I too was a COBOL and Pascal coder in the 1980s, but wrote mostly in Assembler, then C, for airline reservation and travel automation systems. In the first half of the 1990s I was writing less code and doing more "analyst" stuff. I got a consulting job in 1995 which forced me to upgrade skills and learn configuration and scripting for Solaris, OS/2, Windows NT/2000. I then worked as a secondary researcher and essentially did no coding, but read and did self-study, including studying Linux. In 2000, I went back to university and learnt Matlab, and at the same time invested in my first Linux distro: SuSE Linux 6.3. I subsequently obtained a job at the uni which required me to learn Fortran 90. For my masters project I taught myself C++ by writing an open source library, GluCat. In a later job, I had to quickly learn Labview, IDL, Java and MySQL. I am now a postdoc. My teaching now involves Python and Scilab.
My point is, if you know how to program, you just pick up a language manual and do it. Preferably do it using Linux, where you don't need to pay for compilers and tools, and the documentation is all on the DVD or on the web. Sure, the learning curve is initially steep, but if you give yourself some credit, you can get started. As a next step, start your own small open source project on SourceForge, or join a simple, small project. I have found, as a coder, the large projects seem complicated and hard to get my head around.
I upgraded from Kubuntu 9.04 on an Intel machine, with the following problems (from memory, corrections, if any, will be in a reply).
The upgrade process hung, so I killed it and ran "dpkg --configure -a".
The upgrade then completed.
After logging in I noticed that quanta was missing. It looks like quanta is not ready for KDE 4.3.2.
I fixed this by downgrading kdewebdev to KDE 3.5.10:
The KDE software manager KPackageKit was not up to the job of sorting out dependencies, and complained about them one at a time.
I used Synaptic instead.
The screen was flickering, so I used the Display button in System Settings to change the resolution and refresh rate from 1280x1024 @ 85 Hz.
After a hiccup or two (eg. the top 1/2 of the screen not displaying) I changed the settings to 1600x1200 @ 75 Hz.
This now works fine.
Everything now seems to work, including the desktop effects.
I briefly read the article.
The idea is to discourage certain high school students from taking a class which (a) they are likely to fail or at least do poorly, and (b) they will derive little or no benefit from, namely higher level mathematics.
The key problem is how to determine if both (a) and (b) apply to a particular student.
Personally, I'd prefer it if first year science and engineering students knew something about matrices and complex numbers before they begin their university studies, but only if what they know is correct.
It would also help students who need statistics.
On the other hand, it helps nobody if certain underprepared high school students struggle, crash and burn in higher mathematics.
So, maybe discourage those who fail ordinary level mathematics in Year 10 from taking higher mathematics in Year 11 and 12 (NSW system).
But, maybe encourage others, especially those who keep on going with puzzles, maths competitions, etc. (ie. mathaholics, Parabola readers).
Alexander Mayer was listed by the Physics department at Stanford as a visting scholar, but his name is no longer on the list. Stanford has rules for becoming a visiting scholar, including having a PhD. Perhaps Alexander Mayer didn't qualify and managed to get himself a web page on Stanford somehow anyway? Just speculation, but it does fit the publically available facts.
For example, he is apparently an MIT graduate, but at MIT Community Home Pages only his alumnus email address is listed, not a web page. More significantly, a search for his name on the MIT web site turns up nothing.
Finally, a thesis search for his name on Barton, the MIT library catalog, also turns up nothing.
So let's assume he didn't submit a thesis at MIT.
Where did he get his PhD to qualify as a visting scholar at Stanford? And why isn't there any trace of it available via the web?
Maybe he doesn't have one. Just speculation on my part...
Maybe Alexander F. Mayer does have a PhD in physics, but there is no trace of it on the web.
I'm adding some things to Mayer's thought experiment, before his thought experiment starts and after it ends. I'm sorry if my description is unclear. I don't know how to add diagrams to Slashdot comments.
By "an observer at rest at a point O, halfway between A and B", I meant "initially at rest". Sorry for the confusion. O remains halfway between A and B for the duration of my extended thought experiment. I explain further below.
