Powered By Blogger

Tuesday, December 26, 2006

Addicted to the 'Net? You're not alone

Ever feel that you have to publish something as often as possible on the Internet? Crazy to see your name on the screen, in Google listings or on Yahoo!? If so, you're not alone.

Hello, my name is Richard and I am an egosurfer. The habit began about five years ago, and now I need help. Like most journalists, I can't deny that one of my private joys is seeing my byline in print. Now the internet is allowing me to feed this vanity to an ever greater extent, and the occasional sneaky web search has grown into a full-blown obsession with how high up Google's ranking my articles appear when I put my name into the search box. When I last looked, my best effort was a rather humiliating 47th place. You know you have a problem when you find yourself competing for ranking with a retired basketball player from the 1970s.

Not that I'm alone in suffering from a dysfunctional techno-habit. New technologies have revealed a whole raft of hitherto unsuspected personality problems: think crackberry, powerpointlessness or cheesepodding (see "Modern maladies", bottom). Most of us are familiar with sending an email to a colleague sitting a couple of feet away instead of talking to them. Some go onto the web to snoop on old friends, colleagues or even first dates. More of us than ever reveal highly personal information on blogs or MySpace entries. A few will even use internet anonymity to fool others into believing they are someone else altogether. So are these web syndromes and technological tics new versions of old afflictions, or are we developing fresh mind bugs?

Developing a bad habit is easier than many might think.

No argument here.

Phase change memory

A team of scientists has announced a breakthrough in computer memory technology that heralded more sophisticated and reliable MP3 players, digital cameras and other devices.

Scientists from IBM, Macronix and Qimonda said they developed a material that made "phase-change" memory 500 to 1,000 times faster than the commonly-used "flash" memory, while using half as much power.

"You can do a lot of things with this phase-change memory that you can't do with flash," IBM senior manager of nanoscale science Spike Narayan told AFP.

"You can replace disks, do instant-on computers, or carry your own fancy computer application in your hand. It would complement smaller technology if manufacturers wanted to conjure things up."

Technical details of the research were to be presented to engineers gathered at the 2006 International Electronic Devices Meeting in San Francisco.

Interesting and exciting. The quest for better memory devices never ceases, and never ceases to amaze me.

(hat tip: Ilachina)

Wednesday, December 20, 2006

The Three-Body Problem: Book Review

The following review was posted to the Mathematical Association of America's website.

The Three-Body Problem by Mauri Valtonen and Hannu Karttunen



Publisher: Cambridge University Press (2006)
Details: 345 pages, Hardcover

Price: $80.00
ISBN: 0521852242

Category: Monograph
Topics: Mathematical Physics, Dynamical Systems, Classical Mechanics, Celestial Mechanics

MAA Review

[Reviewed by David Mazel, on 12/20/2006]

An undergraduate, having taken calculus and some physics, comes across the two-body problem. Specifically, what is the motion of two bodies in space acting under their mutual gravitational attraction? She quickly finds that she can solve the equations, and for given initial conditions, the solutions are conic sections. Then, the natural question to ask is: What is the solution if we now expand the system to three bodies? Here the problem is not so easy. In fact, it is impossible to solve in closed form.

This book begins by recounting what the student would have learned in that physics class and then goes into specifics of the three-body problem. Not only is the problem unsolvable in closed form; the solution, in general, involves chaotic dynamics. Nonetheless, there is much that can be learned by studying various forms of the problem under differing conditions. This book goes a long way to exploring these forms and explaining how the different scenarios can be approached.

The authors begin with a presentation of Newtonian mechanics and the solution of the two-body problem. The authors use physics to motivate the mathematics and derive the equations of motion — here, and throughout the book. Thus, the discussions are complete and present the ideas from the view of mathematical physics.

After discussion of the two-body problem we are introduced to Hamiltonian mechanics and some restricted three-body problems such as satellite orbits, and scatterings of bodies from a binary orbit. Other topics include escapes, three body scattering, and capture. The final topics deal with perturbations and various astrophysical problems such as black holes and the evolution of comet orbits.

