Gravity Waves Bernard Schutz
<p>Jun 29, 2010 10:10 PM
 
multi-media presentation ... v cool movies, slides, sounds... he narrates it.
 
American working in Potsdam near Berlin.
 for lecture, see below *
Afterward I chat with his prof. colleague Rai (Rainer) Weiss... see Wiki  v famous... head of LIGO.
Laser interferometry grav wave detector.
 
I ask Rai abt reln of BHs black holes and birth of universer BB = big bang.
his A:
 
1) people always thot we lived in closed universe  (inside an event horizon)...
gor far enuf away u come back to yourself...  not so.
U can directly test this ...  objects should get smaller as u go further out  (rather than
smaller as  1/r)... they do NOT.
Universe appears to be Euclidean!
 
two fundamental mysteries ... DM and DE...
DM  is direclty responsible for the clumping that we see in WMAP...
the initl anisotropy.  It could not be ordin matter cuz  ordin matter interacts with
photons and wud've smooshed out the black body radiation into homogeneity...
it would've gotten rid of the regularities.  DM does NOT interact with photons.
 
DE is a total mystery... was competely unknown til recently.
 
BH's...  biggest ones are only perhaps a billion solar masses... also,
biggest galaxies are only abt 1 trillion stars.... no more.
 
So, BH's are not big enuf to directly relate to Universe or big bang.
 
Rai wonders abt incredible effectiveness of math.... in partic. he loves the
Navier Stokes eqn.... explains  waterfalls and ocean spray etc.
Main lecture...
LISA Conference is on-going now at SLAC.
BERNARD SCHUTZ  Bernie Schutz...  Music of the Spheres...
Sound Sources... BHs, Neutron Stars,  all produce gravity waves.
propagate at the speed of light...  produced by anything that alters gravity....
eg irregular sphere spinning around.
 
Great analogy... movie of a jungle  with and without sound...
sound enables u discover birds, wild animals  etc.
 
Neutron stars are remnants of supernovae... spin at 700X/sec
 
white dwarves  orbiting around one another  perhaps once per hour.
 
2 NS  neut stars orbiting then crash into one another and explode.
2 merging BHs  ONLY grav waves are emited ... nothing else...
can only detect by grav waves.
 
Big BHs are produced by supernovae
GIANT BHs  (eg  106 to 109 solar masses are at centers of galaxies.
BH is pure gravity.
 
time on BH may flow at few mins per million years.
 
many land based laser interfer...
AIGO in australia
LIGO in Louisiana and Washington
TAMA in Japan
Virgo in Pisa.
Geo600
 
3 boys crash cymbals ... detct location by binaural disparity.
 
LISA  3 satellites orbiting  in an equilat triangle  and  shooting lasers at each other...
can measure distance btwn them v accurately.
As space btwn them changes (as its warped by grav waves) then will measure
change in distance.
Length change will be 10-12 cm.
 
Compare to LIGO which curr. detects  10-16 cm   not sensit enuf ...
nee dto go down to 10-17 to see effect.
 
At distance of entire galaxy get change of 30 cm.
 
can determine how far away it is,  what its mass is.  how fast orbit is changing  (from chirp)
 
No results so far from any earth system.
Grav waves have never been detected.
 
my Q:  angle resolution   her says 1 degr for a burst.
but a few arc seconds for a continuous signal like a pulsar.
 
Hope to get lots of BHs and NSs   maybe 40 per year.
 
Space is v stiff... takes a lot of energy to deform it.
 
BHs dictate how and where glaxies form  (so , tied up with DM).
 
 
 
 
 
 
 
 
 
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