I would like to translate from bash to python script.
The bash contains awk, sed, pipes, cat commands.
How to write commands in python?
Ubuntu update error: Unable to lock directory /var/lib/apt/lists/
When I update using
sudo apt-get update
or
sudo apt update
I get following error.
E: Could not get lock /var/lib/apt/lists/lock - open (11: Resource temporarily unavailable)
E: Unable to lock directory /var/lib/apt/lists/
I tried updating through Software Updater and Restarted the machine.
Now its fine.
sudo apt-get update
or
sudo apt update
I get following error.
E: Could not get lock /var/lib/apt/lists/lock - open (11: Resource temporarily unavailable)
E: Unable to lock directory /var/lib/apt/lists/
I tried updating through Software Updater and Restarted the machine.
Now its fine.
Trignometric formula
Trig functions
sin(A + B) = sin A cos B + cos A sin B
cos(A + B) = cos A cos B − sin A sin B
cos(A − B) = cos A cos B + sin A sin B
sin(A − B) = sin A cos B − cos A sin B
Useful sites
https://brownmath.com
sin(A + B) = sin A cos B + cos A sin B
cos(A + B) = cos A cos B − sin A sin B
cos(A − B) = cos A cos B + sin A sin B
sin(A − B) = sin A cos B − cos A sin B
Useful sites
https://brownmath.com
Installing VESTA
Check whether curl has been installed or not.
which curl
if curl is installed, it will give you the path.
If not installed,
sudo apt-get install curl
Now, use
This will download the installer to the current directory.
Now,
sudo bash vestacp.sh
This will install vesta. First it will ask for e-mail ID. Enter a valid e-mail ID.
Then, it will ask for host. If want to use default, presee ENTER.
Then, vesta will be installed.
It may take 15 minutes to 30 minutes.
Tetrahedral site
What is tetrahedral site?
Here is a good explanation with clear sketch.
Following description and figures are taken from
https://www.tf.uni-kiel.de/matwis/amat/def_en/kap_1/illustr/t1_3_4.html
"In a tetrahedral site the interstitial is in the center of a tetrahedra forms by four lattice atoms. Three atoms, touching each other, are in plane; the fourth atom sits in the symmetrical position on top. Again, the tetrahedral site has a defined geometry and offers space for an interstitial atom."
"The configuration on top is the tetrahedral position in the fcc lattice. The black circles denote lattice points, the red circle marks one of the 8 the tetrahedral position."
"The picture on the bottom shows the tetrahedral configuration for the bcc lattice. We have (6 · 4)/2 = 12 positions per unit cell."
Figure: The tetrahedral site in FCC (above) and BCC (below) crystal structures
References
https://www.tf.uni-kiel.de/matwis/amat/def_en/kap_1/illustr/t1_3_4.htmlSI Prefixes
-
FactorNameSymbolMultiplying Factor1024yottaY1 000 000 000 000 000 000 000 0001021zettaZ1 000 000 000 000 000 000 0001018exaE1 000 000 000 000 000 0001015petaP1 000 000 000 000 0001012teraT1 000 000 000 000109gigaG1 000 000 000106megaM1 000 000103kilok1 000102hectoh100101decada1010–1decid0.110–2centic0.0110–3millim0.00110–6microµ0.000 00110–9nanon0.000 000 00110–12picop0.000 000 000 00110–15femtof0.000 000 000 000 00110–18attoa0.000 000 000 000 000 00110–21zeptoz0.000 000 000 000 000 000 00110–24yoctoy0.000 000 000 000 000 000 000 001
Source: https://www.bipm.org/en/measurement-units/prefixes.html
Teaching philosophy
Universities ask for statement of teaching interest or teaching philosophy
Important components in the statement
first one: internal honesty with myself
take the time, to think thorough and think fundamentally what it
attitude
take you put into
- statement should be completely personal.
- should use "I" instead of speaking globally
- don't explain others how to teach
- because it is going to be read by already who is teaching (they will get irritated by reading your statement if you teach them how to teach)
Important components in the statement
first one: internal honesty with myself
take the time, to think thorough and think fundamentally what it
attitude
take you put into
- statement should be completely personal.
- should use "I" instead of speaking globally
- don't explain others how to teach
- because it is going to be read by already who is teaching (they will get irritated by reading your statement if you teach them how to teach)
Riemann Hypothesis
Riemann hypothesis is one of the Millennium problems. One who prove or disprove this hypothesis will get 1 Million Dollars.
Youtube channel Numberphile has fantastic vedios explaining Riemann hypothesis. Have a look at these links.
A playlist on Prime Number and Riemann Hypothesis playlist:
http://bit.ly/primevids
Here is a database on the numerical computation of modular forms (L-Function & Modular Form database)
http://www.lmfdb.org
Riemann zeta function, Ramanujan's L-functions and Andrew Wiles's modular forms, other exotic functions. All of these functions are beleived to have Riemann hypothesis (all the non trivial zeroes are at the symmetric line (1/2))
The necesarary thing to do here is to look at the patters of all these functions, finding out the common properties and differences, and find out an idea to unite all of them or differentiate and find out the pattern and coming with the proof the Riemann hypothesis.
