how i think one can cool a room in a college's hostel with no cooler or air conditioner

its getting hotter in india, and especially here in delhi. i am on the 3rd floor of my hostel, and naturally its hotter here than it would be at the ground floor.

my room is approximately 6 meter x 6 meter x 8 meter [l x b/w x h]. only a ceiling fan on top and a fluorescent tube light. the ambient temperature here should be about 34 degree celsius [i have no thermometer with me here, but to find out the ambient temperature, i put my laptop to standby mode, and then after 2 hours- to give it time to cool to ambient temperature- i resumed it from standby mode. immediately i checked the hard disk temperature in hddlife program, which showed me 35 degree celsius. i compensated for slight increase in temperature during resuming by 1 degree, and so 34 should be a very accurate calculation. here in india we call such a method an intelligent jugaad :-)].

anyways, this is uncomfortable. my friend too cribbed about it, and i suggested him something that came to my mind all of a sudden. why not fill a bucket with cold water [from the water cooler in my hostel]. the water's temperature should be at most 13-14 degrees celsius, and thus there is a good difference of about 20 degrees between water and room air.

put this big bucket in room, and let its water absorb heat. water has high specific heat, and according to newton's law of cooling, the temperature difference will ensure rapid heat absorption. i dont know whether this method will indeed be effective in making the room temperature just comfortable, or less uncomfortable at least. i think it should work, after all whatever heat is absorbed by water, its obviously reducing temperature of room. but any reduction in room temperature will also cause heat from outside room to flow in. nevertheless, there should be some benefit of this no-cost method.

if it doesnt work satisfactorily, i simply gonna take that bucket, turn it around over my head and drench myself with cold water to mar the heat.

windows xp's management of thumbs.db has a potential privacy threat

i found this out of curiosity. actually a thought came to my mind minutes back that does windows explorer delete thumbnails of those images which have been deleted from a folder, from thumbs.db too? it turns out that it doesn't.

i put 10 images in a folder

then i switched the folder to thumbnails view and this generated thumbs.db

its sha-1 hash is- E7CB4A8AA45C9CF0E64720AC670EEBFBE34FA6E4

then i removed 3 images from the folder and refreshed and re-entered the folder but thumbs.db's sha-1 hash continued to be- E7CB4A8AA45C9CF0E64720AC670EEBFBE34FA6E4

this confirms that windows xp does not delete redundant data in thumbs.db

i think this is not good engineering. a company which so vehemently emphasizes on its product being secure and responsible when it comes to privacy shouldn't take this issue lightly. its easy for image viewers like irfanview, xnview, or farstone viewer to implement reading thumbs.db and/or extracting thumbnails from it. remnants of deleted images can cause situations akin to those caused by browser's history, or by files that have been deleted, but shortcuts to whom remain in the 'recent' folder [in this case, the filename and file type is the only available data, along with date and time of the shortcut of course].

one good thing windows explorer does is to update thumbnails of those images which have same name as some previously present image in the folder, which had same filename as a newly added image. but in this case too, as i found out, if i modify the image's size and modification date time etc to match that of old image [assuming dimensions etc are all identical], windows explorer does not update the thumbnail. it is not programmed to check if a newly added image with filename and date/time same as a previously added image is different from it. this is not needed too since the probability of a newly added image being of same size and with same specifications and same size/date etc is zero for all practical purposes.

The magnitude of a Gigabyte (Gibibyte actually)

Today a friend of mine told me that good quality blank DVDs are now available for 11 Rupees (approximately 0.25 US $- down from about 15 rupees). I just smiled in surprise. Approximately 4.4 GiB of digital information can be stored for just 11 rupees now. That is about 4 Paisa per MiB. An intriguing fact is that standard floppy disks with 1.44 MB capacity are still available for 10 rupees.

