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Discussion of the Essence# programming language, and related issues and technologies.

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2006-12-31

Chronos 101: "Points" in Time`

It is common to imagine that a point in time is a precise instant in time, based on the idea that a number line is the optimal mathematical model of time, and based on the idea that an instant is a dimensionless point whose location on the number line can be specified as a real number. In practice, however, the "real number line" model of time does not pass muster.

One problem is that the physics of time does not correspond to the real-number line model, because time is quantized: There is a minimum possible measurable length of time, known as the Planck Time, and also a minimum possible measurable amount of distance and of mass, known respectively as the Planck Length and the Planck Mass.

Another problem is that, in practice, we can't measure durations of time to anywhere near a Plank-time level of precision. Few are those with access to a clock that can measure durations of time with even nanosecond precision--and even that's a billion times less precise than the highest precision time duration measurement we've been able to achieve up to now (2006,) and 10^37 times less precise than a Planck Time.

Generally, physical measurements are not infinitely precise. There are usually "error bars" that prevent the "data points" collected by measurement devices from truly being dimensionless "points." This certainly applies to the measurement of time durations. There is little to be gained from pretending otherwise.

And then there's the problem of clock synchronization. Even without considering the fact that General Relativity prevents the concept of simultaneity among a set of events from having any absolute reality or well-defined physical meaning, clocks simply cannot be perfectly synchronized. Even if clocks existed that could timestamp events with infinite precision, no two of those clocks would ever agree as to the precise timestamp of any one event (to infinite precision.) If each clock that timestamps an event (with infinite precision) provides a slightly different time value, which one is correct?

Also, even if durations of time could physically (and not just conceptually) have infinitesimal extent, it would nevertheless not be possible to specify most "points" in time with infinite precision (the exception being those whose location on the timeline happens to be expressible as a rational number.) You can't physically write out a number with an infinite number of digits, nor store such a number in computer memory. The number must be rounded or truncated.

Considering all the points above, it should therefore be clear that any specification or measurement of a "point" in time (as a coordinate on a number line, expressed as a real number) is necessarily an approximation, even without considering the issues of quantization, quantum uncertainty and General Relativity.

In spite of the foregoing problems and issues, we humans insist on measuring time using discrete, countable durations of time. We like to pretend that each event can be timestamped at a precise instant, and so unambiguously placed in a particular second, minute, hour, day, month and year. There's nothing wrong with that, provided we understand that physical law limits us to approximations valid only to some finite limit of precision.

Consequently, Chronos represents "points" in time to some specified resolution, because physical law prevents "time points" from actually being dimensionless points on a timeline. Chronos does not recognize nor attempt to support what most would conceive of as "instants" in time. Rather, a Chronos point-in-time value specifies the initial instant of some interval of time whose duration is no smaller than the resolution of the internal numeric representation. So Chronos points-in-time are not dimensionless points, but rather intervals of time.

Note that the model of time used by Chronos means that there are no gaps in the Chronos timeline. Chronos thus avoids the problem that occurs in the model of time typically adopted by other date/time libraries, which can only represent some of the points on their limeline, and leave most of the points on the line unspecifiable (so that, in effect, they have to translate most timepoints up or down to the nearest point-in-time representable by the internal implementation of their date/time values.) Of course, in practice the result is the same. But the "dimensionless point" model of points-in-time often leads to strange architectural and design decisions that are not well-motivated, and can even cause suboptimal code.

Currently, Chronos provides three different classes that implement the concept of a "point in time." One is the class YearMonthDay, which has a resolution of one calendar day--which means both that its temporal extent is one day, and also that the minimal (non-zero) difference between any two instances of YearMonthDay is one day. The second one is the class Timepoint, which has a resolution of one nanosecond--which means both that its temporal extent is one nanosecond, and also that the minimal (non-zero) difference between any two instances of Timepoint is one nanosecond. The last one is the class InfiniteTimepoint, whose two instances represent either the infinite past ("InfiniteTimepoint past") or the infinite future ("InfiniteTimepoint future.") InfiniteTimepoints have infinite duration.

So a Chronos "date" (instance of YearMonthDay) is simply a point in time whose resolution (and temporal extent) is one calendar day. And since the only difference between a YearMonthDay and a Timepoint is the representational resolution, there is no reason that they both cannot be mostly type compatible (which, in fact, they are.)

There are also two other fundamental types of time values supported by Chronos: Durations of time (temporal extents) and periods of time (temporal intervals.) A time duration has a length of time, but has no location on the timeline (e.g., "one day," "fifty years," "3 minutes 20.3989 seconds.") A time interval has both a starting point-in-time (a location on the time lime, to some limit of resolution) and a duration (whose extent can be any durational value, not just "day" and "nanosecond"; for example "the time interval starting at 2006-12-22T03:13:06.325914 and lasting for 15 days, 12 hours, 19 minutes and 23.43557 seconds.")

Chronos provides several classes that implement durational values, and the class Timeperiod that implements time intervals.

Part 2: Chronos 101: Durational Values


Happy (Gregorian) New Year

2007-01-01 AD [Gregorian]
0163-16-02 BE [Bahai]
1723-04-23 AM [Coptic]
1999-04-23 ZH [Ethiopic]
5767-10-11 AM [Hebrew]
1928-10-11 AS [Indian Civil]
1427-12-11 AH [Islamic (Fatimid)]
2006-12-19 AD [Julian]
2759-12-19 AUC [Julian (Imperial)]
1385-10-11 AP [Persian]
6243-01-11 SY [Solarian]
2007-001 [Gregorian-ordinal date]
2007-W01-1 [ISO]

Mon, 01 Jan 2007 13:00:00 +1300 (NZDT: Pacific/Auckland | New Zealand Time)
Mon, 01 Jan 2007 11:00:00 +1100 (EST: Australia/Sydney | AUS Eastern Time)
Mon, 01 Jan 2007 09:00:00 +0900 (JST: Asia/Tokyo | Tokyo Time)
Mon, 01 Jan 2007 09:00:00 +0900 (WST: Australia/Perth | W. Australia Time)
Mon, 01 Jan 2007 08:00:00 +0800 (HKT: Asia/Hong_Kong)
Mon, 01 Jan 2007 05:30:00 +0530 (IST: Asia/Calcutta | India Time)
Mon, 01 Jan 2007 03:00:00 +0300 (MSK: Europe/Moscow | Russian Time)
Mon, 01 Jan 2007 02:00:00 +0200 (IST: Asia/Jerusalem | Israel Time)
Mon, 01 Jan 2007 01:00:00 +0100 (CET: Europe/Amsterdam)
Mon, 01 Jan 2007 00:00:00 +0000 (GMT: Europe/London | London Time)
Mon, 01 Jan 2007 00:00:00 +0000 (UT: Universal Time)
Sun, 31 Dec 2006 22:00:00 -0200 (BRST: America/Sao_Paulo | E. South America Time)
Sun, 31 Dec 2006 21:00:00 -0300 (ART: America/Argentina/Buenos_Aires)
Sun, 31 Dec 2006 19:00:00 -0500 (EST: America/New_York | Eastern Time)
Sun, 31 Dec 2006 18:00:00 -0600 (CST: America/Chicago | Central Time)
Sun, 31 Dec 2006 17:00:00 -0700 (MST: America/Denver | Mountain Time)
Sun, 31 Dec 2006 16:00:00 -0800 (PST: America/Los_Angeles | Pacific Time)
Sun, 31 Dec 2006 14:00:00 -1000 (HST: Pacific/Honolulu | Hawaiian Time)


