A coder's memoir

kw: book reviews, nonfiction, computer programming, coding, memoirs, philosophy

David Auerbach coded for some twenty years, twelve of that professionally, including a few years each at Microsoft and Google. Now he is apparently more of globetrotting professional speaker. His memoir Bitwise: A Life in Code is less about what coding is—though he doesn't skimp on that—and much more about the ways we are being changed to interact better with computers. It seems that inducing computers to interact as we do has proven just too hard. To this I agree; I've been hearing promises of "Artificial Intelligence" and "Mechanical Brains" for my entire life. Immense breakthroughs are always "just another ten years" away. It will probably always be so!

I almost never include a book's cover in a review, but this time I just couldn't resist showing you this:

I wonder how many readers or even reviewers of this book noticed that the green letters are phosphorescent? Panel 1: white light; Panel 2: UV light turned on; Panel 3: Room lights and UV light off (a little light scattered in from the next room). I noticed this when I had been reading the book in bed, and saw the green glow after turning off the bedside lamp.

In the title, the special characters are from a scripting language I never learned; it has been so long since I saw them that I don't recall which one. The author tells us he first coded in Logo, a coding script that is easy for children to learn; he began using it at age seven. By the time he began getting paid for writing code his language of choice was C++.

When he worked for Microsoft, he spent a period in a behind-the-scenes battle with AOL, modifying code that took advantage of AOL's Messenger Service so that Microsoft IM users could send and receive messages on both platforms, expanding their contact base without everyone having multiple accounts. Later, working for Google, he had various projects, including some of the ongoing tweaks to the Page Rank algorithms. Search Engine Optimization is an attempt to get a page a higher ranking than it might ordinarily merit, by taking advantage of the way Google ranks pages. Some techniques are rather innocuous, but others are rather predatory, and so Google has a number of coders who continually revise the ranking code to flatten the playing field. It is an arms race. It always will be. As a result, the original "Page Rank" method is dramatically out of date.

The author pretty much disposes of the nuts and bolts of his career in the first part of the book. Part II digs around in the differences between the symbols, labels, and names used by humans, and the way labels are assigned in computer code. Every such "tag" we use is invested with meaning to us and by us. Words such as red, blue, orange and magenta have meaning for us. Usually the meanings of colors don't carry much emotional freight. In data, they would just be numbers. (The most common color coding, often called just "rgb" for red-green-blue, assigns the triplet 255,0,0 to the brightest red and 0,0,255 to the brightest blue. Magenta, being an equal mix of red and blue, is stored as 255,0,255). Other words carry much more meaning.

Suppose we have a group of words such as Baha'i, Zoroastrianism, Christianity, and Islam. Since there are a few hundred religious labels (and let's ignore sub-labels such as Baptist or Sunni), in a database, these might just be referred to by numbers such as 12, 497, 44, and 112. To a computer, these are no more meaningful than the color numbers. But to us, they can carry meaning that people fight and die for. Can you imagine a computer giving its "life" in favor of a practice such as water baptism, or the holiness of a shrine in Kyoto? Such things have occurred among humans!

Part III explores further the implications of about 40 years of "home computing" (and, I suppose, 80 years of programmable machinery starting with the Mark I). Twenty years ago I remember talking with a representative of a disk drive manufacturer. He joked that if his company invented a disk with infinite capacity, perhaps called the "god drive", the government would order two of them. I responded, "So would Sears and J.C. Penney". Now that we can buy multi-trillion-byte disk drives for under $100, and both Google and the NSA (and who knows how many others) have warehouses full of disk servers holding billions of times that much, the term "big data" seems rather pale. We are already in an era of "enormous data", with every likelihood that data storage capacities will continue to explode. Not just the government tracks us. So do a multitude of corporations, Google just being the most visible.

In such an environment, what are we, with our little 3-pound brain and its 100-billion-neuron capacity (via a thousand trillion synapses)? Parts II and III of the book show clearly that the dream of genuine human-level AI remains a dream, and a distant one. Each of our neurons exhibits behavior that requires a very fast multicore processor to emulate. That processor may include a few billion transistors, because the neuron is no transistor. So, to duplicate one human brain's activities in real time would require a 100-billion-computer network, attached to one of Google's data warehouses.

