Joel I. Seiferas Retirement Celebration:
JoelFest: A Day of Talks by Zvi Galil, Shafi Goldwasser, Jon Kleinberg, and Muthuramakrishnan Venkitasubramaniam

Monday, September 4, 2017 (Labor Day), 9AM—5PM


Joel I. Seiferas retired on December 31, 2016, after more than 37 years at the University of Rochester's Department of Computer Science, and became professor emeritus of computer science. Rather than have a day of talks devoted to praising him, Joel asked the department to make his retirement celebration be a day of accessible, enjoyable talks.

So to celebrate Joel's career, the department is hosting a day of accessible, enjoyable talks.

The talks are all open to the public, and we very much hope you will attend them. (This day of talks will also be the year's first meeting of the 2017–2018 academic year of Theory Canal: The Rochester Theory Seminar Series.)

Quick Links

Lunch Break
The Department's Retirement-Announcement Text
Room Locations
Getting to Rochester
Directions to River Campus and Information on Parking
Things To Do in Rochester
picture of Joel I. Seiferas
Joel I. Seiferas, 2017


We're very excited to announce that the four speakers will be:

The schedule for the day is as follows:
9:00 -10:00 Zvi Galil; talk title: Online Revolutions: From Stringology with Joel to Georgia Tech's Highly Affordable Master Degree.
10:00 -10:30 Break.
10:30 -11:30 Jon Kleinberg; talk title: Social Dynamics and Mathematical Inevitability.
11:30 -2:30 Free Time for Lunch (see the Lunch Break section on this page).
2:30 -3:30 Shafi Goldwasser; tentative talk title: Crypto Computing.
3:30 -4:00 Break.
4:00 -5:00 Muthuramakrishnan Venkitasubramaniam; talk title: The Status of Zero-Knowledge Proofs.


There is no fee to attend the talks.

But if you will be attending (please do!), please do register by August 22nd. (This will let us know how many will attend and will help us get right the room size for the talks.) To register, please simply send an email to joelfest "at", with the subject JoelFest Registration, and in the body simply let us know that you will be attending, and including your name, affiliation (if any, e.g., UR-CS-UG-student or RIT-Math-faculty or Kodak), and email. Please use this registration link to register; it will put you (if your browser and mail client are playing nice today; otherwise, please just create such an email by hand) inside a draft of such an email, and all you then need to do is fill in the fields and hit send. (Notes: (a) As a general matter and as a courtesy to the planning, please, please do register by August 22. However... if you did not register, but as Sept. 4 arrives you wish to attend these talks, of course do register late and do come on down. (b) The email address goes to all the organizers, including Joel, so please don't put into your email anything that should be confidential from Joel.)

If you cannot attend but would like to send a message to be given to Joel on that day (and it likely will, if time-permits at the event, be read out loud to all), please simply email your message to (not the above email address, as that goes to Joel, but rather to) lane.hemaspaandra "at", with "Message for Joel" as the subject field.

Lunch Break

The lunch period is left free for people to find food (or prove theorems!) in groups of their own, with old or newly made friends.

As to where to do that, there are more than half a dozen different food options available in College Town (though some might be closed due to it being a holiday/Monday), and to see all of them listed so one can choose, simply go to this page and click the "Eat" button! That same "Eat" page has at its bottom a "Download directory" button that will take you to a map that shows where everything is in College Town, and will even show (roughly speaking) how to get there from the UR Campus (basically, go east along Elmwood Ave., which is the two-lanes-each-way street that you almost surely will have used to enter campus, and College Town is the area bounded on the north be Elmwood Ave., on the east by Mt. Hope Ave., on the south by Crittenden Blvd., and on the west by East Dr.; the map that the "Download directory" button leads to shows all of this). To get there very efficiently, a great idea might be to meet a UR CS student at the talks, and ask him or her to be part of your lunch group (and to share with him or her your love of the field!).

College Town is a bit surprisingly far from the campus (because there is a historic cemetery in-between, the Mt. Hope Cemetery, where Susan B. Anthony and Frederick Douglass are buried). The walk is about 24 minutes. But the lunch break is three hours long, leaving time to walk there, eat, and walk back.

An alternative would be that one can stay on campus and eat at one of the on-campus eating places (although beware of holiday closures).

