Category: Science

Robin Hanson tells me this will be huge

There’s a big advantage that you missed, btw. Check out, for example, the “gnu radio” open source software radio project. Then consider this: the FCC can pass any rule that it likes saying you can’t copy digital television off the air or what have you, but anyone who decodes HDTV with a software defined radio (SDR) can just change the software to ignore the desires of the regulators, and open source SDRs are already here. This is yet another instance where general purpose computers make regulation very difficult.

Really, though, SDR isn’t that interesting until it is coupled with another major advance that is creeping up — phased array active antenna technologies. These have the capacity to literally make the amount of bandwidth available in radio unlimited. I do not use the word “literally” figuratively here — I mean “literally”. With phased arrays, you and I can broadcast as much as we want on exactly the same frequency, and so long as we’re slightly spatially separated no one will care.

Consider the way radio works now. Two stations can’t be broadcasting at the same frequency unless they are so far apart that receivers can only hear one of them at a time. Bring them too close together and the
primitive sensors we use for electromagnetic radiation will get both signals and become confused.

Now consider the situation with another sort of electromagnetic sensor — the human eye. There is no rule that says you and your friend can’t wear the same color shirt in the same room for fear that people will
be unable to distinguish the two of you. The eye has no trouble seeing multiple sources of the same electromagnetic frequency and distinguishing them. You can easily focus on any one of several sources of the same electromagnetic frequency even though you are receiving others.

What’s the difference between your eye and your FM radio? Entirely that your eye is directionally sensitive and the radio is not. The radio has much the same view of the world that a non-directional photocell with a color filter would have — it can tell that a particular frequency has arrived but not from where and it can’t distinguish multiple signals directionally. Imagine if you had to see the world that way.

Well, as it turns out, you don’t have to see the world that way. There’s a technology out there (the details aren’t important) called “phased arrays” that allows you to broadcast a signal very directionally (like shining a light at one and only one person) or to focus very directionally on a single signal (so that you can listen to
one FM broadcast on 99.5 and not hear another originating one mile away at the exact same frequency.)

This is not a theoretical technology — it has been in use in military radar systems (such as the one used on the very expensive Aegis ships the navy has) for decades. However, it depends on doing very complicated signal correlations, and until now that has been very expensive. However, if you do the work in software, it turns out to be pretty straightforward and the expense falls by 50% every year.

There are already companies playing this game — look at Vivato (www.vivato.com) for example, which is making phased array WiFi equipment.

With phased arrays, there’s no reason why everyone can’t be using the same spectrum at once. Couple phased arrays, spread spectrum (a modern technology for reducing interference) and SDR and suddenly the way we use radio today looks totally silly.

Miracles are Everywhere?

In the course of any normal person’s life, miracles happen at a rate of roughly one per month…during the time that we are awake and actively engaged in living our lives, roughly for eight hours each day, we see and hear things happening at a rate of about one per second. So the total number of events that happen to us is about thirty thousand per day, or about a million per month. With few exceptions, these events are not miracles because they are insignificant. The chance of a miracle is about one per million events. Therefore we should expect about one miracle to happen, on the average, every month.

Got that? That’s one miracle a month.

So next time something extraordinary happens to you, keep this calculation in mind.

What About Me? I feel cheated. I had a great last month, but no miracle. No miracle the month before that either. I’m not sure I’ve ever had a miracle of this kind. According to this calculation, my history of no miracles is a miracle in and of itself. Now I feel better.

The information is from the August Scientific American, p.32, quoting Freeman Dyson; pick it up if you can, it is one of their best issues this year.

Addendum: Charles Martin points out that a miracle is relative to what you expect. The exact time I arrived at the office this morning was no miracle, although that particular time was extremely unlikely ex ante. So you can eliminate miracles from your life simply by expecting a wide class of possible events. You can increase your number of “miracles” by expecting some very specific outcomes.

