NASA's X-43A unmanned scramjet test vehicle made it's first successful flight today.

Back in January I posted about the ramjet powered Project Pluto, which included this link for a look at various types of ramjets and how they work.

Posted by: Ted at 09:32 PM | category: SciTech
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I have almost 20 years of experience working with the Model 204 Database Management System, aka M204. It's strengths are extreme flexibility coupled with excellent security features and blazing speed when working with massive databases. Here's a link to a recent press release about the product, and below an email I got:

Dear Model 204 User,

I wanted to draw your attention to a new press release posted on our Web site. Centrelink of Australia, one of the world's largest users of Model 204, has just signed an agreement with CCA allowing them to use Model 204 throughout their enterprise for at least the next ten years; that is at least until the year 2014. This is very exciting news not only to all of us here at CCA, but to the entire Model 204 customer base. It means that after 20 years of use at Centrelink, Model 204 continues to be the best product on the market to meet their ever-changing and ever-growing needs -- needs which are very likely similar to your own.

Centrelink originally chose Model 204 back in 1983 because it was the only product that could meet their performance and capacity requirements. Since that time their requirements have grown dramatically. What started out as a traditional database system with just a few thousand online users now services over 24,000 internal users and over 6 million customers over the Internet and Interactive Voice Response systems. They now run the fourth largest information and technology network in Australia and are still growing. With Model 204, they have been able to meet every new challenge, while integrating new technologies as they come to market.

This is the kind of application that would make Oracle do the 'dead bug'.

The tenuous link is that the company I work for had the original contract to optimize the Australian databases, way back in the 1980's. When I first hired on, I was hoping to be assigned to that contract.

Computer-wise, newer is not always better.

Posted by: Ted at 04:26 AM | category: SciTech
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Real Hardware. Photos and some historical background. Especially intriguing is the page about the ROTON. Alas, that company went bankrupt a while ago.

Posted by: Ted at 07:10 AM | category: SciTech
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The superstorm of 1993 was the most devastating blizzard to strike the Northeast in at least a century, according to a new system that rates the impact of East Coast winter storms.

Interesting, but rather limited. Since the 1-5 scale takes into account the population affected, it has to be derived from historical records. It's also only usable in current form for the Eastern Seaboard of the US, other regions will have to have their own custom formula developed.

I would like to see the correlation between IQ, size of the SUV, and bodyshop repair bills immediately following storms.

Northeastern winter storms rated "crippling" or higher on the new Northeast Snowfall Impact Scale.

Category 5: Extreme

1. March 12-14, 1993
2. Jan. 6-8, 1996

Category 4: Crippling

3. Feb. 15-18, 2003
4. March 11-14, 1888
5. Feb. 11-14, 1899
6. March 2-5, 1960
7. Feb. 10-12, 1983
8. Feb. 5-7, 1978
9. Feb. 2-5, 1961

So since I've moved into this area, I've experienced the top 3. Liz remembers 7 and 8, and my mother-in-law remembers 4 and 5 (just kidding!).

Posted by: Ted at 06:18 AM | category: SciTech
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Cavitation is the term for the formation and subsequent collapse of small bubbles in a liquid.

When a propeller spins in the water, the hydrodynamic forces may result in the creation of tiny bubbles. The bubbles are almost immediately crushed upon themselves which causes noise. The cavitation sounds are one method of detecting submarines on passive sonar. Great amounts of time and money are spent on refining propeller design to limit cavitation.

Cavitation can also damage propellers by pitting the metal over time. Naturally, this pitting further reduces the efficiency of the propeller while making it noisier at the same time. Scientists wondered what was actually happening during cavitation, and began to study the process in more detail.

What they discovered was that each bubble underwent an extremely violent death. As the bubbles collapsed upon themselves, the interior experienced supersonic shockwaves which reflected back from the bubble's outer surface. Happening in a fraction of a second, these shockwaves raised the interior temperature enough to rival the surface of the sun. It was these millions of microscopic sunbursts that were causing the pitting on the propellers.