Not only that (the author touches on this, but doesn't dwell), our brain is embodied, attached to millions of sensors of many kinds. Just by the way, not long ago I figured out that the human visual cortex weighs as much as the entire brain of a chimpanzee or gorilla. Among mammals, humans have the most powerful visual engine, by far. Thus, we recognize millions of kinds of items, particularly faces, with ease. The facial recognition software Google and others use still regularly mistakes certain hubcaps and clocks for human faces, and entirely misses most faces that are turned more than 45 degrees from face-on.

What has been the result of a couple of generations of ubiquitous computing, and a generation of "social media" interaction? Simply put, we are getting better at doing things to make it easier for computers to "understand" us. This is not entirely by our choice. When FaceBook added more responses to the "Like" button, they added just five. I am still waiting for a Dislike option. "Angry" doesn't usually suffice; it is a different feeling. However, I realize that they are constraining our choices so they won't have, say, 120 possible responses (yes, we do have something more than a hundred kinds of emotional responses). Six will do, thank you so much, said the FB guru. Six is easier to analyze (and to sell to advertisers). So what do I do? I comment at least as much as I "Like" or "Love", etc. Comments are for people, and as far as I am concerned, my FB friends are still people…the last I checked, anyway.

The upshot is that the latter 2/3 of this book provide the best argument I have seen against the prospect of human-level AI for at least a generation, or two or three, if ever. We really need to consider whether it is really what we want, anyway. I built a 40-year coding career on producing computer products that did things that are hard for people but easy for computers, and making the interface work well enough that the people could also do things people do better, sharing the work appropriately with the machine.

I like the philosophical attitude that David Auerbach brings to the subject.  He made me think about a number of things in ways I hadn't thought before. I got a lot more out of this book than I might have had it been more of a chronicle of all the coding projects and languages he'd been involved with. A book to be savored!

Spiders via Spain

kw: blogs, blogging, spider scanning

In the eleventh hour (~2300 EST) yesterday, about 100 hits occurred:

This time they came via Spain. Who knows where they actually originated?

I wonder if blogs that are much more popular are getting even more webspider attention (maybe much more), but the bloggers don't see it among the larger number of genuine hits.

It has also occurred to me that Google runs spidering operations all the time, but they don't need to run spiders against Blogger, do they, since they already know everything we do…

Genetics – Messier than you ever dreamed

kw: book reviews, nonfiction, biographies, short biographies, genetics, domains of life, trees of life, horizontal gene transfer

The Tangled Tree: A Radical New History of Life by David Quammen took me a week to read, and it was a week well spent. From the Acknowledgements section, it apparently took the author four years to research and write, and that was time well spent.

I have read articles and portions of books about the subjects of Tangled Tree, but I hadn't put it all together. One one level it is a biography of the work of Carl Woese. On another it is a record of the tremendous advances in our understanding the breadth of living things and our increasing understanding of just how complex evolutionary history and genetic inheritance really is. Certainly, there is a great deal more to learn.

Triggered by an offhand remark by Francis Crick, early in his career Carl Woese sought to create and to use tools to discern the sequences of chemical units in genetic polymers. He wanted to use genetic material to look deep into time, to find the relatedness of all life and its deep history. He settled on a group of RNA molecules that are strongly conserved and thus ubiquitous in all cells, the 16s RNA unit of the prokaryotic ribosome and the 18s RNA unit of the eukaryotic ribosome. They have the virtue, from this viewpoint, of changing very slowly, so deep relatedness between many organisms can be determined.

The first breakthrough came in 1977, when Woese produced a kind of RNA fingerprint for certain methane-producing microbes. His colleague Ralph Wolfe remembers him saying, "These things aren't even bacteria." Study of several other methanogens confirmed that impression. Then other special microbes were found that were also "not bacteria" and are now grouped with them in this new domain. After a few names were applied and rejected, the new domain of living things is now dubbed Archaea. They differ in several significant ways from Bacteria. Many thought Woese ought to get a Nobel Prize for this discovery. He thought so also; he was never one to even profess humility! Somehow, he didn't get one.

