25 November 2006

Ubuntu - Linux for Human Beings

ubuntu desktop

One of the major hurdles one finds when attempting to install Linux on his/her computer is the installation itself. Not only do you need to partition your hard disk if you have not done so (unless you have a physically second hard disk), you also need to know your computer specifications (like what ethernet card it is using). And some Linux distribution installers are not able to recognise SATA hard disks which most laptops (including mine - IBM Thinkpad T43) use. This is the case when I tried to install the powerful Debian which all SPS computer uses.

Fortunately, Ubuntu cuts out most of that job. Okay, partitioning of hard disk still remains but that's not really a screwy job as it may sound, though it may be daunting if it's your first time tweaking with the foundations of your computer. I recommend using the Disk Management in Windows to partition the hard drive itself; it is easy to use, comes along with Windows XP, and since it is running on that partition itself, there's little risk of destroying your Windows partition. (Note that two partitions are needed, a "\root" where the Linux will run and a small "\temp" with the memory size same as your RAM.) Apart from partitioning, Ubuntu's graphical installer really makes it friendlier than other distributions' text based installer.

The default interface is Gnome, one of the most popular interfaces for Linux (if you want KDE, go for Kubuntu). Slick and clean and not too different from the Windows interface, the only dissatisfaction I have with it is the huge icon sizes. As compared to Windows, these Linux interfaces' greatest advantage is the multiple desktops, which is most wonderful (but not limited to) situations when you're running programs that uses a copious amount of windows (like Adobe Photoshop or its open-source equivalent, The GIMP; I was tempted to say Internet Explorer for its poor popup blocking abilities, but since IE7 is out, I shall forgive it).

Most programs in Windows have an equivalent in Linux. OpenOffice.org is Linux's equivalent of Microsoft Office (OpenOffice.org is also available in Windows, for those who are too poor to own an original copy or too lofty to have a pirated one). There's of course Firefox in Linux that's equivalent to , well, Firefox in Windows! Thunderbird also works in Linux, or you can also have Evolution Mail which comes pre-installed in Gnome. Ubuntu also has music/video/CD players, as well as instant messaging client Gaim, or if you want an MSN clone, aMSN.

For programs like Thunderbird and aMSN that don't come installed, all you need is a working Internet connection. Then, under the Applications menu (the Start menu equivalent of Windows), choose "Add/Remove...". It works something like the "Add/Remove Programs" in Windows' Control Panel, but unlike the latter which only searches for programs installed in your computer, it goes onto the Internet and search for lists of programs available (from the Ubuntu repositories, which can be modified if you wish). Installing and uninstalling involves just a few clicks. However, installing programs that are not on the repositories can be a headache; fortunately, that situation seldom surfaces.

The best thing about these programs, other than, to a computer programmer, being open source, is that it is free! No more having to fork out hundreds of dollars for programs; no more having to resort to piracy! Of course, that alone means that many Windows-only program like ABAQUS and AutoCAD are not available, which is why I recommend keeping your Windows system alongside with Linux (i.e. dual boot). Alternatively, you can use Wine, a Windows emulator that runs well for quite a handful of Windows-only programs. In fact, according to Wine's official database, games like Diablo 2, Counter-Strike, Warcraft III and World of Warcraft works pretty satisfactorily. But if it is your work computer you should not even have such abominations in it in the first place...

Another advantage I find in Linux is that it takes much shorter for the system to start up. For my laptop to boot Windows completely, I gotta wait for about half a minute before the login dialog drags itself onto screen, then another two or three minutes for Windows to stop spinning my hard disk. For Ubuntu, it takes less than half a minute for the login dialog box to appear, and less than ten seconds after logging in for the system to be ready. Talking about speed!

Other minor plus points about Linux is that it naturally comes with a C compiler (GNU Compiler Collection, or "gcc"), as anyone with formal education in C programming would know (however, it doesn't come pre-installed in Ubuntu, though a "apt-get install build-essential" in the Terminal will resolve that. Gnome also has an amazing amount of screensavers. Also, you can fetch files from any account in your Windows system (which goes to show the security, or lack thereof, of Windows systems).

Personally, I strongly urge one to try out Ubuntu. If anything, take it as an exploration into the various dimensions of computers. For once, don't be a bluepill. Live no longer in the Blue Screen of Death. Free your (computer's) mind.

24 November 2006

Wee Shu Min Wikipedia-ed

This morning in my dish of daily websites, I came across something familiar:

Her name is really becoming an icon... except in a bad way, that is. Poor thing...

