Transcript of An Indian adventure in gravitational wave astronomy Tarun Souradeep, IUCAA, Pune Spokesperson,...
- Slide 1
- An Indian adventure in gravitational wave astronomy Tarun
Souradeep, IUCAA, Pune Spokesperson, IndIGO Consortium (Indian
Initiative in Gravitational-wave Observations) www.gw-indigo.org
IISER, Pune Feb 4, 2012
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- Special Relativity (SR) replaced Absolute space and Absolute
Time by flat 4- dimensional space-time (the normal three dimensions
of space, plus a fourth dimension of time). In 1916, Albert
Einstein published his famous Theory of General Relativity, his
theory of gravitation consistent with SR, where gravity manifests
as a curved 4-diml space-time Theory describes how space-time is
affected by mass and also how energy, momentum and stresses affects
space-time. Matter tells space-time how to curve, and Space-time
tells matter how to move. Space Time as a fabric
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- Earth follows a straight path in the curved space-time caused
by suns mass !!!
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- Einsteins Theory of Gravitation experimental tests Mercurys
orbit perihelion shifts forward Mercury's elliptical path around
the Sun shifts slightly with each orbit such that its closest point
to the Sun (or "perihelion") shifts forward with each pass.
Astronomers had been aware for two centuries of a small flaw in the
orbit, as predicted by Newton's laws. Einstein's predictions
exactly matched the observation.
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- Einsteins Theory of Gravitation Matter bends light:
Gravitational lens The position of a distant star on the sky shifts
due to the gravity of sun First observational confirmation of
Einsteins theory
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- Gravitational lens
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- Einstein Ring Einstein Cross A nearer galaxy lenses a distant
one that happens to be exactly along the same line of sight !! Four
distinct images of gravitationally lensed distant quasar i!!
Interesting Gravitational lens !
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- Grandest Gravitational lens ! Distant galaxies beyond a cluster
lens into arcs .
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- Beauty & Precision
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- What happens when matter is in motion?
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- Einsteins Gravity predicts Matter in motion Space-time ripples
fluctuations in space-time curvature that propagate as waves
Gravitational waves (GW) In GR, as in EM, GW travel at the speed of
light (i.e., mass-less), are transverse and have two states of
polarization. The major qualitatively unique prediction beyond
Newtons gravity Begs direct verification !!!
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- A Century long Wait Einsteins Gravitation (1916-2011): Beauty :
symmetry in fundamental physics mother of gauge theories &
precision : matches all experimental tests till date to high
precision Gravitational Waves -- travelling space-time ripples are
a fundamental prediction Existence of GW inferred beyond doubt
(Nobel Prize 1993) Feeble effect of GW on a Detector strong sources
GW Hertz experiment ruled out. Only astrophysical systems involving
huge masses and accelerating very strongly are potential detectable
sources of GW signals. GW Astronomy link Astrophysical systems are
sources of copious GW emission: GW emission efficiency (10% of mass
for BH mergers) >> EM radiation via Nuclear fusion (0.05% of
mass) Energy/mass emitted in GW from binary >> EM radiation
in the lifetime Universe is buzzing with GW signals from cores of
astrophysical events Bursts (SN, GRB), mergers, accretion, stellar
cannibalism, Extremely Weak interaction, hence, has been difficult
to detect directly But also implies GW carry unscreened &
uncontaminated signals 96% universe does not emit Electromagnetic
signal!
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- Pulsar companion Nobel prize in 1993 !!! Hulse and Taylor 14yr
slowdown of PSR1913+16 Binary pulsar systems emit gravitational
waves Indirect evidence for Gravity waves
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- Courtesy;: Stan Whitcomb 14 Astrophysical Sources for
Terrestrial GW Detectors Compact binary Coalescence:chirps NS-NS,
NS-BH, BH-BH Supernovas or GRBs:bursts GW signals observed in
coincidence with EM or neutrino detectors Pulsars in our galaxy:
periodic waves Rapidly rotating neutron stars Modes of NS vibration
Cosmological: stochastic background ? Probe back to the Planck time
(10 -43 s) Probe phase transitions : window to force unification
Cosmological distribution of Primordial black holes
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- Using GWs to Learn about the Source: an Example Distance from
the earth r Masses of the two bodies Orbital eccentricity e and
orbital inclination i Can determine Over two decades, RRI involved
in computation of inspiral waveforms for compact binaries &
their implications and IUCAA in its Data Analysis Aspects.