The book presents a tangled web of its own, discussing Woese's many collaborators and students, some of which became opponents, at least in his own mind. By 2000, when the first quasi-complete draft of the sequence of the human genome was presented, molecular biology had advanced so rapidly that Woese never fully understood what was going on, and was kind of left in the dust. The book gently presents his increasing paranoia as discovery after discovery was made by former students and colleagues. A core issue was the shape of the "tree of life".

The family tree of organisms has deep origins, and has been used in more ways than I thought were possible. Darwin included a sketchy tree in The Origin of Species. Trees became expressions of theory and political platforms within the biological community. But such trees got into trouble when certain further developments ensued. Two are key.

Firstly, beginning in 1967, ten years before Woese's discovery of the Archaea, Lynn Margulis (then Sagan) published her first paper about endosymbionts, as they are now called. In brief, these are the mitochondria (energy producing organelles) in all eukaryotic cells, and the chloroplasts (energy conversion—from light plus carbon dioxide to energy plus oxygen—organelles) in plant cells. It took Mrs. Margulis and her colleagues and sympathizers decades to make us all clear that these organelles started out as bacteria that took up residence in slightly larger cells, which then grew even larger, over the eons, and became more and more complex, to become all the Eukaryotes, or critters big enough to see without a microscope (and a great many that are still pretty tiny). You are a Eukaryote. Without a few thousand mitochondria in every cell in your body, you would die. Very fast. Or, rather, you could not exist at all.

A quick aside before going on. I used the work Prokaryote above. It refers to everything that is not a Eukaryote. In particular (so far!), it refers to Bacteria and Archaea, because they don't have a nucleus (the "Kary-" bit refers to the nucleus). Woese hated the term. But it is just too convenient a way to refer to the non-eukaryotic microbes that actually dominate all life on Earth.

Secondly, in the late 1990's, genome sequencing had produced enough data that researchers were able to determine that everywhere they looked (initially only among prokaryotic microbes), they saw DNA sequences that came from other organisms. Horizontal Gene Transfer (HGT) was soon understood to be very common among the Prokaryotes, including across the "domain boundary" between Bacteria and Archaea. Initially, HGT was studied as a mechanism by which pathogens quickly acquire, and share, antibiotic resistance. Now it is understood to be so widespread that some think there is really only one "bacterial species" with a couple of dozen semi-stable forms that we used to call species; and only one "archaean species", similarly. Or maybe they are all just one big mess of microbial soup! Stay tuned…

By the "mid oughts" (prior to 2010), it was becoming clear that Eukaryotes also contain substantial amounts of DNA that were acquired via various mechanisms of HGT. To date, it seems that 8% of human DNA is the complete genomes of hundreds or thousands of retroviruses. Viruses, particularly retroviruses, are one way that HGT operates in Eukaryotes.

There are shorter sequences that are still a puzzle, and many of them tend to be present in multiple copies. One sequence of middling size is apparently found three million times in the DNA of every cell in your body, and mine! Nobody yet knows why, or whether it does anything. If it does do something, it must do a lot of it! Nobody yet knows where they come from, except from "some other critter". The result is a "tree" of life that resembles a web, a network, anything but a tree. It is hard to even use the term "tree of life" in any meaningful way any more.

A typical human body contains about 37 trillion eukaryotic cells, of a few hundred varieties that make up the tissues of the body. That same body is inhabited, without and particularly within, by more than 100 trillion prokaryotic cells, of several thousand "species" of Bacteria and Archaea. They are not just passive. Certain ones enable you to eat certain foods. The prokaryotic "glove" of organisms on our skin actually prevent many pathogens from attaching and attacking us. A similar "glove" lines our digestive tract. There is so much still to learn about all this! One consequence is this: our cells and their nuclei (where the DNA is) are pretty robust, and keep inside and outside separate. But disease and various insults to our body's integrity can allow DNA from outside some of our cells to get inside, and sometimes to be incorporated. That is another variety of HGT.

