Lab 6, Part 2, due Thursday, November 21st

This is the second part of Lab 6, the Internet scavenger hunt.

Each answer below is identified by a two or three letter code followed by a number. Please record your answers on a sheet of paper with the associated answer code. You will submit your answers via Catalyst on Thursday, November 21st by 11 pm. We will hand back your answers to part one and part 2 on Tuesday, November 26th so that you can bring the answers to both parts of the lab to the location described below on Tuesday December 3.

Google Earth

Google Earth lets you fly anywhere on Earth to view satellite imagery, maps, terrain, 3D buildings, from galaxies in outer space to the canyons of the ocean. Download and install Google Earth from the URL below:

http://earth.google.com/

Start the application, and click the icon in the toolbar that looks like a little planet to select "sky". Search for Polaris (The North Star; you can simply search for it, or explore the whole Ursa Minor constellation). Click on the star to see all the information that is linked to it. Find the icon(s) that give(s) you the following information and record it. Record certain pieces of information about Polaris here:

GE1: RA:
GE2: DEC:
GE3: Degrees from celestial north:
GE4: Distance, in light years:

Cryptography

In cryptography, a cipher (or cypher) is an algorithm for performing encryption or decryption — a series of well-defined steps that can be followed as a procedure. The following Wikipedia page describes a method know as a Substitution cipher:

http://en.wikipedia.org/wiki/Substitution_cipher

Use the scheme described in the Simple Substitution section to decode the following clue. Instead of using ZEBRAS, you will use ALGORITHM as the keyword.

Encrypted message: IPREJFS AVR F

CY1:

Google Translate

In this part, you will play "Telephone" with Google Translate. Go to www.translate.google.com. In the source language box (on the left) type "She told her she could not vote for herself". Above, make sure the source language is set to English and then set the target language to Russian. Now copy the Russian translation and paste it into the source box. Make sure the source language is set to Russian and set target language back to English. Notice the last word of the English sentence has changed. What is the first letter of that word? Now go to www.asciitable.com. Find this lowercase letter. What is its hexadecimal code? (Hint: look at the second column). Subtract 46 from this number. Record the result below.

GTR1:

By the way, the problem of correctly translating pronouns is know as "coreference resolution" and is one of the still unsolved problems in computational linguistics (also know as natural language processing).

Partial Secrets

You were given one part of a shared secret in the Piano Etudes section of part one of this lab, which you recorded as answer PE1. Exchange secrets with another student in class, so that you have two secrets: yours and theirs.

The shared secrets represent points on a line. The first number of the pair is the x coordinate and the second number is the y coordinate: (x, y). Calculate the x value of the point at which this line intercepts the x axis (i.e. where y = 0).

If you need help, search the web for "line equation from two points" for a method for doing these calculations.

SS1:

Hexspeak

We have talked about binary numbers and how computers use them, in class. There are also hexadecimal numbers, that work in exactly the same way, except their base is not 10 or 2 (as with decimal and binary), but 16. Digits 0 through 9 are used, plus letters A-F, 16 distinct symbols total. As a result, there are hexadecimal numbers which look like words. Programmers often use them to mark certain blocks in memory, thus making their life easier if they have to search for memory problems and bugs.

Check out this Wikipedia article for a few examples: http://en.wikipedia.org/wiki/Hexspeak. Now use this decimal to binary/hexadecimal converter:

http://www.mathsisfun.com/binary-decimal-hexadecimal-converter.html

and find out what decimal number 3405705229 is in hexadecimal (there is a zero in the decimal field by default; make sure you do not add this extra zero to the number! Look up 3405705229, not 34057052290!).

Write it down as your last clue for this part of the hunt:

HS1: __ _____________

Rendezvous

We will not meet in CSE 203 on Tuesday, December 3d. Instead we will meet at a special location on campus where you will receive the final directions to our field trip location. The directions will make use of the answers from part one and two of this lab, so bring these answers with you.

The letters you found for answers GM1, GM2 and GM4 from part one of the lab can be arranged to spell the name of a building on campus. Put the name of that building in RV1.

RV1:

Directions to rendezvous point:

We will meet at the PC1: doors of the RV1: , not far from the outside area for HS1: ______________ , at normal class time: 2:30pm. Don't be late!