What changed?

This is one of those posts that started as one thing, trying to make some sort of Larger Point, but ended up as ... something. It started out on the long-running theme of not-so-disruptive technology, then devolved into a technical exploration as I tried to back that point up, and then went a somewhat different direction because of what I actually found when I went researching, before sorta circling back to the general vicinity of the of the original theme and pulling together some threads from some of the first posts on this blog from, oh, a minute or two ago. Rather than try to polish all this up into some sort of coherent essay, I've decided to leave it pretty much as written. Perhaps as some sort of compensation, I've included a lot more links than I usually do.

Looking back I see that in 2024, I've already doubled my output from 2023 (by a score of two posts to one), so maybe I should quit while I'm ahead. But I had an idea for a post, and after re-reading back to July of 2020 (that is, seven posts), I'm pretty sure I haven't explored this particular point before, at least not recently. Or rather, I have, given that the not-so-disruptive technology tag is in second place behind annoyances, but if I've stepped back and surveyed it from a broader point of view, it hasn't been in the last four years.

(I also notice that the link to Intermittent Conjecture is for a four-year-old post, probably because that particular feature is no longer particularly supported, because of course it's not. Grandpa, what's a "blogroll"?)

I considered editing that last bit of snark out, especially since annoyances is already well represented, but I think that it's probably in line with the rest of this post, though maybe in a roundabout way.

It's almost an axiom that newly-developed technology will Change the World. I say "almost" because technically an axiom is a statement that you assume to be true because it's essential to the rest of your logical framework, but you don't have any other way to prove it to be true, so you have to just assume it. I'm thinking of mathematical axioms like "a thing is equal to itself" or, more esoterically, "if you have a collection of sets, you can form a new set by choosing one element from each" (it took quite a bit of work to figure out that you can't prove that from other axioms like "two sets are equal if you can match up their elements one-to-one in both directions").

"New technology changes everything" is a statement that people often assume to be true, and it's essential to at least some people's logical frameworks, but I wouldn't call it an axiom because you can actually look at any given new technology and, I claim, come to a reasonable conclusion as to whether it changed everything. And then, maybe, as a followup question, by how much?

To take a couple of easy, well-known examples, it's not hard to argue that, say agriculture changed everything, or antibiotics changed everything. Except ... depending on what you call "agriculture", you could argue that agriculture was around for thousands of years before cities like Shuruppak or Dholavira arose. On a smaller timescale, the first modern antibiotic was extracted from mold growing on a bacterial culture in 1928, but it wasn't available in useful quantities until the early1940s.

It's not the discovery of a technology that makes the difference. There wasn't even any one event that you could call "the discovery of agriculture." There was an event that could be called "the discovery of (modern) antibiotics (that were known to work by killing microbes)", but that in itself didn't change anybody's life greatly.

The point here that simple statements like "agriculture/antibiotics changed everything" turn a bit mushy after even a little prodding. More accurate versions might be "over the millennia, developments in agriculture have had a significant impact on human population and living patterns" or "the development, mass manufacture and widespread deployment of several types of antibiotics in the latter half of the 1900s had a significant impact on human health outcomes."

Clearly there have been significant changes in how people live, and clearly developments in agriculture and medicine, including the development of antibiotics, have played a significant role in that, but it's not a simple matter of "agriculture happened" or "antibiotics happened" followed by "everything changed". The actual stories are full of false starts, backtracks, accidental discoveries, social upheavals, twists of fate and all sorts of other seemingly extraneous factors. Which is the interesting part.

What got me started on all this was thinking about how the web has changed communication, and in particular telecommunication. Except, as soon as I wrote that, I realized that it's more a matter of the internet changing communication, since I've already argued that it's the web of links that makes the web webby, and I'll just claim here that this webbiness hasn't had a large impact on how we communicate with each other.

We could just as well have Skype and Zoom without the web. For that matter, to a large extent each social media platform is its own web, and not "the" web. But that way lies yet another round of fretting over what exactly am I blogging about here ... For now, let's file communication technology under "the web at large" or something and get on with it.

For most of human existence, the only way to communicate detailed information over a long distance was by people moving around. Travelers would bring stories and knowledge and trade items with them and information would diffuse across large areas, but if that traveler wanted to send a specific message to someone they'd met years ago while traveling someplace far from their current location, well, good luck with that. It may not have been impossible, but it couldn't have been commonplace.

Several thousand years ago, digital communication came along and changed this. With writing came the option of moving a written message with the sender's exact words (there wasn't any single "invention of writing", either, but let's just roll with it). Messages could be sealed so that their contents couldn't be easily changed, signed so that you could tell who they came from, and even encrypted so that only the intended reader could read them, or at least that was the idea.

Digital telegraph systems, also dating back thousands of years, could transmit text from point A to point B without even needing a person having to carry it. The Greek phryctoria, a system of towers on mountaintops with torches, are a good example but not the only one.

Two key measures of telecommunication are bandwidth, which is how many bits can be transmitted in a given amount of time, and latency, which is how long it takes to transmit any particular bit from sender to receiver. As usual, the actual definitions are more subtle, particularly for bandwidth, but these will do here. If you're feeling technical, feel free to read bandwidth as bitrate.

For example, if it takes three seconds to switch the torches in a telegraph tower around to show a new letter, and there are 24 possible letters, then the bandwidth is about 4.6/3 bits per second, or about 1.5bps. The latency from one tower to the next, around 30km away, is negligible (about 0.1 milliseconds).

If the message is supposed to be relayed to the next tower in a series of towers, it will take some amount of time for someone to read the arrangement of torches in the sending tower and put the same torches up so the next tower can see them.  Let's say there are two people in the tower, one reading and one putting up torches, and it takes an extra second for the reader to read and announce the next letter, on top of three seconds to arrange the torches. Latency is then four seconds per tower.  That is, if the first tower is sending a message and the second is relaying it to the third, the third tower is getting the message four seconds after it is sent. A fourth tower would be eight seconds behind, and so forth.