Carl Woese didn't like his work being eclipsed. He had the misfortune of making a great discovery that was soon just one of many astonishing discoveries, and he sort of got nudged aside. Though he was awarded many prizes and much praised, without a Nobel Prize, it seems he could never be satisfied. Yet he is remembered as a core figure in the great revelations about the way genetics works, that dominated biology in the late 20^th and early 21^st Centuries.

Tragedies that ring the continents

kw: book reviews, nonfiction, climate change, sea level, flooding

I approached Rising: Dispatches from the New American Shore, by Elizabeth Rush, with a skeptical attitude. The book, though filled with stories of people facing tragedy, was actually a pleasant surprise. Ms Rush is a thoughtful, energetic, and compassionate writer. She is definitely not pushing the über-leftist anti-everybody-who-doesn't-agree-with-hyped-climate-propaganda agenda. She visited a lot of people who live along the coasts of the Unites States, particularly those who had recurring flooding problems before "climate change" was "a thing"; she did her best to winkle out the factors that are increasing their suffering; and she tells their stories.

She introduces her subject by describing her first visit to Jacob's Point, Rhode Island, soon after she moved nearby a few years ago. She spoke to long-term residents and others who had know the area and described for her the impact of rising sea level on the marshes. A marsh by the seaside has a way to grow vertically as sediment is brought in by natural processes. Many marsh plants send roots uphill and upwards also, moving away from encroaching salt water. Building a road alongside a marsh blocks this inflow, and gives the migrating root structure nowhere to go. Even without filling a marsh, we can kill it this way.

I knew already, though, that the biggest factor causing "rising sea level" along much of the American coastline, particularly the East Coast, is that the land is sinking. The dissected appearance of the coastline, particularly in New England, is diagnostic of sinking land. Why is it sinking? The technical term is isostasy, or recovery from a past distortion. In this case, the cause is glacial rebound of the northern North American continent because a few miles of ice that were there during the most recent ice age are no longer there. In mid-continent, centered roughly on western Ontario and northern Minnesota, land is rising. How fast? Something less than a centimeter per year, or about 3/4 meter (2.5 ft) per century. Then, why is the land sinking along the East Coast? The ice was a lot thinner there. The ice pushing down the center of the continent caused the edges to rise. Now, as the center rises, the edges are going down.

This doesn't mean that rising global temperatures caused by the the greenhouse effect aren't making the ocean get a little deeper. It just means that this is a minor effect, but it is troublesome because it adds to an existing problem. So let's look at the subject of the first chapter, Isle de Jean Charles, Louisiana. First, images of the area southeast of Houma, including this island community:

These were taken from Google Earth. The panel on the left is from 1990; on the right, from 2015. One must look closely to see that many of the scattered bits of land in the various lagoons that line the southern coast, seen in the 1990 panel, are missing in the 2015 panel. A more prominent feature of both panels is a dark green area...except it has moved over the 25 year span. In 1990, the area north of Isle de Jean Charles was a salt marsh, and looks very dark green. Further to the northwest, west of Chauvin, is what looks like an ordinary piece of coastal land. It was marshy, but upland and more of a fresh water marsh. By 2015, the salt marsh north of Jean Charles is all under water, and the land west of Chauvin is now salt marsh. The difference in water level from one picture to the next is just a couple of feet. That is all it takes.

This picture shows Jean Charles and some surrounding territory, in the same time periods:

In this case, the 1990 imagery at this resolution is grayscale only. But it shows what we need to see: the longish island was significantly larger, and there were more bits of land scattered throughout the bays 25+ years ago. Take note of the small roadway that crossed from left to right in 1990, that had mostly vanished by 2015, and the larger one to its north, that appears impassible now. Prior to 1970 or so, the island had 4-5 times the land area compared to today. I wish I could have located a satellite image from late 2018, after the exceptional hurricane season. In Rising I read that Isle de Jean Charles now hardly exists outside the narrow strip bounded by the levee system. Most of the residents have already moved inland. The residents are native Americans, and have been enabled, financially, to move due to persistent activism by tribal leaders to obtain Federal aid. Prior to the early 2000's, they were ignored by both state and Federal aid agencies.