2006-12-24

Merry Christmas

(At the time of this post, it's already Christmas in the Far East)

2006-12-25 AD [Gregorian]
0163-15-14 BE [Bahai]
1723-04-16 AM [Coptic]
1999-04-16 ZH [Ethiopic]
5767-10-04 AM [Hebrew]
1928-10-04 AS [Indian Civil]
1427-12-04 AH [Islamic (Fatimid)]
2006-12-12 AD [Julian]
2759-12-12 AUC [Julian (Imperial)]
1385-10-04 AP [Persian]
6243-01-04 SY [Solarian]
2006-359 [Gregorian-ordinal date]
2006-W52-1 [ISO]
J.D. 2454095 [Julian Day]
Christmas

Mon, 25 Dec 2006 13:00:00 +1300 (NZDT: Pacific/Auckland | New Zealand Time)
Mon, 25 Dec 2006 11:00:00 +1100 (EST: Australia/Sydney | AUS Eastern Time)
Mon, 25 Dec 2006 09:00:00 +0900 (JST: Asia/Tokyo | Tokyo Time)
Mon, 25 Dec 2006 09:00:00 +0900 (WST: Australia/Perth | W. Australia Time)
Mon, 25 Dec 2006 08:00:00 +0800 (HKT: Asia/Hong_Kong)
Mon, 25 Dec 2006 05:30:00 +0530 (IST: Asia/Calcutta | India Time)
Mon, 25 Dec 2006 03:00:00 +0300 (MSK: Europe/Moscow | Russian Time)
Mon, 25 Dec 2006 02:00:00 +0200 (IST: Asia/Jerusalem | Israel Time)
Mon, 25 Dec 2006 01:00:00 +0100 (CET: Europe/Amsterdam)
Mon, 25 Dec 2006 00:00:00 +0000 (GMT: Europe/London | London Time)
Mon, 25 Dec 2006 00:00:00 +0000 (UT: Universal Time)
Sun, 24 Dec 2006 22:00:00 -0200 (BRST: America/Sao_Paulo | E. South America Time)
Sun, 24 Dec 2006 21:00:00 -0300 (ART: America/Argentina/Buenos_Aires)
Sun, 24 Dec 2006 19:00:00 -0500 (EST: America/New_York | Eastern Time)
Sun, 24 Dec 2006 18:00:00 -0600 (CST: America/Chicago | Central Time)
Sun, 24 Dec 2006 17:00:00 -0700 (MST: America/Denver | Mountain Time)
Sun, 24 Dec 2006 16:00:00 -0800 (PST: America/Los_Angeles | Pacific Time)
Sun, 24 Dec 2006 14:00:00 -1000 (HST: Pacific/Honolulu | Hawaiian Time)


2006-12-23

Buildup of damaged DNA in cells drives aging


Buildup of damaged DNA in cells drives aging from PhysOrg.com

The accumulation of genetic damage in our cells is a major contributor to how we age, according to a study being published today in the journal Nature by an international group of researchers. The study found that mice completely lacking a critical gene for repairing damaged DNA grow old rapidly and have physical, genetic and hormonal profiles very similar to mice that grow old naturally.

[...]




2006-12-15

Taking nanolithography beyond semiconductors


Taking nanolithography beyond semiconductors from PhysOrg.com

A new process for chemical patterning combines molecular self-assembly with traditional lithography to create multifunctional surfaces in precise patterns at the molecular level. The process allows scientists to create surfaces with varied chemical functionalities and promises to extend lithography to applications beyond traditional semiconductors.

[...]




2006-12-09

Chemists create 'nanorobotic' arm to operate within DNA sequence


Chemists create 'nanorobotic' arm to operate within DNA sequence from PhysOrg.com

New York University chemistry professor Nadrian C. Seeman and his graduate student Baoquan Ding have developed a DNA cassette through which a nanomechanical device can be inserted and function within a DNA array, allowing for the motion of a nanorobotic arm. The results, reported in the latest issue of the journal Science, mark the first time scientists have been able to employ a functional nanotechnology device within a DNA array.

[...]




2006-12-06

CSIRO demonstrates world's fastest wireless link


CSIRO demonstrates world's fastest wireless link from PhysOrg.com

The CSIRO ICT Centre today announced that it has achieved over six gigabits per second over a point to point wireless connection with the highest efficiency (2.4bits/s/Hz) ever achieved for such a system.

[...]




Breakthrough in magnetic devices could make computers much more powerful


Breakthrough in magnetic devices could make computers much more powerful from PhysOrg.com

Scientists have created novel ‘spintronic’ devices that could point the way for the next generation of more powerful and permanent data storage chips in computers. Physicist at the Universities of Bath, Bristol and Leeds have discovered a way to precisely control the pattern of magnetic fields in thin magnetic films, which can be used to store information.

[...]




2006-12-05

New Chip Provides High-End Sound


New Chip Provides High-End Sound from PhysOrg.com

(AP) -- Veteran audio engineer Tony Bongiovi, who once worked with Jimi Hendrix, has been disappointed for decades that the equipment most people used to listen to music couldn't replicate the high-quality sound heard in the studio.

[...]




2006-11-30

Strontium atomic clock demonstrates super-fine 'ticks'


Strontium atomic clock demonstrates super-fine 'ticks' from PhysOrg.com

Using an ultra-stable laser to manipulate strontium atoms trapped in a "lattice" made of light, scientists at JILA have demonstrated the capability to produce the most precise "ticks" ever recorded in an optical atomic clock—techniques that may be useful in time keeping, precision measurements of high frequencies, and quantum computers using neutral atoms as bits of information.

[...]




2006-11-08

New sequential decision making model could be key to artificial intelligence


New sequential decision making model could be key to artificial intelligence from PhysOrg.com

“Decision making,” Mikhail Rabinovich tells PhysOrg.com, “is everywhere, and not just with humans. Animals use it, and robots do. But the traditional approach to decision making is too simple.”

[...]





2006-10-16

New motor first to be powered by living bacteria


New motor first to be powered by living bacteria from PhysOrg.com

A new motor designed by scientists from Japan offers the best of both worlds: the living and the non-living. The group built a hybrid micromachine that is powered by gliding bacteria which travels on an inorganic silicon track and pushes a silicon dioxide rotor. The combination takes advantage of the precise engineering of synthetic devices along with the efficient energy conversion and potential for self-repair of biological systems.

[...]




New Quantum Technology Controls Molecules


New Quantum Technology Controls Molecules from PhysOrg.com

A research team at the National Research Council Canada (Ottawa) has developed a new quantum technology which uses laser pulses to control quantum processes. The method, which is described in the October 13th web release by the world's leading scientific journal, Science, was illustrated by changing the outcome a chemical reaction.

[...]




2006-10-13

Scientists make atomic clock breakthrough


Scientists make atomic clock breakthrough from PhysOrg.com

University of Nevada, Reno researchers Andrei Derevianko, Kyle Beloy, and Ulyana Safronova sat down six months ago and began work on a calculation that will help the world keep better time.

[...]




2006-09-30

Entanglement unties a tough quantum computing problem


Entanglement unties a tough quantum computing problem from PhysOrg.com

Error correction coding is a fundamental process that underlies all of information science, but the task of adapting classical codes to quantum computing has long bumped up against what seemed to be a fundamental limitation.

[...]