Suppose I want to send a message to someone ten towers away. Latency is still pretty good, relatively speaking. The last tower will be 36 seconds behind the sender (nine relays for ten towers). If that receiver sends a reply, I can get it just over a minute after sending my message (in more technical terms, round-trip latency is on the order of a minute). While this is glacial by today's standards, it's outstanding in comparison to a multi-day journey to get from where I am to where the receiver is, and I don't have to worry about someone waylaying my messenger along the way (or my messenger deciding they have better things to do with their time).

Bandwidth, though, is not so great. If I'm sending a short message like "Prepare for attack from the north," that's not a problem. Transmitting that message will take a couple of minutes and my receiver will have the whole thing half a minute after I finish sending it. But suppose I'm sending a trade agreement proposal that amounts to 12,000 bits -- still tiny by today's standards. That will take a couple of hours, which is still doable, though not a lot of fun for anyone involved.

But the people on the other end will want to respond with their own counterproposals, and so on. Pretty soon we're into days, and spare a thought for the twenty people up in the towers shuffling torches around and looking out for torches at other towers through the night  (I'm going to go out on a limb and say this system works better at night).

Probably better to send a trusted emissary with the text of my proposal and maybe some other written instructions. And while they're at it, they could carry messages from other people in my area to people in the receiver's area, or anywhere along the way, and we have ourselves the beginnings of a postal system.  The latency of a postal system is measured in days, but the bandwidth is essentially limited only by how fast people can actually write and read and how many people are sending and receiving messages -- you can fit a lot of sheets of paper onto a horsecart. Not to mention that you can also send drawings and diagrams easily on a sheet of paper.

This may seem like a lot of speculative detail about ancient systems of communication, and it probably is, but it covers the bulk of human history (the written-down part, as opposed to prehistory, which is most of human existence). From ancient times until the late 1800s, long-distance communication was mainly a matter of moving physical texts around, with limited use of alternatives that were much faster (in latency) but also much, much slower (in bandwidth), and quite a bit more expensive. This includes the era of the modern optical telegraph (late 1700s) and electrical telegraph (mid 1800s).

What happens next is interesting. I originally wrote "then came along the telephone," with the idea that it was a major leap to have the bandwidth to carry voice instead of the dots and dashes of morse code. Fortunately, I did a little double-checking and discovered that

• The bandwidth of a telegraph was not that low. A punched-tape system around the time of the telephone's invention could transmit upwards of 400 words per minute. At roughly 12 bits per word, that comes out to about 80 bits per second. That's nothing by modern standards, but it's about 50 times my guess for the phryctoria. Some of that is because Morse code encodes text more efficiently than torches, but most of it is due to the switch to electromagnetic transmission (um, light from torches is also electromagnetic ...).
• The bandwidth of human speech is not that high. In this old post I cited a world record of 10 words per second, or about 120 bits per second, but normal speech is much slower.

In other words, a telephone and a high-speed telegraph are transmitting words at about the same rate, though the telephone has the advantage of carrying tone of voice and not requiring someone to transcribe words onto a paper tape. I suppose this shouldn't be too surprising since both the telephone and telegraph are using the same underlying transmission medium of electromagnetic waves traveling along copper wires or, a little later, over the air.

The same technology could also transmit images. The first facsimile machine (perhaps you've heard of "faxes"?) was developed around the same time as the telephone. Later, in the 1920s, a number of inventors on a number of continents (including Leon Theremin, better known for the musical instrument) developed various systems for transmitting moving images. Early television station WRGB ("RGB" can't be a coincidence, can it?) transmitted 40-line images at 20 frames per second. Let's guess that a 40-line image equates to 1600 8-bit pixels. That comes out to about 260 thousand bits per second (260kbps).

This is already a remarkable increase in bandwidth*, from a hundred or so bits per second in the mid 1800s to hundreds of thousands in the early 1900s. By the dawn of the internet, let's say 1974 -- fifty years ago -- when the proposal for TCP was published, a leased telephone line could carry around 50kbps (56kbps as I recall and Wikipedia seems to confirm). That was the basic unit -- it was entirely possible, and typical, to lease more than one. By the mid 1980s, NFSNET was using 1.5Mbps T1 lines. Later came T3 lines at 45Mbs (so a T3 is worth 30 T1, go figure), and today we're talking gigabits or more. 

This is all a matter of how bandwidth is sold. The actual transmission cables are much heftier. Fiber optic cables can carry petabits per second (Pbs). A peta is a million gigas, that is, a petabit per second is a quadrillion bits per second, or about 125 thousand bits per second for every person on the planet. Commercially available cables are somewhat smaller, but not much, measured in hundreds of terabits, that is, hundreds of trillions of bits per second.

There are still some specialized applications that can give that much bandwidth a workout, but in human terms the amount of bandwidth available is absolutely ridiculous ("available to whom?" is a fair question). Which brings me back to one of the earliest themes on this blog: limits on human bandwidth. That is, how much information can any individual person deal with? I discussed several aspects of this in this post about, oh, seventeen years ago.

In terms of bits per second, our highest use of bandwidth is probably the visual system,.which processes somewhere around a gigabit per second considered as raw pixels, but there's a lot of redundancy in there. A good MP4-compressed video stream, which includes audio, is more like 10Mbps. Since a format like MP4 is tuned to provide only the information we actually process, it's probably a better measure of how much data the visual system is actually processing.

There's a lot we don't know about our other sensory input -- touch, smell, proprioception and whatever else, but it's clearly operating at a much lower bandwidth (for example, a walking robot does not need a fiber optic cable to tell the CPU how far its knee is bent or how much pressure its foot is exerting).