This is not all passive changes in water level. Higher water means that hurricanes and other storms can wash away more soil, and the channelization of the Mississippi River over the past century has resulted in very little replenishment. This area is part of the river's delta system. It is worth noting just a few things. The major problem in the area, climate or not, is the channelization of the Mississippi River, that cut off sediment replenishment; secondarily, there is subsidence that every delta system experiences as soil slowly compacts due to gravity pressing out water that it contained when it was first deposited.

All around the US, the author tells of her visits to places in Maine, Staten Island, both northern and southern Florida, and the San Francisco Bay. In some places, the land is subsiding due to compaction, as in Louisiana and S.F. Bay; in others such as Maine, glacial rebound is dragging the land underwater, a few inches per decade. In all these areas, however, governmental inaction coupled with over-development has been the greatest and most tragic force behind the destruction of coastal wetlands and the coastal landscape in general. Two stories of human blindness and greed known to me come to mind:

1) The Rapid City Flood of 1972.

When South Dakota was first settled, by people came in wagon trains up the flood plain in the valley of Rapid Creek. They took note of debris in the trees partway up the valley walls. When they were ready to stop for the night, they would carry everything of value, particularly food, and drive the animals, up to terraces and ledges above this flood line. When they settled Rapid City, they settled on those terraces, which are geomorphological remnants of earlier levels of the flood plain in the distant past. I lived in a house on such a terrace from 1982-86. It is 50 feet above the flood plain.

Later residents with less wisdom built homes and businesses further down, some even right on the flood plain. They installed a "flood control basin", Canyon Lake, upstream. It was designed inadequately, and a big rainstorm that dropped 11 inches of rain in 12 hours caused the flood control dam to burst. Water coursed through the town, destroying hundreds of homes and businesses, killing more than 270 people, and stacking up automobiles from a few car lots like clams on a shelly beach, downstream of town.

When we moved to Rapid City in 1978, areas on the flood plain outside town (now the town had laws against building on the flood plain within city limits) had already been rebuilt with mobile home developments. They are sitting in the crosshairs of the next flood.

2) Newport Beach "view homes", throughout the Twentieth Century.

I was taking an Engineering Geology course in 1971, and we learned about landslides and other earth-engineering matters. The professor, Dr. Martin Stout, is a person I greatly admire. He showed us the sand hills of Newport Beach, and described this scenario:

• An early developer noticed that these hillsides had a great view of the ocean.
• The development company persuaded the city or county government to issue permits to build ocean view homes.
• To get the best view, on each rather steep lot, a cut was made to flatten the land, and the sandy dirt so removed was dumped and leveled so as to extend the flat area beach-ward.
• Each home was built mostly out on this fill dirt, sometimes with pillars installed into the soil to "stabilize" it.
• On such a hillside (there were several), a few dozen such houses were built, sold, and occupied by people who love an ocean view and will pay for the privilege.
• Things rock along fine for a few years.
• An extra-rainy season occurs. The sandy soil gets soft and the houses start falling down, each into the back yard of the one below.
• The homeowners below sue the owners of the homes now in their back yard, for trespass or whatever their lawyer suggests.
• The city or county steps in, condemns all the dwellings involved, and has the homes bulldozed. 
• The land is graded back to an even hillside. Ground cover plants are planted.
• Five to ten years pass. Everyone on the city council or county council that currently has jurisdiction has been replaced with "new faces."
• A development company persuades them to issue permits to build ocean view homes.

On some of these hills, this had happened three times by 1971. When people are this shortsighted, how much hand-holding can we do? And there weren't even any hurricanes!