2006-09-28

Powerful Batteries That Assemble Themselves

The article Powerful Batteries That Assemble Themselves (MIT Technology Review) discusses a research project that has been using "viruses to assemble battery components that can store three times as much energy as traditional materials by packing highly ordered materials into a very small space."

The author of the article apparently believes that the major portent of this research is improved functionality of batteries. I strongly disagree.

It's not that better batteries aren't important. It's just that the ability to manufacture materials, substances, medicines, devices, tools and other artifacts using controlled molecular assembly is far more important. And the existence proof that viruses can be used to do controlled molecular assembly, at least in some cases, is a very significant milestone in the evolotion of human technical abilities. Compared to that, better batteries are a footnote.


2006-09-26

55,000 tiny Thomas Jeffersons show power of new method


55,000 tiny Thomas Jeffersons show power of new method from PhysOrg.com

Ever since the invention of the first scanning probe microscope in 1981, researchers have believed the powerful tool would someday be used for the nanofabrication and nanopatterning of surfaces in a molecule-by-molecule, bottom-up fashion. Despite 25 years of research in this area, the world has hit a brick wall in developing a technique with commercial potential -- until now.

[...]




2006-09-24

Engine on a chip promises to best the battery

Engine on a chip promises to best the battery from PhysOrg.com

MIT researchers are putting a tiny gas-turbine engine inside a silicon chip about the size of a quarter. The resulting device could run 10 times longer than a battery of the same weight can, powering laptops, cell phones, radios and other electronic devices.

[...]




2006-09-18

Julian Day 2,454,000

At noon of 21 September 2006 begins Julian Day Number 2,454,000. A day and a half later, the Autumnal Equinox will occur (2006-09-23T04:03 Universal Time.)

The Hebrew New Year starts at sundown on 22 September (a.k.a Rosh Hoshana.) Note that the first month of the Hebrew year is traditionally known as the seventh month, not the first month.

Julian Day Numbers are an integer count of days since a specific epoch date. Julian Day Zero begins at Noon on 14 November 4714 BC, according to the proleptic Gregorian Calendar--or at Noon on 1 January 4713 BC, according to the proleptic Julian Calendar. Julian Day Zero was a Monday.

A Julian Date is a count of days, including any fractional part of the day, since -4713-11-24T12:00:00+0000 (24 Nov -4713 12:00:00 Universal Time, using Astronomical year numbering, where the year prior to the year 0001 is the year 0000, and not the year 1 BC, as would be traditional.)

It is common, but nevertheless technically incorrect, to refer to an ordinal date (Year-DayOfYear) as a "Julian Date."

Using a Julian Day Number to specify a date, or a Julian Date to specify a precise point in time, is useful for two reasons:

1) It permits dates to specified without reference to any particular calendrical system; and

2) It vastly simplifies astronomical calculations, and other computations where the amount of time between two dates needs to be computed.

The Julian Day system of specifying dates was invented by the astronomer Joseph Scaliger in 1583 (the year after the Gregorian Calendar Reform was put into effect in the Catholic countries of Europe.)

The epoch day of the Julian Day system was chosen to be the most recent day on which three calendrical cycles all were at their respective zero points. The three cycles are the 15-year Indiction Cycle (important in Roman tax law,) the 19-year Metonic Cycle (important for obtaining approximate synchronization of lunar and solar calendars,) and the 28-year Solar Cycle (all possible patterns of Julian Calendar dates and days-of-the-week recur once every 28 years.)

The "Julian" in "Julian Day" refers to Scaliger's father, and not to either Julius Caesar or to the Julian Calendar.

Julian Day 2,454,000 corresponds to the following dates in selected calendars (as computed by the Chronos Date/Time Library):

2006-09-21 AD [Gregorian]
0163-10-14 BE [Bahai]
1723-01-11 AM [Coptic]
1999-01-11 ZH [Ethiopic]
5766-06-28 AM [Hebrew]
1928-06-30 AS [Indian Civil]
1427-08-27 AH [Islamic (Fatimid)]
2006-09-08 AD [Julian]
2759-09-08 AUC [Julian (Imperial)]
1385-06-30 AP [Persian]
6242-09-30 SY [Solarian]
2006-264 [Gregorian-ordinal date]
2006-W38-4 [ISO]
J.D. 2454000 [Julian Day]
732574 days since Gregorian Epoch (1 January 0001 AD)
38614:00:00:00 days:hh:mm:ss.s.. since 1901-01-01T00:00:00Z (ST80 epoch)
1158796800 seconds since 1970-01-01T00:00:00Z (Unix epoch)
128032704000000000 100-nanosecond ticks since 1601-01-01T00:00:00Z (MS WIndows epoch)


Studies Find General Mechanism of Cellular Aging

According to the article Studies Find General Mechanism of Cellular Aging (Physorg.com,) "three separate studies confirm a gene that suppresses tumor cell growth also plays a key role in aging."

The studies found that as the concentration(hence, the rate of gene expression) of the protein p16INK4a in a stem cell increases, the more the stem cell has the characteristics and behaviors of senescence (being aged.) Stem cells lose their ability to divide and replenish themselves as they age, and this loss of function was proven to be a result of the increased expression of the p16INK4a gene.

The implications are that a) aging-related diseases are the result of an ever-increasing inability of stem cells to replenish tissue, and b) since upregulation of a single gene is the culprit, it may be easier than is commonly imagined to develop anti-aging therapies that have dramatic effects (even if they don't provide a total "cure" for aging.)


Version 2006k of the Chronos Time Zone Repository has been published

Arthur David Olson has published version 2006k of the Olson Time Zone Database. Consequently, version 2006k of the Chronos Time Zone Repository has been published--both the Chronos-native and XML versions are available from date-time-zone.com.


2006-09-15

Scientists Discover Memory Molecule

The Science Daily article Scientists Discover Memory Molecule discusses the discovery of a molecule, the enzyme protein kinase M zeta, that preserves long-term memories through persistent strengthening of synaptic connections between neurons. Memories can be erased by inhibiting the enzyme.

This discovery elevates from theory to fact the idea that long term memory is realized in the relative strengths of synaptic connections. Incidently, it also elevates from theory to fact the idea that memories are physically stored in neurons, as opposed to any non-physical explanation.

So now we know what molecular structures must survice cyronic suspension, and/or what molecular structures must be reconstructed when reviving cryonic suspension patients, in order for cryonic suspension/reanimation to preserve memory.


2006-09-09

Atomic Clocks Are Getting More Precise


Atomic Clocks Are Getting More Precise from PhysOrg.com

(AP) -- Some physicists are creating a revolution in the arcane world of ultra-precise clocks. And among them is a researcher who has trouble getting anywhere on time. "I do tend to be a little bit late," said Jim Bergquist, 58. "Quite a bit late."

[...]




2006-08-31

Chronos Version B1.174 Published

Chronos Version B1.174 has been publised ("Beta Release 1--build 174".) Chronos B1.174 is available for VisualWorks, Squeak and Dolphin. The Chronos Seed Archive for B1.174 is also available (the "Chronos Seed" is the platform-independent Chronos codebase, used for porting Chronos from VisualWorks to other Smalltalk pltatforms.)

Chronos Version B1.174 can be obtained from the Chronos Web Site. The VisualWorks version can also be obtained from the Cincom Public StORE Repository. You may also use the direct download link for VisualWorks, the direct download link for Squeak or the direct download link for Dolphin.

The Chronos Time Zone Repository is included in the download archive. Be sure to follow the Chronos Installation Instructions--especially if you have not already done so for a previous version of Chronos.

