Show of 9-15-2012

Best of Tech Talk Edition

  • Segments taken from previous shows.

Email and Forum Questions

  • Email from Arnie: Hi Dr. Shurtz, As a physicist, can you tell me the physics behind memristors that HP is developing? I understand memristors, being developed by HP since 2007, will not be binary so they will be able to do a lot more in terms of computer electronics than transistors, i.e., they will be able to exist in more than two states, on and off, so they may be analog versus digital. How do memistors work – from a physics point of view? What’s their potential use in computers and other electronics?Thanks, Arnie McKechnie Davidsonville, MD
  • Tech Talk Responds: In simple terms, a memristor “remembers” the amount of charge that has flowed through it and as a result changes its resistance.
  • The effect was predicted in 1971 by electronics engineer Leon Chua.
  • Stanley Williams of Hewlett Packard Labs in Palo Alto, California analyzed and constructed these devices.Williams first considered how memristance might originate at the atomic level. He came up with an analytical model of a memristor that consists of a thin piece semiconductor containing two different regions: a highly doped region, which has a low resistance, and a zero-doped region, which has a high resistance. When a voltage is applied across the semiconductor, it causes some of the dopants to drift so that the combined resistance changes, thereby producing the characteristic hysterisis effect of memristance.
  • To put this model into practice, Williams attached a layer of doped titanium dioxide to a layer of undoped titanium dioxide. Through current–voltage measurements, they found that it did indeed exhibit the hysterisis effect of memrisistance.
  • Williams says his team has already made and tested thousands of memristors, and has even used them in circuits containing integrated circuits. The team is now looking at how they can exploit memristance for tasks normally reserved for digital-logic electronics. These applications include a new form of non-volatile random access memory, or even a device that can simulate synapses — that is, junctions between neurons — in the brain.
  • Email from Margaret: Dr. Richard Shurtz, I need to purchase some music for an upcoming vacation. Music needs to be mobile. Just learned about Spotify and have an acct now. What is the best mobile device to put into a pocket or purse to carry around and listen to music with? I don’t have a cell phone and don’t want one. Thanks. Margaret
  • Tech Talk Responds: Spotify is a great listening option. As a first-time user, you install the free Spotify Mac/PC application, open it up, and watch as it automatically imports your music collection and playlists from iTunes and other music software and presents you with a landing page filled with new releases, top lists, and music shared by your friends.
  • You tell your computer what you want to hear, and it plays it for you…for free, and without limitations for up to six months. It doesn’t play something similar to the song you want (like Pandora), or a 30- to 60-second clip of the song you want (like iTunes)–it plays you the whole song or album, just as if it were in your personal music collection.Facebook and Twitter integration enables you to easily share music discoveries with friends.
  • Using the free version of the service, full songs can be streamed on demand in unlimited numbers for up to six months (with the occasional audio ad popping into rotation, similar to Pandora).After that time, free users can only play a given track a maximum of five times per month and are also subject to a cap of 10 hours of streaming per month. If you pay $5 per month, those restrictions (and ads) disappear, but you’re still limited to listening only from your computer. At $10 per month, you can use Spotify on mobile devices (including iOS, Android, and Windows Phone 7), and even cache your favorite music and playlists for offline listening.Spotify’s default sound quality (96-160Kbps Ogg Vorbis), but you can enable high-quality streaming (320Kbps Ogg Vorbis).
  • Spotify Premium subscribers will be able to select their playlists and set them to be ‘Available offline’. Those playlists will then be synced to your computer so you can continue to listen to your favorite tunes if you have a slow connection or even if you have no connection at all. Each computer will be able to store up to 3,333 tracks at a time.To use ‘offline mode’ you’ll need to be running the latest version of Spotify and you may have to log out and back in for the feature to kick in.
  • Since you don’t want a phone, you will need an MP3 player with wi-fi.Spotify supports for iOS, Android, Symbian, webOS and Windows Mobile 6.x devices
  • Email from Alex: Dear Tech Talk I have read many articles on strangers/others sniffing on our network traffic or whatever we call it; in fact, it often appears in your newsletters. But what does it take to sniff on others network usage? How do people really do it? I’m not able to understand how can others see what we are browsing on the internet right now. What does it mean when you say the ‘unprotected data’ is available for others to read it? I am not going to do anything illegal, I am just very curious! Thanks, Alex.
  • Tech Talk Responds: There’s at least one tool that makes it easy to take over someone’s social media connection if they happen to be logged in unprotected in an open WiFi hotspot.
  • Session highjacking
    • Session highjacking with Firesheep, a Firefox add-on, which has been reviewed previously on Tech Talk.
    • The plugin works like this: A user at an unencrypted, open Wifi hotspot has logged in to an online service. While the login step may have used encrypted https connections, the service reverts to unencrypted http for subsequent page views once logged in.
    • You launch Firesheep. In your browser, a list appears of any users, such as those that I’ve just described, that are also using the same unencrypted WiFi hotspot.
    • You click on the user’s name on the list.
    • You are now logged in as them to whatever service it is that they were using.
    • Note: You did not get their password and you did not actually login as them. Firesheep hijacks an already logged in session and transfers to you the ability to “be” the logged in person.
    • And as that logged in person, you can do whatever that person might be able to do while logged in.
  • Packet Sniffing
    • “Sniffing” is nothing more than the laptop examining or looking at the packets that it sees come by, even if they are not intended for that laptop.
    • So, if you have a laptop with WiFi, you probably already have all of the hardware that you need to sniff unencrypted wireless traffic.
    • Packet sniffing software
    • Wireshark is free packet-sniffing software. It’s labeled as a “network protocol analyzer” because it actually interprets the data within the packets based on the various protocols being used. But in order to do so, it starts by sniffing the packets. Then, it analyzes them.
    • But with a basic understanding of how it works, even a moderately technical person can capture data. Without even knowing anything about network protocols, you can typically view the unencrypted data contained within each packet clearly.
    • Including usernames and passwords. Or your email.
    • Install Wireshark, capture packets, and browse packets for “interesting” things.
  • The key to staying safe is, of course, encryption.Https during login prevents your login credentials from being sniffed, but if the service returns to the unencrypted http connection, then everything that follows is visible to anyone who cares to use software such as I’ve described above. If the services simply continue to use https throughout your session, then all is protected. The packets can still be sniffed, but all that’s visible is unintelligible random noise.