(For completeness and to avoid confusion, we should mention that, admittedly slightly awkwardly, on this same day there is a separate event—an invitation-only departmental retirement lunch for Joel. So the UR faculty/staff and a small group of others such as the invited speakers will be going to that during the lunch period. Professor Štefankovič and Diane Seiferas have organized that lunch, have already sent out the invitations and settled the guest list, and as soon as the location of the lunch is finalized Prof. Štefankovič will send out that information too to all those who were invited and said yes. If you were not invited please don't feel at all bad—rather than (fun!) hearing wonderful things about our wonderful colleague Joel during lunch, you'll be able to (fun!) full-court press Proving Theorems with friends old and newly made.)

The Department's Retirement-Announcement Text

Joel I. Seiferas, an internationally respected theoretical computer scientist, retired on December 31, 2016. The Board of Trustees has appointed him Professor Emeritus of Computer Science effective January 1, 2017. Joel's S.B., S.M., and Ph.D. degrees are from MIT. He joined our department in 1979 after five years on Penn State's faculty.

The department will miss him dearly and deeply, though we are very happy that in retirement he plans to continue his engagement with the department. In September, the department will be hosting a day of talks in honor of Joel.

It is difficult to guess what current research will be remembered for posterity. But in Joel's case it is very easy indeed. Joel's work is a central part of the foundation of the field's understanding of the power of computational models and will be studied when the vast majority of current computer science research has long been forgotten.

One of the most important questions in computer science is whether more computing time lets one solve more problems. Joel's paper on this joint with Michael J. Fischer and Albert R. Meyer showed that for nondeterministic computation even very slightly more time allows additional problems to be solved. Their work remains the most important paper on that topic and part of the bedrock of the field. Indeed, Ryan Williams's recent breakthrough on the weakness of even nonuniform circuits, widely viewed as the strongest complexity advance of the decade, draws centrally on Joel's hierarchy result; no earlier result was tight enough to underpin Williams's proof. Joel's work is so strong that decades after it was done it is underpinning some of the field's greatest work.

Another core question of the field is the extent to which shared access to memory affects power. A decades-open, focal-point issue on that was whether a computer with one memory tape and two read/write heads sharing that tape can in real time compute more than a computer with two memory tapes each with one read/write head can compute in real time. In a proof of tremendous insight and beauty, Joel, jointly with Tao Jiang and Paul Vitányi, resolved this by showing that shared access to memory provably yields greater power.

Those examples, and many others we have not mentioned in such far-ranging other areas as string/pattern matching, sorting networks, almost-everywhere separations, positive relativizations, and real-time simulations, show how Joel's inspired work has resolved some of the deepest of questions.

The fact that Joel is completely ego-free and did all that work (and the single-handed development of widely used bibliographic bridging resources) purely for the advancement of the science—while also mentoring (especially in his ambitious and challenging courses) most of the theory students the department has educated, shaping the department's faculty recruiting in theoretical computer science, serving as the department's chair, and wholeheartedly serving the University in his many years on the Academic Honesty Board—makes him all the more of an inspiration to those who know him.

By coincidence, the great economist and public intellectual, Thomas Sowell, retired from his decades of column writing at the same time that Joel retired. At the end of a 2004 interview, Sowell was asked how he would like to be remembered, and he replied: "Oh, heavens, I'm not sure I want to be particularly remembered. I would like the ideas that I've put out there to be remembered." Although our dear colleague Joel is self-effacing and modest, there is no doubt that the deep understanding of computer science that he has contributed will be remembered beyond Joel's life and ours. We are deeply grateful to him for those ideas, and for his warm, wise friendship.

Room Locations

The room for the four talks of JoelFest will be set and announced on this site, shortly after the August 22 end of the registration period. The room most likely will be either in Wegmans Hall (our new home) or in the now poorly named Computer Studies Building (our previous home).

This the UR River Campus Map shows where the two building are. You can see Wegmans Hall's location on it; it is near the lower left-ish part of the core campus, a bit east of the river, and in more detail: south of Hopeman Hall, east of the Wallis Lot, west of Taylor Hall, and north of the (soon to be rather poorly named) Computer Studies Building.

Getting to Rochester

The university and the (see the Lodging section below) suggested hotel are each about a 10-minute drive from the airport.