In other words, there are many, many ordinary houses with much more than enough bandwidth to saturate the sensory input of all the humans in them, if said sensory inputs could all be magically connected to a stream of bits. In practice, it means that there's enough bandwidth for everyone in the place to spend all their time watching video.

But -- and maybe this really is leading to some sort of point about technology changing everything -- that's been true for quite a while, at least since the advent of 24-hour cable TV, which is to say, also about 50 years ago, which I've just called the dawn of the internet. I don't think this is at all a coincidence. Let's try to boil all the stuff about bandwidth down to a few bullet points:

• For most of human existence, long-distance, low-latency bandwidth was zero -- there was no way to get a specific message across a long distance quickly. You could interact with some directly at short distance with high bandwidth and low latency, but that was about it.
• For most of human history, long-distance, low-latency bandwidth has been very low. In some times and places it was possible to quickly transmit a short message over a long distance, but even then, latency was measured in minutes and bandwidth in single-digit bits per second.
• Starting in the 1800s, electromagnetic transmission led to huge increases in low-latency, long-distance bandwidth, from single-digit bits per second to current rates, which are enough to enable video calls between any two internet-connected points.
• In the mid to late 1900s, bandwidth was high enough and cheap enough to enable two innovations:
• Cable TV carrying over a hundred channels 24/7
• Wide-area digital networking

Of the two, digital networking was by far the slower. Early networks mainly transmitted text, whether in human or computer languages. If you had a terminal at home, you could typically connect to your local network at speeds of 110 to 2400 baud (in general a different unit from bits per second, but in this case the same), and hope that you'd remembered to turn off call waiting on your landline. Then, after a long day of hacking, you could flip on the TV and watch at something like a megabit (resolution was lower in those days).

Even backbone connections were very slow by today's standards. This doesn't seem like a technical limitation, since ordinary coax cable could handle megabits, but more a matter of there not being that much digital information to send. If I wanted to talk to a colleague on the other side of the country, I wouldn't have tried to set up a call over the internet at the time. I would just pick up the phone.

The digital convergence that happened gradually over the next couple of decades consisted largely of building up the internet backbone, which was based on telephone and cable technology (mostly telephone, I believe), to the point where it could carry digital information at a rate comparable to the analog technologies that had been around since the beginning of the whole exercise.

Technically, this was revolutionary. For most intents and purposes, anything that was analog in the mid 1900s, particularly television, telephone and radio, is now carried digitally on the same network infrastructure that you can use to send purely digital information like ... text and emails? Source code?

This is a kind of interesting way to look at it. Hiding inside the massive digital network that delivers sound and video to us is a tiny replica of the original internet, albeit expanded from a few thousand researchers to a significant slice of the world's population. Billions are bigger than thousands, of course, a million times bigger, in fact, but overall digital bandwidth has increased by much more than a factor of a million.

(The early internet wasn't just used for email and source or object code. It was also used to transmit scientific data. Some datasets can be quite large, particularly in astronomy and particle physics, large enough to saturate even the modern backbone. But in such cases data is generally transmitted by putting it on physical media, which is then shipped. The postal service still wins on bandwidth. And yes, I am proudly using both data and media as mass nouns here.)

I think what I'm trying to sort out here is that the digital convergence can be looked at two ways. The original vision was to bring the intelligence of the internet to existing audio and video media. A TV cable brings a fixed set of channels into your house and very little back out. An analog phone circuit delivers voice traffic from point A to point B. A digital network can carry information from any number of senders to any number of receivers and do any kind of processing along the way.

On the other hand, technically, the digital convergence was a shift from sending analog data over analog lines (or over the air) to sending the same data over the same lines, or at least the same types of lines plus the cell network (also fundamentally analog), but encoded digitally, then re-encoded into analog signals and likewise decoded and re-decoded on the other end.

Why do that?

The wilder speculations of the 1990s haven't really panned out. A phone call is still a phone call. True, most of the time it's easier just to text, but texting needs much less bandwidth than calling. It certainly does not require a huge buildout of digital bandwidth. All the texts you send in a year would probably amount to a few seconds of audio.

TV shows are still TV shows and movies are still movies. Exciting new possibilities like interactive choose-your-own-adventure TV are an occasional novelty. Live streams allow viewers to interact with the presenter/performer, but so did call-in TV shows.

The difference is control. Outside the occasional news program or sporting event, I'm not sure I can remember the last time I watched something at the same time it was broadcast, if it was ever broadcast at all. I haven't bought an album in years, even in digital form. I stream what I want to watch or listen to, and I'm hardly a bleeding-edge early adopter. If I want to participate in a livestream, I can choose that. More importantly, if a creator wants to put on a live stream, they can easily do that. If I want to set up a video call with some people at work (or not at work), that's easy, too.

Some of these might be possible with the old technology. I could imagine a high-bandwidth phone service that would allow you to call a special number to connect to a video server and pick out what to watch on your video-enabled phone terminal, but putting everything on a digital network that handles data as bits regardless of its content or where it's going has made all of this much easier.

This is all sliced finely enough that individual people can decide which individual people to communicate with, from friend group to celebrity influencers to major organizations and whatever else. I'm personally not sure how much the behavior that this has enabled is new and how much is stuff that people were doing anyway. I explored that theme fairly early on, here, here and here for example, but I don't really do much with social media, even if you count blogging and the occasional visit to LinkedIn.

I think "Digital communication has changed everything" is true in about the same way as "Agriculture has changed everything". On the one hand, it has to be true. Being able to communicate instantly with any of billions of people has to be different from only being able to communicate instantly with the people around you. Being able to transmit high-resolution video across the world with negligible delay has to be different from being able to send a letter across a continent in days or weeks.

Being able to stream from a wide collection of audio and video is certainly different from having to buy or borrow books, records/CDs and videotapes/DVDs, and since that shift has happened well within living memory, it can certainly seem like things are changing rapidly.

