Thursday, June 29, 2017

50 Years of the Turing Award

The ACM knows how to throw a party, a two-day celebration of the 50th anniversary of the Turing Award. Every recipient got a deck of Turing Award playing cards and the ACM unveiled a new bust of Turing perfect for selfies.

The conference featured a number of panels on different challenges of computer science from privacy to quantum. Deep Learning formed a common thread, not only did it have its own panel but the Moore's law panel talked about specialized hardware for learning and deep learning causes concern for the privacy and ethics panels. Even quantum computing used deep learning as an example of a technology that succeeded once the computing power was there.

The deep learning panel focused on what it can't do, particularly semantics, abstraction and learning from a small or medium amount of data. Deep networks are a tool in the toolbox but we need more. My favorite line came from Stuart Russell worried about "Grad Student Descent", research focused on parameter tuning to optimize learning in different regimes, as opposed to developing truly new approaches. For the theory folks, some questions like how powerful are deep neural nets (circuit complexity) and whether we can just find the best program for some data (P v NP).

The "Moore's Law is Really Dead" panel joked about the Monty Python parrot (it's resting). For the future, post-CPU software will need to know about hardware, we'll have more specialized and programmable architectures and we'll have to rely on better algorithms for improvement (theory again). Butler Lampson said "The whole reason the web works is because it doesn't have to." I don't remember how that fit into the discussion but I do like the quote.

The quantum panel acknowledged that we don't quite have the algorithms yet but we will soon have enough qbits to experiment and find ways that quantum can help.

You can watch the panels yourself, but the real fun comes from spending time with the leaders of the field, and not just theory but across computer science.

Monday, June 26, 2017

Best. STOC. Ever.

The Panel on TCS: The Next Decade
Last week I attended STOC as its first new TheoryFest in Montreal. Pretty much everything about TheoryFest went extremely well and for the first time in a long time I felt STOC played a role beyond a publication venue. Great plenary talks from both within and outside the community. The poster sessions were well-attended and caused our community to talk to each other--what a concept. Senior people took junior people to lunch--I had a great time with graduate students Dhiraj Holden (MIT) and Joseph Bebel (USC). I missed the tutorials and workshops but heard they went very well.

By the numbers: 370 attendees, 46% students. 103 accepted papers out of 421 submitted. These numbers are moderate increases over recent years.

The Panel on TCS: The Next Decade talked about everything but the next decade. A few of my favorite quotes: "Hard instances are everywhere except where people care" (Russell Impagliazzo, who walked back a little from it later in the discussion). "I never know when I proved my last theorem" (Dan Spielman on why he keeps trying). Generally the panel gave great advice on how to do research and talk with other disciplines.

Avi Wigderson argued that theory of computing has become "an independent academic discipline" which has strong ties to many others, of which computer science is just one example. He didn't quite go as far as suggesting a separate department but he outlined a TCS major and argued that our concepts should be taught as early as elementary school.

Oded Goldreich received the Knuth Prize and said that researchers should focus on their research and not on their careers. The SIGACT Distinguished Service Award went to Alistair Sinclair for his work at the Simons Institute.

Oded apologized for lying about why he was attending STOC this year. TheoryFest will be a true success when you need reasons to not attend STOC. All happens again next year in Los Angeles (June 23-27) for the 50th STOC. Do be there.

Saturday, June 24, 2017

Joan Clarke (1917-1996)

I'm in San Francisco for the ACM conference celebrating 50 years of the Turing Award. I'll post on STOC and the Turing award celebration next week. Today though we remember another member of Bletchley Park, Joan Clarke, born one hundred years ago today, five years and a day after Turing.

Clarke became one of the leading cryptoanalysts at Bletchley Park during the second World War. She mastered the technique of Banburismus developed by Alan Turing, the only woman to do so, to help break German codes. Bletchley Park promoted her to linguist, even though she didn't know any languages, to partially compensate for a lower pay scale for woman at the time. Keira Knightly played Joan Clarke in The Imitation Game.

Joan Clarke had a close friendship with Turing and a brief engagement. In this video Joan Clarke talks about that time in her life.

