Email and Forum Questions Profiles in IT: Donald Becker Lawmakers Computers Hacked by Chinese NASA's Phoenix Mars Lander Update Automotive Idea of the Week: Inflatable Electric Cars Large Hadron Collider Countdown Science Update: Gravity Express Is Always 42 minutes Food Science: Cooking Chemistry
Email from John: Dear Tech Talk. I an upgrading my Internet connection at home. What is bandwidth and how much do I need? I listen every week. John
Tech Talk Answers: Bandwidth describes the band of frequencies that can be carried in a communications channel. Increasing the band, increases the data rate of the channel. Actually, they quote the transmission rate of the channel rather than the bandwidth and then term it bandwidth. The units for transmission rate is bits/per second (b/s) or kbps or mbps.
File size is given in Bytes, which is approximately equal to the number of characters in the file. The Bible, for instance is approximately 5 MB.
It can be downloaded on a 1.5 mbps channel in 27 second. By the way, Tech Talk is approximately 14 MB. It would be downloaded in 75 seconds.
This numbers assume that you have 100% of your connection available to you (not always true on shared resources like cable).
It also ignores packet overhead, which could be 10 to 15 percent.
As one final exercise for those so inclined, I’ll point out that a data CD holds around 700,000,000 bytes, or 5.6 billion bits. A DVD 4.7 gigabytes, or 37.6 billion bits.
Using the same 1.5 Mbps channel, it would take me a little over an hour to download a CD, and around 7 hours to download a complete DVD.
Profiles in IT: Donald Becker
Donald Becker was a co-founder of the original Beowulf project, which is the cornerstone for commodity-based high-performance cluster computing.
Don holds a Bachelor of Science degree from MIT.
Don’s work began in 1983 at MIT’s Real Time Systems group.
After MIT, Don was a researcher at the Institute for Defense Analyses Supercomputing Research Center.
Becker has written enhancements to the Linux kernel network subsystem to support faster I/O on high-speed networks, device drivers for Ethernet cards, and a distributed shared-memory package.
He has contributed over 60 device drivers to the open-source operating system.
In late 1993, Donald Becker and Thomas Sterling began sketching the outline of a commodity-based cluster system designed as a cost-effective alternative to large supercomputers.
In early 1994, working at CESDIS under the sponsorship of the HPCC/ESS project, the Beowulf Project was started.
The Center of Excellence in Space Data and Information Sciences (CESDIS) is a division of the University Space Research Association (USRA).
Both are located at the Goddard Space Flight Center in Greenbelt Maryland and funded by the NASA Earth and Space Sciences (ESS) project.
Initial prototype was a cluster of 16 DX4 processors connected by Ethernet.
The machine was an instant success and their idea of providing COTS (Commodity off the Shelf) based systems to satisfy specific requirements.
While at Goddard, he led the development of the Beowulf project
Beowulf Project was named after Beowulf is the oldest written English epic poem. It was written in the 11th century about a 6th century Danish hero who fights the Grendel and Grendel’s mother. He dies fighting a third dragon.
Don is a co-author of How To Build a Beowulf: A guide to the Implementation and Application of PC Clusters and a co-editor of the Extreme.Linux CD-ROM, the first packaged Beowulf software distribution.
With colleagues from the California Institute of Technology (Cal Tech) and the Los Alamos National Laboratory, Becker was the recipient of the IEEE Computer Society 1997 Gordon Bell Prize for Price/Performance.
In 1998, Donald founded Scyld Software, which specialized in delivery clusterware based on the Beowulf code.
In 1999 Becker received the Dr. Dobb’s Excellence in Programming Award, which is presented annually to individuals who, "in the spirit of innovation and cooperation, have made significant contributions to the advancement of software development."
In 2003, Penguin Computing acquired Scyld Software.
Don will be remembered for his unwavering support of the open source software movement and his efforts to extend it to high performance clustering.
Lawmakers Computers Hacked by Chinese
Two House members their Capitol Hill computers, containing information about political dissidents from around the world, have been hacked by sources apparently working out of China.
Virginia Rep. Frank Wolf says four of his computers were hacked.
New Jersey Rep. Chris Smith says two of his computers were compromised in December 2006 and March 2007.
In an interview on June 11, Wolf said the hacking of computers in his Capitol Hill office began in August 2006.
The FBI declined to comment.
Wolf said that in his office, the hackers ?got everything,? including all the casework regarding political dissidents around the world.
Following the attacks on Wolf’s computers, a car with license plates belonging to Chinese officials went to the home of a dissident near DC and photographed it.
Wolf said he was introducing a resolution that would tighten security of House computers and information systems.
In the Senate, Senator Dick Durbin of Illinois asked the sergeant at arms to investigate whether Senate computers have been breached.
