out a few days ago that there was some Photoshopping in the above picture. It's still very cool, though not quite as cool as before.
Well, Martin Gould is CEO of Sonalytic, which was just acquired by Spotify! Very well done!
Saturday, March 11, 2017
This article, which has lots of great pictures of mathematical art, is a review of the exhibit Picturing Math at the Metropolitan Museum of Art in New York City.
(Tip of the cap to James Tanton.)
Thursday, March 09, 2017
Wednesday, March 08, 2017
Spicer: "I wish he'd have an affair. That'd be better than defending the stupid s*** he says in Twitter."— Rogue POTUS Staff (@RoguePOTUSStaff) March 8, 2017
Here is an older blog entry about the rogue government Twitter accounts.
Tuesday, March 07, 2017
It should say "specializes" (present tense), by the way, as Karin is still research-active, even though she's retired. In fact, no doubt, she is now more active in her research, as that is how it often works.
As I write this, the tumblr has gotten up to 'M' so far, and there are many great mathematicians profiled (including, thankfully, people besides the same ones that often show up over and over again in such lists).
(Tip of the cap to Association for Women in Mathematics.)
Monday, March 06, 2017
Sunday, March 05, 2017
Saturday, March 04, 2017
Thursday, March 02, 2017
After proposing party affiliation quotas for faculty, lawmaker grilled about business degree from Sizzler Steakhouse https://t.co/9ycYTISAm1— Carl T. Bergstrom (@CT_Bergstrom) March 3, 2017
In his tweet, Carl Bergstrom links to a Boing Boing article, but the article to which it links gives a clearer explanation.
It's not quite as surreal as a National Park Service Twitter account going rogue (initially by simply tweeting basic facts about climate science), but it's still odd.
Garfield contributed a lot to the study of scientific productivity and output, and for better or for worse (often for worse), he gave us the impact factor (which of course has led to many variants).
Wednesday, March 01, 2017
Tuesday, February 28, 2017
Title: Numerical Methods for the Computation of the Confluent and Gauss Hypergeometric Functions
Authors: John W. Pearson, Sheehan Olver, and Mason A. Porter
Abstract: The two most commonly used hypergeometric functions are the confluent hypergeometric function and the Gauss hypergeometric function. We review the available techniques for accurate, fast, and reliable computation of these two hypergeometric functions in different parameter and variable regimes. Themethods that we investigate include Taylor and asymptotic series computations, Gauss–Jacobi quadrature, numerical solution of differential equations, recurrence relations, and others. We discuss the results of numerical experiments used to determine the best methods, in practice, for each parameter and variable regime considered. We provide "roadmaps" with our recommendation for which methods should be used in each situation.
Our Matlab code is available from this website.
Monday, February 27, 2017
* It's too bad that Kevin Mench's last name isn't spelled "Mensch". (And here is a definition page for the Yiddish word putz.)
But my favorite baseball name-combination game is the following: In (at least) one game in 1998 (I think quite a few), the Cincinnati Reds had an outfield of Young, Frank, and Stynes.
(The players were Dimitri Young, Mike Frank, and Chris Stynes.)
There are other good ones as well (e.g., the Giant hardware, with a battery of pitcher (Bud) Black and catcher (Steve) Decker).
Saturday, February 25, 2017
(Tip of the cap to Guillermo Valle Pérez.)
Friday, February 24, 2017
There's some really good stuff in here!
Tuesday, February 21, 2017
Like many Nobel-memorial laureates in economics, Arrow has an undergraduate degree in mathematics (in his case, as part of a double major with social science). He also earned a Masters degree in mathematics. Arrow has an entry in the Mathematics Genealogy Project.
Some of my students have heard me mention "impossibility theorems" in voting and social choices. If you're going to name one pioneer in that area, that person is Ken Arrow.
(Tip of the cap to Jennifer Nicoll Victor.)
A Mandelbrot Pancake is not quite as cool as a Sierpinski Hamentaschen, but it's still rather awesome.