But on the other hand, digital technology, including digital telecommunication, has been around for thousands of years. Analog telecommunication has been around for about a century and a half. What we might call the digital revolution is a change in how we transmit and access information, primarily audio and video, that had previously been analog, sitting on top of a huge increase in overall telecommunication bandwidth that began happening over a hundred years ago.

Just as there is no particular beginning of agriculture, there is no particular beginning of digital communication. Even if you could pinpoint the first time a person deliberately planted a seed with the intention of harvesting food later, or the first time a person deliberately made marks to represent words with the intention of someone else reading them later, it wouldn't tell you much. What matters isn't the particular starting point, but the long history of development and use over the millennia.

So far, advances in communication have been about people communicating with people. Machines do communicate with other machines without direct human involvement, but this is mainly in service of people communicating with people. This may change, but that's for another blog.

As far as people communicating with people, the limiting factor is mainly the people themselves. There are only so many conversations one can have and so many people to have them with. The whole point of a video conversation is to make the call as much like talking face to face as possible, that is, to accommodate our limitations in how we communicate. There are now ways of broadcasting a message from one person to millions of people, or even a billion, but even if one person can broadcast a message to a billion people instantly, those billion people will make sense of it in terms of their own lives, their own views and their own desires. 

The how of communicating with other people has changed greatly over the millennia, and particularly greatly in recent decades. This in turn has significantly affected whom we can communicate with. But what we talk about, even if we're talking about how quickly things appear to be changing, doesn't really seem to have changed much at all.

One of the earliest themes of this blog was trying to understand what effect the web and the internet would have on how we talk to each other. My instinct has been generally been to push back against "It's all different now" narratives, and I think my instinct has largely been borne out (but then, I would think that, wouldn't I?).

And yet, I can't believe that nothing has changed. A lot has changed. Some part of me wishes that, after nearly two decades, I could arrive at some sort of grand summing-up of What The Web Is About and what effect it's had, but after all this time, I'm not sure I have much beyond my original take: "It's not nothing, but I'm not sure what it is, except whatever it is doesn't line up that well with the hype."

Six degrees, more or less, sort of

In reference to a previous post on degrees of separation, I went looking through Wikipedia and found what I was pretty sure I'd seen before about graph theory and the "small world" phenomenon. A few points:

• Actual social networks, and a wide variety of similar networks from all sorts of different fields, don't act like classic random graphs, where each object in the network has about as many connections as any other. Rather, there tend to be a few objects with lots of connections and a lot with relatively few connections. But ...
• ... not a lot is known for certain, especially when it comes to networks of real live people. How connected people are depends on what kind of connections you count. There have been various efforts to measure connections in networks like FaceBook and from looking at instant messaging traffic (anonymized, I would hope!), but it's not clear what you can or can't tell about people in general from that. However ...
• ... networks in general seem to behave roughly similarly, keeping in mind that nice, regular networks are the exception both in theory and real life. In particular, as you add to the network, the diameter (the largest number of hops required to connect two objects in the network) tends to increase logarithmically. To double the diameter, you generally have to square the number of objects. One intriguing result is that if you start with a nice, regular network with a high diameter and add just a few connections here and there, the diameter drops sharply. So ...
• ... the "small world" phenomenon looks to be a general property of networks and not necessarily a product of our modern age. My hunch about human bandwidth is that there are only so many connections a person can keep up and that limit was hit quite some time ago. The question is more to what extent scattered groups of people might be more connected than in times past. And finally ...
• ... the famous "six degrees of separation" is not some sort of deep magic but rather a shorthand description of some early and not particularly rigorous experiments that suggested that most people are probably more or less six hops from each other. There's nothing particularly special about the number six, there are still small pockets of people who are not meaningfully connected to the outside world at all, and in any case the actual upper limit might just as well be twelve or five, depending on how you count (leaving isolates aside).
  

A gigabit behind your eyes

OK, I thought this was going to be an easy one. At a lecture the other day I heard Edward Tufte (author, among other things, of The Visual Display of Quantitative Information and quite a bit of scathing invective aimed in the general direction of Power Point) claim that the human optic nerve has a capacity of around 20 megapixels per second. "And we have two of them!" he continued, pushing one of his major themes: people can easily and naturally process much more information visually than most graphics contain.

Leaving aside the questionable implication that two optic nerves allow us to process much more information than one -- unlikely both because the two eyes generally see almost the same image and because if they don't the result is generally less informative than the normal case -- I was happy to hear some hard numbers, apparently based on a careful, peer-reviewed study, regarding human visual bandwidth.

So all I needed to do was track down Tufte's assertion on the web, follow that to the original study and write it up: Our optic nerves can handle approximately X, so a display purporting to handle more than X may not be that useful (and maybe that's why Blu-Ray doesn't seem to be taking the world by storm). Granted, this is just a crude measure of bandwidth and leaves aside many, many details of human visual perception, but it's still a useful number for sanity checking and ballpark estimates.

Alas, I'm stuck at step 1. I'm only mostly sure the number was 20 and the units were megapixels per second, and I'm assuming that a pixel is more or less three bytes, based on fairly well-known results in color perception. So instead, here are some facts and factoids that turned up:

• The human eye has about 100 million receptors. This is sometimes quoted as "the eye has 100 megapixels," but trying to compare rods and cones to camera pixels is really apples and oranges.
  
• Unlike the uniform grid of digital cameras and video displays, the eye instead has about 100 million light/dark-sensitive rods and 5 million color-sensitive cones. The cones are clustered around the focus point of the lens. Peripheral vision is much less color-sensitive.
• Most people can't really tell the difference between a 6"x4" photograph printed at 150 dpi and one printed at 300 dpi when both are viewed at normal distance. 6"x4"x(150dpi)² is about half a megapixel. Half a megapixel times 20 frames per second is about 10 megapixels per second; that's low of Tufte's figure, but then a 6"x4" photo at normal distance doesn't completely fill the field of vision -- just the most acute portion.
  