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- Neutron star-BH merger
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- Theoretical developments in classical GR
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- Principle behind direct Detection of GW
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- Detecting GW with Laser Interferometer Difference in distance
of Path A & B Interference of laser light at the detector
(Photodiode) Path A Path B A B
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- Challenge of Direct Detection Gravitational wave is measured in
terms of strain, h (change in length/original length ) Expected
amplitude of GW signals Measure changes of one part in
thousand-billion-billion! Gravitational waves are very weak!
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- Courtesy: Stan Whitcomb end test mass beam splitter signal LIGO
Optical Configuration Laser Michelson Interferometer Michelson
Interferometer input test mass Light is recycled about 50 times
Power Recycled with Fabry-Perot Arm Cavities Light bounces back and
forth along arms about 100 times Detecting GW with Laser
Interferometer Difference in distance of Paths Interference of
laser light at the detector (Photodiode)
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- GEO-600 Germany 600m Terrestrial GW observatories
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- LIGO Hanford Washington USA LIGO Livingston Louisiana, USA LIGO
Laser Interferometer Gravitational-Wave Observatory 4 kms
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- Why a GW Observatory in space ? Terrestrial GW observatories
are limited to GW frequencies above 10 Hz due to seismic noise. (
10 Hz 2000 Hz.) Interesting sources abundant at sub-Hertz
frequencies (milli-Hz to Hz range) are accessible. Easier to attain
higher sensitivity with longer baselines.
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- LISA : Laser Interferometer Space Antenna A NASA, ESA joint
proposal for space based GW Observatory ( expected launch 2011). GW
OBSERVATORY IN SPACE !!
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- LISA : Laser Interferometer Space Antenna A NASA, ESA joint
proposal for space based GW Observatory ( launch 2011). Frequency
range: 10 4 Hz - 1 Hz A configuration of three `freely falling
spacecrafts in earth-like orbit linked by optical laser beams
working as an interferometer in space
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- The Orbit of LISA The spacecraft are freely falling in the Suns
field.
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- GW Source for LISA
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- 32 Initial LIGO Sensitivity Goal Strain sensitivity
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- Era of Advanced GW detectors: 2015 10x sensitivity 10x dist
reach 1000 volume >> 1000X event rate ( reach beyond nearest
super- clusters ) A Day of Advanced LIGO Observation >> A
year of Initial LIGO observation Detector Generation
NS-NSNS-BHBH-BH Initial LIGO (2002 -2006) 0.020.00060.0009 Enhanced
LIGO (2X Sensitivity) (2009-2010) 0.10.040.07 Advanced LIGO (10X
sensitivity) (2014 - ) 401020
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- Global Network of GW Observatories improves Global Network of
GW Observatories improves LIGO-LLO: 4km LIGO-LHO: 2km+ 4km GEO:
0.6km VIRGO: 3km future: LCGT 3 km TAMA/CLIO 1. Detection
confidence 2. Duty cycle 3. Source direction 4. Polarization info.
LIGO-India ? Time delays in milliseconds India provides almost
largest possible baselines. (Antipodal baseline 42ms)
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- LIGO-India: the opportunity Science Gain from Strategic
Geographical Relocation Source localization error Courtesy: S.