Sunday, February 19, 2017
Saturday, February 18, 2017
It would also be relevant to include a line for "tenure", because that too has a very good intended effect (time to work on impactful blue-skies research without undo pressure and harmful immediacy) and unfortunate side effects (e.g., slacking, dead weight, insufficient accountability on certain things).
Update: There are some worthwhile comments in my associated Facebook post.
Friday, February 17, 2017
"Macrae: The fourth monster in Ms. Pac-Man is named Sue, which is my sister. I always get to joke about that with her a little bit. I worked really hard to make sure I could name a monster after my sister. It was a great way to take an inside poke at her."
I was always wondering how the orange ghost went from Clyde in Pac-Man to Sue in Ms. Pac-Man.
Amazingly, it's now been just over twice as long between the Ms. Pac-Man/Galaga dual arcade cabinet and now than between the debut of Ms. Pac-Man and that commemorative release.
And as some of you have witnessed, I had mad skillz at that game.
Coolest thesis defense flyer EVER! pic.twitter.com/pXEV8SLOZK— Montserrat Anguera (@montserrat) February 15, 2017
(Tip of the cap to Easter Eggs in Scientific Papers.)
Thursday, February 16, 2017
I hope the music is rational.
The new EP, by the way, is called "The Expanding Domain" (for real).
In case you're interested, here is a link to the Wikipedia entry for the mathematical version of a Dedekind cut.
Wednesday, February 15, 2017
And I'm going to respond by telling them to get off my lawn.
(I look forward to the Coen Brothers version. Because we are in a Coen Brothers movie right now. It's like watching a train wreck in slow motion from a seat on the train.)
Also: Truth is stranger than fiction. Never doubt that.
Update: By the way, Frances McDormand would make a spectacular Bettsy DeVos.
Update: Last year, I referred to the Brexit fiasco as something out of a Coen Brothers film (and I included the train-wreck comparison), but the way things have been playing out in the US (including last year, but especially since the election) is, hands down, even more extreme in that direction.
(Tip of the cap to Alain Barrat.)
Tuesday, February 14, 2017
Monday, February 13, 2017
Along with this paper, we have released a large data set of fungal networks. We hope that you enjoy playing with the data!
Here are some more details.
Title: "Mesoscale Analyses of Fungal Networks as an Approach for Quantifying Phenotypic Traits"
Authors: Sang Hoon Lee, Mark D. Fricker, and Mason A. Porter
Abstract: We investigate the application of mesoscopic response functions (MRFs) to characterize a large set of networks of fungi and slime moulds grown under a wide variety of different experimental treatments, including inter-species competition and attack by fungivores. We construct 'structural networks' by estimating cord conductances (which yield edge weights) from the experimental data, and we construct 'functional networks' by calculating edge weights based on how much nutrient traffic is predicted to occur along each edge. Both types of networks have the same topology, and we compute MRFs for both families of networks to illustrate two different ways of constructing taxonomies to group the networks into clusters of related fungi and slime moulds. Although both network taxonomies generate intuitively sensible groupings of networks across species, treatments and laboratories, we find that clustering using the functional-network measure appears to give groups with lower intra-group variation in species or treatments. We argue that MRFs provide a useful quantitative analysis of network behaviour that can (1) help summarize an expanding set of increasingly complex biological networks and (2) help extract information that captures subtle changes in intra- and inter-specific phenotypic traits that are integral to a mechanistic understanding of fungal behaviour and ecology. As an accompaniment to our paper, we also make a large data set of fungal networks available in the public domain.
"Time-Dependent Community Structure in Legislation Cosponsorship Networks in the Congress of the Republic of Peru"
Title: "Time-Dependent Community Structure in Legislation Cosponsorship Networks in the Congress of the Republic of Peru"
Authors: Sang Hoon Lee, José Manuel Magallanes, and Mason A. Porter
Abstract: We study community structure in time-dependent legislation cosponsorship networks in the Peruvian Congress, and we compare them briefly to legislation cosponsorship networks in the US Senate. To study these legislatures, we employ a multilayer representation of temporal networks in which legislators in each layer are connected to each other with a weight that is based on how many bills they cosponsor. We then use multilayer modularity maximization to detect communities in these networks. From our computations, we are able to capture power shifts in the Peruvian Congress during 2006–2011. For example, we observe the emergence of 'opportunists', who switch from one community to another, as well as cohesive legislative communities whose initial component legislators never change communities. Interestingly, many of the opportunists belong to the group that won the majority in Congress.
