Show of 12-24-2011

Best of Tech Talk Edition

  • Segments taken from previous shows.

Email and Forum Questions

  • Email from Robert Tyler: Dear Dr. Shurtz: Could you explain the recent incident involving certificate authority DigiNotar? Could you also explain what a certificate authority is and how this relates to security on the internet and World Wide Web? I never miss an episode of Tech Talk and I’m listening to all your previous podcasts via itunes. Thank you for such a great broadcast. Robert Tyler
  • Tech Talk Responds: A Certificate Authority (CA) issues digital certificates that contain a public key and the identity of the owner. The matching private key is not made available publicly, but kept secret by the end user who generated the key pair. The certificate is also a confirmation or validation by the CA that the public key contained in the certificate belongs to the person, organization, server or other entity noted in the certificate.
  • A CA’s obligation in such schemes is to verify an applicant’s credentials, so that users and relying parties can trust the information in the CA’s certificates. CAs use a variety of standards and tests to do so. In essence, the Certificate Authority is responsible for saying this person is who they say they are, and we, the CA, verify that. If the user trusts the CA and can verify the CA’s signature, then he can also verify that a certain public key does indeed belong to whoever is identified in the certificate.
  • Email from Margaret: Dear Dr. Richard Shurtz. There appears to be a lot of Issues with this Squeezebox Internet Radio. For about a week now I can’t access Bloomberg Business Radio on my internet radio I bought from Logitech. This station is THE reason I purchased the squeezebox product–it is the main station I NEED to access daily. When I press the preset button I assigned to Bloomberg Business Radio station, I TODAY get a recording telling me my setup is not compatible with this station–Bloomberg Business Radio. I just found out that Bloomberg changed their website to Flash Media. I am told that Logitech must update its firmware to support Flash. HOW do I get this fixed? I am most appreciative if you can solve and explain this and tell me how to again access your station. I have to listen to this station daily for my job! so this is a nightmare! All the Best, Margaret
  • Tech Talk Responds: Everyone is having your problem. It is not a SB issue. Sometimes the station owners aren’t clueless — they know people are listening in other ways (internet radios, Smartphones apps like TuneIn) and don’t like it. They want people to see the ads in their flash players. That may be their motivation.
  • I found this response on their website:
    • Please accept my apologies for any frustration we may have caused with the changes we made recently to the Windows Media streams for Bloomberg Radio and TV. What’s going on is that we’ve been in a year-long process of upgrading our web audio and video streams to higher quality. At some point, it was time to decommission the old infrastructure, so we did that. We were unaware of the usage by (and don’t have any syndication deal with) the Squeezebox folks.
    • Our programming is still available at Bloomberg.com and we do hope you continue to tune in, but we also hope you understand the goal of providing the highest audio and video quality. If anyone here is from Logitech, I can put you in touch with our head of syndication.
    • Email from Snake Eyes: Dr. Richard Shurtz, Do you ever do book reviews, or, why not profile this Physics professor? I’m interested in knowing more:
    • A Harvard professor of physics, Randall, author of Warped Passages, has earned praise for both her science and her skill at making it accessible to the general reader. Here she proves a fascinating guide to the latest discoveries and challenges in theoretical physics. Thanks, Snake Eyes
    • Tech Talk Responds: This is not normally the type of person I feature. If she did some original research that lead to innovation she would be a candidate. By the way, I am looking for suggestions for all listeners on possible people to feature. This week’s Profile came from an earlier listener suggestion.
    • Email from Howard: I have accidentally deleted everything inside my hard drive. How could I restore them? Thanks, Howard.
    • Tech Talk Responds: Restore your most recent backup if you have one.Once restored, you’ve only lost whatever has changed in the time since that backup was taken. You probably don’t have a backup.Stop using the drive, remove it and make it an external drive on another computer. Every time you write on the disk you may lose even more data.With the drive attached as a second or external drive, use a free data recovery tool, like Recuva. Recuva, and other tools like it, scan the drive media looking for deleted, but possibly recoverable files, and allow you to specify which should be restored.
    • The problem is that file recovery tools don’t know the difference between files that you just recently deleted by accident and files that you deleted before that on purpose. Copy the files to be recovered to a different drive. This should avoid writing to the original drive at all.
    • Link to Recuva: http://www.piriform.com/recuva

