Uninnovative Edison

In “Patently Obvious” [December], I find it rather ironic that Edison's lightbulb was chosen as an example for innovation when discussing patents. Not only did Edison not invent the glass, the vacuum, and the filament, but the lightbulb probably wasn’t his idea, either. Edison’s patents were invalidated because of prior art by Joseph Swan, in Britain, and William Sawyer, in the United States.

Michael Hwang

IEEE Student Member

Evanston, Ill.

Security vs. Connectivity

The column “Impossible Tradeoffs” [Reflections, November] raised important points about the cost associated with the risk of opening a network and the value of connectivity, which is interwoven with productivity. Without the latter, the value of a network is null. Therefore, connectivity and security must be balanced and resolved without compromising either one.

To secure a computer by completely locking down everything is not what a successful security manager should do. In fact, implementing information security effectively from a business perspective is an art. IT managers should focus on what is necessary for information security, such as reasonable policies, user awareness, and proven risk management techniques, and should combine these with the needs of connectivity to develop a single solution.

On the other hand, ubiquitous connectivity comes at the cost of constant vigilance and continued investment in security, which should not be sacrificed for any convenience that may cripple a network. As a result, an adequate level of protection is very important to ensure the network’s availability. In other words, finding the right balance enables both the risk and the value to be counted on immediately as a crucial factor for productivity.

Hong-Lok Li

IEEE Member

Vancouver, B.C., Canada

Fuel Efficiency

I read Jeff Robertson’s letter [“Fuel Efficiency,” Forum, December]. For the record: I owned a 1981 VW Diesel Rabbit for 12 years, drove it 402 000 kilometers (until I ran it into a curb in a freak Washington, D.C., snowstorm), and routinely got 5.23 liters per 100 kilometers (45 miles per gallon) in the city (with air conditioning running) and 4.61 L/100 km (51 mpg) on the highway (driving solo).

On a 14 000-km trip in 1983, pulling a small utility trailer, with a wife and four children in the car, we went from Maryland, across the northern plains, down through Utah, and home through the South on 670 liters (177 gallons) of diesel—on a production model that would now be 25 years old—an “antique” by most car licensing requirements.

Where is today’s “technology”?

Richard G. Reynolds

IEEE Member

Greenbelt, Md.

A Vote Against E-Voting

Please! The system described in “Making Every E-Vote Count” [January] requires more software—meaning more errors, meaning more exposure to malware, meaning only the elite can understand it. It's so obvious it's painful to have to say it: hand count paper ballots—machine free.

Samuel Scharff

Via the Internet

Ready, Set, Launch

I read “Does NASA Need a Better Launch Site?” [Spectral Lines, October]. It’s indeed way past the time that we should be putting money into alternative sites/options if we intend to continue a manned presence in space.

It was surprising to me in reading your editorial that no mention at all was made of Vandenburg Air Force Base. This, despite that Vandenburg for 14 years (1972 to 1986) was at the top of the list for a secondary shuttle launch facility, especially for polar orbit payload delivery. In fact, back in 1981 when I toured Vandenburg as part of a U.S. Air Force engineering recruitment tour, we were shown the launch control center under construction and the launchpad, which was at that time being modified to be able to launch the Space Shuttle. I still have pictures I took of the facility. (I doubt that today you'd be allowed to photograph anything.)

It's a shame that while the NASA Space Shuttle online chronology (http://history.nasa.gov/sts25th/chronology.html) shows that in 1972 Vandenburg was selected as the second shuttle launch facility, no further mention of Vandenburg appears in that chronology.

Meanwhile, in the land down under, an online kids’ encyclopedia (http://encyclopedia.kids.net.au/page/sp/Space_shuttle) reveals that it was the Air Force that abandoned plans to complete shuttle launch facilities at Vandenburg. The encyclopedia also puts the blame on the poor NASA/Air Force relationship: “Perhaps the most annoying aspect of the shuttle system is to consider the Air Force participation. While the blame rests solely at the feet of NASA for getting them involved in the first place, it was the Air Force requirements that certainly drove the system to be as complex and expensive as it is today. Ironically neither NASA nor the Air Force got the system they wanted or needed, and the Air Force eventually threw in the towel and returned to their older launch systems and abandoned their Vandenburg shuttle launch plans.”