If you are reinstalling Chronos into an image in which an earlier version is already resident, and do not install the new version from the Cincom Public StORE Repository using StORE, it is necessary to first remove the earlier version. StORE has been able to correctly install the new version on top of every earlier version I have tried--but I haven't tried them all.

About Chronos Version B1.174


Chronos Version B1.174 corrects the list of dates on which the NYSE was closed, based on more authoritative information.

The Squeak version was modified to address changes to the base libraries that have been made in Squeak 3.9. A few Chronos methods are now added programmatically (and conditionally) to base library classes, instead of being a static part of the file-in.



Version 2006j of the Chronos Time Zone Repository Published

Arthur David Olson published version 2006j of the Olson Time Zone Database. Consequently, version 2006j of the Chronos Time Zone Repository has been published--both the Chronos-native and XML versions are available from date-time-zone.com.


2006-08-20

128000000000000000

Microsoft NT counts time as the number of 100-nanosecond ticks since 1601-01-01T00:00:00Z (1 January 1601 00:00:00 Universal Time.) I just happened to notice that the NT clock struck 128000000000000000 a few days ago, specifically at 2006-08-14T03:33:20+00:00 (14 August 2006 03:33:20 Universal Time.)

You can easily compute that using the following Chronos code:


ChronosFunction
daysAndSecondsSinceStartOfDayFromSeconds: 128000000000000000 // 10000000
into: [:days :seconds |
Timepoint
daysSinceEpoch: days + (YearMonthDay year: 1601 day: 1) daysSinceEpoch
seconds: seconds
timeZone: #UT]


If you'd prefer to have the result computed relative to your local time zone, use the following variation:


ChronosFunction
daysAndSecondsSinceStartOfDayFromSeconds: 128000000000000000 // 10000000
into: [:days :seconds |
Timepoint
utDaysSinceEpoch: days + (YearMonthDay year: 1601 day: 1) daysSinceEpoch
seconds: seconds]


2006-08-10

New light microscope sharpens scientists' focus


New light microscope sharpens scientists' focus from PhysOrg.com

A new light microscope so powerful that it allows scientists peering inside cells to discern the precise location of nearly each individual protein they are studying has been developed and successfully demonstrated by scientists at the Howard Hughes Medical Institute's Janelia Farm Research Campus in collaboration with researchers at the National Institutes of Health and Florida State University.

[...]




New method of growing carbon nanotubes to revolutionise electronics


New method of growing carbon nanotubes to revolutionise electronics from PhysOrg.com

A new method of growing carbon nanotubes is predicted to revolutionise the implementation of nanotechnology and the future of electronics. Researchers at the University of Cambridge have successfully grown nanotubes at a temperature which permits their full integration into present complementary metal-oxide semiconductor (CMOS) technology (350 ºC).

[...]




A Beautiful Working Environment

I recently purchased my first digital camera. Today I used it to take some photos of my employer's campus. I've been wanting to do that for years. To understand why, just have a look at the photos:

CIMG0169
CIMG0185
CIMG0186
CIMG0182
CIMG0179


2006-08-01

Visualising invisibility


Visualising invisibility from PhysOrg.com

Invisibility has been an ingredient of myths, novels and films for millennia – from Perseus versus Medusa in Greek legend to James Bond’s latest car and Harry Potter’s cloak. A new study published today by the Institute of Physics reveals that invisibility is closer than we think.

[...]




2006-07-31

Scientists Test Anti-obesity Vaccine


Scientists Test Anti-obesity Vaccine from PhysOrg.com

In what may be the first published breakthrough of its kind in the global battle against obesity, scientists at The Scripps Research Institute have developed an anti-obesity vaccine that significantly slowed weight gain and reduced body fat in animal models.

[...]




2006-07-19

Research dishes out flexible computer chips


Research dishes out flexible computer chips from PhysOrg.com

New thin-film semiconductor techniques invented by University of Wisconsin-Madison engineers promise to add sensing, computing and imaging capability to an amazing array of materials.

[...]




Scientists Discover a Genetic Code for Organizing DNA


Scientists Discover a Genetic Code for Organizing DNA from PhysOrg.com

DNA – the long, thin molecule that carries our hereditary material – is compressed around protein scaffolding in the cell nucleus into tiny spheres called nucleosomes. The bead-like nucleosomes are strung along the entire chromosome, which is itself folded and packaged to fit into the nucleus. What determines how, when and where a nucleosome will be positioned along the DNA sequence?

[...]




2006-07-17

Researchers create fiber webs that see


Researchers create fiber webs that see from PhysOrg.com

In a radical departure from conventional lens-based optics, MIT scientists have developed a sophisticated optical system made of mesh-like webs of light-detecting fibers. The fiber constructs, which have a number of advantages over their lens-based predecessors, are currently capable of measuring the direction, intensity and phase of light (a property used to describe a light wave) without the lenses, filters or detector arrays that are the classic elements of optical systems such as eyes or cameras.

[...]




2006-07-14

"Quantum leap" towards quantum computing

Science Daily reports that scientists in Germany have overcome a major hurdle towards constructing a working quantum computer: Laser Tweezers Sort Atoms: Major Hurdle On Path To Quantum Computer


2006-07-10

Chronos Version B1.173 Published

Chronos Version B1.173 has been publised ("Beta Release 1--build 173".) Chronos B1.173 is available for VisualWorks, Squeak and Dolphin. The Chronos Seed Archive for B1.173 is also available (the "Chronos Seed" is the platform-independent Chronos codebase, used for porting Chronos from VisualWorks to other Smalltalk pltatforms.)

Chronos Version B1.173 can be obtained from the Chronos Web Site. The VisualWorks version can also be obtained from the Cincom Public StORE Repository. You may also use the direct download link for VisualWorks, the direct download link for Squeak or the direct download link for Dolphin.

The Chronos Time Zone Repository is included in the download archive. Be sure to follow the Chronos Installation Instructions--especially if you have not already done so for a previous version of Chronos.

If you are reinstalling Chronos into an image in which an earlier version is already resident, and do not install the new version from the Cincom Public StORE Repository using StORE, it is necessary to first remove the earlier version. StORE has been able to correctly install the new version on top of every earlier version I have tried--but I haven't tried them all.

About Chronos Version B1.173


Chronos Version B1.173 fixes a bug in ChronosParser that was reported by John Rubier. For the Squeak version only, the Passport classes HttpRequest and HttpResponse have been renamed (to PPHttpRequest and PPHttpResponse, respectively) in order to avoid a class name conflict with Seaside (these classes exist only in the Squeak version of Passport.)

The Squeak version of Chronos is now available as either a zip or SAR archive. The SAR archive is available from SqueakMap (http://map.squeak.org/account/package/46b5731f-5112-4157-94d3-d40c4ed8304d).


2006-06-26

Dabble DB Raises Cash

According to a posting on the GigaOM blog, Smallthought Systems have received $2 million in venture financing for their Dable DB structured-data web application.

Congratulations to Avi Bryant and Andrew Catton, the founders of Smallthought Systems. Well done, dudes!


Stealth Radar System Sees Through Trees, Walls -- Undetected

The ScienceDaily article Stealth Radar System Sees Through Trees, Walls -- Undetected discusses an ultrawideband radar system that a) operates undetectably and without interfering with other EM signals, b) operates over even very short distances (unlike curent radar technology,) c) is able to see through just about any obstruction, and d) costs less than $100 to manufacture.