Profiles in IT: Alan Field Shugart

  • Alan Field Shugart is widely considered a pioneer of the disk drive.
  • Alan Shugart was born September 7, 1930 in Los Angeles, CA.
  • He received a BS in Engineering Physics from the University of Redlands.
  • In 1951, he began his career at IBM in San Jose, California, where he worked on the IBM 305 RAMAC. He worked on the IBM 305 RAMAC. The IBM 305 RAMAC was the first commercial computer that used a moving head hard disk drive.
  • Shugart contributed to or managed a number of difficult disk drive development programs over his 18-year career at IBM, including the groundbreaking RAMAC 305–IBM’s first disk drive–and the legendary 1311 removable disk pack drive.
  • The floppy disk was invented by IBM engineers led by Alan Shugart.
  • The first floppy was an 8-inch flexible plastic disk coated with magnetic iron oxide; computer data was written to and read from the disk’s surface. The first Shugart floppy held 100 KBs of data.
  • The nickname “floppy” came from the disk’s flexibility. The floppy disk was considered revolutionary because it provided a new and easy way to transport data.
  • Shugart rose to become director of engineering in 1969 but left that same year to become vice-president of product development at competitor Memorex.
  • In 1971, IBM introduced the first “memory disk” or now known as “floppy disk.”
  • Shugart remained at Memorex until 1972
  • He then launched Shugart Associates in 1972, taking several loyal followers with him, where they worked on, among other things, perfecting the eight-inch floppy disk drive as a mass-produced device.
  • After a dispute over company direction with his board, Shugart left in 1974, moved to Santa Cruz, opened a bar with some friends, bought a fishing boat, and wrote a book.
  • In 1976, the 5 1/4″ flexible disk was developed by Alan Shugart for Wang Labs.
  • One interesting story about the 5 1/4-inch floppy disk is how the size was decided. Two engineers were discussing the floppy with An Wang at a bar. Wang motioned to a drink napkin and stated “about that size” which happened to be 5 1/4-inches wide.
  • In 1979, he and Finis Conner founded Seagate Technology with $1.5 million in start-up funding with the mission of producing hard disk drives for the personal computer.
  • Their first commercial product was a 5 1/4″ 5-MB hard disk drive that sold for $1,500 and became a major enabling technology for the PC industry.
  • Within a decade, Seagate became the world’s largest producer of disk drives.
  • In July 1998, Shugart resigned his positions with Seagate.
  • In 1996 he launched an unsuccessful campaign to elect his dog, Ernest, to Congress.
  • He later wrote a book about it, Ernest Goes to Washington (Well, Not Exactly).
  • In 2000, he backed a failed ballot initiative in 2000 to give California voters the option of choosing “none of the above” in elections.
  • Shugart is considered by most industry analysts as one of the most influential and admired figures in the storage industry.
  • In 1997, he won the IEEE Rey Johnson Award for the advancement of information storage technology.
  • Shugart died on December 12, 2006 in Monterey, California.

Rovio Mobile Web Cam: My New Toy

  • Website: http://www.myrovio.com/
  • Rovio is a mobile robotic web camera with omni-directional movement.
  • It uses a tri-wheel design that lets it go in any direction and rotate in place.
  • Rovio uses two infrared spots projected on the ceiling by the docking station to navigate back for recharging.
  • Additional projectors can be used for multi-room navigation.
  • It web camera has audio and video streaming capability so you can spy on your home from anywhere in the world.
  • It uses the 802.11b/g WiFi access and can be accessed over the web, if configured properly.
  • List price: $300. Street price: $250.

Quick Network Tutorial So We Can Configure Rovio

  • Network Address Translation (NAT) Servers
    • Internal IP addresses are not registered or seen externally
    • External IP address is registered. Only one is needed for your network.
  • Each computer address has two parts: the IP address and the port number.
    • IP address identifies the computer
    • Port Number identifies a particular program on the computer
  • A NAT device translates internal IP addresses to an external IP address.
  • The firewall blocks all incoming port requests. To connect to a webcam, you must open up the ports required to establish the connection. To maintain security for the other computers on the network, the ports are forwarded to only the device which needs them.