Tuesday, June 20, 2017

Harvard revokes admission of students based on what was said in a private(?) chat room

Harvard revoked the admission of 10 students (see here) based on what the students said in a private (can't have been too private) chat room.

(ADDED later upon reflection- Harvard has only confirmed that there is a clause students are made
aware of about immaturity and moral character. As for the reason for the revoking- we only have
what is reported and that comes from the students. Are the students trustworthy on this?  Given that they are being expelled for moral reasons... But more seriously we really don't' know. I just want to caution that we do not know the full story and never will. Note that Harvard is not  legally allowed to disclose why they revoked, while the students can say what they want.  For an example of how off a reported story can be see this though I am sure you all know other examples.)

Normally I would be aghast (and I may still be aghast) because of the slippery slope:

Today you revoke admissions because students mock sexual assault, the Holocaust, and the death of children, and call the hypothetical hanging of a Mexican child ``pinata time''

Tomorrow you revoke admissions because a student is a Trump Supporter.  (Readers: I assume that you would find revoking admission because a student is a Trump supporter to be disgusting and absurd.)

I felt strongly against this and sought out some other viewpoints. Here are some:

1) Harvard is within their rights to do this legally according to what they agree to when they accept you. This is true. This is also irrelevant- I am interested in if its the right thing to do, not if its legal.

2) The content of the chat rooms indicates a lack of moral character.  This is a stronger argument. However the nebulousness of ``moral character'' reminds me of the origin of taking moral character into account: it was an excuse to let in less Jews (see the book t Harvard, Yale, and Princeton, see The Chosen: The hidden history of admissions and exclusion a review here).  Jews do not have less moral char, but it was used as an excuse to admit less of them.  Even though in the case at hand moral char is a legit issue, the history of the use of this issue bothers me. Slippery slope again.

3) For crying out loud bill, LIFE is a Slippery Slope! You have to draw the line somewhere! And wherever you draw it, these kids are over that line.  This argument, combined with the moral-point of item 2, I do find compelling.

4) Here is a one border (I do not know if it was crossed): If a student personally attacks another student then this is grounds for  revoking. Sounds good but what constitutes a personal attack?

Counter argument: : Whenever a disgusting point of view is censored or punished the conversation shifts from

                                              That is a disgusting point of view


                                         Free Speech! Oppressing unpopular views!

I would rather the conversation be about why the point of view is wrong (or disgusting)  rather than on Free Speech.

Right now I am 75% against the revoking of the students admissions. This has no effect- I am not in any position of power, I won't give less money to Harvard (I am an alum-Grad school, which is why I noticed the story in the first place). I find the question interesting and, more than usual, welcome your comments. Based on your comments that 75 might change! In either direction!

Wednesday, June 14, 2017

The Power of Economic Inefficiency

I grew up in a time when long distance domestic phone calls from AT&T costed $0.20/minute off peak ($1.30 in today's dollars). I also grew up close to AT&T Bell Labs, a mecca that claimed more PhDs than any university many doing independent research. Now I get all the phone minutes I can use and Bell Labs is a tiny fraction of what it once was. Was it a good trade?

Technology has helped eliminate many of the economic inefficiencies. Usually for the better but sometimes these inefficiencies has good side effects. For another example take airlines--we can now so easily compare airlines on price so they often compete on price at the cost of service. Don't even get me started on newspapers.

Universities remain one of the institutions where technological change has not had the cost savings effect that we've seen in communication and transportation. That's one of the reasons that universities have become more expense. We can't keep raising tuition and being pushed to focus on eliminating inefficiencies, seeking new ways to deliver classes for example. Will the research university as we know it survive?

Monday, June 12, 2017

Climate Change: The Evolution of the Deniers/Does Paul Ryan Hate His Grandchildren?

I went to the Mach for Science and then Drumpf pulled out of the Paris Accords. Causation or Correlation? I then posted about climate change (CC). That's caustation.

1) Deniers:

  The deniers have gone through several phases:

There is no CC

There is CC but its not caused by humans.

There is CC and its caused by humans but since China and India and other countries aren't doing anything about it, if only we do it will have no effect except to ruin our economy.
(Counter argument: the effects of climate change are economically devastating- are insurance companies trying to pressure governments to do something about CC since CC's effects cause damage which hurts their bottom line?)