As a reminder to myself of the huge amount of information that 1 GiB represents, I thought this. Consider a man with life span of 80 years. The number of seconds in his life are

80*365*24*3600 + 20*24*3600= 2522880000 + 1728000= 2524608000

1 GiB has 1073741824 bytes.

So if this man were to dictate the decoded (assume binary to decimal) form of each byte at the rate of 1 byte per second, he would manage to dictate only about 2.35 GiB in his entire lifetime, assuming he never sleeps, never eats and just keeps dictating 1 byte per second. And that is just about half of a DVD. An 11 rupee DVD.

percentage is not always the right indicator of magnitude of change of something

when i read this news, the one thing going on in my mind since many days finally got confirmed- that percentage is not always the right way of expressing change of a quantity. example this news makes one feel that reliance has reduced the rates to a lesser extent than others, whereas the reality is that they their old rates were already lower than others, and their new rates are same as rivals. mathematically, the change expressed may be correct. but from a marketing perspective, its incorrect to say that reliance reduced their rates to a lesser extent than rivals [thus implying that their final rates are higher than rivals- because initial rates of all companies were not told in the first place]. this makes me feel that if changes are to be told in percentage form, then initial values of the quantities involved must be mentioned. otherwise the inference one can draw from those percentages [or in simpler words the mental impact on reader] may not be correct, and can convey a wrong message. if i sell just 1 copy of my software today and sell 2 tomorrow, is it right for a news story to say that i achieved 100% growth? it must mention absolute numbers too. the funny thing is that this news story does mention actual numbers [although it may be seeming that i am writing something 'against' this story]. what i am writing is about many stories -some of them in respected publications like the new york times or cnet news.com- which talk only in percentages.

that said, percentage is a good indicator in many situations. example is a company sells 1 million copies of a software per month, and sells 1.1 million in a particular month, then its good to say that there was 10% growth in sales [although merely telling 10% growth still leaves something to be desired- and again this is the intial numbers]. in this case, user's inference [or impact] will not be different from what it should be. there wont be any incorrect inferences drawn unintentionally by anyone.

basically, when reporting some change, our ultimate aim shouldn't be to just mathematically

in general, i have found percentage to be good indicator when numbers involved are large compared to magnitude of change. this looks like manifestation of real world- where 'sudden huge growth or sudden huge declines' either do not happen, or happen rarely. and generally only slow growth or decline happens, which is nicely indicated by percentages.

i think one can decide on a case-by-case basis as to what to use

time to nitpick on gmail:-)

ok i know what i'm gonna write sounds really stupid but i observed this and so will write it. gmail homepage [this one i captured on 18-2-07 near 1 am] says 'over xyz' megabytes. now i assume that the number shown shows currently available space. in this sense, calling it 'over xyz' is incorrect, because its not over xyz megabytes, but equal to xyz megabytes at that instant of time. little mistake. anything wrong with this? (or with me...)

firefox's 'session restore' feature can be annoying or a privacy threat

this is what i discovered last year in my college's library where there was a problem with the ups system. it would keep shutting down all of a sudden, turning off all computers instantly. i was using minefield nightly builds then, and current firefox 2.0.0.1 implements session restore in same manner, so my experience applies to it. actually what i observed was that when firefox restores a user's session, it also logs you back into any email/blog etc that you were logged into before the crash. while this is certainly very good thing for personal/private computers, it caused me problem back then. why? i was usually logged into my email account, and had to wait till power was restored so that before leaving, i could ensure that i power up the computer, cause minefield/firefox to restore my session, and then log-out and clear the cache. i couldn't leave the place simply when computers would get turned off as if i didnt wait and log-out, someone else later would be taken straight to my email account by minefield/firefox. this made me feel that this feature is not suitable for public computers. imagine, a user using firefox at public terminal is logged into his email account, and by chance firefox crashes. the annoyed and pissed-off user leaves things as it is [either assuming that like in internet explorer, browser crash means one has to re-login, or 'not knowing at all about existence of some feature like session restore']. this wont do him good. this issue needs to be solved.