In Mayer's original experiment, A and B are fixed to an accelerating spaceship, and the direction from A to B is at right angles to the direction of acceleration.
My additions *do not change this* during the period of acceleration. I just imagine that *before* the period of acceleration, the spaceship is at rest, so that A and B are inertial frames, and that *after* the period of acceleration, the spaceship is coasting, and A and B are again inertial frames.
To emphasize the point that Mayer's interpretation is incorrect, I add an observer at O, halfway inbetween A and B. O is fixed to the spacecraft and *stays* halfway inbetween A and B for the duration of the experiment.
*After* the period of acceleration and *after* a period where A, O and B are inertial frames, I bring A and B together symmetrically at O. This last step is not strictly necessary to my additions to Mayer's thought experiment, but I want to make the clocks at A, O and B coincide in spacetime so that the comparison between their clocks is simple and direct. By A and B moving "completely symmetrically" towards O, I mean that from O's point of view, at any time, A and B are in opposite directions and at the same distance. Remember that *after* the period of acceleration, O is an inertial frame.
Finally, I can't understand why you don't see my point about clocks. If you have two clocks A and B which initially agree, then clock B runs slowly for a period of time T according to clock A, then at that time clock B will have recorded a time less than T. If the two clocks then and forever afterwards run at the same rate, clock B will still lag clock A by a fixed amount.
1) By "O's final position", do you mean a location in space or an event in spacetime? In my version of Mayer's thought experiment, I bring A and B together and they coincide with O at an event in spacetime. The only light pulses which arrive at this event are those which lie on the backward light cone from this event. Since we suppose that the spaceship and the objects within it cannot travel at the speed of light, there are no light pulses from A, B or O on this backward light cone.
2) You say "all of the light pulses from each clock will also have arrived at O's final position - and thus all three clocks should agree". I do not follow your reasoning. It seems to me a non-sequitur. How does the "and thus" work? What is the connection between the light pulses arriving at the same point (in space? in O's inertial frame?) and the clocks agreeing?
As I explain above, there is no "RTR effect" to cancel out. Mayer's interpretation of his though experiment is simply wrong. It leads to an unavoidable paradox.
Slashdot Mirror
I too was a COBOL and Pascal coder in the 1980s, but wrote mostly in Assembler, then C, for airline reservation and travel automation systems. In the first half of the 1990s I was writing less code and doing more "analyst" stuff. I got a consulting job in 1995 which forced me to upgrade skills and learn configuration and scripting for Solaris, OS/2, Windows NT/2000. I then worked as a secondary researcher and essentially did no coding, but read and did self-study, including studying Linux. In 2000, I went back to university and learnt Matlab, and at the same time invested in my first Linux distro: SuSE Linux 6.3. I subsequently obtained a job at the uni which required me to learn Fortran 90. For my masters project I taught myself C++ by writing an open source library, GluCat. In a later job, I had to quickly learn Labview, IDL, Java and MySQL. I am now a postdoc. My teaching now involves Python and Scilab.
My point is, if you know how to program, you just pick up a language manual and do it. Preferably do it using Linux, where you don't need to pay for compilers and tools, and the documentation is all on the DVD or on the web. Sure, the learning curve is initially steep, but if you give yourself some credit, you can get started. As a next step, start your own small open source project on SourceForge, or join a simple, small project. I have found, as a coder, the large projects seem complicated and hard to get my head around.
Left out:
1.5. Mkramfs ran out of disk space on the boot partition. I had to delete the files for one old kernel and continue the upgrade from there.
Also, Flash does not fully work in Firefox.
I upgraded from Kubuntu 9.04 on an Intel machine, with the following problems (from memory, corrections, if any, will be in a reply).
Everything now seems to work, including the desktop effects.
Julian Havil's book, Gamma, is both a popular mathematics book and a mathematics book. It gives both history and results.
http://press.princeton.edu/titles/7494.html
I briefly read the article. The idea is to discourage certain high school students from taking a class which (a) they are likely to fail or at least do poorly, and (b) they will derive little or no benefit from, namely higher level mathematics. The key problem is how to determine if both (a) and (b) apply to a particular student.