Fairhurst Launch of Gravitational wave Astronomy
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- vit GWIC Roadmap Document Gravitational wave Astronomy :
Fundamental physics Astronomy & Astrophysics Cosmology
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- Scientific Payoffs Advanced GW network sensitivity needed to
observe GW signals at monthly or even weekly rates. Direct
detection of GW probes strong field regime of gravitation
Information about systems in which strong-field and time dependent
gravitation dominates, an untested regime including non-linear
self-interactions GW detectors will uncover NEW aspects of the
physics Sources at extreme physical conditions (eg., super nuclear
density physics), relativistic motions, extreme high density,
temperature and magnetic fields. GW signals propagate un-attenuated
weak but clean signal from cores of astrophysical event where EM
signal is screened by ionized matter. Wide range of frequencies
Sensitivity over a range of astrophysical scales To capitalize one
needs a global array of GW antennas separated by continental
distances to pinpoint sources in the sky and extract all the source
information encoded in the GW signals
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- LIGO-India: a good idea for GW community ! Geographical
relocation Strategic for GW astronomy Increased event rates (x2-4)
by coherent analysis Improved duty cycle Improved Detection
confidence Improved Sky Coverage Improved Source Location required
for multi-messenger astronomy Improved Determination of the two GW
polarizations Potentially large Indian science user community in
the future Indian demographics: youth dominated need challenges
Improved UG education system will produce a larger number of
students with aspirations looking for frontline research
opportunity at home. Substantial data analysis trained faculty
exists in India and Large Data Analysis Center Facilities are being
planned under the next five year plan for consolidated IndIGO
participation in LSC for Advanced LIGO
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- LIGO-India: the opportunity Strategic Geographical relocation -
the science gain Sky coverage: reach /sensitivity in different
directions Courtesy: Bernard Schutz
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- LIGO-India: the opportunity Polarization info Homogeneity of
Sky coverage Courtesy: S.Kilmenko & G. Vedovato Strategic
Geographical relocation: science gain
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- NetworkHHLVHILVAHLV Mean horizon distance 1.741.571.69
Detection Volume 8.988.778.93 Volume Filling factor
41.00%54.00%44.00% Triple Detection Rate(80%) 4.865.956.06 Triple
Detection Rate(95%) 7.818.138.28 Sky Coverage: 81%
47.30%79.00%53.50% Directional Precision 0.662.023.01 Strategic
Geographical relocation: science gain Courtesy: Bernard Schutz
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- LIGO-India: Attractive Indian megaproject On Indian Soil with
International Cooperation (no competition) Shared science risks and
credits with the International community. AdvLIGO setup &
initial setup risks primarily rests with USA. AdvLIGO-USA precedes
LIGO-India by > 2 years. Vacuum 10 yr of operation in initial
LIGO 2/3 vacuum enclosure + 1/3 detector assembly split (US costing
: manpower and h/ware costs) Indian expters can contribute to
AdvLIGO-USA : opportunity without primary responsibility US
hardware contribution funded & ready AdvLIGO largest NSF
project funded in USA LIGO-India needs NSF approval, but not
additional funds from USA Expenditure almost completely in Indian
labs & Industry Very significant Industrial capability upgrade
in India. Well defined training plan Large number of highly trained
HRD Host a major data analysis facility for the entire LIGO
network
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- Schematic Optical Design of Advanced LIGO detectors LASER AEI,
Hannover Germany Suspension GEO, UK Reflects International
cooperation Basic nature of GW Astronomy
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- Schematic of Advanced LIGOdetectors Large scale Ultra high
Vacuum to be fabricated in India 10 mega -litres at nano-torr!!!
Highly Multi- disciplinary Astro ++ Every single technology theyre
touching theyre pushing, and theres a lot of different technologies
theyre touching. (Beverly Berger, National Science Foundation
Program director for gravitational physics. )
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- Multi-Institutional, Multi-disciplinary Consortium 1.CMI,
Chennai 2.Delhi University 3.IISER, Kolkata 4.IISER, TVM 5.IISER,
Pune 6.IIT Madras (EE) 7.IIT Kanpur (EE) 8.IUCAA, Pune 9.RRCAT,
Indore 10.IPR, Ahmedabad Members from TIFR Mumbai IISc, Bangalore
RRI, Bangalore Nodal Institutions
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- IndIGO Consortium a brief history Dec. 2007 : ICGC2007 @IUCAA:
Rana Adhikaris visit & discussions 2009: Australia-India
S&T collaboration (Iyer & Blair) Establishing
Australia-India collaboration in GW Astronomy Establishing
Australia-India collaboration in GW Astronomy IndIGO Consortium:
IUCAA Reunion meeting (Aug 9, 2009) GW Astronomy Roadmap for India;
2009-2011: Meetings at Kochi, Pune, Shanghai, Perth, Delhi to
Define, Reorient and Respond to the Global (GWIC) strategies for
setting up the International GW Network. Bring together scattered
Indian Experimental Expertise; Individuals & Institutions March
2011: IndIGO-I Proposal: Participation in LIGO-Australia May 2011+:
LIGO-India.. Note: IndIGO was admitted to GWIC in July 2011 : Intl.