• The optic nerve contains about 1.2 million fibers. That's a bit more than one for every hundred receptors, so either some aggregation is done on the retina, or the neurons are able to multiplex information from multiple receptors, or both.
• 1.2 million fibers times 20 frames per second is close to Tufte's 20 million per second.

All this suggests that, to a rough approximation, we can process still images of about a megapixel and moving images with around 20 megapixels per second of useful information. 20 megapixels per second at three bytes per pixel is 60MB/s or about 500Mb/s, so we have something close to a gigabit network right behind our eyes. This sort of thing is one reason I tend to put "broadband" in quotes.

If we can only process a megapixel or so, why have a bigger display than that? Good typographic resolution is more like 1200dpi. On an 8 1/2" x 11" page that's over 100 megapixels. Isn't that overkill?

Not really. You don't look at the entire page at once. You scan it, focusing on on piece, then the next. Each of those pieces needs to be sharp. A large, finely-printed page will give you about a hundred high-resolution patches to focus on. Similarly, you can't take in all of an IMAX image at once. Rather, you have a huge image that looks sharp no matter where you look at it.

A sharp display with only a megapixel of resolution would have to cover the entire field of view, and it would have to track eye movements so that which megapixel you got depended on where you were looking. Maybe some sort of really high-tech contact lens?

All of human knowledge

In the annual (?) appeal for funding for the Wikimedia Foundation, Jimmy Wales asks us to

Imagine a world in which every single person on the planet is given free access to the sum of all human knowledge.

This seems like perfectly fine wording for a fundraising appeal, a decent description of what Wikipedia is about, and a noble ideal to boot. So let's rain on the parade by picking it apart, shall we?

Is it possible, even in principle, to give even one person access to the sum of all human knowledge? Actually, what does "the sum of human knowledge" even mean? Some time ago, I was convinced it was "everything in the encyclopedia". Now I'm not so sure. Wikipedia itself specifically excludes knowledge that isn't "notable" (what did I have for breakfast yesterday?) and "original research" such as tends to creep in as people summarize pieces of articles and draw conclusions from them. It also goes to great lengths to exclude or at least neutralize opinion (POV in the jargon (*)).

In other words, it aims to gather information generally accepted as "known". This is the kind of philosophical quicksand that holds up just fine so long as all you do is walk blithely across it. So let's just walk ...

Assuming there's such a thing as the sum of human knowledge, for some value of "knowledge", could anyone access it? Well, you don't really want to access all of it. You couldn't anyway. You want to be able to access the bit you need at the moment, right then and there.

This runs directly into the limits human bandwidth. Not only is there only so much raw information you can process at one time, there is only so much metadata -- information about what and where other information is -- that you can process at one time. Sure, the knowledge you're looking for is in there, and you have both the careful work of editors and categorizers and the raw horsepower of text search at your disposal. But can you find it? Empirically, the answer so far is "often". I doubt it will ever be "always".

Nonetheless, an unachievable goal is still worth aiming for so long as we produce useful results along the way.

(*) The Wikipedia article on POV contains a very relevant bit of wisdom:

In Thought du Jour Harold Geneen has stated:^[1]

The reliability of the person giving you the facts is as important as the facts themselves. Keep in mind that facts are seldom facts, but what people think are facts, heavily tinged with assumptions.

The slowest fiber service in Europe

British phone/internet provider BT is rolling out fiber-optic service to homes in Ebbsfleet, Kent. BT says the speeds are "Higher in fact that anyone currently needs." Critics say it's "The slowest fiber service in Europe". Both statements are factual, but neither seems very helpful.

On the one hand, how much bandwidth does one need? The answer could range from zero, given that thousands of generations of humans survived before the internet, to "enough to saturate the senses of everyone in the house simultaneously" (not currently available anywhere I know of).

The BT offering is somewhere in between. Sustained bandwitdh is 2.5Mb/s, shy of full DVD, but it can also handle "bursts" of up to 100Mb/s. That's a fairly broad range, and it's not clear how long a burst can be. If it's say, 10 seconds, then in that time you could buffer up about four minutes of DVD video, and if you could do it again every few minutes you should be able to keep the buffers full. Of course, if you "need" HD, you'll need to buffer more at the outset. If you "need" to watch two or more different live HD offerings at once, you're probably out of luck.

On the other hand, if your bandwidth is adequate to your needs, what does it matter how big a pipe they have on the Continent, or in Asia or wherever? But maybe that's just sour grapes from a (relatively) bandwidth-constrained Yank.

How much bandwidth does a man need, Mr. Tolstoy?

Earl comments that we probably already have enough, or nearly enough bandwidth to saturate human capacity, but not enough to satisfy our human desire for new shiny pretty things. Or at least I hope that's a reasonable paraphrase.

I would say it depends on what kind of information you're trading in. If you're dealing in metadata like who knows whom, or dealing in random facts like the score of every major sports event in the world, or in text like newspaper copy, even a dial-up connection can feed you information faster than you can process it.

If you're dealing in sound, a dial-up connection can certainly carry voice (that's what it was designed for, after all). Decent stereo sound requires more like 100kb/s (mp3 takes about a megabyte a minute). That's a bit beyond dial-up, but cable and DSL can handle it.

Analogously, if you want YouTube-quality video, you can certainly get that over cable or DSL, but plain DVD quality, at 4Mb/s, needs what's still an uncommonly big pipe. And that still leaves plenty of room before we hit the limits of perception. Those finely-tuned eyes of ours are bandwidth-hungry.

On the other hand, as Earl points out, you hit diminishing returns well before you hit the limits of perception. That last Mb/s of bandwidth doesn't improve the experience nearly as much as the first one. The difference between regular TV and HD is not nearly the difference between TV and no TV (and some would argue whether that last one represents an improvement, either).