2006-06-23

Chewing Up A Key Regulator Of Fat Synthesis Keeps Mice Lean Despite A High-fat Diet

According to ScienceDaily's article Chewing Up A Key Regulator Of Fat Synthesis Keeps Mice Lean Despite A High-fat Diet:


Scientists at the Salk Institute for Biological Studies have identified a novel pathway that regulates the body's ability to store or burn fat, a discovery that suggests new ways to reduce obesity, diabetes and other fat-related human diseases.






2006-06-22

Stem cell superpowers exposed

According to the journal Nature, a method to convert adult cells into embryonic stem cells is on the verge of discovery:


Biologists say they are close to finding a cellular elixir of youth: a cocktail of proteins that can convert adult cells into embryonic stem cells that are able to grow replacement tissues.

Assuming this pans out, it means we are very, very close to a stunning new medical technology, whose impact should be as great as the sum of the germ theory of disease, antibiotics, anaesthetics, blood transfusions and x-rays. It would appear that, by the end of the next decade, 21st-Century medicine will be as far advanced over that of the late 20th Century, as 1990s medicine was over that of the 19th Century.


2006-06-20

Film Recommendation: History's Hidden Engine

The Socionomics Institute and Elliott Wave International have published a fim entitled History's Hidden Engine:


History's Hidden Engine is the result of more than three years of research and creativity by filmmaker David Moore. Moore traveled North America to capture the insights of 17 brilliant minds, then wove them into this film. In just 59 minutes and with the help of pop songs, news footage and cultural images that are familiar to everyone, this documentary shows how social mood drives trends in movies, music, fashion, finance, economics, politics, the media and war.

You can download or stream it for free.


Slow-frozen People? Latest Research Supports Possibility Of Cyropreservations

In Slow-frozen People? Latest Research Supports Possibility Of Cyropreservation, ScieneDaily reports on research that suggests that it may be possible to cryopreserve animals (including humans) without formation of damaging ice crystals.

If so, the principal implications would be a) reversible cryonic suspension of the terminally ill (in the expectation that the patient's condition would not be terminal from the perspective of future medical technology, b) "suspended animation" for long-distance time/space travel (for that trip to the other side of the Galaxy, or into the 24th Century,) and c) indefinite storage of tissues and organs.

It would be a socioculturally disruptive technology.


2006-06-19

IBM's 'frozen chip' claims speed record

From EE Times: IBM's 'frozen chip' claims speed record.

Even at room temperature, the clock speed is still 350-GHz--2 orders of magnitude faster than typical high-end desktop CPUs.


2006-06-08

New mathematical method provides better way to analyze noise


New mathematical method provides better way to analyze noise from PhysOrg.com

Humans have 200 million light receptors in their eyes, 10 to 20 million receptors devoted to smell, but only 8,000 dedicated to sound. Yet despite this miniscule number, the auditory system is the fastest of the five senses. Researchers credit this discrepancy to a series of lightning-fast calculations in the brain that translate minimal input into maximal understanding. And whatever those calculations are, they’re far more precise than any sound-analysis program that exists today.
[...]




2006-06-06

A Sponge's Guide to Nano-Assembly

From A Sponge's Guide to Nano-Assembly:


One of the ongoing goals of nanotechnology is to easily and inexpensively create high-performance materials structured at the nanoscale. And one of the most promising strategies is to attempt to mimic nature's remarkable ability to self-assemble complex shapes with nanoscale precision. Now researchers at the University of California, Santa Barbara (UCSB), using clues gleaned from marine sponges, have developed a method of synthesizing semiconducting materials with useful structures and novel electronic properties. The first applications could be ways to make materials for more powerful batteries and highly efficient solar cells at a lower price.


Link to complete article


2006-06-05

Growing Nanostructures on Micro Cantilever Provides New Platform for Materials Discovery


Growing Nanostructures on Micro Cantilever Provides New Platform for Materials Discovery from PhysOrg.com

Researchers have developed a new technique that could provide detailed information about the growth of carbon nanotubes and other nanometer-scale structures as they are being produced. The technique offers a way for researchers to rapidly and systematically map how changes in growth conditions affect the fabrication of nanometer-scale structures.
[...]




A Cosmic Coincidence Resurrects the Cyclical Universe


A Cosmic Coincidence Resurrects the Cyclical Universe from PhysOrg.com

Over the past five years or so, scientists have finally converged on a model of the universe that explains (or at least permits) all of its characteristics. The new cosmological model has one very surprising feature, however, which is supported by several robust and unrelated observations. In addition to matter and radiation, it seems that the vacuum of space is filled with a mysterious ‘dark energy’ that pushes the universe apart. While the dark energy helps us explain a great many things, it also resurrects an old problem once thought buried—the idea that our universe is the product of a highly unlikely cosmic coincidence.
[...]




2006-05-26

Drinking every day chases heart disease away in men only: study

If you want or need an excuse for your beer habit, here ya go:


Drinking every day chases heart disease away in men only: study from PhysOrg.com

Drinking alcohol every day cuts the risk of heart disease among men but women who indulge less frequently enjoy the same benefits, according to a study published Friday in the British Medical Journal.
[...]




2006-05-25

New Tools for a Nanotechnology Workshop


New Tools for a Nanotechnology Workshop from PhysOrg.com

Until recently, nanoscale devices could only be crafted through chemical reactions or by pushing components together on a smooth surface. Researchers at the Technical University of Denmark have developed and demonstrated practical tools allowing the precise manipulation and assembly of complex, three-dimensional nanomachines.
[...]


If Professor Mølhave and his colleagues continue working at their present pace, the mass production of nanomachines may be closer than we think!


Theoretical blueprint for invisibility cloak reported


Nano World: Invisibility through nano from PhysOrg.com

Invisibility cloaks that bend light might develop using nanotechnology, experts tell UPI's Nano World.
[...]




Scientists Predict How to Detect a Fourth Dimension of Space


Scientists Predict How to Detect a Fourth Dimension of Space from PhysOrg.com

Scientists at Duke and Rutgers universities have developed a mathematical framework they say will enable astronomers to test a new five-dimensional theory of gravity that competes with Einstein's General Theory of Relativity.
[...]




2006-05-24

Squeak Relicensed Under APSL2

Craig Latta, speaking for the board of the Squeak Foundation, made the following announcement today to the Squeak-Dev mailing list:

Hi all--

Thanks to long-running efforts by folks at Viewpoints Research Institute, Apple Computer and elsewhere, Apple has given Viewpoints permission to make a release of the original public Squeak system using the Apple Public Source License[1].

Squeak 1.1, with an APSL2 license, is available here:

http://squeakland.org/installers/Squeak1.1-APSL.zip

The Squeak Foundation board would like to thank the above groups for making this happen, and everyone else for being so patient!

And now we live in interesting times. This only applies to the original release of Squeak (version 1.1 of 23 September 1996); we now have a choice between APSL2 and the original Squeak License[2] for that release. We need to decide what to do about subsequent code, and code written by third parties. We might choose to rewrite some things so as to create a better licensing situation. We probably want to have a policy whereby contributors agree to grant a particular license to their work explicitly before we can accept it.