recognition of the growing community in India. IndIGO has been
accepted into the LIGO Science Collab. (LSC) : pan-Indian 7
institutes: 15 members: Theory, DA + EXPERIMENTERS ) : Sept.
2011
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- Data Analysis & Theory Sanjeev Dhurandhar IUCAA Bala Iyer
RRI Tarun Souradeep IUCAA Anand Sengupta Delhi Univ. Archana Pai
IISER,-TVM Sanjit Mitra JPL, IUCAA K G Arun CMI Rajesh Nayak
IISER-K A.Gopakumar TIFR IndIGO Consortium IndIGO Consortium T R
Seshadri Delhi University Patrick Dasgupta Delhi University Sanjay
Jhingan Jamila Milia L. Sriramkumar, IIT M Bhim P. Sarma Tezpur
Univ. Sanjay Sahay BITS, Goa P Ajith Caltech Sukanta Bose, Wash. U.
B. S. Sathyaprakash Cardiff University Soumya Mohanty UTB,
Brownsville Badri Krishnan Max Planck AEI Satyanarayan MohapatraUM,
Amherst
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- C. S. Unnikrishnan TIFR G Rajalakshmi TIFR P.K. Gupta RRCAT
Sendhil Raja RRCAT S.K. Shukla RRCAT Raja Rao RRCAT exx Anil
Prabhakar, IIT M Shanti Bhattacharya IIT M Pradeep Kumar, IIT K
Ajai Kumar IPR S.K. Bhatt IPR Vasant Natarajan IISc. Umakant
RapolIISER Pune Shiva Patil IISER Pune Joy Mitra IISER Tvm S. Ghosh
IISER Kol Supriyo MitraIISER Kol Ranjan Gupta IUCAA Bhal Chandra
Joshi NCRA Rijuparna Chakraborty Cote dAzur Rana Adhikari Caltech
Suresh Doravari Caltech S. Sunil U. W. Aus. Rahul Kumar U. of
Glasgow Biplab Bhawal LIGO ex K. Venkat U. Washington B. Bhadur U.
of Illinois Instrumentation & Experiment
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- LIGO labs LIGO-India ? LIGO-India: unique once-in-a-generation
opportunity
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- Courtesy: Stan Whitcomb50 Advanced LIGO Laser Designed and
contributed by Albert Einstein Institute, Germany Much higher power
(to beat down photon shot noise) 10W 180W (narrow sub kHz line
width) Better stability 10x improvement in intensity (nano ppm) and
frequency stability (mHz) Unique globally. Well beyond current
Indian capability. Would require years of focused R &D effort.
Both power and frequency stability ratings. AdvLIGO laser has
spurred RRCAT to envisage planning development of similar laser
capability in the next 5 year plans. IIT M group also interested.
Multiple applications of narrow line width laser : Freq time stand,
precision metrology, Quantum key distribution, high sensitivity
seismic sensors (geo sc.), coherence LIDAR (atm sc.), .