Youtube channel Numberphile has fantastic vedios explaining Riemann hypothesis. Have a look at these links.
A playlist on Prime Number and Riemann Hypothesis playlist:
http://bit.ly/primevids
Here is a database on the numerical computation of modular forms (L-Function & Modular Form database)
http://www.lmfdb.org
Riemann zeta function, Ramanujan's L-functions and Andrew Wiles's modular forms, other exotic functions. All of these functions are beleived to have Riemann hypothesis (all the non trivial zeroes are at the symmetric line (1/2))
The necesarary thing to do here is to look at the patters of all these functions, finding out the common properties and differences, and find out an idea to unite all of them or differentiate and find out the pattern and coming with the proof the Riemann hypothesis.
Diradicals and Triplets
Diradicals are the elusive molecules. Oxygen is one of the highly-stable diradicals.
Here are the list of diradicals
Oxygen, O2 (Exist in both singlet and triplet states)
Methylene or carbene, CH2
Dichorocarbene, CCl2
Triplets
Trianglulene
O2
Here are the list of diradicals
Oxygen, O2 (Exist in both singlet and triplet states)
Methylene or carbene, CH2
Dichorocarbene, CCl2
Triplets
Trianglulene
O2
Why getting ground-breaking results are not enough?
Consider following discoveries.
Photo electric effect
DNA - double helix structure
Asymptotic Freedom
C60 fullerene
Carbon Nanotubes
What are common in both of these discoveries?
Both discoveries, the authors failed to notice the big picture of the result. No wonder, the interpretation in both of these cases worth Nobel prize.
In this post, I will describe experimental or theoretical results that the scientists got but failed to noticed by some one but noticed by some other scientist (or by the same later). There are numerous examples to discuss. Let us see one by one.
DNA double helix story
Linus Pauling was working on finding the structure of the molecular make up of our body. He had proposed a triple-helix model earlier. At the same time, Rosalind Franklin, a brilliant postdoc tried hard to get X-ray photograph of molecular structure. She found that there are two different structures called A and B and she found in and outs of these structures. She captured the famous "Photo 51" in which the X-ray structure of DNA is clear. This was her 51st picture of B structure. Some interesting structure. But, what is the meaning? May be she don't know?!!!. If you get a result that would revolutionize this file, would you be calm and just keep the result? No. The first thing you would do as a researcher is to try to publish. This clearly shows that she doesn't realize the structure. In fact they published the paper in Nature (Molecular Configuration in Sodium Thymonucleate
Rosalind E. Franklin and R. G. Gosling, Nature 171 (1953) 740. In this paper, the authors provide the X-ray photo that gave the key hint to Watson and Crick to infer that the molecular make up of our bond is a double-helix not the triple helix as proposed by Linus Pauling. The important point here is that the original authors (Franklin and Gosling) were (in my opinion) not able infer that the structure is made of double-helix.
How Watson and Crick were able to interpret the structure?
Photoelectric effect
Albert Einstein provided correct explanation for the observed curve even though many experimental results were obtained much earlier by many scientists.
Asymptotic Freedom
The following passage is from Wikipedia.
Gerard 't Hooft, a Physics Noble laurete missed another Nobel Prized because, he failed to notice the physical significance of asymptotic freedom.
Following description is taken from Wikipedia.
"According to 't Hooft's calculations, this type of theory possessed just the right kind of scaling properties (asymptotic freedom) that this theory should have according to deep inelastic scattering experiments. This was contrary to popular perception of Yang–Mills theories at the time, that like gravitation and electrodynamics, their intensity should decrease with increasing distance between the interacting particles; such conventional behaviour with distance was unable to explain the results of deep inelastic scattering, whereas 't Hooft's calculations could.
When 't Hooft mentioned his results at a small conference at Marseilles in 1972, Kurt Symanzik urged him to publish this result; but 't Hooft did not, and the result was eventually rediscovered and published by Hugh David Politzer, David Gross, and Frank Wilczek in 1973, which led to their earning the 2004 Nobel Prize in Physics."
C60 Fullerene
Kroto was interested in the linear carbon chains that are formed in outerspace in extreme environment environment like star's atmosphere. The used laser pulses to create high temperature and expected the formation of linear chains. However, they got a sharp peak where the number of atoms that formed that particular molecule is 60. No body knew what it was. How exactly 60 carbon atoms can form a molecule which is highly stable? Even thought organic chemistry is a separate field in chemistry, this was a great puzzle. Kroto found the structure and discovered that the structure resembles the dome structure that was designed by Buckminister Fuller many years before in the field of architecture. Kroto found that 12 pentagons and 20 hexagons would form a soccer ball type molecule that caused the sharp peak in the observed spectrum.
