tag:blogger.com,1999:blog-85767302017-07-24T10:12:33.868-05:00SedenionDavid Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.comBlogger1292125tag:blogger.com,1999:blog-8576730.post-31010979503216708272017-07-12T00:27:00.000-05:002017-07-12T00:27:11.417-05:00<a href="https://fredrikdeboer.com/2017/07/10/study-of-the-week-to-remediate-or-not-to-remediate/">On a randomized control trial at CUNY on replacing remedial college algebra with introductory college statistics:</a>
<blockquote>
[T]here is a significant and fairly large (16% without covariates in the model, 14% with) difference in odds of passing the course for those randomized to the intro stats course compared to the elementary algebra course...
<p>I will hold with Hacker in suggesting that this does represent a lowering of standards, and that this is a feature, not a bug. That is, I think we should allow some students to avoid harder math requirements precisely because the current standards are too high. Students in deeply quantitative fields will have higher in-major math requirements anyway.
</blockquote>
Yep. And statistics is more directly useful for non-STEM majors who, for example, want to understand the news.
<p>I also found it interesting that "support workshops" for remedial college algebra students didn't measurably improve pass rates in this study. I'm not sure what to make of that. I suppose it's consistent with my anecdotal, non-randomized-control-trial experience that more conscientious students are both more likely to pass and more likely to take the time to get help from tutors and/or their professors on a regular basis.David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-32752853774680233062017-07-08T17:27:00.001-05:002017-07-08T17:27:14.308-05:00<a href="https://nationalaffairs.com/publications/detail/federalism-in-blue-and-red">Replace</a> the federal income tax deduction of state income taxes with block grants for states with below-average per capita income. Such "equalization grants" work well in Canada and Australia.David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-16530870248873835392017-07-01T16:47:00.000-05:002017-07-01T16:47:08.558-05:00I've long been a fan of Scott Sumner's <a href="http://econlog.econlib.org/archives/2017/06/my_views_on_mon.html">views</a> on monetary policy. I recently <a href="http://www.arnoldkling.com/blog/scott-sumners-macroeconomics-my-thoughts/#comment-474147">commented</a> on Arnold Kling's blog in defense of Sumner. In summary:
<blockquote>
If the Fed wanted 2018 US NGDP to be more than $20T (for example), it could say, "whenever betting markets generally predict 2018 US NGDP under $20T, we will start to buy and hold assets of our choosing, at a rate of $1B the first day and doubling the rate every day thereafter, until betting markets generally predict 2018 US NGDP over $20T."
<p>When there is a large negative expected NGDP, the mismatch between downward-sticky wages and much more plastic hiring/firing/layoffs aggregates into a large short-term misallocation of real resources.
<p>Therefore, the Fed should buy whatever it takes to reverse large downward surprises in expected NGDP.
</blockquote>David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-4750286192853109082017-06-26T15:08:00.001-05:002017-06-26T15:08:46.738-05:00News of <a href="http://blog.achernya.com/2017/06/by-installing-nat-mit-stifles-innovation.html?view=classic">MIT's</a> <a href="https://en.wikipedia.org/wiki/Network_address_translation">NAT</a> saddens me.
<p>I remember when the names iteration.mit.edu and recursion.mit.edu
were mine; they pointed to my public IPv4 address 18.238.3.106.
I don't claim to have done anything innovative with them,
but what I did was very educational.
I wrote a minimal <a href="http://dkmj.org/sigmafield/webserver/webserver.html">http server</a>
in C++ and hosted a static website
<a href ="http://dkmj.org/mathimages/">with</a> fractal <a href="http://dkmj.org/mathimages/z%281+.5%28z-exp%281.4i%29%29%29-zoomed-in.jpg">images</a> I created and a Mandelbrot set Java applet I wrote.
<p>I probably never would have been motivated to learn
how to write an http server without such public visibility.
Security risks?
<a href="https://slashdot.org/comments.pl?sid=28902&cid=3103368">Yes.</a>
(I promptly fixed that one.)
Despite this, MIT thrived without a NAT for many years.
Even if security risks are greater today,
firewalls can be made arbitrarily strict without a NAT.
David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-33845270170599634662017-06-19T17:42:00.001-05:002017-06-19T17:45:25.107-05:00A bit of TeX hacking<p>I've decided that if I state, say, Theorem 2.2.15 but don't prove it until many pages and lemmas later in Section 5,
then, for the reader's sake, I should repeat the theorem verbatim, including the original theorem number, immediately before the proof, as opposed to going straight from the proof of Lemma 5.2.33 to "Proof of Theorem 2.2.15." (Granted, if the delay between statement and proof is just for one "Main Theorem" whose statement is easy to remember, then this is not necessary. My decision is in the context of revising a longer paper with several theorems stated early and proved much later.)