related official webpage
http://wiki.mozilla.org/Session_Restore

an interesting physics/mathematics problem on distances, speeds and time (and my solution to it)

minutes back when i logged in to my gmail account, i saw a very interesting problem sent to all his orkut friends by my junior cousin. i couldn't resist the temptation to get my hands on it. since i could not find a piece of paper nearby, i opened microsoft paint and tried solving it there (very stupid thing). i hurriedly declared victory, having thought that i had solved it, and mailed the png format image to my cousin, only to be struck by a thought that made me feel my solution was incorrect. i hastily replied again to him that previous solution is incorrect. and i set out to solve it again, this time finding a piece of torn paper. i solved it, and will soon tell him the solution too. here are the resources

below is part of mail/puzzle he sent to me
this is a real brain teaser..
WARNING:the answer may seem logically correct as the figures here have been arbitarilly chosen..

ok..so there's this girl who reaches the station at 6am everyday.Her driver comes and picks her up and they reach home by 7am.
Now,one day the girl reaches the station early..at 5am and decides to walk towards her house.She meets the driver on the way and that day they reach home by 6.40 am..
The ques is..for how long was the girl walking??..and NO the answer is NOT 20 mins....
Best of luck folks!



[red][b]please inform me the ans and the way u found it[/red][/b]

and here is original incorrect solution i sent to my cousin



here is final (hopefully correct) solution
and here is the logic

• let distance from station to home be x km
• since driver picks up girl at six (obviously he would travel from home such that he picks her immediately) and reaches at seven, x km traveled in 1 hr. driver speed= x km/hr
• since it takes him 1 hr from station to home, it takes him 1 hr from home to station. so he starts from home at 5 am
• girl too started at 5 am that day. let distance [from station] at which they meet be z km
• let girl speed be y km/hr
• girl travels z km at y km/hr, so time = z/y hr
• driver travels x-z km at x km/hr, so time= (x-z)/x
• equate time by girl to time by driver to get first equation
• since girl started at 5 and reached at 6:40, total time [girl on foot+ girl in car] = 1 hour 40 minutes. 2nd equation obtained
• since driver started at 5 and reached home at 6:40, his journey to meeting point took half of 1 hour 40 minutes i.e. 50 minutes. his distance till meeting place = x-z and time= 50 minutes and his speed as already established is x km/hr. 3rd equation obtained. 3 variables 3 equations the problem is solved!
  

I made a high score in Rocket Mania Deluxe :-)

I am happy today, because this is just 5th or 6th time I'm playing this game. Each time I had played it previously, I was casual. This was the first time I played it with seriousness and it paid off nicely. I played a 'Strategy' type round this time at Hard level- the topmost level available in this game.

Here are some of the screenshots

This one below is when I launched 6 rockets at once...

Finally, this one shows how I build complex paths to maximize the number of simultaneous rocket fires while including all the matches present on board...

Which game consoles would I buy If I had USD 500-600, and why not to buy a PlayStation 3

ALSO SEE: A related post by me on Facebook [link].

Currently, the Sony PlayStation 3 starts at about $500 for the standard version, and goes up to $600 for the premium version. Although many people are buying the $600 PS3, I believe that they could have got much more value for their 600 dollars. If I were to spend $600 on video game consoles, what I would not have done is to buy a PS3, and what I would have done is:

• Buy a Sony PlayStation 2 for $125, plus a Nintendo Wii [$250], as well as a Sony PSP [$200], for a total of $575. With the remaining $25, I would have bought a Wii classic controller [$20]. I would have spent the remaining 5 dollars feeding myself with a burger and a coke - celebrating a wiser buy! It is not hard to observe that this deal provides significantly higher value for money [VFM] than a PS3 alone. Specifically, this deal allows one to use the huge library of now-cheap PS2 games, the fun-filled modern gaming of Wii, and the portable entertainment and gaming experiences of the PSP. This deal is also more suitable for those households which have more than one kid. However, this package lacks the ultra-advanced graphics of PS3 games.
• An alternative deal, suitable for those who don't want to sacrifice graphics quality is - an Xbox 360 Core [X360] for $300, a Wii [$250], 2 Wii classic controllers [$40], and double the amount of burgers and coke... This package provides two next-generation game consoles, without sacrificing on graphics quality. Undoubtedly, this deal is better than the $600 PS3.
• Yet another alternative is to go for the X360 Core [$300], the PS2 [$125] and accessories/games worth $175. Once again, this package provides more VFM than the $600 PS3.
• Yet another alternative is to buy the standard X360 [$400], a PS2 [$125] and accessories worth $75. Again, a better buy than the $600 PS3.

PS3's VFM increases if one goes for the $500 version. It's more difficult to produce an alternative package that provides as much VFM as the $500 PS3. Some individuals may find more value in the X360 Core + PS2 + accessories [total $500] package, while others may find more value in Wii + PS2 + accessories + some games [total $500] package.

Of course, one can work out a similar alternative deal for the $400 X360 - a $250 Wii + $125 PS2 + a Wii classic controller.

The whole idea behind these alternative deals is to maximize the VFM while minimizing loss of functionality. One must also remember that these alternative deals get the owner multiple devices, providing redundancy [decreased usage of each device will increase their life; since there are multiple devices, more people can use them simultaneously].

Two things to note here:

1. The PS2 can play DVDs, as well as games from the first generation PlayStation [PS1].
2. The Wii can play NES, SNES, Sega Genesis, Turbo-Grafx 16, Nintendo 64 and GameCube games, in addition to Wii games. It is 7 game consoles in one body.

As a side note, it must be remembered that the PS3 can play all PS3, PS2 and PS1 games. One must carefully weigh one's gaming requirements before choosing a particular package. It must also be remembered that the PS3 includes an inbuilt Blu-ray player, which may be provide more value to select individuals.

Update (April 2009): It is now possible to buy an Xbox 360 Pro ($299) along with a PS2 ($99) for the price of one PS3 ($399 - and this PS3 does not even have backward compatibility with PS2 games). It is also possible to buy an Xbox 360 Arcade system along with a Blu-ray player for $399 total, a more sensible deal in my opinion than a PS3.

Update [Jul'16]: Following article is directly related to this idea - "Why The US Navy Should Build Smaller Aircraft Carriers".

Update [Mar'21]: Other things I could have spent that $1,000 on while waiting to order an iPhone X at 3am [link].

Update [May'21]: One of my relatives bought a Kit Seltos HTX and also got accessories installed from the showroom for a total of about INR 15.5 lakh [current Seltos prices are about 50K higher than when he bought]. This is his only car and he really needs two cars. He could've bought two cars while spending the same amount of money - a Skoda Rapid and a Nissan Magnite. I don't know about others, but to me this dual car deal looks much, much better than the single Seltos.

***

Update [Jul'21]: The general idea of choosing more "value" applies even to picking a single product. It isn't just about splitting a costlier product into two, higher-value-received products. For example, there's no comparison between the MG Hector / Hector Plus and the Skoda Kushaq - size, grandeur, body weight, road presence, solidity, etc. The screenshot below shows that only a fool would buy the Kushaq instead of Hector / Hector Plus.

***

Update [Jul'21]: We booked Hector Plus 7-seater diesel Super variant for approximately INR 18.5 lakh rupees on-road price. Did we violate my own principles and ideas outlined in this post? Likely yes. Could we have bought two good cars for this price instead of one great car - theoretically yes, practically no, since the reason why we bought the Hector Plus was specifically related to the current situation and requirement.

***

Yes! Yes! Yes! I Cleared Number Madness :-)

I'm all smiles. Especially because this is the first time ever I played this game :-)
Although the large number - 260 - is a little worrying...

P.S. This is an extension for Mozilla Firefox, and can be download at the official AMO website

My Photography On Flickr