Intermixed with these arguments have been:

Just because 87% of all lung cancer victims  smoke, that's just a correlation. Maybe people the lung cancer gene is also the smoking gene. Correlation does not equal causation. OH, sorry, that's a flashback to the Correlation NOT causation arguments made by the Tobacco companies. Do they still believe that? Mike Pence does (see here). How can they stay in business? (here's how) ANYWAY, some are making the correlation NOT causation argument for why Polar bears are dying, etc.

AND the classic

Technology will bail us out. (This would be a better argument if it was followed by hence we will give lots of funding for such technology  which is NEVER what its followed by.)

OKAY, so where are we in 2017?

The economist had an argument about how Solar and Wind will soon be MORE cost effective than Oil and Gas- though we still have the problem of what happens on a cloudy, windless day- so we need technology to store (see here though its behind a pay wall). China and India ARE doing things about CC. How much? Effective? Hard to say- though both are really concerned with pollution.

I predict the new argument will be:

We're all doomed anyway so why take our economy down at the same time.

Unfortunately this argument might be correct.

(ADDED LATER- a commenter says that I conspicuously left out religious arguments to not do anything about CC.  I now conspicuously ask you to read his comment.)

2) Take Paul Ryan. Please.
Seriously-- I assume he KNOWS that CC really is a problem and the longer we put it off the worse it will be for his grandchildren, and perhaps his children. So why does he fight ANY attempt to even admit we HAVE a problem (And note there ARE some market-based solutions- a Carbon Tax, Cap and Trade.)  Some speculation

a) Despite being smart he's in deep deep denial. Okay, but why is that? If you believe in small government then if something comes along that REQUIRES big government, you just DENY it since it does not fit into your world view.

b) Paul Ryan hates his Grandchildren.

c) Paul Ryan thinks that HIS grandchildren will be among the few people who survive and live in a VERY gated community. He's probably wrong about that as even those in gated communities will suffer the effects of CC.

d) Paul Ryan is stuck. If he tries to do ANYTHING then it will not work AND he'll lose his speakership and possibly his seat in congress. And there are a large number of congressman and senators who feel the same way but they're all afraid to say. If they ALL said so then... they'd ALL lose their seat in congress. One of the downsides of politics is ending up STUCK on the WRONG side of history and KNOWING it. Well, at least there won't be much history left so he won't be stuck on the wrong side for long.

3) Game Theory. I used to think that it was in NO countries SHORT term interest to do anything serious about CC (that is, do it alone) and hence we were all DOOMED! Doomed I say! And part of the problem is that if Country A emits greenhouse gases its bad for THE ENTIRE WORLD EQUALLY, and not for Country A in particular. But a few things make me more optimistic:

Pollution is a here-and-now problem for China and India so they will tackle that. That somehow has to be part of the solution.

Technology- as mentioned before Solar and Wind is catching up to Gas and Oil. (downside of technology- Fracking and oil extraction are also getting better and cheaper. Hubbert's Peak Oil Theory doesn't seem to be true) But the real advantage of Solar and Wind will be that you don't have to Extract and ship Oil (or Coal or whatever).

4) I wrote that last positive point before President Drumpf. Having a CC denier in the white house means four more years of no action which sounds really bad- especially since the longer we put off doing something about the problem, the harder and more expensive it will be to slow down CC (Some ponders that Trump won't be that bad for the environment: here)

5) Okay Bill, what would YOU do? Carbon Tax will give financial incentive for companies to curb Carbon emissions. And its simple. The Tax has to be high enough to have an effect. Another added bonus will be to help America pay down its deficit. ALSO more research into renewables. Oddly enough I would also recommend NOT forcing Gas to contain Ethanol- make Ethanol compete with Solar and Wind. (Recall that Ethanol is funded only because of the Iowa Caucus. If you don't know what I'm talking about, don't worry, its too stupid to explain.) Some may disagree and have other ideas. Thats FINE- I would rather be having a debate about what to DO about the problem rather than one about whether or not there IS a problem. Though even a debate about what to do about the problem should be SHORT so we can begin DOING something.