Storage hardware is already entering a new regime of plenty. You can now get a terabyte disk off the shelf. My spell checker flags "terabyte", but soon enough we'll be throwing around (I'm guessing) "T" like we now throw around "gig" and "meg". Borrowing from those displays you see in the camera/music player department, a terabyte can hold:

• A million minutes, or more than two solid years, of music.
• Hundreds of thousands of high-quality photos.
• Hundreds of hours of DVD-quality video.

For less than the cost of a humongous monitor to watch it on, you can now get enough disk to store your entire DVD collection and (likely) every home video you ever shot, plus your entire song collection. Or you could store every phone conversation you've ever had in your life (phone quality requires much less than mp3, in case you've spent more than two years of your life chatting).

If you have dial-up at 56Kb/s, it would take 4-5 years to fill a terabyte, assuming the connection is running full-tilt, constantly, with every bit recorded on the disk. When you're done with that, you'll probably be able to pop in a 10TB disk for the same price and keep going ... The question is, will you still have a 56Kb/s dial-up connection?

In the big happy family of Moore's law, bandwidth into the house is the poor cousin (processing power is the crazy uncle in the attic, but maybe I'll get to that later). At some point, bandwidth will reach the point that disk is reaching now, where we'll actually have to think a bit about how to use it all. Anomalously, that point still seems fairly far off.

But then, how much do we really need? In Tolstoy's famous story How much land does a man need? (which I haven't read), it turns out you need about three feet by six feet. By six feet deep.

Blobs, metadata and web content

Every time I price hard drives, the cost for a given size looks ridiculously cheap, even by comparison to the ridiculously cheap price from the last time I looked. If you spend $X on a disk drive every year, this year's drive will generally be able to swallow last year's whole without great effort.

And yet, we still manage to fill it all up.

Many years ago, at my first geek job, we splurged a somewhat scary amount of money and bought The Ten Megabyte Disk. It was about the size of a beer fridge and I remember wondering what we could possibly do with all that storage. I mean, it could hold the entire 128K expansion memory of the computer it was attached to (a box about the size of a large set-top cable box) almost 100 times over ...

So what's going to fill up today's terabyte-plus disks (100,000 times the beer fridge, if you're keeping score)? It would have to be video, I'd think. A terabyte will hold around about 80 hours of mini-DV video, 250 single-sided DVDs, 125 double-sided DVDs, or 40 blu-ray DVDs (assuming they're more-or-less full).

I previously estimated 3D IMAX at around 1GB per second, so if that's more or less right a terabyte will hold about 17 minutes of really high-definition video. There's no good way you could watch that in most people's houses right now, but give it time (I'm thinking some sort of VR glasses, not a humongous IMAX screen in every home).

What strikes me here is the vast difference between video and everything else.

A terabyte is about a million minutes of mp3 sound, or if you prefer, 70 solid 24-hour days, or two solid weeks if you prefer high-quality FLAC to mp3. It's hundreds of thousands of high-quality digital photos. It would hold all the actual software installed on my computer, including bitmap images, PDF versions of documentation and so forth, hundreds of times over. If you put every word and line of code I've ever typed in my entire life on a piece of the disk and painted that piece neon candy-apple red, you'd need a microscope to see it.

In the business, we call things like movies and songs BLOBs (Binary Large OBjects). Blobs become much more useful if you attach other information to them, for example the title of a movie, an index of scenes, cast and crew credits, and all the other kinds of stuff you'd find in IMDB. This sort of descriptive information about another piece of data is called metadata.

Metadata is very important. Imagine having 1000 songs and 100 DVDs stored on your disk, listed only by a 4-digit number. It's also absolutely tiny. The entire IMDB entry for a typical movie would fit into a small fraction of a single frame of that movie. You couldn't even use it as a cuing dot. It would flash by too quickly.

By comparison, typical web content is very rich in metadata. For example, this blog entry contains a couple of links and tags (that I put in) and some other indexing information (that Blogger puts in). It sits in a page full of other links and indexing information. Overall there is more text in this blog than metadata, but not thousands or millions of times more.

Many (but not all) web offerings are similarly metadata-rich. A typical social-networking site is all about the links. Google makes its money handing you piles of links. Even something like flickr adds value by categorizing blobs and otherwise making them easy to find.

All of which brings me back to my recurring theme of human bandwidth. We humans can consume vast amounts of visual information, large amounts of audio information, but only so much metadata. As a corollary, the amount of space per user on a web site will be tiny (from the computer's point of view), unless it happens to be rich in audio or video.

What is the bandwidth of one voice talking?

A side question to the previous post: About how much information does a voice convey per unit time? Let's neglect tone of voice here; it's clearly important in real speech, but my guess is that if you could quantify it, it would come out to not very many bits (Happy? yes/no. Angry? yes/no. Sarcastic? yes/no. etc., each changing fairly seldom). It's also not something that computers are terribly good at picking up, so it's not relevant to the particular case of speech recognition.

At an upper limit, how fast can people talk? Appearances can be deceiving here. That auctioneer rattling on a mile a minute is really just continually refreshing two 2- or 3-digit numbers (possibly with some zeros attached) that change every few seconds. That person zipping along in a foreign language isn't really talking significantly faster or slower than you would, but it sounds like a lot since you don't understand it. And of course, some people can say more with a word than others can say with a paragraph.

The record for speaking English appears to be around 10 words per second (yikes!). Mind, this is most likely someone spewing out a prepared spiel that they've practiced over and over again. Assuming about 10 bits per English word (estimates vary a bit), that's about 100 bits per second. My guess is that most of us, particularly those of us actually coming up with the words as we go along, would do well to hit half that. On the other hand, most of us type considerably more slowly than that.

So let's figure 50 bits/second for running speech, for example, if you're dictating a letter. What if you're just barking out commands from a set list? Interestingly, bandwidth drops considerably. For example, if it takes half a second to bark out one of 16 commands, that's 8 bits/second. Not exactly broadband.