<p>
<pre>
%#1 theoremstyle inpute (plain/definition/remark/...)
%#2 type of theorem (Theorem/Lemma/Corollary/...)
%#3 label of theorem to be repeated
%#4 unique new input for \newtheorem
%#5 statement of theorem
\def\repeattheoremhelper#1#2#3#4#5{
\theoremstyle{#1}
\newtheorem*{#4}{#2 \ref{#3}}
\begin{#4}
#5
\end{#4}
}
\def\repeattheorem#1#2{
\repeattheoremhelper{plain}{#1}{#2}{repeat#2}{\csname state#2\endcsname}
}
%usage example
%\theoremstyle{plain}
%\newtheorem{thm}{Theorem}
%...
%\def\statemytheorem{blah blah}
%\begin{thm}\label{mytheorem}\statemytheorem\end{thm}
%...
%\repeattheorem{Theorem}{mytheorem}
%\begin{proof}
%...
%\end{proof}
</pre>David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-4133593436792746812016-11-19T10:14:00.002-06:002016-11-19T10:14:34.887-06:00I think I need a red ink pad and stamp with
"<a href="http://algebrarules.com/">AlgebraRules.com</a>"
on it.
David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-59107390276196303962016-11-03T08:33:00.000-05:002016-11-03T08:33:15.449-05:00<a href="http://www.themoneyillusion.com/?p=32058">"I always say that politics takes 30 points of[f] a personâ€™s IQ, including me."</a>David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-52328293859102270452016-10-18T14:58:00.001-05:002016-10-18T14:58:34.411-05:00<a href="https://imgcert.com/image/yJzh">The old ways are the best ways.</a>
David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-29641514440932904942016-10-08T14:04:00.000-05:002016-10-08T14:04:05.183-05:00<a href="http://www.nytimes.com/interactive/2014/12/22/upshot/what-2000-calories-looks-like.html?contentCollection=smarter-living&_r=0">What 2000 calories looks like.</a>David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-31197016290098367972016-09-22T19:16:00.003-05:002016-09-22T19:16:30.995-05:00<a href="http://theresurgent.com/coming-to-terms-with-trump/">I just cannot vote for either one.</a>David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-42956484650230532662016-09-20T16:15:00.001-05:002016-09-20T16:15:56.831-05:00<a href="https://www.wired.com/2016/09/physics-love-james-bond-cocktail-tricks/">No torque, no spill</a> (in the accelerated reference frame).David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-62925035688418533442016-09-09T11:13:00.001-05:002016-09-09T11:13:06.274-05:00An excellent two-minute time-lapse video of two weeks of evolution of <a href="https://youtu.be/plVk4NVIUh8">antibiotic resistance</a>.
David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-9632767682646566602016-09-07T20:12:00.001-05:002016-09-07T20:34:29.965-05:00<a href="https://arxiv.org/abs/1609.01421">Struggles with the Continuum,</a> the most enjoyable survey paper I've read in a long time. It concerns singularities in mathematical physics.David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-70915145916350166562016-08-29T21:30:00.004-05:002016-08-29T21:30:43.469-05:00<a href="https://math.dartmouth.edu/~pw/solutions.pdf">Seven puzzles you think you must not have heard correctly.</a> (The solutions are at the end.)David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-68223938380481535022016-08-25T17:38:00.001-05:002016-08-25T17:38:17.920-05:00<a href="http://arxiv.org/abs/1608.05284">How much damage would a space probe take flying through the interstellar medium at <i>v=0.2c</i>?</a> (See also <a href="http://arstechnica.com/science/2016/08/could-breakthrough-starshots-ships-survive-the-trip/">this</a>.)
<p>Bottom line: I am seriously entertaining the possibility that I will live to see digital images transmitted from another planetary system.
David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-27611518195179043502016-08-24T13:59:00.000-05:002016-08-24T13:59:43.050-05:00<a href="https://en.wikipedia.org/wiki/Houthi_insurgency_in_Yemen">If</a> Saudi Arabia and Iran are fighting a proxy war in Yemen, <a href="http://www.abc.net.au/news/2016-08-23/yemens-children-die-from-bullets-bombs-and-hunger/7777316">why</a> is the US taking sides?David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-51690932322920369522016-08-23T16:54:00.003-05:002016-08-23T16:54:44.964-05:00<a href="http://www.calculatedriskblog.com/2016/07/the-future-is-still-bright.html">Good reasons for optimism about the US economy.</a>David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-71780035499721548232016-08-20T12:59:00.000-05:002016-08-20T12:59:31.715-05:00<a href="http://arstechnica.com/science/2016/08/had-it-been-a-tropical-cyclone-louisiana-storm-likely-among-10-costliest/">Had it been a tropical cyclone, last weekend's Louisiana storm would likely be among America's 10 costliest.</a>David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-3799532120323498452016-07-22T19:08:00.001-05:002016-08-23T16:36:54.410-05:00At this date, I think it good to revisit my earlier
<!--selfref--><a href="http://sedenion.blogspot.com/2016/05/given-my-apparent-choices-in-november-i.html">comparison</a>
between a million and one. Large numbers are sometimes difficult to reason about, so perhaps using a log scale would help. Let's see... Yep, six strictly exceeds zero.
