photo du jour

the "L" on all 6 faces with beautiful rotational symmetry

the “L” on all 6 faces with beautiful rotational symmetry

greetings all from a lovely village near Aix! i’ve seen many many lovely sights and been hosted by the marvelous Yvette and D here! But this has got to make highlight of the day: the “L” !! loong loong time ago during teenage years i spent days and weeks fiddling around with the rubik cube and found a very nice L-pattern with beautiful rotational-symmetry.. and for the last 20+ years unable to get anyone to dissect the move with, mainly because, as you can see from the video below, i can’t do it while looking 😀 . More importantly it took *six* forward rotational-symmetric moves to get there but only a combo of 3+1 (3 forward and 1 backward) rotational-symmetric moves to get back! and even more critical: there’s only a 10% chance to get back to 6-faces, other 90% i had to restart from scratch.. until this noon when i consistently (hence found a way) to get back.. In the past, every time i tried to sit down to try to understand, the continuous rotations made my head go dizzy…

debugging code

debugging code

that is until i demonstrated to the wonderfully knowledgeable D here, who promptly forwarded me the ENTIRE book on rubik cube, as well as conducted an analysis based on definition of moves, and voilà we now have a systematic language (generic formula) to get there and back from any orientation! The fact of the 3+1 offered an insight: first that you only need 4 instead of 6 moves, and that the +1 being a backward move is equal to 3 forward moves, hence the extra 3+3 forward vs 3+1 for+back! took us 1 day to ponder and 1 full evening for D to devise language and test, after i self-taped for demonstration! So, how’s that for solving a 20+year puzzle eh!

geography 102

a bit saturated in brain, so how about something fun. i quite proud of it :-), even used a virtual shovel to dig a couple of very important channels. Amazingly, a certain strait is missing!

ps- oh, colorscale + contours are in unit [km]. For completeness, i should really put lat/lon contour, but too tired… and too late. those text labels took ages.
ps2- don’t be alarmed by the 2-headed greenland, i see it all the time.

music to start the night

of pool fighting, not exactly related to the photo below, but interesting nonetheless now that i realized it was taken exactly 1 year ago! how time flies.

Read more of this post

ig opera

and Ig nobel prize, such a thing got me giggling reading today. i was first aware of it only after it’s published on the front page of the school newspaper. they hold this award ceremony every year at Harvard to celebrate unusual achievements in science. This year’s theme is “chemistry” and featured “Chemist in a Coffee Shop”, a 5-act mini-opera about chemical composition and the effects of coffee (with local soprano Maria Ferrante)

You can watch the entire ceremony here or watch the clip above from the beginning.
Read more of this post

climate change lecture & more

quite late in posting this of course, since it will take place 2 hours from now… but in case anyone out there stumbling on my site and wants to attend a free public talk about climate change’ timescale:

Here‘s full info. and location.

PS- if you’re gonna be at MIT attending this lecture, don’t forget the FREE concert of opera arias across the river. Here‘s info:

What: Opera arias and highlights
Who: Boston Landmarks Orchestra and Boston Lyric Opera
Where: Hatch Shell on the Boston Esplanade
When: Wednesday 03-Aug-2011, 7PM
Cost: Free

Here’s Event’s site.

MIT experts to discuss Japan’s nuclear crisis

Update 3:

Sites to follow:
MIT nuclear science and engineer blog
BBC news

The student-host event today (Thur Mar 17, 2011) by the MIT Energy Club was extremely resourceful.  Two figures attached here to explain essentially the basics of the nuclear power structures at Fukushima site.  You can use these 2 figures and point (1) in Update_2 to understand all needed terms that are being tossed around by the news media.  Below are my very beginner-level understanding.  Please check the MIT Nuclear Science and Engineer blog for much more accurate details and terminology.

Figure 1: hand copied from black board

Figure 1:  A schematic of the nuclear vessel at site Fukushima.  Radioactive uranium are stored in small pellets inside zirconium rods called “fuel rods“.  The whole system is submerged  under water.  As
(a) the chain nuclear reaction takes place,
(b) the generated heat boils the liquid and
(c) the steam gathered at the top is piped through channels to
(d) turn the turbine to
(e) generate electricity.  Then
(f) the steam is collected in the cooling channel which is
(g) connected to the ocean (for cooling purpose) before arriving back in the vessel.

In an emergency event such as when the cooling system is disabled,
(h) a set of “control rods” is inserted from below next to the fuel rods to stop the reaction (shut down mode).  At this point,
(i) there is still heat (termed “decay heat“) being generated from the reactions of the by-products of the original nuclear reaction, though at slower rates and capacity that during active reaction phase.  There is a need to remove this heat.  Otherwise,
(j) this heat will continue to boil and
(k) the water level in the vessel begins to drop (see liquid/steam line in vessel in Fig.1). When this water level drops below the fuel rods,
(l) the rods are exposed and heats up at faster rate. If temperature reaches ~1100C to 1200C,
(m) chemical reaction between the zirconium alloy covering the rods and steam produces hydrogen gas.
(n) The steam (and hydrogen gas mixed in) creates very large pressure inside the vessel and is vented out in a controlled manner.
(o) When the vented steam reaches open air and encounter oxygen, an explosion can happen. All this is expected.
(p) Meanwhile back in the vessel, if no water is added, the rod continues to heat up and eventually reaches the rod’s melting temperature ( > 2400 C). I’ll now point you to the scenerio presented at blog for further reading.

So, in summary, all efforts are to keep the level of water above the fuel rods in the vessel.

Figure 2, hand copied from black board

Figure 2. The vessel in Figure.1 is made out of very thick steel. Outside of that is the containment, made out of meters-thick concrete. outside of that is the secondary containment, also made of concrete. The whole thing is then housed in the reactor building. This last layer is only to keep the weather out among other minor purposes, and is not meant to as a layer of protection of radiation.