Personally, I'd prefer it if first year science and engineering students knew something about matrices and complex numbers before they begin their university studies, but only if what they know is correct. It would also help students who need statistics.
On the other hand, it helps nobody if certain underprepared high school students struggle, crash and burn in higher mathematics.
So, maybe discourage those who fail ordinary level mathematics in Year 10 from taking higher mathematics in Year 11 and 12 (NSW system). But, maybe encourage others, especially those who keep on going with puzzles, maths competitions, etc. (ie. mathaholics, Parabola readers).
Dyson is right in that heretics are needed, and right that biomass needs to be considered in global climate models, but wrong in assuming that only meteorologists produce climate models. Have a look at (eg.) Fatih Evrendilek and Mohan K. Wali, Changing Global Climate: Historical Carbon and Nitrogen Budgets and Projected Responses of Ohios Cropland Ecosystems and the references.
For example, he is apparently an MIT graduate, but at MIT Community Home Pages only his alumnus email address is listed, not a web page. More significantly, a search for his name on the MIT web site turns up nothing.
Finally, a thesis search for his name on Barton, the MIT library catalog, also turns up nothing.
So let's assume he didn't submit a thesis at MIT. Where did he get his PhD to qualify as a visting scholar at Stanford? And why isn't there any trace of it available via the web? Maybe he doesn't have one. Just speculation on my part... Maybe Alexander F. Mayer does have a PhD in physics, but there is no trace of it on the web.
PS. We are not talking about Alexandre Mayer.
I'm adding some things to Mayer's thought experiment, before his thought experiment starts and after it ends. I'm sorry if my description is unclear. I don't know how to add diagrams to Slashdot comments.
By "an observer at rest at a point O, halfway between A and B", I meant "initially at rest". Sorry for the confusion. O remains halfway between A and B for the duration of my extended thought experiment. I explain further below.
In Mayer's original experiment, A and B are fixed to an accelerating spaceship, and the direction from A to B is at right angles to the direction of acceleration.
My additions *do not change this* during the period of acceleration. I just imagine that *before* the period of acceleration, the spaceship is at rest, so that A and B are inertial frames, and that *after* the period of acceleration, the spaceship is coasting, and A and B are again inertial frames.
To emphasize the point that Mayer's interpretation is incorrect, I add an observer at O, halfway inbetween A and B. O is fixed to the spacecraft and *stays* halfway inbetween A and B for the duration of the experiment.
*After* the period of acceleration and *after* a period where A, O and B are inertial frames, I bring A and B together symmetrically at O. This last step is not strictly necessary to my additions to Mayer's thought experiment, but I want to make the clocks at A, O and B coincide in spacetime so that the comparison between their clocks is simple and direct. By A and B moving "completely symmetrically" towards O, I mean that from O's point of view, at any time, A and B are in opposite directions and at the same distance. Remember that *after* the period of acceleration, O is an inertial frame.
Finally, I can't understand why you don't see my point about clocks.
If you have two clocks A and B which initially agree, then clock B runs slowly for a period of time T according to clock A, then at that time clock B will have recorded a time less than T. If the two clocks then and forever afterwards run at the same rate, clock B will still lag clock A by a fixed amount.
1) By "O's final position", do you mean a location in space or an event in spacetime? In my version of Mayer's thought experiment, I bring A and B together and they coincide with O at an event in spacetime. The only light pulses which arrive at this event are those which lie on the backward light cone from this event. Since we suppose that the spaceship and the objects within it cannot travel at the speed of light, there are no light pulses from A, B or O on this backward light cone.
2) You say "all of the light pulses from each clock will also have arrived at O's final position - and thus all three clocks should agree". I do not follow your reasoning. It seems to me a non-sequitur. How does the "and thus" work? What is the connection between the light pulses arriving at the same point (in space? in O's inertial frame?) and the clocks agreeing?
As I explain above, there is no "RTR effect" to cancel out. Mayer's interpretation of his though experiment is simply wrong. It leads to an unavoidable paradox.
I'm the author of the comment above. Sorry for not logging in previously, but I had problems logging in yesterday.
See Reuters and ABC 7:30 report and slashdot