Profiles in IT: Samuel Finley Breese Morse

  • Samuel Finley Breese Morris was inventor of the single wire telegraph and co-inventor of the Morse code used to communicate
  • Samuel Finley Breese Morse was born April 27, 1791 in Charlestown, Massachusetts.
  • He attended the Phillips Academy in Andover, Massachusetts.
  • He enrolled in Yale College, studying philosophy, mathematics and science of horses.
  • He supported himself by painting and in 1810 graduated with Phi Beta Kappa honors.
  • In 1811, he sailed to England with artist Benjamin West to perfect his painting.
  • By the end of 1811, he was admitted to the Royal Academy, where he learned neo-classical art of the Renaissance and paid close attention to Michelangelo and Raphael.
  • After observing and practicing life drawing and absorbing its anatomical demands, the young artist successfully produced his masterpiece, the Dying Hercules.
  • He left England on August 21, 1815 and began his career as an American painter.
  • From 1815–1825, he sought to capture the essence of America’s culture and life.
  • From 1830 to 1832, Morse returned to Europe to improve his painting skills.
  • On the sea voyage home in 1832, Morse met Charles Thomas Jackson who showed him experiments with electromagnets.
  • Morse developed the concept of a single-wire telegraph, which he promptly patented.
  • He proposed to send information over the line using the Morse code.
  • His first patent was not officially awarded until 1840.
  • Morse could not send a telegraphic signal more than a few hundred yards of wire.
  • With the help of Leonard Gale, a NYU professor, he sent a message ten miles.
  • Morse and Gale were joined by Alfred Vail, who had skills, insights and money.
  • Morse and Vail made the first demonstration of the telegraph on January 11, 1838.
  • The first public transmission, with the message “A patient waiter is no loser.
  • Morse was awarded a contract for $30,000 to connect Washington and Baltimore.
  • On May 24, 1844, the line was officially opened as Morse sent the famous words “What hath God wrought” His telegraph could transmit thirty characters per minute.
  • In May 1845 the Magnetic Telegraph Company was formed in order to connect New York City towards Philadelphia, Boston, Buffalo and the Mississippi.
  • Samuel Morse received a patent for the telegraph in 1847 in Istanbul, which was issued by Sultan Abdülmecid who personally tested the new invention.
  • The Morse telegraphic apparatus was officially adopted as the 1851.
  • In the US, Morse had his telegraph patent ignored for many years.
  • In 1853, the Supreme Court upheld his patent for the telegraph. However, the Court denied the Morse code patent, a decision has applied to patenting software.
  • In addition to the telegraph, Morse invented a marble-cutting machine that could carve three dimensional sculptures in marble or stone.
  • Morse was a leader in the anti-Catholic and anti-immigration movement.
  • Morse had four children with his first wife and four more with his second.
  • Morse died of pneumonia at his home in New York City April 2, 1872.
  • Morse estate was valued at some $500,000 ($9.14 million today).
  • He held four patents dealing with the communication information by signals by the application of electro-magnetism.