21 November 2006

Fastest Spinning Black Hole on Record

Just had my SP2172 presentation on Monday at 1600. And then, an article closely related to our project appeared just less than 24 hours later.

This is especially related since during the Q & A session, people asked on the existence of a theoretical limit on how fast a black hole can spin.

As usual, I emphasized the more relevant parts.

Spinning black hole is fastest on record
15:39 20 November 2006
NewScientist.com news service
David Shiga

A black hole has been found to be spinning faster than ever seen before, a new analysis suggests. The finding supports the idea that only fast-spinning stars can collapse to create powerful explosions called long gamma-ray bursts.

To measure the spin of black holes, astronomers measure the size of the discs of matter that orbit them. A spinning black hole drags space-time around with it as it spins, boosting the speed of matter in orbit around it. That allows the matter to orbit closer in without getting sucked into the black hole itself – so the faster a black hole spins, the closer matter can stably orbit around it. [Pandemonium: technically, this means that the radius of the event horizon (or the point of no return), becomes smaller as the black hole spins faster; this agrees with our theoretical analysis and computer simulation.]

Watch an animation showing the difference between spinning and non-spinning black holes.

But the innermost edge of this disc is too small to see directly. So previous measurements of black hole spins have had to make assumptions about properties such as the tilt of the disc to Earth's line of sight.

Now, astronomers have measured the spin of a black hole with a new method that requires fewer assumptions. The team was led by Jeffrey McClintock of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Massachusetts, US.

Hot gas

McClintock's team examined a black hole in our galaxy called GRS 1915+105, which lies about 36,000 light years away. Matter gets hotter as it gets closer to the black hole, so the team used X-ray observations from NASA's Rossi X-ray Timing Explorer to measure the temperature of the gas in the disc.

They found the innermost stable orbit around GRS 1915 is so close that the black hole must be spinning at nearly 1000 times per second – the fastest ever recorded.

"The application of this to understanding black holes and black hole physics are really quite important," McClintock told New Scientist. "It’s the most exciting thing I've worked on."

But a second study of GRS 1915 suggests that the spin could be lower, according to an analysis of the same RXTE data by Matthew Middleton of the University of Durham, UK, and his colleagues.

Stellar collapse

Chris Done, a member of Middleton’s team, says their analysis suggests the spin is “substantial but not extreme”. They argue that X-rays scattering off of electrons in the disc make the temperatures appear higher than they really are. This gives the illusion of a closer-in disc, and therefore a faster spin for the black hole, they say.

But if McClintock's team is right, the black hole is spinning at 98% of the theoretical maximum rate, which is calculated by how fast stars can spin before they collapse to form black holes.

The observation provides support for the idea that gamma-ray bursts – fleeting but powerful explosions – are produced by fast-spinning stars.

In this scenario, a black hole forms at the centre of such a fast-spinning star and some of the remaining stellar material forms a disc that spirals into the black hole.

High spin

The interaction of the black hole and the disc produces jets, which emit copious amounts of gamma rays. But the star has to be spinning very quickly when it collapses for this disc to form, and some astronomers have expressed doubt that stars would be spinning fast enough at this stage in their lives.

The new research may quell some of those doubts. "It says sometimes stars do find some path for dying with a huge amount of rotation in their middle," says Stanford Woosley of the University of California in Santa Cruz, US, who is not a member of the team.

Christopher Fryer of the Los Alamos National Laboratory in New Mexico, US, who is also not on the team, agrees. He says it is "strong evidence that nature can get the high spin rates in stars to produce gamma-ray bursts".

McClintock says he hopes that analysing similar observations for other systems will allow them get spin rates for half a dozen more black holes within the next two years. "We're going to apply it as widely as we can," he says.

Journal references: The Astrophysical Journal (vol 652, p 518)

Monthly Notices of the Royal Astronomical Society (DOI: 10.1111/j.1365-2966.2006.11077.x)

Sometimes you just wonder why such related articles cannot be published a day earlier.

17 November 2006

Machine Gun Sentry

Samsung has developed a machine gun-equipped sentry that will be planted along the demilitarised zone border in South Korea (outside of it, of course). They have even produced a commercial for it, and frankly I found it pretty funny, in particular the way the "enemies" move "in stealth". Says a lot about South Korean's (or at least Samsung's) impression of North Korea military.

You can read the news and watch the video clip on this news site, which I got to via Slashdot.

