To the fans of Graphene: meet silicene...

Silicene is just one atom thick layer of silicon


  http://www.newscientist.com/article/mg21428625.400-move-over-graphene-silicene-is-the-new-star-material.html

The papers:
Physical Review Letters, DOI: 10.1103/PhysRevLett.108.155501
Appl. Phys. Lett. 97, 223109 (2010); http://dx.doi.org/10.1063/1.3524215
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Graphene is one-atom-thick planar sheets of carbon atoms packed in honeycomb-like structures. It has been of great research interest because of its unique physical properties. We already saw that papers with the term "graphine" was increasing drastically since 2006 [Link ].

Silicene is the silicon equivalent of graphene.
Because it can be integrated more easily into silicon chip production lines, newscientist.com speculates that its integration into electronic devices might help produce cheaper electronic devices.

Final touchdown for the shuttle Discovery

Discovery has made its final touchdown. This time on the back of another aircraft, Boeing 747, specially made for transporting the shuttle.
Discovery was regarded as a leader of the shuttles, making the most flights: 39 missions throughout its life. The era of shuttle came to an end  in 2011.

It will be in display at the Smithsonian Air and Space Museum.
I have taken few screenshots from the NASA broadcast. Enjoy! ...

Counting arguments fail, think better!

Here is a puzzle (the answer is below, do not scroll unless you want to see it!):

8809=6            5555=0
7111=0            8193=3
2172=0            8096=5
6666=4            1012=1
1111=0            7777=0   
3213=0            9999=4
7662=2            7756=1
9313=1            6855=3
0000=4            9881=5
2222=0            5531=0
3333=0            2581=?

This one was posted in Lifehacker, the author took it from a flying Facebook post.
The clue provided was that the kids could get the answer faster than the educated thinkers who tend to think in more complex ways.  I can  imagine if your brain is going round the world to solve the problem.
I would urge you to try and guess the answer, which is much fun! Please still do not scroll.
I will even put a youtube video of Simon's cat just to avoid the answer to be seen.





 Please scroll down for the answer.



:)







:)

The answer is
2581=2.

The answer is arrived once you realize that there are two "o" in 8. Go back and check the other answers in the list counting the "o"s in the numbers on the left hand side of the puzzle.

However, this counting argument fails miserably when the numbers are written in another script.
Here, the same example is being provided in coded form of Devanagari numbers. Suppose the left hand side is the code, and right hand is the answer to the code):
८८०९ =6            5555=0
७१११ =0            8193=3
२१७२ =0            ८०९६ =5
६६६६ =4            १०१२ =1
११११ =0            ७७७७ =0   
३२१३ =0            ९९९९ =4
७६६२ =2            ७७५६ =1
९३१३ =1            ६८५५ =3
०००० =4            ९८८१ =5
२२२२ =0            ५५३१ =0
३३३३ =0            २५८१ =?
In this case, You can not count the "o" on the left hand side to arrive at the (same) answer!

 >

--> ---
Symbols: compute the values of the symbols.
Well,  think of the numbers as "variable" So that
०  ०  ०  ०  = 4 means: "०"+"० "+"० "+"० " = ४
 ie 4 of "० " = 4
=> "० " = 1
Similarly,
 ६६६६  = 4
 => "६ " = 1.
9999=4
=> "९ " = 1
and, २२२२ =0 gave: "२ " = 0
 ११११ =0 => "१ " = 0
 ३३३३  = 0 => "३ " = 0
५५५५  = 0 => "५ " = 0
७७७७  = 0 => "७ " = 0
Now do a test case: २१७२  = 0
LHS= "२ "+"१ "+"७ "+"२ " = 0+0+0+0 = 0 = RHS
proved!
Now, to solve, ८८०९  = 6
Suppose, "८ "=y
Substitute values
 y+y+1+1 = 6
 2y+2 = 6,
 => 2y = 4
 =>y=2
Therefore, y="८ "=2

 We tested it for all the examples.
Therefore, we can say:
2581 = "२ "+"५ "+"८ "+"१ " after substitution:
= 0+0+2+0 =2

The answer is 2. The method is more general


The addition is still the counting argument isn't it?
:P

(Thanks to my wife for bringing this solution to my attention.)

Bookworm @ Arxiv visualizing trends #physics

Arxiv.org is a great place to put your papers, which is in waiting for the journal line.
This is also useful to get the time stamp on your work too. Moreover, by putting the pre-print in arxiv, you will be doing a favor to many readers who wants to read your paper off the campus/institution.

They have a tool called bookworm which can search for particular words/terms that you might be interested. It is very handy to visualize how the terms are being used in the published papers.
For example, I searched for the use of "entropy", and mutual information in physics, to get the following graph.

You can use bookworm to visualize interesting trend in the use of terms for the papers submitted to arxiv. Source

See how the use of graphene has "exploded", while qubit is kind of saturated, while superluminal neutrinos spiked recently

As you can see, the  graph is very useful to see the trends of certain terms being used. Please feel free to comment whether it helps to visualize anything about the scientific field.