just browse the web and found that the year 2038 problem...
from http://www.dewtronics.com/msdn_090798a.html
How Many GUIDs, Again?
Henrik Vallgren and Peter Schaeffer took the time to let Dr. GUI know that he's dead wrong about there being enough GUIDs for each atom in the universe to have its very own. The number of particles (not atoms) in the universe is somewhere around 1079 or so—even Dr. GUI isn't sure of exactly how many.
A GUID comprises 128 bits, so the number of GUIDs is 2128. That's only about 1038, or 100,000,000,000,000,000,000,000,000,000,000,000,000. And that's a factor of 1041 short of 1079. So a GUID could hold a unique number for only 1 out of every 1041 particles in the universe. Thankfully, each particle doesn't need its own interface ID and/or class ID. (IElectron? IQuark?) So there are still plenty of GUIDs for our uses.
Henrik's line of reasoning was especially interesting:
"Consider the sun's mass 2*10^30 kg. Assume that the sun consists of only hydrogen. One gram of hydrogen is 6*10^23 (Avogadro's number) atoms, one kilogram 6*10^26 atoms.
"The number of atoms in the suns is thus approximately 10^54 (~2^179).
"The hydrogen assumption is wrong so that number should be divided by the true average atomic weight, of which I have no idea. [But it's certainly less than 100—perhaps less than 10—so the assumption of a pure hydrogen sun doesn't affect these numbers much. Like a factor of 100 isn't much.—Dr. GUI]
Then consider billions and billions of stars in the Milky Way. And quite a few galaxies on top of that. You'll get the picture ... "
Indeed, the good doctor does get the picture. Dr. GUI begs your forgiveness 1041 times.
Note that if the GUIDs were somewhat bigger, they WOULD be big enough to give each particle its very own GUID, or PID (for particle ID). It would take about 264 bits—33 bytes for each GUID.
Thanks again to Henrik and Peter for taking the time to write.
Tuesday, January 24, 2006
Tuesday, January 17, 2006
Saw a comment that quite describe what programmer feels...
Source: http://www.javalobby.org/java/forums/m91982704.html
"Re: Tools for screening new Java developers
Yes, but this opens up the bigger question, doesn't it? Where technology stands in the post-bubble world.
I've seen people without degrees who could write incredible algorithms and could quote Knuth by heart. Then I've also known Computer Science degreed graduates who barely grasped programming at all. Add to this the technical schools and the "Information Technology" degree that has made it's appearance in colleges of late, and you have a horrible bloated landscape for skilled professionals.
Continuing this problem is the fact that those who enter technology are not exposed to peer-reviewed journals and a strict respect for the scientific process and experimentation to further the science, but to press release junk and market driven but vaporous software ideas that have little benefit to computer science. Software developers are more likely to Google for ideas than to search EBSCO Host. Is there really computer science anymore? Or is it all just a hacking flaming sub-culture?
I think this breeds the signifigant lack of creativity and innovation we've seen in technology in the last few years, as we have a glut of people who got in to technology because of the money and not because of the love of the science. I certainly believe that a big driver of open source development is the absolute failure of companies to manage technology professionals and their creativity. When talented people give away their work for free just to see it breathe, you know an industry is in trouble.
Add to this the fact that many IT programming jobs are, let's face it, simply to wrap a database in Java and be done with it, and you have a situation where even people who love the science may quickly become bored with it and move on to something more fulfilling.
Knowing this, seeing a sea of mediocre developers come through your door can't be that surprising. The question is: does McDonaldizing the interview process further this mediocrity or protect you against it? I suggest it furthers it.
This is a company issue that one person can't solve, but in evaluating the hiring process you have to be careful the image you generate towards the candidates as well. Those companies that treat developers as professionals tend to create an atmosphere that automatically repels the least among the group.
How many mediocre candidates do you think Google or Microsoft or Apple or Accenture gets? In contrast, how many do you think your general staff-augmenting quick-in/quick-out consulting firm gets? This can also manifest itself on a local city-wide scale, not just a national scale.
In other words, you should be compiling a list of questions to submit to your CIO, not to your candidates :-)"
"Re: Tools for screening new Java developers
Yes, but this opens up the bigger question, doesn't it? Where technology stands in the post-bubble world.
I've seen people without degrees who could write incredible algorithms and could quote Knuth by heart. Then I've also known Computer Science degreed graduates who barely grasped programming at all. Add to this the technical schools and the "Information Technology" degree that has made it's appearance in colleges of late, and you have a horrible bloated landscape for skilled professionals.
Continuing this problem is the fact that those who enter technology are not exposed to peer-reviewed journals and a strict respect for the scientific process and experimentation to further the science, but to press release junk and market driven but vaporous software ideas that have little benefit to computer science. Software developers are more likely to Google for ideas than to search EBSCO Host. Is there really computer science anymore? Or is it all just a hacking flaming sub-culture?
I think this breeds the signifigant lack of creativity and innovation we've seen in technology in the last few years, as we have a glut of people who got in to technology because of the money and not because of the love of the science. I certainly believe that a big driver of open source development is the absolute failure of companies to manage technology professionals and their creativity. When talented people give away their work for free just to see it breathe, you know an industry is in trouble.
Add to this the fact that many IT programming jobs are, let's face it, simply to wrap a database in Java and be done with it, and you have a situation where even people who love the science may quickly become bored with it and move on to something more fulfilling.
Knowing this, seeing a sea of mediocre developers come through your door can't be that surprising. The question is: does McDonaldizing the interview process further this mediocrity or protect you against it? I suggest it furthers it.
This is a company issue that one person can't solve, but in evaluating the hiring process you have to be careful the image you generate towards the candidates as well. Those companies that treat developers as professionals tend to create an atmosphere that automatically repels the least among the group.
How many mediocre candidates do you think Google or Microsoft or Apple or Accenture gets? In contrast, how many do you think your general staff-augmenting quick-in/quick-out consulting firm gets? This can also manifest itself on a local city-wide scale, not just a national scale.
In other words, you should be compiling a list of questions to submit to your CIO, not to your candidates :-)"
Friday, January 06, 2006
Leap second in kernel message...
"Clock: inserting leap second 23:59:60 UTC" was found in linux servers I managed.
Remember we have one more second at 2006 Jan 01 00:00:00 GMT
http://www.maths.tcd.ie/~dwmalone/time/leap2005.html
Remember we have one more second at 2006 Jan 01 00:00:00 GMT
http://www.maths.tcd.ie/~dwmalone/time/leap2005.html
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