Throughout the book the authors present diagrams to illustrate their points but these diagrams are limited in their utility. The authors could have presented more illustrative diagrams and figures to better qualify the text.

When I started reading I thought the book would discuss chaos and its relationship to the three body problem. After all, that's the first thought that comes to mind today. There is mention of this phenomenon, but very little, and no attention given to simulating orbits of three-body motion. For me, this was a disappointment.

Finally, the spirit of the book is mathematical physics; consequently, the authors often leave it to the reader to sort through the mathematics. I often found, for example, that I had to review earlier parts of the text and search for the equations — always present somewhere in the text but not explicitly noted nor cited — needed to follow the derivations and fill in many of the steps.

In short, this is a good text on the mathematical physics of the problem for the experienced practitioner. Everyone else, I'm afraid, will find it a challenge to read and follow the mathematics.

Friday, December 15, 2006

Mathematics in the court room

Ivars Peterson writes of two cases where mathematics comes to light in court.

Robots as Transformers

Remember as a kid how you could take a robot and with a few twist and changes make the robot into something else? The robot wasn't actually a robot and while it didn't move by itself, you had a pretty good idea of how, if you had the technology, that robot could move. A little imagination and your play robot was the real thing. Then, if you had a little sadistic bent to yourself, you could pull off a limb of your robot. Now, could you imagine how to make this deformed robot move? I bet you could.

Fast forward to the present and meet Victor Zykov from Cornell University. He and he colleagues have built a robot that, when it loses a limb, is able to visualize itself (not as seen by a child playing with the robot) and determine how to move with the limbs it has left.

So, this robot can remake itself in terms of mobility when it's damaged.

Read the article, it's fascinating and is a leap forward in robotics.

Wireless power: No more extension cords?

1) Power from mains to antenna, which is made of copper
2) Antenna resonates at a frequency of 6.4MHz, emitting electromagnetic waves
3) 'Tails' of energy from antenna 'tunnel' up to 5m (16.4ft)
4) Electricity picked up by laptop's antenna, which must also be resonating at 6.4MHz. Energy used to re-charge device
5) Energy not transferred to laptop re-absorbed by source antenna. People/other objects not affected as not resonating at 6.4MHz
It's not the end of extension cords, but it is the beginning of looking at how we might use the concept of resonance to delivery electricity to electronic devices.


The answer the team came up with was "resonance", a phenomenon that causes an object to vibrate when energy of a certain frequency is applied.

"When you have two resonant objects of the same frequency they tend to couple very strongly," Professor Soljacic told the BBC News website.

Resonance can be seen in musical instruments for example.

"When you play a tune on one, then another instrument with the same acoustic resonance will pick up that tune, it will visibly vibrate," he said.

Instead of using acoustic vibrations, the team's system exploits the resonance of electromagnetic waves. Electromagnetic radiation includes radio waves, infrared and X-rays.

hat tip: Ilachina

Images by Neutrinos

This a photo of the sun. Not taken with the usual medium for viewing the sun (photons), but taken with neutrinos. Partly at night. Through the earth. It was photographed by the Super-Kamiokande experiment in Japan with 503.8 days and nights of exposure.


More on neutrios here.

Earth from Space: Smithsonian Institution

These sand dunes in Yemen are part of Earth's largest expanse of desert, which covers much of southern Saudi Arabia as well. Data from two satellites were combined to produce this image's vivid colors: blue indicates the rocky composition of the land surface and contrasts sharply with the highly reflective sand dunes in yellow.

Here's a wonderful site that lets you view our planet Earth from space. Unlike Google Earth that lets you move through imagery of the planet, this site allows you to view our planet based on ecology and social topics.
(hat tip: ilachina)

Tuesday, December 05, 2006

Understanding Black Holes

This is clever and instructive site that explains black holes in an interactive manner.