a = 0.998M: Waveform sounds

The results given here describe the evolution of orbits around a black hole with a/M = 0.998, fairly close to the event horizon (from r/M = 4.0 down to either r/M = 1.3 or to the last stable orbit, whichever comes first).

The sound files come in 3 flavors: 8 bit mono .au files, 16 bit mono .wav files, and 16 bit stereo .wav files. The stereo files encode the plus polarization in one channel, cross in the other; the mono files encode plus and cross separately.

My results here include only a truncated set of multipoles and harmonics of the two orbital frequencies. (Recall l is similar to the usual spherical harmonic index, m is the multiple of the phi frequency and ranges from -l to l, and k is the multiple of the theta frequency and ranges - in principle - from -infinity to infinity.) In particular, I fix lmax to 4, and allow k to range from -lmax to lmax.

.au files

I play the .au files using sox: 
sox sound.au -U -b -r 8000 -t au /dev/audio
8000 is the sample rate. If you use this value, the sound you hear is equivalent to a .013 solar mass body spiraling into a 130 solar mass black hole. You can change the mass normalization by fiddling with this rate: doubling the rate doubles the masses, etc. (The mass ratio is set in stone - I fixed it at 104 when I generated the sounds.)

Initial iota = 0 degrees (note that only k = 0 contributes):

  • Viewed down the pole: The plus polarization. The cross polarization.
  • Viewed 30 degrees off the pole: The plus polarization. The cross polarization.
  • Viewed 60 degrees off the pole: The plus polarization. The cross polarization.
  • Viewed in the equator: The plus polarization. The cross polarization.

    Initial iota = 20 degrees:

  • Viewed down the pole: The plus polarization. The cross polarization.
  • Viewed 30 degrees off the pole: The plus polarization. The cross polarization.
  • Viewed 60 degrees off the pole: The plus polarization. The cross polarization.
  • Viewed in the equator: The plus polarization. The cross polarization.

    Initial iota = 40 degrees:

  • Viewed down the pole: The plus polarization. The cross polarization.
  • Viewed 30 degrees off the pole: The plus polarization. The cross polarization.
  • Viewed 60 degrees off the pole: The plus polarization. The cross polarization.
  • Viewed in the equator: The plus polarization. The cross polarization.

    Initial iota = 50 degrees:

  • Viewed down the pole: The plus polarization. The cross polarization.
  • Viewed 30 degrees off the pole: The plus polarization. The cross polarization.
  • Viewed 60 de4rees off the pole: The plus polarization. The cross polarization.
  • Viewed in the equator: The plus polarization. The cross polarization.

    Initial iota = 60 degrees:

  • Viewed down the pole: The plus polarization. The cross polarization.
  • Viewed 30 degrees off the pole: The plus polarization. The cross polarization.
  • Viewed 60 degrees off the pole: The plus polarization. The cross polarization.
  • Viewed in the equator: The plus polarization. The cross polarization.

    .wav files

    Initial iota = 0 degrees (note that only k = 0 contributes):

  • Viewed down the pole: The plus polarization. The cross polarization.
  • Viewed 30 degrees off the pole: The plus polarization. The cross polarization.
  • Viewed 60 degrees off the pole: The plus polarization. The cross polarization.
  • Viewed in the equator: The plus polarization. The cross polarization.

    Initial iota = 20 degrees:

  • Viewed down the pole: The plus polarization. The cross polarization. Both polarizations in stereo.
  • Viewed 30 degrees off the pole: The plus polarization. The cross polarization. Both polarizations in stereo.
  • Viewed 60 degrees off the pole: The plus polarization. The cross polarization. Both polarizations in stereo.
  • Viewed in the equator: The plus polarization. The cross polarization. Both polarizations in stereo.

    Initial iota = 40 degrees:

  • Viewed down the pole: The plus polarization. The cross polarization. Both polarizations in stereo.
  • Viewed 30 degrees off the pole: The plus polarization. The cross polarization. Both polarizations in stereo.
  • Viewed 60 degrees off the pole: The plus polarization. The cross polarization. Both polarizations in stereo.
  • Viewed in the equator: The plus polarization. The cross polarization. Both polarizations in stereo.

    Initial iota = 50 degrees:

  • Viewed down the pole: The plus polarization. The cross polarization. Both polarizations in stereo.
  • Viewed 30 degrees off the pole: The plus polarization. The cross polarization. Both polarizations in stereo.
  • Viewed 60 degrees off the pole: The plus polarization. The cross polarization. Both polarizations in stereo.
  • Viewed in the equator: The plus polarization. The cross polarization. Both polarizations in stereo.

    Initial iota = 60 degrees:

  • Viewed down the pole: The plus polarization. The cross polarization. Both polarizations in stereo.
  • Viewed 30 degrees off the pole: The plus polarization. The cross polarization. Both polarizations in stereo.
  • Viewed 60 degrees off the pole: The plus polarization. The cross polarization. Both polarizations in stereo.
  • Viewed in the equator: The plus polarization. The cross polarization. Both polarizations in stereo.
    Last modified 8 April 2002.