<p>I am reminded of Peter Thiel's <a href="http://www.cato-unbound.org/2009/04/13/peter-thiel/education-libertarian">2009</a> counsel to escape politics (though he clearly hasn't escaped yet). He sees technology as liberty's only hope. I wish the techno-libertarians well. Why do I say that, when I have become much less individualist over the years? I am simply concerned for the freedoms of my religious community. The Democratic presidential nominee promises nothing but setbacks on that front, and the Republican nominee's promises on that front are worthless because (1) he is incompetent and foolish in a million ways and (2) his harshness invites a huge backlash to come after him. I have reservations about the libertarian nominee, but I have yet to think of a better protest vote.
<p>Update: See also <a href="http://www.nationalreview.com/article/438680/gary-johnson-pro-life-conservatives-best-pick">this</a> and <a href="https://www.bloomberg.com/view/articles/2016-08-04/trump-s-meaningless-vow-on-the-supreme-court">this</a>.David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-24617282283806125012016-06-08T15:28:00.000-05:002016-06-08T16:43:48.001-05:00Don't carry much cash on a road trip, and now don't carry prepaid debit cards either.
<a href="http://www.news9.com/story/32168555/ohp-uses-new-device-to-seize-money-used-during-the-commission-of-a-crime">The bandits have new technology.</a>David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-59372853953854501302016-06-01T16:02:00.000-05:002016-06-01T16:02:43.069-05:00<a href="https://arxiv.org/pdf/1605.09223v1.pdf">This</a> is the easiest yet still significant mathematics paper I've read in a long time. (See also Quanta Magazine's <a href="https://www.quantamagazine.org/20160531-set-proof-stuns-mathematicians/">coverage</a>.)David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-29062599762403057212016-05-07T15:20:00.000-05:002016-05-07T15:20:27.596-05:00Given my apparent choices in November, I can think of a million reasons not to vote for him who shall not be named, and <a href="http://balkin.blogspot.com/2016/05/abandoning-defensive-crouch-liberal.html">one</a> reason to vote for him.David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-80908545385494101172016-04-13T20:37:00.002-05:002016-04-13T20:46:56.841-05:00An 8-dimensional and then a 24-dimensional analog of Kepler's sphere-packing conjecture, widely believed to be true (and actually used for error-correcting codes), were proven true <a href="https://www.quantamagazine.org/20160330-sphere-packing-solved-in-higher-dimensions/">last month</a>, with the major breakthrough due to Maryna Viazovska. (Hales proved the original conjecture in the 1990s.) I noticed that the <a href="http://arxiv.org/abs/1603.06518">paper</a> on dimension 24 has Abhinav Kumar as a coauthor. On my dorm floor way back when, Abhinav was a "greater math god" and I was a "lesser math god."
<p>P.S. Why does that paper talk of "+1 eigenfunctions"? What's wrong with "fixed point"?David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-11889766281238044842016-04-07T19:00:00.000-05:002016-04-07T19:00:33.089-05:00In the asymptotically safe gravity proposal, quantum gravity is weaker at high energies. In <a href="http://arxiv.org/abs/1208.5874">this proposal</a>, gravity is both weaker and less quantum (meaning the effective Planck length (but not the Planck mass) is smaller) at high energies. <p>Imagine that "everybody wins" mathematically, i.e., it is proven there are elegant mathematical models consistent with observation and unifying all of fundamental physics, including an asymptotically safe gravity model, a string theory model, loop quantum gravity model, maybe other models I don't want to take the time to mention, and maybe even an "unquantizing" model like in the link. Which theory will win the parsimony contest? Since parsimony is not the same as mathematical elegance or beauty, I'm not confident that the most parsimonious theory will also become most popular.
David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com0tag:blogger.com,1999:blog-8576730.post-22150481525133110932016-03-18T00:57:00.002-05:002016-03-18T00:57:59.398-05:00Positive question: was Rubio the <a href="https://en.wikipedia.org/wiki/Condorcet_criterion">Condorcet winner</a> of the Republican Presidential primary? I don't have the data to say, but it seems at least plausible.
<p>Normative question: Should not the Condorcet winner (if one exists) be the actual winner? (This isn't special pleading; I didn't vote for Rubio in Texas.) Why not let voters <a href="https://en.wikipedia.org/wiki/Ranked_voting_system">somehow</a> rank candidates on their ballots?
David Milovichhttps://plus.google.com/109637306067900610878noreply@blogger.com2