Sunday, May 24, 2009
Wednesday, July 19, 2006
Sunday, October 30, 2005
Monday, August 15, 2005
Self portrait on a moving bus in a large London airport around sunset after a long flight in a small seat in the middle of a row
Tuesday, July 12, 2005
Moore's Law, Bandwidth Scaling and Metcalf's Law
I went to physorg today to catch up on the Tempel 1 mission, but found several items that will have a lot more impact.
One of the primary drags on Moore's Law is heat production. As transistor size decreases with each generation of manufacturing technology, more are packed onto a smaller area, and the heat that needs to be removed goes up per unit area. A novel way of removing heat has been devised.
What makes this method even more interesting is that it appears to have broad utility outside the computer industry:
"In addition to computer and other electronics applications, bulky liquid-liquid heat exchangers - found in everything from automotive oil coolers to ice cream makers - could be made 30 to 50 times smaller if the new approach is adopted."
Where are liquid-liquid heat exchangers used? Just about everywhere. What's more, there are a lot of places (like cell phone towers) where they aren't used because they are just too bulky. As the discoverer says:
"I think we may be looking at a paradigm shift in how heat exchangers are designed."
The Bandwidth Scaling Law states that the amount of bandwidth available to consumers doubles every so often. How frequently has varied between 6 months to 18 months, so it's not a reliable law, but it's still remarkable. The law initially applied to wire and optical networks. Now, versions of the law include wireless networks, but there is a qualitative difference that can't be overstated: the network goes with the user. So far, this difference has come in bubbles: low-bandwidth limited capability bubbles like cell phone service cover large regions; high bandwidth, full capability bubbles with full internet access are limited mostly to buildings and some designated public spaces. The major qualitative shift will come when the high-bandwidth bubbles converge. The industry has been moving towards a technology called WiMAX which appears to be the best candidate for bringing convergence. Its primary drawbacks have been cost, heat and power. An old new technology, the ribbon electron beam may well have solved all three at a stroke.
Metcalf's Law essentially states that the value of a network scales as the square of the number of nodes. Roughly stated, a network with twice as many people provides four times as much value to its subscribers. In part, this is what creates lock-in. Once enough people are connected to a network, the relationships they develop in the context of that network make it much easier for them to accomplish certain kinds of goals by virtue of the amount of specialization they have access to, and to switch to another network would require a great deal of reinvestment. Once a network reaches a certain size, it grows itself. Working out the behavior of such networks as they scale keeps many disciplines very busy. What's the easiest way to find someone or a service in a large network? How and why do parts of networks clump? What kinds of clumps are stable? How do these clumps communicate? How do clumps-of-clumps clump (and so on, up the chain). Are there ways to characterize clumps at different scales which allow meaningful comparisons to be made without masking the essential nature of each scale? Some interesting work has been done with regard to the sensitivity and robustness of networks at different scales. They show that networks whose decay exponent (the logarithm of the ratio between the probabilities of finding a number of connections on randomly selected nodes between adjacent decimal scales) is between 2 and 2.5 can store and are very sensitive to a large number of patterns (selective perturbations), and very resistant to random perturbations. Furthermore, this behavior is scale free. As long as the ratio is observed, the network can scale to infinity and its storage capacity is proportional to its size. The decay exponent for the brain was found to be about 2.1.
Friday, June 24, 2005
Alfonso the Wise regarding the Ptolemaic epicycles
"Had I been present at the creation, I would have given some useful hints for the better ordering of the universe."
Sunday, June 19, 2005
The irreducibly complex evolution of the argument from ignorance
I do not know that, therefore this.
I do not know that and no one knows that, therefore this.
No one knows that, therefore this.
No one knows that, therefore it cannot be. I'm not saying it means this, but it makes you think, doesn't it?
No one knows that, therefore it cannot be, we've known that for a long time now.
I know a lot of people say they know it, but there are more people who can't see how it could be, so it cannot be.
I know a few people still say they know it, but really, there's no way to know that, we've known that for a long time.
There's no way to know that reliably.
There's no way to know that.
There's really no way to know anything reliably.
There's no way to know anything, naturally.
There's no way to know anything naturally, therefore this.
This is the only thing you can know reliably. Everybody knows that.
You don't believe this so you can't be trusted. You're on the slippery slope to the primrose path to the purifying fires of the all-knowing.
You can't be trusted, and people who can't be trusted are obviously dangerous. Everybody knows that.
You and the people who associate with you are dangerous, someone should do something.
I know you say you didn't do anything, but reliable sources have complained about you, so we have to check it out. We're just doing our job under the provisions of the Patriot Beliefs Act. Every true patriot knows that.
Your honor, not only did we find these books, but the perpetrator cannot explain how the tale circulating about his bugging of the fifty-party Chinese Whispers contest homed in on his guilt with each retelling. Furthermore, his attempts to convince us that his inability to reconstruct how the tale actually started to take shape without the record of the bug might be remedied if only he were able to investigate the Chinese Whisperers themselves is not only highly irregular, but also unnatural, his woeful tale of it being premature without the proper tools and sufficient preparation notwithstanding. Everyone knows they whisper because what they have to say cannot be known, and that the whole of their whispers is more than the sum of the whispers of the parties.
Well, sir, you say in your defense that you didn't do anything and that given time and resources you can show it beyond a reasonable doubt, but the sooner we end this charade, the better it will be for everyone. The public morale must be upheld. You do admit to owning these books we've learned have a corrupting influence on children, so even though you didn't know they had been banned, I have no choice but to sentence you accordingly. Ignorance of the law is no excuse.
I know you say you were just defending yourself, but it's your word against theirs. They've been model inmates. The one you claim killed his friend accidentally has been an asset to prison ministries for several years. I can't see how he could have broken your legs. Frankly, with your whispered history of willful unbeliefism I'm inclined to side with their account. I'm afraid I have no choice but to sentence you to death, such execution to be carried out in the maximum security wing of the One True Exodus 2006 Memorial Penitentiary at sunrise on the day marking the start of the third year and the sixth month since the nuclear desolation of Jerusalem which was foretold in the revelations of the Bible Code and carried out by our Righteous Army. This court urges you to spend your final days in repentance and worship that you may know even as you are known.
We should do something about his friends and family. One bad apple and all that. You have to prune a tree to save it. Everybody knows that. It's simple, really. I don't get why people have to make it so hard. Life is a tale told by an idiot.
Ain't that the truth. Hey, what's the chapter and verse on that?
I don't remember. Probably Proverbs. Nothing like the old wisdom.
Ain't that the truth. Hey, can you get me in the room when they fry that guy?
I would, but I don't do anything that can get me noticed any more. Things are dicey these days, a lot of the bigs gettin' the axe, if you know what I mean. Sorry. Stick your neck out, it gets chopped off. It's better not to rock the boat.
Ain't that the truth.