Sunday, February 12, 2017
The most lucrative food crop in each US state— Amazing Maps (@Amazing_Maps) February 13, 2017
Source: The Huffington Post pic.twitter.com/AuO92nr5bU
Note to self: I need to have pecans the next time I go to Santa Fe Institute.
Also: It pleases me that "maple syrup" is the item in Vermont, it's fitting that California is still "grapes", and I had no idea about shrooms in Pennsylvania.
Saturday, February 11, 2017
Here are some article details.
Title: 88 Lines About 44 Mathematicians
Author: Mason A. Porter
Abstract: Well, there isn't really an abstract per se.
Note: In 2014, somebody else recorded a song by the same name on YouTube, although the lyrics are entirely different. Also, that guy focused much more on mainstream mathematicians than I did.
Friday, February 10, 2017
Thursday, February 09, 2017
Tuesday, February 07, 2017
(Tip of the cap to George Takei.)
We can talk later about maximum likelihood estimation.
P.S. I stole the title from Won Chang's comment on the Facebook post by PhD Comics.
Saturday, February 04, 2017
More are apparently in the works.
Update: In addition to the ones compiled on the webpage above, I have seen one for Kazakhstan (which I saw via suggested YouTube videos from one of the ones above). I'll post a link to a page that has a comprehensive compilation once I find one.
Update (2/07/17): Here is a compilation of parodies from European Union countries. Right now, there are many grayed-out flags for ones that don't yet exist, but I'm sure many of them will be filled in eventually.
Update (2/09/17): Yesterday I noticed that the above compilation site has expanded to include countries across the globe. However, it doesn't include the one from Mars. :)
But how can there not be an Achievement Unlocked for the way I did it? I took over a different Civ's apostle, following a different religion from mine, and then I got it killed by attacking a third Civ's apostle (from yet another religion).
Well, at least I get to keep the relic and earn some tourism points.
Thursday, February 02, 2017
Also, it's particular style reminds me a bit of Hunter Pence Signs.
(Tip of the cap to George Takei.)
Here is a choice quote from their abstract: "How human learners exploit this information remains an essential question. Here, we focus on the temporal constraints that govern such a process. Participants viewed a continuous sequence of images generated by three distinct walks on a modular network."
This is a missed opportunity: They could have used the Zachary Karate Club for these experiments. (It's probably still worth writing up a short blurb about this paper for the Improbable Research blog.)
Tuesday, January 31, 2017
It includes entries about community detection (in the Harry Potter universe), education issues, and UCLA salaries.
Monday, January 30, 2017
Sunday, January 29, 2017
And if you've never heard of Marty Feldman, you should watch Young Frankenstein, among other movies.
(Tip of the cap to Kent Cordray.)
Update: Here is a video of Feldman performing National Brotherhood Week.
As I mentioned a few days ago on Facebook, "National Park Service Twitter Account Goes Rogue" would make a great event card for the 2K16–2K17 version of Illuminati. (I don't know of any plans for one, but given that the world feels now that way, it simply has to happen.) The dystopian fiction novels and movies also seem to have missed out on that. Well, some probably do have something like that, but truth is definitely stranger than fiction. The Rogue POTUS Staff account is also right out of dystopian fiction (except that now it's dystopian fact, or "dystopian nonfiction", if you prefer).
Indeed, like now feels like an Illuminati, with some aspects of Paranoia involved for good measure.
Update: Here is one version of a meme that has been going around during the last few days.
Thursday, January 26, 2017
I am being hosted by my Caltech undergrad friend Jaideep Taggert Singh (a fellow Lloydie), who is on the physics faculty at MSU.