Genuine sea level change is real, but it is not happening nearly as rapidly as the natural cycles I've mentioned, such as glacial rebound and subsoil compaction. Governmental regulations of the past actually made things worse for people who received aid to deal with a flooded house: They were required to use the money to rebuild the house exactly where it stood before. Only recently have rules in some places been changed to allow people to take their payout and move further uphill or inland to rebuild there.

Here is the actual magnitude of climatic sea level change: 

• Sea water has a moderate coefficient of volumetric thermal expansion, approximately 0.00025 for temperatures between 0°C and 5°C, the temperature of the oceans deeper than a few tens of meters.
• Unlike fresh water, sea water does not get less dense in the lower degree or two before it freezes. It keeps getting more dense.
• The average depth of the oceans is about 3,700 m.
• Multiply this by 0.00025, to get 0.925. That means, if the entire ocean becomes one degree warmer (Celsius), it will get nearly one meter deeper.
• The best figure I can find is that the average ocean temperature has risen 0.2°C in the past century. That means the oceans are 0.185 m (about 7 inches) deeper due to thermal expansion.

The wild card is melting of ice caps. Contrary to what many vocal critics worry about, melting of the the Arctic ice cap cannot contribute to sea level rise because that ice is floating already. The major ice cap that can cause trouble is Antarctica. If it all melts, the seas will get roughly 60m deeper, or 200 feet. That would be catastrophic. The secondary ice cap is Greenland. It has about a tenth as much ice, so melting it entirely would mean a 6m, or 20 ft, rise in the oceans. Less catastrophic, but still catastrophic. I cannot find a good estimate of how many people would be displaced by a 6m rise; the reports are all over the place. It is somewhere between 1/20 and 1/5 of the human race, between 400 million and 1.5 billion.

I have no way to know how likely this is. There was a report just this week that the deep ocean is actually cooling, due to delayed effects of the "Little Ice Age" of the 1700's and early 1800's. Some portions of the Antarctic ice cap are also being strengthened rather than weakened, as this cold pulse works its way down through the miles of ice. But other portions of both Antarctica and Greenland are softening.

What is Ms Rush's conclusion? Humans are to blame for the human tragedies, it is true. But local matters are bigger and more damaging than global effects. It is hard for people to think in terms of centuries, or to plan for the ages. She writes of a "five generation window": most of us knew our grandparents and we may know their stories, and we expect to know our grandchildren and tell them our stories, and maybe some of our own grandparents' stories also. For most of us, that is about a one-century window. But we see evidence everywhere that most decision makers do not plan beyond their next promotion, or the next election, or sometimes the next paycheck. At least 1/3 of Americans have less than $5,000 in any kind of retirement savings account, and 1/5 of them have nothing...zero. zip, nada. I can understand for the 12% that live below the "poverty line", saving isn't feasible. But for the rest, who could save but don't, their "golden years"...not so golden.

We need a national consciousness like the wisdom of the people in those wagon trains, looking for signs of old floods to inform them of safe places to spend the night or locate their new homes.

A lot of things time isn't

kw: book reviews, nonfiction, physics, time

Just over two years ago I reviewed an earlier book by Carlo Rovelli, Seven Lessons On Physics. That was a fun and interesting read, so I was happy to find a new book of his, The Order of Time. It is equally fun and interesting.

Let's first get to the bottom line: Nobody yet knows just what time IS. So of necessity, a lot of this book is about things that time is NOT. Understanding how time works, and perhaps to approach knowing what it is, constitutes Dr. Rovelli's life's work.

Now that we can make comparatively affordable (cheaper than an automobile) instruments that "measure time" to incredible accuracy, it is possible to obtain two of them, place one on the tabletop, and the other on the floor…Then, within perhaps a half hour, the one on the tabletop will show a slight positive difference in "what time it is", to the nearest picosecond or so. You can then switch their places. After a while, the one that is now on the tabletop will have caught up with the other, that is now running slower, and then will pass it by, so to speak. Why? The force of gravity is just a tiny bit greater at floor level than at tabletop level, and gravity slows time.