How shall we proceed with future releases of Squeak? Let's discuss it.


thanks again,
your Squeak Foundation board

[1] http://www.opensource.apple.com/apsl/2.0.txt
[2] http://www.squeak.org/SqueakLicense

--
Craig Latta
improvisational musical informaticist
www.netjam.org
Smalltalkers do: [:it | All with: Class, (And love: it)]




2006-05-20

Old Dudes Who Know Smalltalk

Joseph Moore has some nice things to say about Old Dudes Who Know Smalltalk:

Ah, there it is -- These are Old Dudes! I love Old Dudes! And I really love Old Dudes Who Know Smalltalk! I was nurtured, sculpted, and brainwashed by Old Dudes Who Know Smalltalk from my very first day as a professional programmer, and they universally "get it". Young whipper-snappers out there, take note: if you ever here some Old Dude say the words "in Smalltalk you could blah blah blah" or "In VisualWorks you could yada yada", spend as much time with this person as possible. You will learn more from them about software development than the Young Dude who only wears black and thinks that the bash shell is "too bloated".

And what does "get it" mean? Maybe I'll get into that some other time (it will be ugly, as this is one are where I am very opinionated), but the important thing is this: these guys don't come from the school of web scripting hackery in vi, they come from the land of building real enterprise applications, where real tool support is appreciated. And at this point in the Ruby IDE game, I'd place my bets on them to produce the first a truly usefully development tool.


Joseph mentions that he is an "Eclipse zealot." Eclipse is also a product of "Old Dudes Who Know Smalltalk."


Time for Smalltalk to focus on its future, not its past

Bob Nemec, the new director of STIC, recently made a point in a blog post that echoes a point I made recently on the Squeak-Dev mailing list.

Excerpt from what I said (e-mail sent Wed, 17 May 2006 -0700):

"Those of us `old timers` who went through the learning curve on Smalltalk years ago no longer clearly remember what it was like, nor what the conceptual stumbling blocks were. We have now fully internalized the `Smalltalk way,` and don't really grok why newcomers don't instantly realize why its so superior.

I think our attitude is wrong, even if we're `right.` We absolutely should enable more `traditional` approaches for doing Smalltalk programming. If the Mountain won't come to Mohammed, then Mohammed must go to the Mountain."

Excerpt from what Bob said:
"We had a rare sighting at last night’s meeting: a couple of Smalltalk newbies. One of them, Chris, was very willing to talk about his frustrations in getting into Smalltalk, which he’s been looking at for only a few weeks. He’s a webmaster with an interest in Seaside. In his opinion, the Smalltalk community presents a significant barrier to entry by coming across as arrogant and aloof. It was difficult defending some of his criticisms; in many ways, he was right. I had thought those days were behind us.

He made some very good points. Basically, we don’t provide the baby steps needed to learn our environment. There are virtually no easy to find introduction materials on the web for people poking around with Smalltalk for the first time. The fact that Smalltalk was able to do things 15 years ago that some languages struggle with today is irrelevant to him. He wants to learn, not be preached to."

I would add that educational materials accessible to beginners is only one approach. Another is to enable newbies to use Smalltalk in ways that much more resemble the tools and environments they already understand. Just because we know that such "traditional" tooling is actually inferior is no reason not to provide it--especially when that's one of the main stumbling blocks to early/easy acceptance by newcomers.

Who knows, perhaps we will discover that the "traditional" tooling has certain advantages, and/or that there is a synergistic effect when the traditional Smalltalk approach is combined with the traditional Unix/Windows approach.

But the bottom line is simply that Smalltalk needs to get rid of its "holier than thou" attitude, stop mumbling about all the great forward-looking achievements of its past, and start dealing with the issues of today and planning for its future.


2006-05-18

New laser technique that strips hydrogen from silicon surfaces

New laser technique that strips hydrogen from silicon surfaces from PhysOrg.com

A team of researchers have achieved a long-sought scientific goal: using laser light to break specific molecular bonds. The process uses laser light, instead of heat, to strip hydrogen atoms from silicon surfaces, a key step in the manufacture of computer chips and solar cells.
[...]

Selectivity of this kind could provide a way to control the growth of nanoscale structures with an unprecedented degree of precision, and it is this potential that most excites Cohen. "By selectively removing the hydrogen atoms from the ends of nanowires, we should be able to control and direct their growth, which currently is a random process," he said.
[...]


Clocking events at the nanoscale


Clocking events at the nanoscale from PhysOrg.com

As scientists and engineers build devices at smaller and smaller scales, grasping the dynamics of how materials behave when they are subjected to electrical signals, sound and other manipulations has proven to be beyond the reach of standard scientific techniques.
[...]




2006-05-17

Electric field can align silver nanowires


Electric field can align silver nanowires from PhysOrg.com

Scientists have discovered how to align silver nanowires in a controlled manner with an electric field. Their technique offers a possible route to sculpting and writing on nanowires, an ability that will likely have applications in industrial manufacturing.
[...]




2006-05-16

Nanotube bundles could be used as motors for nanodevices

Quote from Nanotube bundles could be used as motors for nanodevices:

“We’re looking at the very fundamentals of machinery in the nanoscopic world and what it takes to move the components of these machines, ultra-fast, super-efficient and with extreme precision” Jiang said. “A nano-motor generating rotational motion, a nano-oscillator (like a piston) generating linear motion forward and backward. We’re looking at how best to generate these motions in a nano-environment.”

Link to full article




2006-05-14

Scientist Revs Up The Power Of Microbial Fuel Cells In Unexpected Ways

ScienceDaily reports that Scientist Revs Up The Power Of Microbial Fuel Cells In Unexpected Ways:

"Scientists have boosted the power output of microbial fuel cells more than 10-fold by letting the bacteria congregate into a slimy matrix known as a biofilm. The research, led by microbiologist Derek Lovley of the University of Massachusetts Amherst, suggests that efficient technologies for generating electricity with microbes are much closer than anticipated. Lovley presented the results Wednesday in a plenary meeting of the Electrochemical Society in Denver."

Link to full article


2006-05-12

Researchers Look Beyond the Birth of the Universe


Researchers Look Beyond the Birth of the Universe from PhysOrg.com

According to Einstein’s general theory of relativity, the Big Bang represents The Beginning, the grand event at which not only matter but space-time itself was born. While classical theories offer no clues about existence before that moment, a research team at Penn State has used quantum gravitational calculations to find threads that lead to an earlier time.
[...]




Biological motors sort molecules one by one on a chip


Biological motors sort molecules one by one on a chip from PhysOrg.com

Researchers from Delft University of Technology’s Kavli Institute of Nanoscience have discovered how to use the motors of biological cells in extremely small channels on a chip. Based on this, they built a transport system that uses electrical charges to direct the molecules individually.
[...]




2006-05-11

Light's Most Exotic Trick Yet: So Fast it Goes ... Backwards?


Light's Most Exotic Trick Yet: So Fast it Goes ... Backwards? from PhysOrg.com

In the past few years, scientists have found ways to make light go both faster and slower than its usual speed limit, but now researchers at the University of Rochester have published a paper today in Science on how they've gone one step further: pushing light into reverse. As if to defy common sense, the backward-moving pulse of light travels faster than light. Confused? You're not alone.
[...]




2006-05-08

Cutting Calories Slightly Can Reduce Aging Damage

According to the article Cutting Calories Slightly Can Reduce Aging Damage:


Scientists from the University of Florida's Institute on Aging have found that eating a little less food and exercising a little more over a lifespan can reduce or even reverse aging-related cell and organ damage in rats. [From ScienceDaily]


12-qubits reached in quantum information quest


12-qubits reached in quantum information quest from PhysOrg.com

In the drive to understand and harness quantum effects as they relate to information processing, scientists in Waterloo and Massachusetts have benchmarked quantum control methods on a 12-Qubit system. Their research was performed on the largest quantum information processor to date.
[...]