Is hyperreality the new reality?

While searching for a different article (on which I'll probably comment if I run across it) I found a piece by Daniel Rourke on "hyperreality". It expresses a notion that I've run across from time to time, one which seems compelling at first blush. Jumping right into the middle:

Could Wikipedia at its broadest boundaries be a metaphor for the future of human society? Take away our cultural memes and humanity would quickly revert to the simple cultures seen in our monkey and ape relatives. It was the evolution of language which bound humanity into a shared consciousness - a cultural brain which did more thinking than any individual identity could do alone.

This is practically self-evident, which makes it automatically suspect. Are other primate cultures really so simple? A primatologist might well disagree. Is human culture really that different from primate culture? There's more in common than we like to admit

Is language so big a factor in propagating culture? A good deal of cultural behavior consists in things we "just know to do" (or not do), and which we often have trouble putting into words. Writing an etiquette guide is a difficult endeavor; getting people to follow it even more so.

What is this shared consciousness that we all have? How much of it is inborn? How much of it is absorbed by immersion or learned by example? When we talk about how we do things, to what extent are we just verbalizing what the non-verbal parts of our brains are doing without our say-so?

What aspect of our shared consciousness does the web stand to change? Yes, the web can bring the same experiences and ideas to large numbers of people very quickly, but so can radio and television. To some extent, so can mass assemblies.

In all the above, I'm not saying the non-web world is the same as the web, but I want a bit more detail on how the web is different.


Rourke continues the theme of the net as an agent of profound change a bit further on

Over the next few years as the internet becomes ever more a totality of culture rather than simply a referent the lines bordering reality, hyper-reality and pure imagination will dissolve around us. I would go so far as to suggest that many generations from now cyber-entities once labeled 'human' will find it impossible to distinguish what was past-real, what is present-hyper-real and what will never be real in the seething masses of datum [sic] the internet will have become.

In other words, in a few years we will be so immersed in the internet that we won't know or care what's real and what's not. I think this misses out two important points.

One is that we are physical creatures. No matter how far off into cyberspace we float, at least for the near to medium future, we will need to eat. We will not be able to physically be two places at once. The laws of physics will still apply.

Even generations from now, if we have somehow slipped the bonds of our physical chains, our cyber-heirs will still be embedded in time. It seems unlikely that the distinction between past and present will cease to be useful.

The other point, closely related, is that our brains are very much shaped around physical reality. We automatically and subconsciously make any number of assumptions about what perceive based on what tends to work in the real, physical world.

These things we know that ain't necessarily so go by the general name of cognitive biases, and the striking thing about them is how many (along with their cousins like optical illusions) make sense in the context of an embodied being scrabbling to find food and mate in an environment of relative scarcity and danger.

In short, no matter how powerful the communicative machinery of the web becomes, or how great the bandwidth, we experience it (and will continue to experience it for some time) through our human wiring, with all its quirks and limitations. It seems to me an unproven assumption at best that, as scenarios like the one Rourke describes tend to assume, we have some hidden potential within us just waiting for something like the web to unlock.

A distinguishing feature of human networks

OK, so the real distinguishing feature is that humans are involved. Duh. But I had a particular feature in mind ...

In the example of the spread of contract bridge, I guessed that a critical event, then as now, would be a well-known authority publicly endorsing a new idea. Well-known authorities are by definition connected to a large portion of the general population, because large numbers of people read/watch/listen to their pronouncements. This is a classic "small world" feature, which keeps the overall diameter of the graph (the maximum number of "degrees of separation" between any two members) small.

In a network like the internet, there are also a relative few "hubs" that are connected to a large number of more peripheral nodes. These tend to have monstrous bandwidth available and will carry huge amounts of traffic, both in and out. When I publish this post, for example, it will almost certainly pass through one or more of a relatively small number of "backbone" servers along with a mass of completely unrelated information.

In the human case, the well-known authority produces human-sized traffic, just like everyone else. It's just that this information gets broadcast, verbatim, to a large number of people. Similarly, anyone can try to send a message to the authority, but only a human-sized portion of it will actually get through. In practice, the authority's input will be heavily biased toward a small number of trusted people (who thus may be influential without being well-known), with maybe occasional input from random people.

I'm not sure what all the consequences of this may be, though I've been grasping at them a recent post or two. One way to look at it is that in a human network everyone's CPU and network are more or less the same size, while in a computer network they can vary by orders of magnitude. This in turn affects scalability.

Nor is it at all clear (to me, working off the top of my head here) that throwing more people at the problem would work, even if they'd sign up for it. Even if I decided to have ten or a hundred or a thousand people act together as a virtual hub, there's a limit to how fast they can talk to each other.

Hmm ... to what extent does something like Wikipedia act as a virtual hub?

The small world of contract bridge

In the spread of a new idea, which is more important: the speed at which information flows or the speed at which we absorb it?

I have no doubt that modern communication, including the net, has increased the speed of information, but let's not underestimate our forebears. From a recent New Yorker book review on contract bridge:

The modern version, contract bridge, was created in 1925 by the railroad heir and master yachtsman Harold Stirling Vanderbilt, who had been annoyed by what he felt were deficiencies in the previous version, auction bridge. Vanderbilt was a passenger on a ship that was travelling from Los Angeles to Havana by way of the Panama Canal, and on the evening of October 31st, while playing with three friends, he introduced several improvements that he’d been mulling over, including a method of scoring that required players to more accurately assess, during the bidding, the number of tricks they would take, a prediction known as a contract. Vanderbilt shared his ideas with a few other friends in Newport and New York, and his game spread across the country and around the world at almost unbelievable speed. “Half a year after Vanderbilt’s voyage,” McPherson writes, “a notice appeared in the Los Angeles Times announcing that a Chicago woman was suing her husband for divorce on the inexcusable grounds that he trumped her ace.”