I didn’t learn much from the Starr Forum on Mar 16, 2011 (a summary of which is here).  I’m now rearranging this post to highlight what provides me with the most informative background and updates to understand the current situation in Japan:

1. Here’s a very good starting point to understand the construction of a nuclear power structure with various safety barriers to prevent radioactive materials from releasing into the atmosphere in Japan.  The post also explains the meaning of “fuel rod”, “control rod”, and other jargon and inaccurate terms with misleading meaning like “melt”. Use this picture to help you along the way. That site (nuclear energy institute) also has very good info.

2. MIT Department of Nuclear Science and Engineering briefing on Japan Nuclear Crisis, Tues Mar 15, 2011.  Here’s the video of the brief from MIT Tech TV (lots of technical details similar to the blog in point (1) above).

3. MIT “Nuclear science and engineering students, with support from faculty, are also now maintaining a blog at with information about about the incident at the Fukushima nuclear power plants in Japan.”  I’d suggest following this blog closely to get reliable up-to-date information. You can also get the most up-to-date reports from the Japanese Atomic Industrial Forum (JAIF).

There’s another event on Thursday Mar 17, 2011 (in room 56-167, @6-7pm) by the Energy Club at MIT to focus on “Energy Discussions: Hazards and Nuclear Power – Understanding the Situation in Japan“.


i haven’t read much of the news lately because every site i’ve been to has “FEAR”, “PANIC”, and their variations in gigantic letters.  I hope to get some answers at this”Starr Forum: Japan’s Nuclear Crisis” event today.  Will be back later to add more.  The intention to list it ahead of time is just in case anyone around Cambridge / Boston stumbled on my post and can make it, they can get all info here.

total lunar eclipse dec 21

In case you can see the moon on dec 21 morning, take some time to look up! full information is at

If you’re as confused about UTC / GMT / time change / etc. as i am, use this UTC world clock to sort out the time. Full schedule is also listed below.

In summary:
“If you’re planning to dash out for only one quick look -­ it is December, after all -­ choose this moment: 03:17 am EST (17 minutes past midnight PST). That’s when the Moon will be in deepest shadow, displaying the most fantastic shades of coppery red.” (NASA site quote)

schedule (if you can wake up in europe to catch moon-set 🙂 )

Tuesday 21-Dec-2010 morning

Begin, moon-set in Western Europe + England
P1 = 05:29:17 UT/GMT, 06h29 CET, 00h29 EST, 21h29 (-1day) PST
U1 = 06:32:37 UT/GMT
U2 = 07:40:47 UT/GMT
Best time: 08:16:56 UT/GMT, 09h16 CET, 03h16 EST, 00h16 PST
U3 = 08:53:08 UT/GMT
U4 = 10:01:20 UT/GMT
P4 = 11:04:31 UT/GMT, 12h04 CET, 06h EST, 03h PST
End, moon-rise in Asia

global warming, fact or fiction? — Julia Slingo

intro slide


Last week, I attended a very informative talk by Julia Slingo, the chief scientist of the UK Meteorological Office , one of the top research institutions in weather forecasting and climate research. When i’m not inside a concert hall or playing with my nephews/nieces or hiking up the mountains somewhere, this is my passion, doing research related to the polar region in particular and climate change in general.

Quite a few years ago, while in transit at an airport somewhere in the middle of the US, a woman asked me what I do for a living.  At the time, i was a graduate student just getting started in looking at melting of the ice sheets in response to global warming, so I told her as such.  Her response: “well, i’m not sure if i believe in global warming.”  My first reaction was that it’s not a religion, not like you believe in God or not.  It’s a scientific question, and there are evidences to back up conclusions about global warming.  She didn’t seem to care for reading up, and I was also stuck because as such a beginner, I didn’t know enough to give her concrete evidence.

Fast forward to now, of course there are plenty of evidences, it’s just a matter of taking the time to read and analyze them yourself.  As I can not be the expert in every field related to this complex problem, it would have taken me a long time to pull all the evidences together from this 997-page report of the intergovernmental panel on climate change (IPCC) titled “2007 IPCC report: the physical scientific basis“.

That’s what Dr. Slingo’s talk offers: a very good overview of global warming, climate change, human impact, consequences and mitigations.  Specifically, what she gave in her talk are concrete numbers.  This is my attempt to make these numbers available to everyone, as well as pointing you to where to find answers for how scientists arrive at those numbers and error bars.  Someone in the audience asked Dr. Slingo at the end of her talk what the scientific community’s response should be to questions regarding “climate change”.  Her (rough, i can’t remember word-for-word) response is that we need to be honest and provide all the available numbers.  “Climate change” is a very complex problem, and we don’t know yet all the answers.  However, what we begin to have now are actual numbers to support evidences for global warming and human impact.  There will always be doubters regardless of whether we provide them with details or not.  However, for our own goods, everything should be transparent.

So, (if you have read it this far, which makes me happy 🙂 ), I hope you will follow the trail of evidence below and make decision for yourself. The rest of this post is a very brief attempt to provide some answers / references (from Dr Slingo’s talk and IPCC-2007 report) to the following questions:

1) Is global warming happening?  What are the evidences?
2) Is human responsible for the warming?  What are the evidences?
3) What are the consequences?  What is needed now?

Read more of this post


we have another bout of “santa ana wind” this weekend. And as i’m sitting in my own pool of sweat drinking cold water and eating fruits to cool down, I’ve decided it’s time to sort out what the santa ana wind is…

screen grab from

So, here’s a rough explanation for beginners (me). the only formula needed here is pV=nRT. Read more of this post

inspirational speaker

Read more of this post