Configuring Rovio for Web Access

  • Step One: Enable Port Forwarding the Router. In this case both Port 80 and Port 554 must be forwarded. Connect to your router using either 192.168.0.1 or 192.168.1.1. Port Forwarding is part of the Firewall Configuration. Forward those two ports to the internal web address of Rovio, which in my case was 192.168.1.6. I directed by router to always give it this address.
  • Step Two: Check if the connection works. Go to another network (like Starbuck, McDonalds, or your neighbor’s network) and log onto the external web address of your router. You can discover this by logging onto your router and checking the main screen. Or you can just go to http://whatismyipaddress.com/
  • Step Three: If the connection does not work, your ISP may be blocking Port 80. In my case, Verizon FIOS does block Port 80 (as well as Port 25). I changed the web port for Rovio to from Port 80 to Port 8080 using the network tab under settings and then adjusted the port forwarded to forward 8080 in addition to 554.
  • Step Four: Set up a Dynamic DNS so you don’t have to remember the external IP address. Configure your router to automatically communicate with your Dynamic DNS whenever you IP address changes. One of the oldest free Dynamic DNS providers is www.dyndns.com.
  • Step Five: Enjoy. Remember to include the Port 8080 in the web address (e.g. http://mywebcam.dyndns.org:8080/)

Science of Snowflakes- Is Every Snowflake Unique?

  • Can you ever be sure that no two are alike?
  • The short answer to the question is yes, since it is indeed extremely unlikely that two complex snowflakes will look exactly alike. Notice I said complex snowflake.
  • Variations caused by isotopes
    • If we restrict ourselves to water molecules which contain two ordinary hydrogen atoms and one ordinary oxygen atom, then again physics tells us that all such water molecules are exactly alike
    • However about one molecule out of every 5000 naturally occurring water molecules will contain an atom of deuterium in place of one of the hydrogens.
    • One in 500 will contain an atom of O (with an atomic weight of 18) instead of the more common oxygen (with an atomic weight of 16).
    • Since a typical small snow crystal might contain 1018 water molecules, we see that about 1015 of these molecules will be different from the rest.
    • The probability that two snow crystals would have exactly the same layout of these molecules is very, very, very small.
    • Even with 1024 crystals per year, the odds of it happening within the lifetime of the Universe is indistinguishable from zero.
    • However, if we consider a crystals of only 10 molecules, here’s a reasonable probability that two would be exactly alike.
  • Variations caused by stacking faults
    • When a crystal grows, the molecules do not stack together with perfect regularity, so a typical snow crystal contains a huge number of crystal dislocations, which again are scattered throughout the crystal in a random fashion.
    • One can then argue, like with the isotopes, that the probability of two crystals growing with exactly the same pattern of dislocations is vanishingly small.
    • Again one has the exception of few-molecule crystals, which can easily be free of dislocations.
  • Variations caused by variable growth dynamics
    • The number of possible ways of making a complex snowflake is staggeringly large. Now when you look at a complex snow crystal, you can often pick out a hundred separate features if you look closely.
    • Since all those features could have grown differently, or ended up in slightly different places, the math is similar to that with the books.
  • Thus the number of ways to make a complex snow crystal is absolutely huge.

Driving on Slippery Roads Speed- Speed is Your Enemy on Slippery Roads.

  • Kinetic energy is increases as velocity squared. Doubling the speed increases kinetic energy by four. This makes stopping distance four times longer.
  • Stopping Distance – In slippery conditions, the coefficient of friction is as much as eight times lower than it is for dry conditions. This means that stopping distance, compared to dry conditions, is eight times longer.
  • Recovering from Skidding – If the care skids to the one side, steer the car in that direction until you get some traction. Then gradually steer the car back on track.
  • ABS — Maximum traction between the road and the tire is the point just before the tire begins to slip. The Anti-lock Braking System (ABS) keeps near that point by releasing the brake as soon as the wheel locks and then immediately reapplies it. It is the electronic equivalent of “pumping” the brakes. If you have ABS brakes, apply constant pressure. You will feel vibration when they are active.
  • Positraction Differential – The differential divides the power between the left and right wheels. If one wheel begins to slip, the positraction differential immediately transfers all power to the other wheel. If the positraction light comes one, slightly ease off on the gas petal to maintain traction with both wheels.

Food Science: Frozen Turkey Revisited

  • Cooking a frozen turkey cooks the dark meat longer and maintains a moister white meat.
  • We experimented on Thanksgiving.
  • A 20 pound turkey (thawed) should have been in the oven for 4.5 hours.
  • A 20 pound turkey (frozen) should be in the oven 50% more time or 6.75 hours.
  • We did the experiment and the results were perfect.
  • Careful calculations show that cooking time is proportional to the square of the size of the food, rather than the weight.