266. First two weeks of February on NEQNET

It seems that I did not do summary of activities on NEQNET for quite a bit Let me first quickly go through some relevant and irrelevant statistics.

First of all, the number of subscribers to NEQNET has finally crossed the magic number of 200 (two-three days ago). Thank you so much, all of you, who decided to subsribe – you made me extremely happy, made my day! On the other hand – the number of daily visitors is currently more than 1000 and, as I see, at least half of them are not newcomers. If, by a chance, you are reading NEQNET on a constant basis but are not yet subscribed – could I ask you to become a subscriber? It is possible to either subscribe to NEQNET RSS feed or get sent new posts directly to your Inbox.

Second, NEQNET Alexa rank has dropped below 250000 in February (that is, according to Alexa we are in the list of best performing 250000 sites in the world). NEQNET has outperformed “Not even wrong” long time ago (a couple of months ago or so) and will hopefully outperform Lubos Motl’s “The reference frame” in March. Lubos, even if I won’t be able to do that, the process of competition will give me a lot of fun

So, what was the buzz about at NEQNET during previous two weeks?

1. Turbulence

1.1. Turbulence: Kolmogorov law derived in one line

I explain how to derive Kolmogorov law for developed turbulence from simple dimension analysis.

1.2. Turbulence: brief introduction into phenomenon

I give a brief physical introduction into the subject of developed turbulence and transition to it.

1.3. Physics of turbulence: four puzzles

I shortly discuss four main puzzles that do not allow us to understand the physics of turbulence quantitatively: the order of magnitude of Reynolds number corresponding to transition to turbulence, universality vs. non-universality, importance of viscosity and intermittency. The post gave rise to a bunch of very interesting comments including the one by Prof. Tanveer, where he discusses the issue of turbulent viscosity.

2. String theory, field theory

2.1. Starting dS/CFT: Hilbert space

With this post, I start to discuss the controversial dS/CFT correspondence. In this post, I explain why it should be a rather strange duality – since the dimension of dS Hilbert space is finite.

2.2. Continuing dS/CFT – why it is so hard to prove?

I continue discussion of dS/CFT correspondence turning to the criticisms by Dyson, Susskind and Lindesay.

2.3. Continuing dS/CFT – the correspondence. Part 1.

I identify the main potential problem of dS/CFT correspondence – there is no causal contact between and physics at the bulk.

2.4. Counting states in the Bousso-Polchinski landscape

The guest blog post by Antonio Segui and Cesar Asenio from the U. of Zaragoza who explain how to properly count low energy states on Bousso-Polchinski landscape.

2.5. Winding effects on brane/antibrane pairs

Another guest blog post by Niko Jokela who explains how to treat brane/antibrane systems on compact spaces.

3. Physic: other

3.1. Top ten open problems in physics

I present a list of top ten unsolved problems in physics: nature of time, turbulence, confinement, string theory, information loss, thermonuclear fusion, high superconductivity, etc.
Somehow, the post became rather popular

3.2. Book review: D. Yoshioka, “The quantum Hall effect”

That’s what it is: a brief review of a very nice textbook on fractional and integer quantum Hall effect.

4. Economics, biology, things other than physics

4.1. On credit market debt

I briefly discuss the issue of US credit market debt in its relation to GDP and explain how it lead to the take-off of global financial crisis.

4.2. An efficient local method for community detection in large networks

A guest blog post by Symeon Papadopoulos (Informatics and Telematics Institute, Greece) who teaches us how to identify a closed community within a network.

4.3. Interesting news from PI

Exciting news from the Perimeter Institute – Nima Arkani-Hamed, Subir Sachdev, Yakir Aharonov, Neta Bachall, Juan Igancio Cirac, Gia Dvali, Ashoke Sen, Leonard Susskind, Xiao-Gang Wen are new distinguished research chairs.

4.4. Scientist’s gadgets: Kindle 2 vs. Palm

where I explain how to convert your existing ebooks and pdf files into native Kindle 2 format.

Cheers and thanks so much for coming back!