Sex and violence

In the Company of Strangers examines economic institutions in light of what we know of man’s evolutionary history. The division of labor, for example, looks even more amazing when one contrasts it with man’s inclination to violence. If you are familiar with the material in say McMillan’s Reinventing the Bazaar and Pinker’s The Blank Slate much of this book will be familiar but the author, Paul Seabright, does have a knack for the apposite phrase or quotation. I’d never read Shakespeare so literally, for example, as Seabright does in this passage:

Killing an unrelated member of the same sex and species eliminates a sexual rival. This incidentally seems a likely explanation for the disturbing tendency of violence to be associated with a sexual thrill; it is not, regrettably, a pathological response of a sick minority …It is one that has been reinforced down the ages by a tendency on the part of females – far from universal, but sufficient to make a difference – to be drawn sexually to those who have displayed prowess in contests of force, as Shakespeare knew well he made Henry V rally his troops before Agincourt with the cry that:

…gentlemen in England now abed

Shall think themselves accurs’d they were not here,

And hold their manhoods cheap while any speaks

That fought with us on St. Crispin’s Day.

Why are some young boys myopic?

Contrary to popular belief, people in east Asia are no more genetically susceptible to short-sightedness than any other population group, according to researchers who have analysed past studies of the problem.

The epidemics of myopia in countries such as Singapore and Japan are due solely to changes in lifestyle, they say, and similar levels could soon be seen in many western countries as lifestyles there continue to change…

Myopia is on the increase in most places, but in countries such as Singapore it has reached extraordinary levels. There, 80 per cent of 18-year-old male army recruits are myopic, up from 25 per cent just 30 years ago.

Or how about these examples?

70 per cent of 18-year-old men of Indian origin living in Singapore have myopia, while in India itself the rate is roughly 10 per cent.

Another study found myopia rates of 80 per cent in 14 to 18-year-old boys studying in schools in Israel that emphasise reading religious texts. The rate for boys in state schools was just 30 per cent.

Here is the full story, and I will vouch that blogging has made me more myopic.

What is the most expensive substance?

Antimatter. According to one estimate (Discover magazine, August, p.68), it costs $1,750 trillion per ounce to produce; here is another cost estimate. Gold looks absolutely cheap by comparison, and who cares if a possibly fake Vermeer just sold for $30 million?

Here are some people who think antimatter will become cheaper. So perhaps you should sell your stockpile now…!

Neuroeconomics and the sexes

Neuroeconomists let people play economic “games” while hooked up to MRI scanners. Here is one recent result:

The cingulate cortex, which processes both emotions and abstract thinking, becomes especially active after one player betrays the other by cutting back on how much he shares–as if the brain, or at least this crucial part of it, is “hypertuned” to detect betrayal. Quartz has also seen intriguing differences between men and women in the scanner. Men’s brains tend to shut down after they’ve made their decision, awaiting a reply from the other subject. But women don’t relax so easily; they show continued activity in at least three areas–the ventral striatum (the brain’s center for anticipating rewards), the ventral medial prefrontal cortex (which is involved with planning and organizing) and the caudate nucleus (a checking and monitoring region, sometimes associated with obsessive-compulsive disorder). Women, says Quartz, seem to obsess more over whether they did the right thing–and how the other subject will react to them [emphasis added].

There’s one other intriguing discovery coming out of this work, which has even the scientists baffled: with approximately 85 percent accuracy, the subjects, separated by the distance from Los Angeles to Texas, can guess whether they’re playing against a man or a woman. They appear to be picking up on subtle clues in the interactions that the scientists themselves haven’t identified.

Here is a recent MR post on neuroeconomics, citing the same link of relevance. This page offers a good introduction to neuroeconomics, including home pages for the authors cited above. Here is a course reading list for a neuroeconomics class. Here is a long essay on neuroscience and economics.

Monkey see, monkey do: Neuroeconomics in action

…[monkeys] have a rudimentary concept of economic choice, and researchers have discovered a medium of exchange — Berry Berry fruit drink — that can usefully stand in for money in a monkey’s mental life. To illustrate how monkeys make economic decisions, Glimcher’s former colleague Michael Platt, now at Duke, has investigated how they value status within their troop. Male monkeys have a distinct dominance hierarchy, and Platt has found they will give up a considerable quantity of fruit juice for the chance just to look at a picture of a higher-ranking individual. This is consistent with field observations, Platt says, which have found that social primates spend a lot of time just keeping track of the highest-ranking troop member.

Here is the full story, which is in fact a fascinating study of the new discipline of (human) neuroeconomics. Read the whole thing for an update on where economics is headed. Here is the ever-interesting Randall Parker on recent advances in the technology of neuroeconomics. Here is Kevin McCabe’s occasional neuroeconomics blog.