So while the Vandenburg Shuttle launch facility was nearly ready to go in 1986 (see the summary of Vandenburg as shuttle launch site No. 2 at http://www.suite101.com/article.cfm/residence_space/87642), the Challenger disaster in January 1986 caused NASA to refocus its ambitions with the shuttle. So NASA gave up...and nothing has happened in the past 25 years to complete the nearly completed second launch facility at Vandenburg.

Why should we be surprised? And why should we start from scratch somewhere else if the Vandenburg facility was essentially ready to go nearly 11 years ago now?

Myles Twete

IEEE Member

Portland, Ore.

The author responds: I didn’t mention Vandenburg because its location constrains it to do mostly polar launches, which is fine for military missions such as launching spy satellites, but not so good for most other applications. Also the original shuttle launchpad was ultimately reconfigured to launch Delta rockets, so the pad is available for use.

More on Metcalfe

While it is impossible to give the right answer to the question “How does the value of a network scale?” [Spectral Lines, November 2006] without a lot more information about the network, I would like to lend my support to the approach taken by Briscoe, Odlyzko, and Tilly [“Metcalfe’s Law Is Wrong,” July 2006]. But that approach leads to different answers, depending on your assumptions.

In a small network, where each person communicates with all others with nearly equal probability, the answer is roughly n ². Under the Zipf’s Law paradigm, their answer of roughly n log(n) is very plausible for medium-size networks. For real people, however, the value of connections might decay according to Zipf's Law at first, but it eventually decays more rapidly or becomes zero. This implies an eventual answer of roughly n. If you don’t agree with this at first, I simply ask, “How many different people will you call this year?” Today, it is actually more common to have fully connected networks where the connection price depends on network membership.

Consider, for example, cellphone providers offering free calls to in-network phones. If all your friends are on one system, it makes a lot of sense to use that network. Once your top 5 to 10 people (depending on your social network) are all on the same system, however, you get very little advantage from new subscribers (many of whom you will never call) joining the network. The value of your network membership has become saturated for you.

In fact, the value of the network to you is much more heavily influenced by the defection of your close friends, thus leading to instability and large correlations between groups switching back and forth between two popular carriers.

Henry Pfister

IEEE Member

College Station, Texas

Valued Certification

I was surprised that your article summarizing the rising concerns about the certification treadmill [“Certification Uncertainty,” November] failed to mention the IEEE Computer Society’s Certified Software Development Professional (CSDP) examination.

Our program focuses on developing technical professionals rather than training technical experts. The goal is to nurture adaptable engineers, not to develop specialists whose niche expertise might become obsolete.

The CSDP provides a true measure of the software engineering professional. It requires 9000 hours of current software engineering experience within at least six of the core software knowledge areas. In addition, CSDP certificate holders must demonstrate that they are maintaining their software engineering skills and knowledge through formal reports filed every three years. [For more, go to http://www.computer.org/certification.]

The goal of any manager should be to help technical professionals in their careers and to encourage growth and development, and I feel the CSDP supports this goal.

Susan K. Land

IEEE Senior Member

Huntsville, Ala.

The editor responds: We thank the writer for pointing out our omission.

Viewed in the Round

I read with pleasure “Escape From Flatland” in IEEE Spectrum Online [December, http://www.spectrum.ieee.org/dec06/4781]. In 1994 I submitted a patent application that could also be used with large LCDs. And just as the Holografika’s system seems to do, my scheme relied on the trajectories of light beams rather than on light interference, as in traditional holography.

Nevertheless, the goal of comfortable, high-quality 3‑D remains elusive. For medical and engineering purposes, I would say that smart glasses (including direct picture projection onto the retina) or some sort of virtual-reality helmet is the way to go. But for more popular uses—in video games, for example—where no need for diving into the deep details is needed, three-dimensional displays have a future.

As for recording events in 3-D in order to play them back later in 3-D from any angle desired, I consider that a bit hopeless in the near future. To do it, you’d need low bit-rate sampling—not many cameras, in other words—with enormous computational power to reconstruct the 3-D and calculate views on demand. Or you’d need expensive, high bit-rate sampling—many cameras. The former would probably yield quality below viewers’ expectations; the latter would be over their budgets. For now, anyway.

Here’s the best part: as soon as you have access to easy, virtual navigation to 3-D, you may easily get a touch of spatial 4-D by projecting an imagined 4-D world onto 3-D “planes.” Optical lenses may work also in 4-D!

Henrik Somogyi

IEEE Member

Budapest