Thursday, June 08, 2017

Theory Jobs 2017

In the fall we point to theory jobs, in the spring we see who got them. Like last year and years past I created a fully editable Google Spreadsheet to crowd source who is going where. Ground rules:
  • I set up separate sheets for faculty, industry and postdoc/visitors.
  • People should be connected to theoretical computer science, broadly defined.
  • Only add jobs that you are absolutely sure have been offered and accepted. This is not the place for speculation and rumors.
  • You are welcome to add yourself, or people your department has hired.
This document will continue to grow as more jobs settle. So check it often.


Monday, June 05, 2017

Big News on W(3,r) !

This is a JOINT POST with   Evangelos Georgiadis who brought this problem to my attention.)

In 2010 I posted about how dense a set of integers has to be before you know there is a 3-AP in it (a 3-AP is a set of three numbers equally spaced). Such results were motivated by and are applied to getting upper bounds on

W(3,r) = the least W such that any r-coloring of {1,...,W} has a monochromatic 3-AP.

That blog, which also has history and context, is here

At the time of that post the following was known (and had just been proven by Sanders see here)

If A ⊂  {1,...,N} and |A|  ≥ N*(log log N)5  / log N  then A has a 3-AP

and hence

W(3,r) ≤ 2r(log r)5

(Added later: Bloom's paper (see link on next line) reports that Sanders result is a bit weaker than claimed- the 5's should be 6's, calculation error.)

This has now been improved!. Thomas Bloom, in this paper has shown

If A ⊂  {1,...,N} and |A|  ≥ N*(log log N)4  / log N  then A has a 3-AP

and hence

W(3,r) ≤ 2r(log r)4

An easy prob argument gives

W(3,r)  ≥ r3/2

So is W(3,r)'s growth rate poly? Exp? in between? Is there a connection to SAT?

One can phrase the question  W(k,r)=m as asking of a certain Boolean Formula is it satisfiable.  IF we can get theorems about that kind of formula, that might help.

However, I doubt that it has much real connection to the general SAT problem.

I don't know if the consensus of the community is that W(3,r) is poly or exp.

(Warning: I've seen W(3,r) to mean something else: W(3,r) is the least W such that any 2-coloring of {1,...,W} with colors 0 and 1 has either a 0-colored 3-AP or a 1-colored k-AP. This is NOT the function we are talking about, though that one is also interesting. )

ADDED LATER: Knuth's Volume 4, Fascicle 6 has theorems about this W(3,r)

ADDED LATER: A commenter said that a simple prob greedy algorithm using salem-spencer sets

W(3,r) ≥ exp(C (ln r)2)

I reconstructed the proof from these comments, though using Behrends sets instead of SS

The proof is here: here

Thursday, June 01, 2017

Who Sets Policy?

In April the New York Times Magazine ran an article Is it O.K. to Tinker with the Environment to Fight Climate Change?  The article asks about the ethics of even running tests on such methods and has this quote froms David Battisti, an atmospheric scientist at UW.
Name a technology humans have developed that they haven't used. I can't think of any. So we can work on this for sure. But we are in this dilemma: Once we do develop this technology, it will be tempting to use it.
The article skirts the question on who makes this decision. Maybe the United Nations after some unlikely agreement among major powers. But what if the UN doesn't act and some billionaire decides to fund a project?

As computer scientists we start to face these questions as software in our hyper-connected world starts to change society in unpredictable ways. How do we balance privacy, security, usability and fairness in communications and machine learning? What about net neutrality, self-driving cars, autonomous military robots? Job disruption from automation?

We have governments to deal with these challenges. But the world seems to have lost trust in its politicians and governments don't agree. How does one set different rules across states and countries which apply to software services over the Internet?

All too often companies set these policies, at least the default policies until government steps in. Uber didn't ask permission to completely change the paid-ride business and only a few places pushed back. Google, Facebook, etc. use machine learning with abandon, until some governments try and reign them in. The Department of Defense and the NSA, in some sense industries within government, set their policies often without public debate.

What is our role as computer scientists? It's not wrong to create the technologies, but we should acknowledge the ethical questions that come with them and what we technically can and cannot do to address them. Keep people informed so the decision makers, whomever they be, at least have the right knowledge to make their choices.