Animation of the Italy Earthquake’s Seismic Velocity


A “real-time” animation of the seismic (vertical) velocity of Italy’s 5.5 Mw earthquake that hit between the Aquila and Rieti provinces. The second half of the animation shows the whole country and surrounding area.

Real-time indicates that the video reflects how the waves propagated in real-time. It’s neither slowed down not sped up.

Red color indicates relatively higher vertical velocities indicating the ground is moving upwards while the blue color indicates the lower (negative) velocities indicated a downward movement of the ground. Color intensity refers to the magnitude.

Jacqueline du Pré – Interview & Dedication


In a previous post you read about Jacqueline du Pré‘s loss of ability to play. In this post I share with you a previously unpublished interview with her from 1980. Following that is a re-edited version of a film made in 1967. She was in love with Elgar’s concerto (see previous post for her performance)

Continue reading

Facebook Introduces Physical Keys (FIDO U2F) as Security


Today, January 26, Facebook announced that they have introduced ‘physical keys’ (i.e. usb keys) as an option of the two-factor authentication. Google has already introduced this two years earlier.

A few years ago two-factor authentication was introduced by Google and Facebook among many other companies which allowed the user to set an extra security measure to avoid loosing their account in case their password was stolen. This extra layer required the user, if using a new computer or IP, to enter an authentication code generated (regularly) through an app (e.g. Google’s authenticator for Google accounts).

Continue reading

Check if you’ve had a security breach


Many of the popular websites and services have been or at some point or will be targetted and exploited. As a result, it is most likely that at least one of your online accounts has been pwned at some point. This doesn’t mean your account has been cracked but it could mean that some of your private information has been leaked (e.g. email, password, personal info like date of birth, etc…). Recently Gmail has been exploited by attachement phishing.

There’s no guaranteed way to check if your account has been hacked but one way is to check if you’ve been pwned. Just enter your username or email to check if you’ve been pwned.

Fluid Mechanics video lectures


In a previous post we selected some resources on fluid dynamics. In that post we suggested the videos from the National Committe for Fluid Mechanics (notes on the website) that date to the 1960’s and is an excellent exposition to fluid mechanics. We share them below following a very clear demonstration of Euler’s equation and Bernoulli’s integral:

Continue reading

Sound of the Moving Earth


What do you think an earthquake would sound like if you could hear it?

Here’s a sample (opens in a new tab).

The audio was generate by processing seismic data.

More samples are available on from the source where you can also find the corresponding spectrograms, (i.e. the representation of the frequency content of the signal and how it varies in time).

via Zhigang Peng @ Georgia Institute of Technology

Credit: Peng, Z., C. Aiken*, D. Kilb, D. Shelly, B. Enescu (2012), Listening to the 2011 magnitude 9.0 Tohoku-Oki, Japan earthquake, Seismol. Res. Lett., 83(2), 287-293, doi: 10.1785/gssrl.83.2.287. , and Kilb, D., Z. Peng, D. Simpson, A. Michael and M. Fisher* (2012), Listen, watch, learn: SeisSound video products, Seismol. Res. Lett., 83(2), 281-286, doi: 10.1785/gssrl.83.2.281.

As a follow-up here’s a nice video from USGS

Links – Have Fun Typing & Learning Vi/Vim Shortcuts


Vim Adventures – navigate the Vi/Vim land by learning Vi/Vim shortcuts

ZType – Typing (shooting) Game