The Impact of Computing Ganesh Gopalakrishnan School of

The Impact of Computing Ganesh Gopalakrishnan School of Computing University of Utah Courtesy to Pat Phillips of Microsoft and Jeanette Wing of CMU/NSF for the slides on Computational Thinking; John Regehr for some of the hardware photographs; etc. School of Computing 1

Why Compute? l Tool usage is a measure of intelligence and power l Information processing tools have always been widely sought School of Computing 2

Early Information Processing Tool: An Adder School of Computing 3

Early Mechanical Computer: Babbage’s Difference Engine (now rebuilt at the London Museum) School of Computing 4

Nowadays, computers are used everywhere! School of Computing 5

They will soon replace bar-codes on milk-cans! (RFID tags being experimented by Wal-mart). (Photo courtesy of wikipedia. ) School of Computing 6

With Advances in Electronics have come Much Faster and Capable Computing Devices! School of Computing 7

Supercomputers have eliminated the need to do experiments by building scale models of airplanes, or mixing (dangerous) chemicals ! IBM Blue. Gene • Does 400 Trillion multiplications per second ! (Photo courtesy of IBM/LLNL) School of Computing 8

Virtual Roll-out of Boeing 787 “Dreamliner” Entire Airplane being Designed and Flown inside a Computer (Simulation Program). The first plane to fly is the real one (not a mockup model). (Photo courtesy of Boeing. ) School of Computing 9

Supercomputers can now safely simulate explosions ! This simulation employed 600 processors for approximately 1 week in a sophisticated parallel application to simulate all of the fluid dynamics, thermodynamics, chemical reactions and structural mechanics of this system from fundamental laws of physics. [Steve Parker, CSAFE, U of U] School of Computing 10

The Entertainment Art Engineering (EAE) Program at the U of U – a Machinima Movie School of Computing 11

And yet… We do not acquire technical skills simply from the use of technology any more than engineering skills evolve from using automobiles or aeronautical engineering skills from flying. Robert Tinker, Alvaro Galvis, and Andrew Zucker The Concord Consortium We need to apply Computational Thinking! School of Computing 12

What is Computational Thinking? l Asking: What is the power and limit of human and computer intelligence? l Asking: How difficult is the problem? l Asking: How can it be solved? l Asking: How can technology be applied to the problem? l Asking: What computational strategies might be employed? School of Computing 13

CT is about developing an appreciation of large numbers • Compute installation consumes 3 MW of power • Can provide for 20, 000 average homes • Equal to 100, 000 brains thinking hard! School of Computing 14

What it’s not… l It’s not just more technical details for using software l It’s not thinking like a computer l It’s not programming (necessarily) l It doesn’t always require a computer l It’s not yet one more thing to add to your curriculum School of Computing 15

How is it different from other learning strategies? l Not just procedural l Not just constructionist l Not just integrated School of Computing 16

Why is it important? l l l It moves students beyond technology literacy It creates problem solvers instead of software technicians It emphasizes creating knowledge rather than using information It presents endless possibilities for creatively solving problems It enhances the problem-solving techniques we already teach It allows us to see that computing (like any other paradigm) is a double-edged sword, and we need to work hard to get the good elevated and the bad demoted School of Computing 17

CT enables asking questions about ALL computers: One can mathematically prove that NO computer can solve ALL “Post Puzzles. ” One Post Puzzle is … 0 1 2 3 01 01 01 1 0 101 1 The solution for this Post Puzzle is 3, 2, 0, 3, 1 3 2 0 3 1 01 01 1 101 0 1 101 School of Computing i. e. 1 01 Reads 1 01 01 Reads the SAME ! 18

And yet… One cannot predict how long the solution sequence is… 0 1 2 3 1000 01 1 00 0 0 101 001 The shortest solution for this Post Puzzle has 206 steps! School of Computing 19

Application of the Impossibility Result: Given a Grammar for parsing, it is impossible to tell, using a computer, whether the grammar can be used to parse things in TWO incompatible ways (similar to the following) : Given 2*3+4 = 10 we should consider it to be saying (2 * 3) + 5 = 10 and NOT 2 * (3 + 4) = 10 School of Computing 20