The effect has also been exploited in various ways by weapons designers. One 'underwater' missile rides in it's own cocoon of cavitation bubbles, which form a barrier to the surface-drag caused by dense water, and allows the missile to 'fly' underwater at several times the speed of typical torpedos.

Now researchers are taking advantage of cavitation outside of naval affairs. According to this report regarding Bubble Fusion:

The research team used a standing ultrasonic wave to help form and then implode the cavitation bubbles of deuterated acetone vapor. The oscillating sound waves caused the bubbles to expand and then violently collapse, creating strong compression shock waves around and inside the bubbles. Moving at about the speed of sound, the internal shock waves impacted at the center of the bubbles causing very high compression and accompanying temperatures of about 100 million Kelvin.

These new data were taken with an upgraded instrumentation system that allowed data acquisition over a much longer time than was possible in the teamÂ’s previous bubble fusion experiments. According to the new data, the observed neutron emission was several orders of magnitude greater than background and had extremely high statistical accuracy. Tritium, which also is produced during the fusion reactions, was measured and the amount produced was found to be consistent with the observed neutron production rate.

Earlier test data, which were reported in Science (Vol. 295, March 2002), indicated that nuclear fusion had occurred, but these data were questioned because they were taken with less precise instrumentation.

Note that this was described as cavitation in a vapor. Most definitions I've seen specify liquid, although a vapor could be described as a low-density liquid.

Thanks to Fred for the Bubble Fusion link.

Posted by: Ted at 09:41 AM | category: SciTech
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1 And thought I Bubble Wrap was fun.

Posted by: Stephen Macklin at March 09, 2004 12:50 PM (UquFN)

2 Cool! I just learned more in 4 minutes than I learned in 7 years of High School!

Posted by: Tuning Spork at March 09, 2004 10:47 PM (T1xwK)

3 Interesting.

If they're seeing neutron emission and tritium production, it's pretty clear that fusion really is taking place. (In the cold fusion debacle, neither neutrons nor tritium were detected.)

I saw this a couple of years ago, but at the time the supporting data was a lot weaker.

I want one!

Posted by: Pixy Misa at March 09, 2004 11:19 PM (kOqZ6)

4 Would it qualify as an uninteruptable power supply?

Posted by: Ted at March 10, 2004 07:29 AM (blNMI)

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Five planets will be visible to the naked eye later this month. The next best chance to see this somewhat rare alignment is in 2036. Details here.

Thanks to J-Walk Blog for the pointer.

Posted by: Ted at 05:04 AM | category: SciTech
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Awarded annually, according to the official site:

The winners have all done things that first make people LAUGH, then make them THINK.

Some of my favorites (go to the link above for full credits and cites):

Physics, 2003 - "An Analysis of the Forces Required to Drag Sheep over Various Surfaces."

This one's from Australia. Is anyone surprised? Montana residents put your hands down.

Biology, 2003 - for documenting the first scientifically recorded case of homosexual necrophilia in the mallard duck.

You really find out who your friends are.

Physics, 2002 - University of Munich, for demonstrating that beer froth obeys the mathematical Law of Exponential Decay.

More beer research, now this is something I can support.

Astrophysics, 2001 - a televangelist and staff, who for their discovery that black holes fulfill all the technical requirements to be the location of Hell.

So does Sunday morning television programming.

Peace, 2000 - The British Royal Navy, for ordering its sailors to stop using live cannon shells, and to instead just shout "Bang!"

As opposed to the more aggressive "Boom!"

Chemistry, 1999 - a detective in Japan, for his involvement with S-Check, an infidelity detection spray that wives can apply to their husbands' underwear.

The thrifty version is called superglue.

Peace, 1999 - a South African design for an automobile burglar alarm consisting of a detection circuit and a flamethrower.

I've barely scratched the surface here, go check 'em out. Science doesn't have to be boring, and stuff like this certainly makes me think... about committal papers.

Posted by: Ted at 04:50 AM | category: SciTech
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