Rochester, New York is served by the Greater Rochester International Airport, whose airport code is ROC. (Please do not accidentally buy plane tickets to Rochester, Minnesota; they probably don't even have a theory seminar there that day!)

Rochester also has train service (Amtrak) and bus service (Greyhound), which each drop you near downtown, about a 15-minute taxi ride to the university and the suggested hotel.

Directions to River Campus and Information on Parking

Information on visitor parking at River Campus of University of Rochester (the "River Campus Visitors" initial parts are what to look at, not the stuff at the bottom about Eastman School of Music, which is downtown rather than on River Campus, so for goodness's sake, don't drive to Eastman).

You should please follow the instructions at that link. But since it is a holiday, it is quite possible that even during the day the information booth will be closed. So read on, please.

Thus what you should do is drive up to the visitor's information booth. The Visitor Info booth is just north of Elmwood Avenue and Trustee Rd., on Wilson Blvd.; you can find its location on this map of the parking lots, namely, it is the thing labeled Visitor Info a bit to the east of the river in the lower half of the map. Or alternatively, here is a map that puts a red pin in its location:

If the booth is staffed, buy (or get for free if they are in holiday mode) a one-day guest permit if the agent there says you need to (a one-day permit is currently—as of 5/2017—$5), get a campus map, and then park in whatever lot the agent directs you to park in.

If the booth is not staffed (that would be if they don't staff it on Labor Day due to the holiday; Parking says they often don't staff the booth on holidays... except when they do; to be safe, please do print out a campus map and a parking map before arriving in Rochester), then the right thing to do, Parking tells us, is to drive right about ten feet past the booth, U-turn, then turn left on Trustee Blvd. and then turn right on Intercampus Drive and then park in any space not specially marked as Handicapped/Reserved/Etc. in the Zone 2 South lots ("Bridge Lot" and the north end of Park Lot) or the Zone 3 South Lot (all of Park Lot except its north end). This map of the parking lots shows where both of those lots are; they are sort of near the bottom-left of the map.

Oh... please leave extra time... parking will probably take longer than you expect, and the Information Booth agent (depending on what is available that day) may well put you in a lot halfway across campus, although he or she will (unless the booth is closed, and by the way it is likely to be closed) give you a campus map if you ask so you can at least find your way to park at the appropriate lot and then to walk to the talks.


For anyone who will be staying overnight, we recommend the new Hilton Garden Inn Rochester/University & Medical Center, located at 30 Celebration Drive, Rochester, NY, 14620, in the new College Town area; its phone number is +1-585-424-4404. It is an 18-minute walk to the department from the hotel.

Melissa Singkhamsack, the CS department's administrative staff member who most often interacts with that hotel, says that you should be able to get the (UR) corporate rate by letting them know you are coming to attend a University of Rochester event. She says that if they need to verify that you are, you should please ask them to contact her, at +1-585-275-5478 or at her email address of

Note, though, that: (a) If you are eligible for a AAA or AARP or other discounted rate, please do also ask the hotel about its rate under that discount, as it could be better than the corporate rate; and (b) Melissa warns that the corporate rate fluctuates sharply (and as of when she last checked can be as high as the mid $200s a night) based on availability, and so booking early may result in a substantially lower rate than booking late.

The only other hotel within walking distance of the department is Staybridge Suites Rochester University (phone: +1-585-527-9110).

Things To Do in Rochester

In case you arrive early or leave late, here are some pointers to fun things to do in Rochester:

As our own advice, the George Eastman House/Museum is probably the top attraction of Rochester. But there are many other great things to see: the Strong National Museum of Play (esp. for kids), the Seneca Park Zoo (esp. for kids), the Memorial Art Gallery (a very nice fine art museum), the Rochester Public Market (a large street market), the Lake Ontario shore (e.g., walking in Durand Eastman Park), and much more. The link in the list above provides links to each of these along with reviews and information.


Please don't hesitate to contact us if you have any questions; you can email the entire set of organizers by sending an email to the user-id "joelfest" in the domain "".

Lane A. Hemaspaandra, University of Rochester.
Diane Seiferas, dseiferas at
Joel I. Seiferas, University of Rochester.
Daniel Štefankovič, University of Rochester.
Muthuramakrishnan Venkitasubramaniam, University of Rochester.