Wednesday, January 25, 2017
Tuesday, January 24, 2017
Here is the lead in Caltech's Facebook post today about the course: "Among the classes a Caltech freshman can take, Physics 11 stands out. Those who make it through its series of intellectual hoops embark on a unique classroom experience with no set curriculum or exams and without strict adherence to any single scientific discipline—despite the course's name."
This is why at Caltech we had the "youngest non-math-major" convention for figuring out how to split a bill for a meal.
As an applied math (AMa) major, I was usually safe — except for the one time when everybody else at my table was majoring in pure mathematics (Ma). D'oh!
Monday, January 23, 2017
(Tip of the cap to multiple people.)
Update (1/24/17): Apparently the video isn't just taking lots of words and phrasing The King in Orange likes to use but was parodying his inauguration speech in particular. (I hadn't bothered watching or reading his speech, so I didn't realize that. That makes the video even funnier.)
I became one of Charlie's supervisors last fall to help out his main official supervisor Andrea Bertozzi. Of course, although she doesn't get official credit for it (because she's a postdoc and isn't in the official listing), Puck Rombach has been Charlie's main supervisor in practice.
Sunday, January 22, 2017
The following line expands on the title: "But answer me truthfully: Who among you wouldn’t do the same exact thing if an evil 400-year-old witch had trapped your father’s eternal soul inside a cursed iron lantern, flickering faintly each time his agonized moans escaped the murky, otherworldly ether that is his prison?"
Saturday, January 21, 2017
The article title is also great: White House press secretary attacks media for accurately reporting inauguration crowds.
(When I see a story about such ridiculous, flagrant lies (which anybody can see from all available data, including videos, transportation data, and more) posted on Facebook, I need Facebook to add a nuanced 'reaction' that modifies their laughter icon into the type of hysterical laughter that occurs as one is losing one's mind. Their reactions aren't nuanced enough for this. Sure, I'm angry, but I want a 'hysterical laughter' reaction.)
Update (1/24/17): And Spicer's feud against Dippin' Dots ice cream is simply bizarre (and free advertising).
Update: Here is a Vox article, which includes among the first of the pictures I saw yesterday. I also saw pictures from friends yesterday who were beginning their treks, and of course it's been great to see many pictures of the well-attended Women's Marches today (especially the one in Washington, D.C.).
Update: Here are a bunch of pictures. When the dust settles as to the numbers in the Marches worldwide, I'll post put a link to an article that hopefully gives a reasonable indication of them. I have read that this may be the largest Presidential Inauguration protest in U.S. history. (Many more people have shown up to the Women's March protest in Washington, D. C. than showed up for the Inauguration.)
Update: The protests have been occurring across the globe, including in Antarctica!
Update: The number of protesters worldwide is estimated to be more than 2.5 million people.
Update: Here are more pictures from around the world. Such a historic event! The world will remember this day.
Update: Here are some estimated numbers.
Update: I would like to make the following comment: "20 January 2017: A day that will live in infamy (though, technically, not as much infamy as 8 November 2016). 21 January 2017: A far more important day, and one of the most important days in United States history."
Update: The Women's March protest is now estimated to be the largest single-day protest in U.S. history. Excellent! I approve!
Update: In solidarity with the Women's March, Dave Stewart and Annie Lennox of the Eurythmics posted a music video of their song Sisters Are Doin' It For Themselves. It's hard to think of a better fit for today.
Update: In Washington, D.C., numerous protesters left their signs at Donald Trump's D.C. hotel.
Update: Apparently, there were a grand total of four arrests in the U.S. Protesting peacefully is the way to do it. Very good!
(Tip of the cap to way too many people to mention.)
Update (1/22/17): One of my favorite pictures from yesterday is this one.
Update (1/22/17): Here is yet another great sign. (Tip of the cap to Wendy Ames.)
Update (1/23/17): Fivethirtyeight.com estimates the total number of participants (I didn't check whether this was an estimate for the U.S. or for the world) in the Women's Marches to be about 3.2 million people, though they were concentrated mostly in Blue states.
