Victoria Kaspi Public Lecture: The Cosmic Gift of Neutron Stars

A very fine introduction by Prof. Dr. Victoria Kaspi to neutron stars, pulsars, magnetars, binary pulsars. Explaining their use in test for general relativity, and detection of gravitational waves.

She also mentions Einstein@Home.

Homepage of Prof. Kaspi is here. A recent (6-Jan-2017) observation by Prof. Kaspi was given by NASA. She was a pupil and Ph.D. candidate under Joseph Taylor (K1JT).

Arnold Heinrich Klausmeier

On 16-Dec-2016 my father died after a long and suffering disease.

Born on 28-Nov-1934, he witnessed World-War-II, 1939-1945, separation of Germany, Suez Crisis, 1956, Cuban Missile Crisis, 1962, Vietnam War, Chinese Cultural Revolution, 1966-1976, but also the German reunification, and the Euro.

As requested by my father we four children each held a funeral eulogy.

In school:
2-pult

The family:
3-familie-in-dtmd

Two of the nine grandchildren:
5-kunstarnoenkel

Standing in Commerzbank tower in Frankfurt:
100_0561

Cablesurf Channel Statistics

Cablesurf is a German internet-cable-provider. They deliver Technicolor modem and set-top boxes to the end customers.

My cable modem model is:

HW Revision       1.0            VENDOR           Technicolor
BOOT Revision     2.4.0          SW Revision      STDD.01.05
MODEL             TC7200.20      Software Version STDD.01.05
Serial Number     00997509604426		
Mta Serial Number 00997509604426

Software Build and Revision
Firmware Name         TC7200.20-DD.01.05-150924-F-1FF.bin
Firmware Build Time   11:45:59 Thu Sep 24 2015

Signal/Noise ratio for downstream is:

Channel	Lock     Modulation  Channel   Symbol   Freq  Power      SNR
        Status               ID        Rate
1       Locked   QAM256      145       6952000        4.1 dBmV   40.3 dB
2       Locked   QAM256      146       6952000        4.4 dBmV   40.4 dB
3       Locked   QAM256      147       6952000        4.8 dBmV   40.8 dB
4       Locked   QAM256      148       6952000        5.1 dBmV   40.8 dB
5       Locked   QAM256      149       6952000        5.2 dBmV   40.8 dB
6       Locked   QAM256      150       6952000        5.0 dBmV   40.8 dB
7       Locked   QAM256      151       6952000        4.7 dBmV   39.9 dB
8       Locked   QAM256      152       6952000        4.1 dBmV   40.3 dB

Signal/Noise ratio for upstream is:

Channel	Lock    Modulation   Channel   Symbol   Freq   Power
        Status               ID        Rate
1       Locked  QAM64        1         5120 Ksym/sec   45.5 dBmV
2       Locked  QAM64        2         5120 Ksym/sec   47.0 dBmV
3       Locked  QAM64        3         5120 Ksym/sec   47.0 dBmV
4       Locked  QAM64        4         5120 Ksym/sec   47.5 dBmV

I ordered 120MBit/s, but speed according T-Online speedtest is as follows:
cablesurf-speed1

I attribute the drop from the bought speed to peering between Telekom and Cablesurf.

Checking my Unitymedia connection with T-Online speedtest gives:
unitymediaspeed2

slurmd confused of pid-file

I wrote on SLURM used on Ubuntu here. As I moved to Arch Linux I of course use the fine AUR package slurm-llnl maintained by Gordian Edenhofer.

After upgrading to version 16.05.7-1 I noticed the following: If slurmd is started by systemd then the pid-file specified for systemd in /lib/systemd/system/slurmd.service (PIDFile) should match the pid-file location (SlurmdPidFile) given in /etc/slurm-llnl/slurm.conf.

By the way, if one gets an error

slurm_receive_msg: Zero Bytes were transmitted or received

check your date and time of your nodes.

Statistics of this Blog: Crossed 40.000 Views

This blog was viewed more than 40.000 times and had more than 30.000 visitors. As in this post, here are the numbers:

viewspermonthnumbers2016-11

All these increases by 10.000 views all come roughly every eight months, see 30.000 (Jan-2016), 20.000 (Apr-2015), 10.000 (Sep-2014). So I kind of have reached a steady-state.

The averages per day are:

viewsavgdaynumbers2016-11

The development of visits is as below:

viewspermonth2016-11

Top posts (all time) are:

topposts2016-11

Statistics since February 25, 2012, most visits come from US and Germany by a wide margin, India has replaced France as third place:

viewspercountry2016-11

Bluetooth Headphones in Arch Linux

There is a big difference between noise-cancelling headphones, and classical headphones without noise-cancelling ability! Especially when you use them in a noisy environment, like a plane or a large office bureau. Inspired by a positive review of the Bose headphones by Marques Brownlee, I bought them.

Here is the review:

Pairing with my OnePlus One smartphone was completely automatic and works like a charm. No further explnation is required.

Paring with a PC/laptop running Arch Linux needed a little more effort. Some advice in Bluetooth headset helped me alot.

One-time configuation:

systemctl start bluetooth.service
hciconfig hci0 up piscan
pacmd list-sinks | grep index:
bluetoothctl

In bluetoothctl enter

help
show
devices
pair xx:yy:...
trust xx:yy:...
paired-devices

I had to delete the directory below /var/lib/bluetooth. Apparently something was stored there which shouldn’t have been there.

Once the pairing works, as described above, I just use:

systemctl start bluetooth.service
hciconfig hci0 up piscan

for starting bluetooth and making my PC with bluetooth visible. I switch on the headphone, which normally finds the PC in less than a second. Then I have to set the right sink via pacmd:

pacmd set-default-sink `pacmd list-sinks | grep index: | tail -1 | cut -d " " -f6`

Checking that all is well is:

pacmd list-sinks | grep index:

Once paired with your Linux machine, yo have to repeat set-default-sink if you lose the connection to your Linux machine, for example by walking too far away. If you lose Bluetooth connection apparently sound output will go to the regular speakers of your Linux machine. In case you are working in a large office other people will hear your music. Of course, you can mute the regular loudspeakers of your Linux machine using

pacmd set-sink-volume 0 0

assuming sink #0 is regular loudspeaker.