November 18, 2003

Hillbilly Astronomy

CMB: a bit of progress in understanding the data. What I want is to consider the universe as a resonant space and see what it sounds like when given a hefty thwack. I thought that I could use the data in this way but not so sure now. The data I have - if I understand it correctly - is a measure of temperature fluctuations against angular resolution of observation.

Temperature fluctuations can be read as amplitude (actually amplitude squared) and angular resolution as wavelength. The wavelength of a particular angular resolution being the length of the section of the circle it describes. As the length of the radius is the age of the universe less 300,000 years that's going to be pretty large.

So I'm going to interpret the data as amplitude v frequency, ie an FFT of the snapshot of the universe at the point that the CMB is frozen. I just have to figure out the small detail of how to put it into an IFFT and see what sound comes out. Probably be really boring and rubbish. No matter.

According to my logic, that will be the sound signature - or a sound signature  - of the CMB. If one reads about the CMB then one discovers that data is interpreted as acoustic phenomana :

What we actually see is the pattern of the sound waves that is imprinted on the temperature of the CMB.

Compressing a gas heats it up.  Letting it expand cools it down.  The CMB is locally hotter in regions where the acoustic wave causes compression and cooler where it causes rarefaction.

 . . . according to the website.

Band : there are now several members; a couple of guitars, cello, bass, banjo, vocals. The idea is to keep it to members of the department and use material relating to Astrophysics through its title. Telstar, Satellite of Love, Fly me to the Moon, Starman, The Yellow Moon of Texas, Blue Moon of Kentucky . . . . .

The Pulsars, The Astrophysicists, Cygnus X1, The Oxford Pulsars . . . .

Little Universes: made the first little universe, a small cube mirrored on the inside.

Hillbilly Astronomy: making enquiries into the hows, whys and wherefores of building equipment to make astronomical observations using cheap household materials and jumk.

What I have in mind at the minute is to build a large radio telescope, Jodrell Bank style, out of cardboard, tinfoil, radios and tvs. First though I'll start small.

Attended a seminar about merging elliptical galaxies which was pretty comprehensible except for some of the maths.

Posted by Jem Finer at November 18, 2003 10:17 PM