Thomas Saraceno's 'On Air' exhibition

• Date: October 17th, 2018 - January 6th, 2019
• Where: Palais de Tokyo, Paris
• Link: https://www.palaisdetokyo.com/fr/evenement/air

Description

Thomas' idea was to develop a sort of multimessenger control room where all the data coming from the various experiments (VIRGO, KM3Net, Auger, Antares, AMS) would be available to the visitors.

People Involved

• EGO: V. Boschi, S. Cortese, G. Di Biase, G. Hamming, S. Katsanevas
• INFN: V. Napolano
• KM3Net: G. Riccobene
• Auger: A. Etchegoyen, M. Platino
• AMS: M. Duranti
• Studio Sareceno: S. Cantoni, V. Castellano, T. Saraceno

Technical Requirements

• A set of 11 Raspberry PIs: one for each screen plus one for h(t)
• A set of 10 monitors with HDMI input
• Fixed IP to be added to the firewall white list
• A virtual machine dedicated to both the Telescreen and h(t) sonification process has to be created (vid03.virgo.infn.it).

Room overview

h(t) sonification

• Link: http://vid03.virgo.infn.it/sound
• Description: A python script (/users/vboschi/Saraceno/Saraceno.py) was developed to acquire h(t), and process it. If the interferometer is working and live data are available in the last 5 minutes, the script prepares the audio file from the live data. If the not it processes a random 5 minute segment from last scientific run data (O2). Only two files are created (h1.wav, h2.wav) that are overwritten every cycle. The process runs of vid03 dedicated virtual machines. The files are written in a local folder that is synchronized with a public one. The sound fles are played through a simple web based html5 player called wimpy (https://www.wimpyplayer.com/).

Screens pictures

Live Video Stream 1

Live Video Stream 2

Virgo Dashboard (DMS)

Binary Neutron Star Horizon (BNS Range)

Suspensions

Spectrogram

Noise Budget

Screens captions

A new istance of the Telescreen (TelescreenArt) and a series of VIM configurations file have been created. In order to reload the screens containing the VIM data, a plugin called AutoRefresh had to be installed in the RPi default browser (chromium).

Live Video Stream 1:

• NE, WE: video stream of the laser beam reflected from the Virgo end mirrors, 3 km far from the laser.
• IMC, MC: video streams that show the status of the laser, before entering the detector. They are acquired inside the so-called mode cleaner cavity.

Live Video Stream 2:

• B1, B1p, B1s2: video stream of the laser beam reaching the output photodiodes. Here the signals containing the gravitational waves are acquired. Depending on the status of the detector, interference fringes can be clearly seen.
• B4: The interferometer guardian angel: The power recycling pick-off photodiode. It is used to monitor the light sent back to the laser and gives an indication of the overall alignment of the detector.

Virgo Dashboard (DMS): live monitoring system of all interferometer subsystems. This screen gives an idea of the complexity of the detector. In a fully working interferometer all the flags should be green.

Sensitivity Curve: Current noise of the detector as a function of frequency (Hz). The extremely small numbers on the y axis, if multiplied by the length of the arm (3000), give the differential displacement in meters the interferometer is able to measure. This plot gives an idea of the incredible sensitivity of this amazing ruler. At the minimum of the curve (100 Hz) we have for example 3000*2*10^{^-23}=6*10^{^-20} m, that is about 1/15000 of the proton radius !!

Binary Neutron Star Horizon (BNS Range): This number express the radius of the universe in which the interferometer is currently able to detect binary neutron star gravitational-wave signals, such as the GW170817 last year event. The number is expressed in Mpc: 1 Mpc = 3000000 light years !!

Suspensions: In the six top row plots the position of the Virgo superattenuator stages of the end mirrors are plotted. The signals sent to their relative coils in order to move the mirrors are plotted in the bottom row. The effect of ground motion caused by the moon gravitational attraction can be seen on time scales of the order of 48 hours.

Earthquakes and Sea Activity: This plots show the seismic noise of the last 24 hours measured by seismometers located close to the end mirrors. The plots on the left column show the noise caused by nearby or remote earthquakes, while on the right the ground motion due to the
sea activity is displayed.

Weather: This plots shows the summary of the weather conditions of the last 24 hours at Virgo site. In the left column plots, the wind speed, its direction and the intensity of rain dropped are shown. The left column plots display the relative humidity of all Virgo buildings.

Spectrogram: This plot show how much the various frequency
components of the output signal of the detector had changed in the last 24 hours.

Noise Budget: This complex plot is a summary of all the noise sources affecting the interferometer sensitivity. They comes both from the environment and the detector components.

Screens links

• Live Video Stream 1: https://vid03.virgo.infn.it:8084/display.html?monitor=1&update=0
• Live Video Stream 2: https://vid03.virgo.infn.it:8084/display.html?monitor=2&update=0
• DMS: https://dms.virgo-gw.eu/
• Sensitivity: https://vim.virgo-gw.eu/?config=65
• BNS Range: https://vim.virgo-gw.eu/?config=65
• Suspensions: https://vim.virgo-gw.eu/?config=68
• Earthquakes and Sea Activity: https://vim.virgo-gw.eu/?config=69
• Weather: https://vim.virgo-gw.eu/?config=70
• Spectrogram: https://vim.virgo-gw.eu/?config=67
• Noise Budget: https://vim.virgo-gw.eu/?config=66

-- Main.Vboschi - 27 Jan 2019