I doubt that communication speed was the limiting factor here. More likely, it was the time required for a player to try out the new rules, mull them over, deem them good and decide to try to introduce them in their next game. By the small world principle, it doesn't take too many such hops to reach the entire community.

From a graph theory point of view, you have a set of players connected by lines of communication (we play with the so-and-so's at our Tuesday game; I correspond with such-and-such; we all read thus-and-such's column in the Times). Propagation through the graph is a matter of incubation time (playing, mulling it over) and transmission time (the epidemiological terms are deliberate here; I'm sure there is quite a bit of relevant research in that field).

In the present case, there is probably a classic small world graph, with a few well-connected nodes (major celebrities like Vanderbilt and the major columnists) and lots of less-connected nodes (the Tuesday night games of the world). It would be interesting to see when the new rules first appeared in print. It would also be interesting to see how long it took contract bridge to supplant auction. That's clearly not a matter of propagation speed.

These days communication time is much more limited by the reader than by the medium. If a headline appears in a major news source, it may still take some amount of time before everyone gets around to reading it. Blogs and online news sources shorten the time from writing to availability to practically nothing, but they don't necessarily make me read it that much sooner.

Which has had more impact overall: "Old-school" electronic communication (think telegraph, radio, TV) or the internet? One could make a decent case for the old school.

What you look like to your computer

We're used to thinking of computers as mind-bogglingly fast, but it's useful to look at it the other way as well: from the hardware's point of view, people are mind-bogglingly slow.

A decent CPU can now execute huge numbers of instructions in the time it takes for my fingers to move from one key to the next. If you assign some human-scale unit to an instruction cycle, actual humans move at a geologically slow pace.

Storage and bandwidth have to keep up with the CPU (more or less), so it's the same story there. An email (or this post) is tiny compared to a terabyte disk. Audio and video are still computer-sized, but this will change. Human bandwidth is shifting, in our lifetimes, from completely overwhelming computer capacities to being dwarfed by them.

For my money this disparity is the hole in Searle's "Chinese room" argument. The scenario with a person in the room would take millions of years at the least to play out, if scaled to match any plausible AI.

Limits on human bandwidth

Along the lines of the "Rules of Thumb" posts:

I won't claim that the internet has changed nothing. It's at least changed how far and how fast news travels, and this has a number of subtle and unsubtle effects. But no matter how fast the network, storage and processors, as long as people are using the web there will be certain hard limits. Some that come to mind:

How much information can a person absorb?

If we're talking about raw sensory input, which appears to be dominated by sight and (to a lesser extent) sound, then my guess is that HD video comes pretty close to the limit. That's on the order of 20Mbit/s, or 10GB/hour, 250GB/day or 100TB/year. I'm taking the MPEG compressed rate as opposed to the raw frame rate as that more closely represents what the visual system is really processing (because successful lossy video compression is finely tuned to the way the visual system works)

Given that disk capacity increases about 100-fold every decade, in ten years one could reasonably afford to buy enough storage to store a fairly immersive audio/video stream that would take a year, 24/7, to watch. Taking time out for things like, um, sleeping and eating, it would probably be more like two or three years.

Conversely, if you wanted to record everything you saw and heard, you could do it for a reasonable -- and decreasing -- annual cost in the not-too-distant future. Anyone could do it, unobtrusively. "Be careful, his bowtie is really a camera".

If you want to boil that raw content to the more abstract images stored in the rest of the brain, there's a pretty well-established medium that covers that reasonably well, though not perfectly: words and pictures. It's trivial now to store all the words a person could reasonably process or produce in a lifetime, or even every mouse click or keypress, timestamped to, say, the nearest millisecond.

A picture on disk is probably worth more like hundreds of thousands of words, but storing tens of thousands of pictures is no big deal these days, either. That's a lot of pictures, if you want to take the time to look a them.

In short, when it comes to words and pictures, the limitation is not what the computer can handle but what the people using it can handle. Audio and video are rapidly approaching the same state.

How many people can a person keep in touch with?

With modern technology, I can now keep in touch with people all over the world, but I can't keep in touch with any more people than I ever could. Somehow the advent of the internet didn't add any new hours to the day. I don't have objective numbers handy on how many people people interact with, though I'm sure there are studies on the subject. At a guess, I'd expect the usual log-normal distribution, with a handful of people accounting for most of a typical person's interactions and maybe a few dozen accounting for almost all of it.

Balancing that is the small world property of social networks and many other structures, including the web itself. In such cases the degree of separation between any two individuals grows very slowly, if at all, as the network expands. In the movie version, there are no more than six degrees of separation between any two people. The actual number (neglecting any groups that really are totally isolated) is probably larger but not much larger. [See these later posts for a bit more on the topic]

How quickly can a group reach consensus?

Whether it's everyone deciding that magenta is the new chartreuse or a deliberative body deciding that the bylaws should be amended to allow for amendments to amendments, the game has probably not changed appreciably in recorded history.

In the mass-consensus case of global pop culture, the scope is bigger, but one of the "small world network" results is that both the average person's view of the social network and the overall structure of the network itself change little as the network grows. In other words, fashions in the malls of the world are driven by the same basic forces as those in, say, Louis XV's France or Julius Caesar's Rome, just on a bigger scale.

In the small-scale case of a deliberative group, the limiting factor is how quickly the members can get the others to understand and (ideally) accept their view of the world. Again, it seems to matter little whether the members are sitting around a campfire or exchanging messages electronically.

I do find it interesting that most of the distributed groups I've been involved with develop a mix of email, live conferencing and face-to-face meetings. Most of the routine stuff can be worked out via email, sometimes you have to pick up the phone and talk to a particular person, and every so often you should all meet. Most of those meetings can be by phone/IRC, but a few of them should have everyone sitting in the same room. It'll be a while yet before technology can completely replace this.