2006-05-05

One Big Bang, or were there many?

From The Guardian, One Big Bang, or were there many?:


The universe is at least 986 billion years older than physicists thought and is probably much older still, according to a radical new theory.

The revolutionary study suggests that time did not begin with the big bang 14 billion years ago. This mammoth explosion which created all the matter we see around us, was just the most recent of many.

The standard big bang theory says the universe began with a massive explosion, but the new theory suggests it is a cyclic event that consists of repeating big bangs and big crunches - where every particle of matter collapses together.


Link to rest of article


Learning The Language Of DNA

From ScienceDaily, Learning The Language Of DNA:


An international consortium of scientists, including a team from The University of Queensland's Institute for Molecular Bioscience (IMB), is a step closer to the next generation of treatments to combat disease, after publishing a comprehensive analysis of the human and mouse transcriptomes.

A senior member of the consortium and IMB researcher Professor David Hume said transcriptome describes all of the information read from the genome by a cell at any given time.

"Essentially, we need to understand the language that cells use to read DNA in order to know how processes in the body are controlled," Professor Hume said.

"This knowledge will be a major resource to the biomedical research community."

Part of understanding the language of cells lies in identifying promoters - the DNA regions at the start of genes that regulate their activity.

"We have identified the core promoters of the large majority of genes in the mouse and human genomes, expanding the number of known promoters by five- to ten-fold," Professor Hume said.

The findings of the consortium have also upended the traditional view that each gene has a single promoter and a single starting position.

The team found that, while genes that are only turned on in a specific tissue or at a specific point in time use the traditional model of a single start site, genes used in many tissues have a broad distribution of start sites.

This new model may help explain why some organisms, such as humans, are much more complex than simple organisms such as worms, despite having a similar number of genes.

If some genes have a broad range of start sites, individual species can differ subtly in the way they control these genes, meaning the genes can evolve faster, and organisms with these genes can become more complex.

The consortium also found that many pseudogenes -- traditionally thought to be "fossils" of ancient genes -- are actually active, and are therefore likely to have some as yet unknown function.

The results obtained by the FANTOM consortium, led by the Japanese scientific institute RIKEN and Genome Network Project, have been published in the current edition of the prestigious journal Nature Genetics in a paper of which Professor Hume is corresponding author and first co-author.


2006-05-04

Engineers announce breakthrough in nanoscale semiconductor spin wave research


Engineers announce breakthrough in nanoscale semiconductor spin wave research from PhysOrg.com

Engineers at the UCLA Henry Samueli School of Engineering and Applied Science are announcing a critical new breakthrough in semiconductor spin-wave research.

UCLA Engineering adjunct professor Mary Mehrnoosh Eshaghian-Wilner, researcher Alexander Khitun and professor Kang Wang have created three novel nanoscale computational architectures using a technology they pioneered called "spin-wave buses" as the mechanism for interconnection. The three nanoscale architectures are not only power efficient, but also possess a high degree of interconnectivity.
[...]




2006-05-03

Incredibly short light pulses capture our microscopic world


Incredibly short light pulses capture our microscopic world from PhysOrg.com

An international collaboration including researchers from Amsterdam, Paris, Baton Rouge (USA) and Lund University, (Sweden), has made a breakthrough which moves some of the mathematics of quantum mechanics off of the blackboard and into the laboratory - from theory to reality. Using extremely short pulses of light, new knowledge about the wave-like nature of matter can be obtained.
[...]




IBM Researchers Demonstrate New Method for Rapid Molecule Sorting and Delivery


IBM Researchers Demonstrate New Method for Rapid Molecule Sorting and Delivery from PhysOrg.com

IBM researchers have demonstrated a new nanoscale method that both rapidly separates very small numbers of molecules and also delivers them precisely onto surfaces with unprecedented control. When fully developed, the new technique has the potential to improve such diverse applications as medical lab tests and future nanoelectronic circuit manufacturing.
[...]




2006-05-02

"666" sense: Date marked with caution

From the Denver Post:

"While some say June 6, 2006, is a day to fear for its biblical significance, officials see little to dread."

Link to full article.


2006-05-01

Bug fixed; New Version of Time Zone Repository Published

Version 2006e of the Olson Time Zone Database has been published. Consquently, version 2006e of the Chronos Time Zone Repository has been generated by the Chronos Time Zone Compiler (from the Olson data,) and is now avaiable from the Chronos web site (download link: Chronos Time Zone Repository.)

Also, I found and fixed a bug that will be encountered if a) you're using a recent version of Chronos, and b) you haven't properly installed the Chronos Time Zone Repository. When the Chronos Time Zone Repository has not been properly installed, Chronos is supposed to complain, but not not present you with an exception traceback. The bug is that you are in fact presented with an exception traceback. The bug has been fixed in version B1.172, which is now avaiable from the Chronos web site.

If you'd prefer to fix the bug without installing a new version of Chronos, just change the source code of the method ChronosResourceRepositoryContext>>invalidateResourcePaths to the following text:


invalidateResourcePaths
"The resource paths may be invalid. Reinitialize them."

"{ChronosSystemFacade current resourceRepositoryContext invalidateResourcePaths}"

| oldResourcePathPrefix |
self resourcePathsExist ifTrue: [^true].
oldResourcePathPrefix := resourcePathPrefix.
^(self findValidResourcePathPrefix:
[:resourcePathPrefixString |
self resourcePathPrefix: resourcePathPrefixString])
ifTrue: [true]
ifFalse:
[resourcePathPrefix := oldResourcePathPrefix.
false]



2006-04-30

Chronos Version Published for Dolphin

I am pleased to announce the availability of a version of Chronos ported to Dolphin (Chronos version B1.171, also now available for VisualWorks and Squeak.)

The Dolphin version currently has no support for any locales other than en_US (US English,) and has no support for retrieiving time zone rule sets over HTTP. Other than that, it provides all the same functionality as the VisualWorks version.

Links to download Chronos:


You should also read the Chronos installation instructions (which admittedly need to be updated to cover both Dolphin and Squeak.) Dolphin uses "package files" (ending in *.pac) instead of either "file ins" or "parcels." The Dolphin version is distributed as the file Chronos.pac (in the archive file Chronos.zip, which also includes the Chronos Time Zone Repository.)


Static typing is so last century

In the article Schizoid Classes published on the ACM Queue, Rodney Bates (of Wichita State University) does a good job of explaining what's wrong with the class models of the curly-braced mainstream langauges.

However, in his last paragraph, he says:

"Smalltalk pays a high price elsewhere for taking object orientation to the extreme, notably in complete loss of static typing and serious runtime efficiency penalties. Special, one-instance forms of classes are, for many programming problems, not as good a conceptual match as modules. But at least it provides a single, consistent, and syntactically explicit call mechanism."

He's right to say that "special, one-instance forms of classes are, for many programming problems, not as good a conceptual match as modules." But he's demonstrably wrong to say that "Smalltalk pays a high price elsewhere for taking object orientation to the extreme, notably in complete loss of static typing and serious runtime efficiency penalties."

Firstly, it is only sometimes true that Smalltalk pays a measurable performance penalty due to the lack of primitive types. In fact, it is very often the case that Smalltalk programs benchmark as faster than equivalent programs written in C++, C# or Java--for any of a variety of reasons I won't go into here.

Secondly, Smalltalk pays no net penalty for its lack of static typing--commonly-believed myths to the contrary notwithstanding. In fact, it receives the net benefit of making developers more productive and making code more generic and reusable.