Rep. Chris Smith said his office no longer stores the names of Chinese dissidents on computers.
Separately, U.S. authorities are investigating whether Chinese officials secretly copied the contents of a government laptop computer during a visit to China by Commerce Secretary Carlos M. Gutierrez and used the information to try to hack into Commerce Department computers.
In Beijing, the Chinese Ministry of Foreign Affairs had no immediate comment.
Last week, China denied the accusations regarding Gutierrez’s laptop and the alleged effort to hack Commerce Department computers.
NASA’s Phoenix Mars Lander Update
"We have an oven full," Phoenix co-investigator Bill Boynton of the University of Arizona, Tucson, said today. "It took 10 seconds to fill the oven. The ground moved."
Boynton leads the Thermal and Evolved-Gas Analyzer instrument, or TEGA, for Phoenix. The instrument has eight separate tiny ovens to bake and sniff the soil to assess its volatile ingredients, such as water.
The lander’s Robotic Arm delivered a partial scoopful of clumpy soil from a trench informally called "Baby Bear" to the number 4 oven on TEGA last Friday, June 6, which was 12 days after landing.
A screen covers each of TEGA’s eight ovens. The screen is to prevent larger bits of soil from clogging the narrow port to each oven so that fine particles fill the oven cavity, which is no wider than a pencil lead.
Each TEGA chute also has a mechanism that vibrates the screen to help shake small particles through.
Only a few particles got through when the screen on oven number 4 was vibrated on June 6, 8 and 9.
Boynton said that the oven might have filled because of the cumulative effects of all the vibrating, or because of changes in the soil’s cohesiveness as it sat for days on the top of the screen.
"There’s something very unusual about this soil, from a place on Mars we’ve never been before," said Phoenix Principal Investigator Peter Smith of the University of Arizona. "We’re interested in learning what sort of chemical and mineral activity has caused the particles to clump and stick together."
Automotive Idea of the Week: Inflatable Electric Cars
"XP Vehicles, Inc. is an electric powered automobile technology startup with patent protected technologies utilizing safe non-grid-connected energy cassettes to produce the electricity to run a polymer airbeam, carbon fiber constructed ultra light automobile.
300 Miles on one charge
Hot swapping can increase the range indefinitely.
Hot-swap XPack Multi-CoreTM Battery/Fuel Cell power plant has been patented
Vehicles can be flat-pack shipped directly to users. Users perform final inflation.
Cost less that $5,000. This may be a real innovation.
Special stabilization provides stability on the road. Some speculate that air cushion makes the cars very safe in collision. May be able to survive going over a cliff.
Scientists have been counseled to say that there is ?zero chance for the creation of a black hole that would swallow the earth?.rather than a infinitesimal chance of a black hole.?
Science Update: Gravity Express Is Always 42 minutes
How long to each the other side of the earth through an evacuated tunnel ? 42 minutes
Los Angeles to Paris ? 42 minutes
Los Angels to Toyko ? 42 minutes
It takes 42 minutes regardless of the path you take.
Food Science: Cooking Chemistry
Why does cooked food go brown?
All foods – meat, fish, and vegetables – brown at temperatures above 154°C. This is known as the ‘Maillard Reaction’.
It generates the characteristic color and aroma of foods cooked over a flame, in the oven, or in oil.
The Maillard reaction was discovered in 1912 by the French chemist Louis Camille Maillard.
It happens when sugar molecules and amino acids (a chemical found in proteins) are heated together.
The reaction produces a group of highly flavored molecules responsible for the brown color, smell and taste of cooked meat.
But not all cooked food goes brown. When you boil something in water, the temperature of the food never exceeds the boiling point of water (100°C). So it doesn’t get hot enough for the Maillard Reaction to happen. However, deep-fried food does go brown because oil boils at over 154°C.
Avoiding soggy vegetables
When plants, like vegetables or rice, are plunged into boiling water, their structure changes from crisp and firm, to soft, wilted, or mushy.
All living things are made up of millions of cells, but plant cells differ greatly from animal cells. First, they contain a substance called cellulose in their cell walls, which makes the plant rigid. But when their cells are heated up, cellulose softens and the plant starts to wilt.
The vegetable cell walls eventually collapse opening up their structure and releasing water and air. For most vegetables, this happens within 10 minutes of heating at 98°C.
Plants also contain starch granules inside their cells, where they store the energy they capture from the sun. Starch swells when it is cooked in water ? this is known as ‘gelatinization’. Pasta and rice both contain a lot of plant starch, which is why they swell when cooked.
Vegetables also lose their appetizing colors at temperatures between 66-79°C.
This is why you should always put vegetables straight into boiling water.
When they have finished cooking, chefs often plunge the vegetables straight into ice-cold water.
This rapidly chills them to below 66°C, so they stop cooking and don’t start to discolor.