You can also take one of the "clocks" for a joyride, and when you return, it will have recorded the passage of a little less time than the one that remained behind. Motion slows time.

While we are at it, the equivalence of gravity and acceleration that underpins the General Theory of Relativity by Einstein indicates that acceleration also slows time. It's a bit harder to measure, since we don't have a simple way to divorce acceleration from velocity of motion. Even driving around with a hyper-precise clock, we don't know how to distinguish the change in what it measures that is due to the acceleration from that which is due to the speed(s) traveled.

The fact that time flows differently because of one's velocity, and one's position relative to a large mass, results in the necessity for the satellites used in the GPS system to correct the time their very precise clocks record. Otherwise, in just a day, your navigation device would be misplacing your calculated location by a few kilometers. These corrections, for both the speed of the satellite and its elevation (~22,000 km) above Earth, are sufficiently accurate that your device can know its location within a 5-to-10-meter radius, and a military-grade (and much more costly) device can determine its location within a centimeter or so. The radio signals that the satellites send travel about a foot (0.3m) in a nanosecond. Centimeter-level precision implies time accuracy of ~10 picoseconds, or trillionths of a second.

Back to the book. We have a number of practical and customary definitions of time, that allow us to go about our day-to-day work. Part I of the book draws us to realize that, to a physicist, time is changeable. Physics equations that include time and rate terms work in either direction. There is no "past", "future", or "present". Even the notion of Entropy, which is a physicist's description of the direction of time, is actually based on the "blurring" of our perceptions.

We may think we have pretty sharp vision. Indeed, since our visual cortex is nearly as large as the entire brain of a chimpanzee, our general vision is better than any other animal's (the very acute vision of a hawk is in a very small part of the bird's visual field). But how sharp is sharp? Human visual acuity ranges from 1/20 to 1/60 of a degree of arc. That means, if you hold something in your hand at "reading distance" of about 16 inches (40 cm), you'll be able to distinguish features on its surface as small as 1/60 inch, or perhaps 1/200 inch apart (0.4 to 0.13 mm). But we know we need a microscope to see "small stuff" like pollen grains (10-100 times smaller) or bacteria (even smaller). Special microscopes are needed to "see" atoms, which are smaller than a millionth of a millimeter.

So, we cannot see the molecules moving in a glass of water, but their motion gives the water its temperature. What we measure as a temperature of, say 20°C or 68°F, represents a certain average velocity of the molecules in the water. We don't see that. But the basic concept of entropy can be considered this way: moving energy through a system tends to make it less ordered. Thus, ice is very ordered, because the water molecules are in fixed relationships to one another. When ice melts, the molecules come "unglued" and can move about. Even a small glass of water contains, not just millions or billions, but billions of trillions of them. So there are a lot of ways for those molecules to be arranged, but they all look the same to us. In the glass full of ice, there was only one arrangement. We can't distinguish the motion; to us the glass of water just sits there. That is the blurring of our perception.

In the second part of the book the author describes a world without time; where there are no "things", just events. Not only do you and I not understand this, neither does he. Some very smart scientists have developed mathematical formulas that describe events with no time element. That doesn't mean we have any way to experience utter timelessness.

In Part III, he claims that "Time is Ignorance" (a chapter title). We can say that "Time is nature's way of keeping everything from happening at once", or "Time is a dimension" (as Relativity states). Whatever time "really is", we have our perceptions, which include a flow and direction of time, because that's what we need to survive. We evolved to perceive successions of events as time. We are pretty far from really knowing much more than that.

The spiders continue

kw: blogs, blogging, spider scanning

Just a couple of days ago I remarked on a different tack being taken by a spider scanning operation in Russia. They are continuing:


A closeup look at that last spike, containing 19 hits, shows that 11 of them came within one minute, and 8 of them in the minute following. So it is not someone typing! A spike of ~20-40 hits that take a minute or so to accomplish happens every hour or two.


Anyway, the 200 or so hits not from Russia, plus perhaps 7-10 from Russia (Google only shows top ten), constitute normal traffic to this blog.