Static typing is so last century. Interest in dynamic languages is growing. A Kuhnian revolution may be brewing. I sense that it won't be long now before the general community of programmers wakes up to reality, and stops believing the myths of the past.


Scientists make water run uphill

From the BBC, Scientists make water run uphill:


Physicists have made water run uphill quite literally under its own steam.

The droplets propel themselves over metal sheets scored with a carefully designed array of grooves.

The US scientists did the experiment to demonstrate how the random motion of water molecules in hot steam could be channelled into a directed force.


2006-04-28

Nano World: Roadmap for nano-imprinting


Nano World: Roadmap for nano-imprinting from PhysOrg.com

Scientists could soon easily fabricate electronics and other structures only nanometers or billionths of a meter in size by stamping them out, following a new strategy that could help guarantee results, experts tell UPI's Nano World.
[...]




2006-04-27

I think, therefore I am...granted access

From Wired: Your Thoughts Are Your Password

I guess this just wouldn't work for some people. After all, it requires that one actually has thoughts :-)


Hormone Found To Decrease Appetite And Increase Activity

From Science Daily:

"New research shows how topping up the levels of a hormone found in the gut could help reduce the appetite and increase activity in overweight and obese people."

Link to the full story: Hormone Found To Decrease Appetite And Increase Activity


2006-04-26

Water, nanoelectronics will mix to create ultra-dense memory storage


Water, nanoelectronics will mix to create ultra-dense memory storage from PhysOrg.com

Excessive moisture can typically wreak havoc on electronic devices, but now researchers have demonstrated that a little water can help create ultra-dense storage systems for computers and electronics.
[...]




MIT Chemist Discovers Secret Behind Nature's Medicines

From Science Daily:

"MIT scientists have just learned another lesson from nature. After years of wondering how organisms managed to create self-medications, such as anti-fungal agents, chemists have discovered the simple secret."

Link to full article: MIT Chemist Discovers Secret Behind Nature's Medicines.


2006-04-25

Our Universe: A Quantum Loop


Our Universe: A Quantum Loop from PhysOrg.com

“There are two classical branches of the universe connected by a quantum bridge. This connects the former collapse with the current expansion.” While Abhay Ashtekar and his colleagues, Tomasz Pawlowski and Parampreet Singh, may not have come with a completely new theory, what they have done is create a systematic way, through quantum equations, to look back in time to the birth of our current universe.
[...]




Taking Exception To Smalltalk Exceptions

About 3 weeks ago, Cincom's James Robertson posted a blog entry that showcased Smalltalk's exception handling capabilities.

About three days later, some posters at Lambda The Ultimate took exception to the power of Smalltalk's exception handling capabilities [fixed URL]:

"So what you're saying is that you want to be able to bind exception throw behaviour dynamically, rather than lexically. The end result being that a caller can bind handler code into any (uncaught) exception throw, without having any way of knowing the source(s) of the possible exceptions, or their root cause.

How, exactly, is one supposed to document the exceptional behaviour of a library class in that case? What possible security gaurantees could one give, if a calling library can inject arbitrary code on any error condition, and ignore or mask the error as it will? How would you even exhaustively test such a thing, other than by ignoring the horrible stuff that your caller could have done to you and pretending you're in some some language?" -- Dave Griffith [I assume that "some some language" was intended to be "some sane language."]

I have news for Mr. Griffith: Programs Are Data. That truth is one of the pillars of computer science. Deal with it.

If programmers can't be trusted with the stack, they can't be trusted to assign the right value to a variable, nor to pass the right value as a parameter to a function. Compilers are tools, not hall monitors.


2006-04-24

Nano machine switches between biological and silicon worlds


Nano machine switches between biological and silicon worlds from PhysOrg.com

Scientists have created a molecular switch that could play a key role in thousands of nanotech applications. The Mol-Switch project successfully developed a demonstrator to prove the principle, despite deep scepticism from specialist colleagues in biotechnology and biophysics.
[...]


The nanotechnologists have been proving the naysayers wrong time after time. This is just the latest example.


Interstellar Deathray Not Likely to Hit Earth

From Space.com, yet another headline that ought to win an award: Interstellar Deathray Not Likely to Hit Earth.




2006-04-22

Time Semantics: Getting it wrong is easy

Outlook, Appointments and Time Zones:

"To many people, Outlook really seems really bad at handling time zone changes, and that's being kind. This is in part because people don't understand that Outlook uses UTC time for appointments and adjusts the time using the time zone offset configured on the computer."

Translation: You're stupid. Learn to think like your computer!

"Note that this is not "an Outlook problem", as this is how computers, email clients and mail servers handle time zones."

Translation: Other programs work just like Outlook, and the programmers can't all be wrong. [Or can they?]

"Outlook does not support an absolute time option for the calendar, which would permit you to enter 2 PM and the appointment would always stay on 2 PM, no matter how many times you changed the time zone. It also doesn't have an option for ‘in what time zone?’ so that you could make an appointment for 2 PM and select Pacific time zone and it would show up as 5 PM in your calendar when the computer is using the Eastern time zone."

Translation: Ok, we fess up: The problem really does lie in the fact that Outlook uses the wrong time semantics.

The Moral of the Story: Even Billion-Dollar Corporations can get time semantics wrong.

Sometimes, you want timestamps that are invariant to nominal time, so that 3pm = 3pm, with the time not bound to any time zone at all. Other times, you want timestamps that are invariant to Universal Time--so that 2pm in San Francicso will be equal to 5pm in New York.

Sometimes, you want timestamps statically bound to a specified time zone, so that 2pm in San Franciso always is displayed as 2pm (even though the computer treats it as equal to 5pm in New York.) Other times, you want timestamps whose "local time" changes dynamically to match whatever time zone the user specifies as the "local time" of the computer--so that the time displays as 2pm when you've set the computer's time zone to San Francisco time, but displays as 5pm when you've set the computer's time zone to New York time.

Unfortunately, not only do most applications get this wrong, most date/time libraries don't support both nominal-time invariance and Unviersal Time invariance, nor do they support both timestamps statically-bound to a specified time zone and also timestamps bound dynamically to the current system time zone.

Chronos does it all.


2006-04-20

A Strategic Opportunity for Smalltalk

Mark Shuttleworth:

"Instead of fighting over turf or syntax, I sensed a genuine willingness to synthesize the best work from both camps into something that could have both Python's pop-culture widespread appeal, and pedagogical foundations that build on years of Alan's experience in the Squeak world. The mouse might yet become the snake's strongest ally."

The computational model (which depends heavily on the VM) is strategic.

Syntax (which is just a matter of which compiler one happens to use) is tactical.

Avi Bryant had the right idea: Strategic thinkers in the Smalltalk community should create strong, compelling implementations of Python, Ruby and Perl, hosted on Smalltalk VMs--such as Squeak's.

Adding Erlang, Haskell, Io and Ocaml wouldn't hurt, either.

When it comes to advanced, dynamic programming languages, it's "United we stand, divided we fall."


John Koza Has Built an Invention Machine

Its creations earn patents, outperform humans, and will soon fly to space. All it needs now is a few worthy challenges

As a high-school student in the 1950s, John Koza yearned for a personal computer. That was a tall order back then, as mass-produced data processors such as the IBM 704 were mainframes several times the size of his bedroom. So the cocksure young man went rummaging for broken jukeboxes and pinball machines, repurposing relays and switches and lightbulbs to make a computer of his own design.

[Click here for the rest of the story]