And here is a neuroeconomics link on how love can turn off parts of your brain.

Is light slowing down?

Read the latest update. Yes I will defer to the experts, but in my gut I have never bought into the idea that the speed of light should be constant for all space and time. Maybe I am simply too used to economic models, where all the measured magnitudes fluctuate over time. That being said, a faster speed of light in previous times might, among other things, explain why the universe appears to be so uniform. Here is a collection of relevant stories and links.

Get this:

The speed of light, one of the most sacrosanct of the universal physical constants, may have been lower as recently as two billion years ago – and not in some far corner of the universe, but right here on Earth.

Do we economists sound that funny to outsiders?

Are trains environmentally friendly?

“I know this will generate howls of protest, but at present a family of four going by car is about as environmentally friendly as you can get.”

Can this be true?

They [researchers] calculate that expresses between London and Edinburgh consume slightly more fuel per seat (the equivalent of 11.5 litres) than a modern diesel-powered car making the same journey.

It gets even less politically correct:

Roger Ford, of Modern Railways magazine, said one reason for declining energy efficiency [of trains] was the impact of health and safety and disability access regulations.

Here is a relevant Telegraph article. Here is David Nishimura’s post, my source on this matter. Here is the researcher’s home page. Here is The Transport Blog, perhaps they will offer comment.

N.B.: I have not seen the underlying data, and cannot find the study on the web. In the meantime, for some further revisionism, read Eugene Volokh on the myths of the Cuyahoga River Fire.

Department of Uh-Oh

Has the Riemann hypothesis in fact been solved?

A French mathematician is claiming to have solved a fiendishly difficult problem, upon which rides a million dollars of prize money. But other mathematicians are sceptical that he has really done it.

On Tuesday, Louis de Branges de Bourcia, a professor of mathematics at Purdue University in Indiana, issued a press release claiming that he has proved the Riemann hypothesis is true.

This proof is perhaps the most tantalising goal in mathematics today. If true, it tells us that prime numbers, which are those exactly divisible only by one and themselves, are scattered utterly randomly along the number line. If not, then mathematicians may be able to predict where the prime numbers fall.

For almost 150 years, mathematicians have been struggling to establish whether or not the Riemann hypothesis holds. And de Branges has claimed to have solved the problem before, only for others to later find flaws in his work.

“For the past 15 years he has been periodically announcing a proof and posting preprints” says Jeffrey Lagarias, a mathematician at AT&T Labs in New Jersey, who has followed de Branges’ work.

Here is the full story.

Global warming links

Courtesy of Jane Galt. The upshot of her post is that the problem is very very hard to solve.

I thought that The Day After Tomorrow, which I saw in Poland, had more bad cliches than perhaps any other movie I have seen, ever. The bad science is actually one of the least ridiculous things about the movie.

Did you know that the film had the widest “day-and-date” release in movie history? (See June 7-13 Variety, p.12.) It topped 108 markets at the same time, in early June. It failed to earn the number one spot in Greece and Serbia, however. Can you guess why?

How many words can your dog understand?

If it is a collie, perhaps up to 200 words.

The researchers found that Rico knows the names of dozens of play toys and can find the one called for by his owner. That is a vocabulary size about the same as apes, dolphins and parrots trained to understand words, the researchers say.

Since dogs-as-we-know-them co-evolved with humans, I don’t find this surprising. More generally, we underrate the intelligence of many animals. But even I found this part hard to believe:

Rico can even take the next step, figuring out what a new word means.

The researchers put several known toys in a room along with one that Rico had not seen before. From a different room, Rico’s owner asked him to fetch a toy, using a name for the toy the dog had never heard.

The border collie, a breed known primarily for its herding ability, was able to go to the room with the toys and, seven times out of 10, bring back the one he had not seen before. The dog seemingly understood that because he knew the names of all the other toys, the new one must be the one with the unfamiliar name.

Here are some of the words that Rico understands. Keep in mind that this dog understands only German, the text is translated. Note also that most “tricks” (remember Hans the horse?) still represent some form of communication with the animal.

Here is another summary report. And yes, the work is published in the highly respected journal Science, in case you were wondering.

On a related note, I just read (and recommend) this book on how animals talk to each other.