Everything is going “Computational” Computers are like telescopes and microscopes for learning in EVERY branch of science and many branches of mathematics! Computational – – – – – School of Computing Physics Biology Chemistry Mathematics Computer Science Law Economics Aeronautics Education 21

For instance… Even many mathematical proofs cannot be written out or checked (in our lifetimes) without the use of computers Famous Computer-Finished Proofs – The Four Color Theorem – The Kepler Conjecture School of Computing 22

And yet… We depend on computers for controlling and predicting virtually every aspect of our lives… l Hospitals no longer can manually check which patients are admitted and what their symptoms are. They have to rely on the data the computers have l We no longer have the ability to forecast weather, process bankrolls, or hey, even watch television, without some computer playing a major role l Billions more of applications (the sales of small computers approaches the 10 Billion mark each year) School of Computing 23

And yet… They can cause an immense digital divide l The older population of the nation – – – l inability to use the web yet all the information is there sometimes one has to see certain patterns and type into a web browser The illiterate population School of Computing 24

And creep into the least suspected places. . Use of Linux in the real world l Desktops and laptops for sure l But these too: – – l Toyota Prius Sony Bravia TV Various Linksys routers Doorlocks in the School of Computing What if there was one common bug in these versions of Linux? one common attack? School of Computing 25

Who is responsible for bugs? How can we prevent bugs? l Employ mathematically based debugging methods, such as “model checking” – debug Scientific Computing codes using – debug thread software such as Linux using – empirically shown to have very few “bug escapes, ” assuming that the modeling was right, and the verification tools themselves worked correctly (and the human, using the tool, did not misinterpret its results… etc. . ) “Execution Checking” School of Computing “Model Checking” 26

And yet… They can have a significant carbon foot-print l The first Petascale computer will consume 20 MW of electrical power l Equivalent to the electrical energy use of 200, 000 average homes l If the software we use on these machines is buggy and wastes one month of simulation time… ? School of Computing 27

And yet… This is also one of the best hopes for world-wide unity, awareness, education… l l l The Web Skype Email $100 laptop for poor nations … School of Computing 28

And yet… One needs a balanced view of the world l The world does not owe us anything – it was here before us! [ Mark Twain ] l We owe a lot to the world l The carbon footprint can wreak havoc by 2050 if kept unmitigated l Leaving the world better than we found School of Computing 29

And yet… All technologies are double-edged Learn to have the good ascending and the bad descending in impact School of Computing 30

Conclusions l Be capable of understanding what computers are l where they are being employed – where they are creeping into our lives l how indispensable they have become l how to keep using them to our advantage l to use them to understand how we think l use them to understand who we are – beware of the digital divide they cause when used poorly – the carbon footprint they leave when used wastefully – the toxic waste they cause when not recycled l WITH ALL THIS, be part of the exciting world of computing, whatever your field of study be !! School of Computing 31

All this fun and Fantastic Employment Potentials!! School of Computing 32

So how do you get involved with the U ? http: //www. cs. utah. edu School of Computing 33

Extra slides School of Computing 34

Another Example (of CT): Exponentials l l l l Developing an appreciation for the “Exponential” 4 – size of a typical family 40 – family reunion 400 – runs in a high-scoring cricket match 4000 – cost of a good desktop machine 40000 – cost of a good high-end car 400000 – one-sixth of Utah’s population 400000 – 3/4 th of the world population -- > number of seconds a human lives School of Computing 35

Exponentials l l l Developing an appreciation for the “Exponential” 4 0000000000 0000000000 0000000000 0000000000 0000000000 number of atoms on earth Using logarithmic amount of ink, we can talk about huge numbers! Using N amount of ink, one can talk about 2^N School of Computing 36

Exponential algorithms, Polynomial algorithms, Unknown complexity algorithms l Poly: Sorting the employee records of N employees l Exp: The number of arrangements of N employees in a single-file procession l Unknown: Given N employees, are there K who form a clique? l Unknown, possibly harder: Given N employees, is it that NO K employees form a clique? School of Computing 37