14 November 2006

GST: Reshuffling the Cards of Wealth?

Okay, the bomb is out, and the blogosphere is, expectedly, buzzing like a disturbed hive. The primary reason outlined for the hike is

to finance the enhanced social safety nets, needed to help the lower income group

That sounds great, huh? Why then is the blogosphere so angry? Is it an instinctive response to blast any penalising policies of the hegemonic government, or are they seeing something I cannot? Seriously, if we raise taxes to help the poor and bridge the rich-poor divide which is dangerously becoming a threatening social issue, what's wrong with that?

Unless you're in financial difficulties, the rise in GST won't pose much problems for you. Certainly with my stingy lifestyle, it will be the least of my worries. Of course, the poor still has to buy stuff and hence the increase will affect them, but as mentioned, there are social nets that'll help them overcome this barrier. Furthermore, it is usually the more affluent that makes more purchases, so they will be the one who pay more. And if this money they pay gets channeled back to the poor, then isn't that a good idea?

Of course, there are better ways to fund this purpose, specifically a rise in income tax instead of GST. However, income tax hikes will pinch the richer citizens much harder than a rise in GST, and since most (if not all) of the MPs and ministers earn five digit salaries every month, they naturally won't support such a motion. (This assumes that our MPs and ministers are selfish, which I see no reason why not to, given our fanatically meritocratic and elitist system. It's no use challenging this assumption; it is a fact of reality.) So that leaves GST as the second best option available (enlighten me, anyone, of better plans that I've missed).

That is not to say I support the hike, however, at least not yet. The principle of the hike is good, but I must wait for the details first before deciding if I really agree with the hike. It is no use if the "safety nets" mentioned is just an appeasing farce, an empty gesture. It is redundant if these nets have holes big enough for the likes of Tan Jee Suan to fall through. In another words, my official stand is: I'm neutral with the hike; I need to see the details before making my decision.

04 November 2006

A Scientific Reason Why We Should Emigrate

(...or why we should air-con the island.)

Sorry if this is turning into a news aggregator, but these few days I've really been lacking in time, thanks to an upcoming report deadline for my SP2172 project as well as three term tests. So, again, no more comments on this articles except for some highlighting of interesting details.

(From New Scientist via Slashdot)

Cool down – you may live longer
11:20 03 November 2006
Roxanne Khamsi

The refrigerator is used to lengthen the life of your food, and a new study suggests a similar principle could prolong your life, too.

Researchers have found that lowering the body temperature of mice by just 0.5°C extends their lifespan by around 15%. In the future, people might be able to take a drug to achieve a similar effect on body temperature and enjoy a longer life, they say.

The only previously proven method of significantly increasing the lifespan of an animal has been through a restricted calorie diet.

Bruno Conti at Scripps Research Institute in La Jolla, California, US, and colleagues designed genetically engineered mice with a specific brain-cell defect in a region called the lateral hypothalamus. The defect forces brain cells into "overdrive", causing the region to heat up and become warmer than in a normal mouse.

Female benefit

Since, in mice, the lateral hypothalamus sits just 0.8 millimetres away from the brain’s body-temperature-controlling thermostat – called the preoptic area – it was tricked into thinking its body temperature was too high, causing the mouse to cool down.

The average body temperature of the genetically engineered mice was about 0.6°C lower than that of their control counterparts.

Even this small decrease in body temperature appeared to have a noticeable effect on lifespan, extending their lives by 12% to 20%. And the decrease in body temperature extended the lifespan of female mice more than male mice, the team found, although they are unsure why.

Free radicals

Caloric restriction, another method shown to extend animals’ lives, also causes a decrease in body temperature, Conti notes. In his study, both groups of mice ate about the same amount. In fact, the genetically engineered male mice ended up about 10% heavier than the normal male mice.

Conti says the findings show it is the lowering of body temperature – and not necessarily the consumption of fewer calories – that plays the most important role in extending lifespan.

This may be because the body burns less fuel when it is at a lower temperature, which results in the production of fewer free-radical compounds that damage cells and promote the wear and tear of ageing. Previous studies have shown that worms and fish that have decreased body temperatures live longer.

Conti says that in the future people might be able to take a drug that specifically targets the preoptic “thermostat” area in their brains to trick the body into cooling down slightly. Coming up with such a drug “will be very challenging”, but he hopes it would allow people to live longer without cutting back on the calories.

Journal reference: Science (DOI: 10.1126/science.1132191)