Skip to main content


What do we really know about computers? Are they really so clever?

The Bloomfield Science Museum Jerusalem presents – the CAPTCHA exhibition

  • What are the limits of the computer’s ability?
  • What can’t it compute?
  • Will the computer ever attain self awareness comparable to ours?
  • Can a computer be creative? And what does all this say about us and our thinking?

CAPTCHA - Completely Automated Public Turing test to tell Computers and Humans Apart

The electronic computer was invented 70 years ago. Since then it has pervaded our lives to such an extent that we have forgotten to question the meaning of this machine, its scientific basis, and its influence on scientific thinking, both now and for the future. The person who did ask these questions was Alan Turing, the English mathematician who foresaw the computer as early as 1936. Even then, before the first computer was invented, he realized that it would be the mirror through which we would be able to explore the essence of our mind and our awareness. This philosophical breakthrough has established computer science at the forefront of modern science, enabling us to tackle challenging and intriguing problems.

The curator of the CAPTCHA exhibition at the Jerusalem Science Museum is Nathan Zeldes, in collaboration and under the sponsorship of Intel, Check Point, Google, and Medton. The exhibition will remain on display for several years. It explores the ways in which the computer has influenced our lives and the extent to which it has (or has not) changed the world. It is a fantasy setting, the direct antithesis to the hi-tech environment one would expect, very colorful, utilizing natural materials, soft lines, and interactive displays.

There are five sections, each one comprising many interactive displays:
  • What is ‘computation’?
  • The computer is not omnipotent
  • The thinking computer
  • Cryptography
  • How is computer science changing our lives?

In the ‘Why is it Important?’ section, visitors learn about algorithms by preparing a (virtual) pizza. They will see how the desired outcome is obtained (or not) according to instructions given to the computer.  

The section “The Computer is not Omnipotent” demonstrates intuitive tasks that appear simple, yet the computer is unable to execute them. Tiling a level surface, for example. The question of whether the entire surface can be tiled with the colored tiles provided is not decidable, as demonstrated by means of wooden tiles. In addition, with reCAPTCHA in Hebrew, visitors can witness historic collaboration in the national ReCaptcha.IL project.

The collaboration of recent months between the Science Museum and the National Library comes in answer to the pressing need to identify unreadable Hebrew texts, which are undergoing a process of digitization at the National Library. However, the computer (scanner) has failed to decipher some texts. To this end, an interactive stand has been set up where visitors are invited to take part in this national project and help decipher texts. By taking part in this enterprise they will learn about CAPTCHA, reCAPTCHA, and man’s superiority over the computer.

At the coding stand visitors will learn the principles of encryption and decoding by means of simple, symmetric home language ‘secret writing’ that children are familiar with – ATBASH, Caesar, etc. The display includes large interactive Decoder Wheels, and an exchange of coded messages for visitors to decipher at two stations. Another decoding device depends on the frequency of letters in the language – deciphering texts through the use of statistics (computerized interactive exhibit). Also at this unit, visitors will be able to view an original Enigma machine, on loan to the Museum from the Ministry of Defense.

At the “The Computer is Changing our Lives” unit visitors will experience interactive displays demonstrating the contribution of computer science in every aspect of our lives – vehicles, medicine, communications, research, and so on. One display, entitled “A Small Jump Overseas”, enables you to “travel the world” in real time, viewing sites that are being photographed by web camera every hour of the day.

Another intriguing display built by visitors touches on the sphere of media and the Crowd  wisdom.  “Plant a Comment” is a fascinating interactive exhibit by artists Omer and Tal Golan, a three-dimensional world where thoughts turn into trees made up of texts, the written expression of thoughts and ideas sent by viewers as SMS messages. These are semantically analyzed and integrated into graphic “trees” according to their content. In our changing world, visitors can view the popularity of various concepts supplied by the masses.

The entire exhibition combines the life of Alan Turing and his immense contribution to the field with those made by Israeli computer scientists in software and hardware. It also portrays Israelis who have won prestigious awards, in the hope of attracting both younger and older visitors to the field of computer science.
Date Created: 21/04/13
Date Updated: 21/04/13