Update (1/23/17): Here is another excellent sign, although over the years I have seen many pictures of old people at protests with these words (or similar ones) on a sign. I saw this picture on Saturday, but I forgot to include a link then, so I'm glad to see it again.
Update (1/23/17): Here's another nice sign.
Update (1/24/17): Here are a few more signs. I like the Star Wars one.
Friday, January 20, 2017
I also considered others, but they're considerably more rude (and this one is also an optimal fit). These are "Springtime for Hitler" from The Producers and a cover of The Supremes' "You Can't Hurry Love" by Mike Pence and the Supreme Court Justices. (This last song was probably performed last time at the Inaugural concert.)
Update: REM posted several performances of their song "World Leader Pretend on their Facebook page.
Update: Another appropriate song is "The Dictator Decides" by the Pet Shop Boys. The general weariness and the lines about giving speeches are both rather apt.
Update (1/21/17): A really apt one is the "Imperial March" from Star Wars.
Update (1/22/17): I think that my suggested song for Mike Pence and The Supreme Court Justices would make a great skit for Saturday Night Live, by the way. Also, it now occurs to me that a cover of "Love Child" (also by Diana Ross and The Supremes) would be an even more appropriate song than "You Can't Hurry Love".
Thursday, January 19, 2017
Note: I did a quick calculation, in which I assumed 100 full years; this gives an estimate of 52,596,000 minutes. The article didn't indicate even the month in which the book was checked out. In my calculation, I took 100 years, 365.25 days per year, 24 hours per day, and 60 minutes per hour.
Wednesday, January 18, 2017
Rodríguez made it (with 4 votes more than the minimum) on the first ballot, becoming the second catcher (the other was Johnny Bench) to do so. It's about damn time that Bagwell and, especially, Raines made it into Major League Baseball's Hall of Fame. They both should have been inducted years ago. Trevor Hoffmann (5 votes short) and Vladimir Guerrero (15 votes short) both cracked 70% of the vote (at least 75% is needed) and should make it next year. Roger Clemens and Barry Bonds made good progress and finally seem on their way. (If not for their extracurricular issues, they would have of course been inner-circle Hall of Famers and made it with exceptionally large vote percentages on the first ballot.) Mike Mussina gained enough votes to crack 50% of the vote and should gain more next year and hopefully make it soon. Edgar Martínez gained a very large number of votes, and he (along with Mike Mussina) are who we now need to get behind so that they get their richly deserved enshrinements into the Hall. Curt Schilling's vote total went in the wrong direction, seemingly because of his controversial tweets, but he richly deserves to be in the Hall of Fame, so hopefully he'll eventually make it as well.
Larry Walker, in his 7th year on the ballot, surpassed 20% of the vote and made some progress, but it looks like he's going to have to wait until some version of the Veterans Committee selects him for the Hall. In my mind, Walker is a Hall of Famer, and a lot of people don't realize just how good he is. Manny Ramírez, who comes with a particularly enormous performance-enhancing-drug (PED) cloud (with two suspensions to his name), cracked 20% of the vote. Voters are clearly softening on this front, as was expected and as I believe is correct, but a rather large difference between Ramírez and players like Bonds and Clemens is that the cloud is much darker for Ramírez, so it will probably take him a long time to get elected. (I suspect he will make it eventually, perhaps from a Veterans Committee.) His statistics on their own obviously merit induction, but Ramírez's relationship with PEDs is very far beyond the border. Jeff Kent, who also belongs in the Hall, continues to get much less support than he deserves. (Fellow middle infielders Bobby Grich, Lou Whitaker, and Alan Trammell can commiserate. Whitaker even fell off the ballot, which is ridiculous.)
Former commissioner Bud Selig and executive John Schuerholz were elected to the Hall of Fame earlier this offseason by a Veterans Committee.
You can find more information on the Hall of Fame tracker.