Here, if Kroto didn't push why this peak happened, there may not be such fast growth in the carbon nano science.
Carbon Nanotubes.
What is the answer to the question "Who discovered carbon nanotubes"? The answer would be mostly the Nobel Laureate Iijima. You may read a related paper titled Who should be given the credit for the discovery of carbon nanotubes? you can see that the first observation of carbon nanotubes (or not tubes?) is by Russian scientists. But they failed to know the big picture. What Iijima did? He found the tubes in soot and characterized them. He didn't stop there. He keep on contributing to the development of carbon nanotubes. After founding something, if you don't keep on adding contribution so that the field flourish further. If some one did not do this, their contribution is much less only.
What is your favorite here?
Do you have any suggestion? Write here in the comments.
Photo electric effect
DNA - double helix structure
Asymptotic Freedom
C60 fullerene
Carbon Nanotubes
What are common in both of these discoveries?
Both discoveries, the authors failed to notice the big picture of the result. No wonder, the interpretation in both of these cases worth Nobel prize.
In this post, I will describe experimental or theoretical results that the scientists got but failed to noticed by some one but noticed by some other scientist (or by the same later). There are numerous examples to discuss. Let us see one by one.
DNA double helix story
Linus Pauling was working on finding the structure of the molecular make up of our body. He had proposed a triple-helix model earlier. At the same time, Rosalind Franklin, a brilliant postdoc tried hard to get X-ray photograph of molecular structure. She found that there are two different structures called A and B and she found in and outs of these structures. She captured the famous "Photo 51" in which the X-ray structure of DNA is clear. This was her 51st picture of B structure. Some interesting structure. But, what is the meaning? May be she don't know?!!!. If you get a result that would revolutionize this file, would you be calm and just keep the result? No. The first thing you would do as a researcher is to try to publish. This clearly shows that she doesn't realize the structure. In fact they published the paper in Nature (Molecular Configuration in Sodium Thymonucleate
Rosalind E. Franklin and R. G. Gosling, Nature 171 (1953) 740. In this paper, the authors provide the X-ray photo that gave the key hint to Watson and Crick to infer that the molecular make up of our bond is a double-helix not the triple helix as proposed by Linus Pauling. The important point here is that the original authors (Franklin and Gosling) were (in my opinion) not able infer that the structure is made of double-helix.
How Watson and Crick were able to interpret the structure?
Photoelectric effect
Albert Einstein provided correct explanation for the observed curve even though many experimental results were obtained much earlier by many scientists.
Asymptotic Freedom
The following passage is from Wikipedia.
Gerard 't Hooft, a Physics Noble laurete missed another Nobel Prized because, he failed to notice the physical significance of asymptotic freedom.
Following description is taken from Wikipedia.
"According to 't Hooft's calculations, this type of theory possessed just the right kind of scaling properties (asymptotic freedom) that this theory should have according to deep inelastic scattering experiments. This was contrary to popular perception of Yang–Mills theories at the time, that like gravitation and electrodynamics, their intensity should decrease with increasing distance between the interacting particles; such conventional behaviour with distance was unable to explain the results of deep inelastic scattering, whereas 't Hooft's calculations could.
When 't Hooft mentioned his results at a small conference at Marseilles in 1972, Kurt Symanzik urged him to publish this result; but 't Hooft did not, and the result was eventually rediscovered and published by Hugh David Politzer, David Gross, and Frank Wilczek in 1973, which led to their earning the 2004 Nobel Prize in Physics."
C60 Fullerene
Kroto was interested in the linear carbon chains that are formed in outerspace in extreme environment environment like star's atmosphere. The used laser pulses to create high temperature and expected the formation of linear chains. However, they got a sharp peak where the number of atoms that formed that particular molecule is 60. No body knew what it was. How exactly 60 carbon atoms can form a molecule which is highly stable? Even thought organic chemistry is a separate field in chemistry, this was a great puzzle. Kroto found the structure and discovered that the structure resembles the dome structure that was designed by Buckminister Fuller many years before in the field of architecture. Kroto found that 12 pentagons and 20 hexagons would form a soccer ball type molecule that caused the sharp peak in the observed spectrum.
Here, if Kroto didn't push why this peak happened, there may not be such fast growth in the carbon nano science.
Carbon Nanotubes.
What is the answer to the question "Who discovered carbon nanotubes"? The answer would be mostly the Nobel Laureate Iijima. You may read a related paper titled Who should be given the credit for the discovery of carbon nanotubes? you can see that the first observation of carbon nanotubes (or not tubes?) is by Russian scientists. But they failed to know the big picture. What Iijima did? He found the tubes in soot and characterized them. He didn't stop there. He keep on contributing to the development of carbon nanotubes. After founding something, if you don't keep on adding contribution so that the field flourish further. If some one did not do this, their contribution is much less only.
What is your favorite here?
Do you have any suggestion? Write here in the comments.
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