Hurricane Physics

  • Dedicated to Irene, the hurricane of the moment
  • Wind and Rain
    • Air flows clockwise around a high pressure system and counter-clockwise around a low in the Northern Hemisphere.
    • Hurricanes are areas of deep low pressure, so their winds swirl counter-clockwise around the center of the storm – where the eye is located.
    • Both rotations are caused by the Coriolis force
    • Hurricanes impacting the East Coast usually have a northwesterly track. That movement affects the wind speeds felt on the ground: The winds in the northeast quadrant of the storm which blow to the north (counter-clockwise around the eye) combine with the northwesterly movement of the storm.
  • Storm Surge
    • Air  pressure presses down against ocean water at an average sea-level pressure of 1013 millibars.
    • In the eye of a hurricane, the pressure is far lower than average and doesn’t push down as hard on the water. This causes the water to rise higher than water outside the hurricane.
    • This moving hill of water carried in the center of the hurricane is known as storm surge.
    • When the hurricane makes landfall, this hill of water is carried onshore, causing flooding. If the landfall timing coincides with high tide, the flooding can be even worse.
  • Hurricanes always have the potential to spawn tornadoes, though usually weak ones. So no matter how nice it looks outside, keep an eye on the local weather station and stay indoors just to be safe!

Food Science: Microwave Oven

  • Microwave radiation is around 2400 MHz, near the absorption peak of water
  • The frequency is slightly detuned from the absorption peak so the radiation penetrates to the center of the food.
  • The radiation heats the water molecules so the temperature never exceeds the boiling point of water.
  • Not good for heating meats that require browning through Maillard reaction , which occurs above 285 F.
  • Good for heating eggs, steaming vegetables, poaching fish, making caramel from sugar

Food Science: Potatoes

  • There are many different types of potatoes, and each has a best cooking method.
  • Potatoes are all about starch and water; the cooking method controls the reaction between the two.
  • As a high-starch potato is baked, the starch inside the potato absorbs water from other parts of the potato and swells, making a space between cells, creating a mealy, dry texture.
  • When a potato is deep fried, pan fried, or roasted, the starch on the surface expands, sealing the edges and the surface, creating a crisp crust and keeping the interior moist.
  • Boiling, or low starch potatoes, do not absorb as much water, so the cell structure stays intact, and the potato holds its shape.
  • Potato Types
    • Russet potatoes have a high starch content with low moisture. These potatoes bake mealy and fluffy, and are the best choice for mashed potatoes and baked potatoes.
    • Medium starch potatoes include Yukon Gold and Yellow Finn potatoes. They aren’t as fluffy as russet potatoes, but have great flavor. Yukon Gold potatoes, especially, taste buttery when cooked.
    • Potatoes with a low starch content and high moisture include red and white potatoes. These potatoes are most often boiled or roasted and used in potato salad because of their creamy texture. They hold together well after being cooked.
    • Sweet Potatoes and Yams are actually two different tubers. Yams are a member of the lily family, and sweet potatoes are members of the morning glory family. In the United States, you’re almost always buying sweet potatoes; true yams are not very available.