Baseball-reference.com has a page detailing who will (and others will likely) appear on the 2018 Hall of Fame ballot. Hoffman and Guerrero will surely make it next year. I don't think any of the other holdovers will make it next year, but watch for Martínez, Mussina, Clemens, and Bonds to make further progress. Among the newcomers, Chipper Jones will make it easily, Jim Thome will get a lot of votes (but is unlikely to make it in his first year), Scott Rolen will probably get a lot less support than he deserves (though he may be inducted into the Hall of Fame eventually), Omar Vizquel will get a bunch of votes, and perhaps Johnny Damon and Andruw Jones will get enough votes not to get kicked off the ballot. I suspect Thome will make it in his second or third try, and Vizquel will likely make the Hall eventually as well.
Update (1/19/17): I completely forgot to bring up The Crime Dog, Fred McGriff, whose consistent excellence gets overlooked because of the ridiculous numbers from the PED era. It makes it harder to see how great he was, and I think that he should eventually be enshrined as well. He is getting enough votes to stay on the ballot, but his candidacy isn't really going anyway, so he'll probably eventually be selected by a Veterans Committee. Gary Sheffield is another player with enough support to remain on the ballot but who won't make the Hall any time soon. I am not sure whether he should make it.
Tuesday, January 17, 2017
And in that catalog, Applied Math and Math required 483 units, and each of the other options required 516 units. (So then at some point that 516 was changed to 486. So Applied Math and Math were the pioneers!)
In prior years, each option (perhaps with some commonality due to influence of Divisions) essentially listed the requirements in their own format (occasionally including the modern format). Some of them listed required unit numbers (e.g., 530), but they were different for different options. Applied Math in 1973–74 required 537 units, but Math didn't list any one number in this format (though one could compute a minimum based on other types of requirements, such core courses, electives, and units per term). So somehow for 74–75, Applied Math and Math decided to be different from everybody else (naturally).
* except for the "Independent Studies Program", which is understandably much less structured in the catalog
Note: See this discussion for further background.
Note 2: I majored in Applied Math at Caltech. I graduated in 1998, and I first enrolled there during the 1994–95 school year.
This was really bugging me. Now I'll get back to what I was supposed to be doing.
Sunday, January 15, 2017
Thursday, January 12, 2017
As they write: "We're sick of it. It's time to do something, and as educators, one constructive thing we know how to do is to teach people. So, the aim of this course is to help students navigate the bullshit-rich modern environment by identifying bullshit, seeing through it, and combatting it with effective analysis and argument."
(Tip of the cap to the Bansal lab.)
Update: I have updated this blog entry (adding and slightly changing some text above) to make it clear that the course isn't literally being offered yet, but its material has been assembled, so go take a look at it!
Update (1/14/17): I wrote a blurb about this course for the Improbable Research blog.
Tuesday, January 10, 2017
Monday, January 09, 2017
(Tip of the cap to George Takei.)
Anyway, let's talk about the paper that does have its coordinates. It's about plankton modeling, and here are the details.
Title: A Predator–2 Prey Fast–Slow Dynamical System for Rapid Predator Evolution
Authors: So a H. Piltz, Frits Veerman, Philip K. Maini, and Mason A. Porter
Abstract: We consider adaptive change of diet of a predator population that switches its feeding between two prey populations. We develop a novel 1 fast–3 slow dynamical system to describe the dynamics of the three populations amidst continuous but rapid evolution of the predator's diet choice. The two extremes at which the predator's diet is composed solely of one prey correspond to two branches of the three-branch critical manifold of the fast–slow system. By calculating the points at which there is a fast transition between these two feeding choices (i.e., branches of the critical manifold), we prove that the system has a two-parameter family of periodic orbits for su ciently large separation of the time scales between the evolutionary and ecological dynamics. Using numerical simulations, we show that these periodic orbits exist, and that their phase di erence and oscillation patterns persist, when ecological and evolutionary interactions occur on comparable time scales. Our model also exhibits periodic orbits that agree qualitatively with oscillation patterns observed in experimental studies of
the coupling between rapid evolution and ecological interactions.