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- Courtesy: Stan Whitcomb51 Advanced LIGO Mirrors Larger size 11
kg 40 kg, 25 34 cm Smaller figure error 0.7 nm 0.35 nm Lower
absorption 2 ppm 0.5 ppm Lower coating thermal noise Feb 2011
Status All substrates delivered Polishing underway Reflective
Coating process starting up Surface specs ( /1000) : 100 x best
optical telescope Surface specs currently available in India for
much smaller sizes /20 Indian industry may now be challenged to
achieve on small scale, eg., for TIFR 3m prototype Technology for
such mirror useful for high optical metrology and other specialized
applications
- Slide 52
- Courtesy: Stan Whitcomb52 Advanced LIGO Suspensions UK designed
and contributed test mass suspensions Silicate bonds create quasi-
monolithic pendulums using ultra-low loss fused silica fibres to
suspend interferometer optics Pendulum Q ~10 5 ~10 8 resonance
subHz suppression 1/f^4 per stage (6 stages) 52 40 kg silica test
mass four stages
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- Quantum measurements to improve further via squeezed light:
Potential technology spin-offs will impact quantum computing and
quantum key distribution (QKD) for secure communications. (IITM
approached by ITI for QKD development.) New ground for optics and
communication technology in India High Potential to draw the best
Indian UG students, typically interested in theoretical physics,
into experimental science !!! LIGO-India: unique
once-in-a-generation opportunity
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- LIGO-India : Vacuum structure & engineering LIGO-India: the
challenges
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- 1. Large scale ultra-high Vacuum enclosure S.K. Shukla (RRCAT),
A.S. Raja Rao (ex RRCAT), S. Bhatt (IPR), Ajai Kumar (IPR) To be
fabricated by Industry with designs from LIGO. A pumped volume of
10000m 3 (10Mega-litres), evacuated to an ultra high vacuum of
nano-torr (10 -9 torr ). Courtesy: Stan Whitcomb Spiral weld UHV
beam tubes 1.2 m dia: 20 m sections. Sections butt welded to 200m
UHV Optical tanks to house mirrors : end, beam splitter, Expansion
Bellows btw 200m beam sections, 1 m gate valves
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- LIGO Vacuum Equipment Courtesy: Stan Whitcomb Large vacuum
chamber fabrication under stringent UHV requirement Significant
capability upgrade for Indian industry Comparable, but smaller UHV
chambers in IPR facility
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- LIGO Beam Tube LIGO beam tube under construction in January
1998 16 m spiral welded sections girth welded in portable clean
room in the field 1.2 m diameter - 3mm stainless 50 km of weld NO
LEAKS !! (10Mega-litres at nano-torr) Major Engg. Challenge
Unprecedented scale Courtesy: Stan Whitcomb Constructed > 1
decade back. Operating in Initial LIGO for ~10yrs
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- Concrete Arches beamtube transport beamtube install girth
welding Beam Tube Construction Courtesy: Stan Whitcomb
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- IndIGO - ACIGA meeting59 LIGO beam tube enclosure minimal
enclosure reinforced concrete no services Courtesy: Stan
Whitcomb
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- Detector Installation using Cleanrooms Chamber access through
large doors Courtesy: Stan Whitcomb
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- Optics Installation Under Cleanroom Conditions Courtesy: Stan
Whitcomb High precision skills Low contamination labs & trained
manpower for related Indian labs & industry Application in
other sciences, eg. Material sciences, Space, biotech,
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- Science Payoffs New Astronomy, New Astrophysics, New Cosmology,
New Physics A New Window ushers a New Era of Exploration in Physics
& Astronomy Testing Einsteins GR in strong and time-varying
fields Testing Black Hole phenomena Understanding nuclear matter by
Neutron star EOS Neutron star coalescence events Understanding most
energetic cosmic events.. Supernovae, Gamma-ray bursts, LMXBs,
Magnetars New cosmology..SMBHBs as standard sirens..EOS of Dark
Energy Phase transition related to fundamental unification of
forces Multi-messenger astronomy The Unexpected !!!!!
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- Technology Payoffs Lasers and optics..Purest laser light..Low
phase noise, excellent beam quality, high single frequency power
Applications in precision metrology, medicine, micro-machining
Coherent laser radar and strain sensors for earthquake prediction
and other precision metrology Surface accuracy of mirrors 100 times
better than telescope mirrors..Ultra-high reflective coatings : New
technology for other fields Vibration Isolation and suspension..
Applications for mineral prospecting Squeezing and challenging
quantum limits in measurements. Ultra-high vacuum system 10^-9 torr
(1picomHg). Beyond best in the region. The largest UHV system will
provide industry a challenge and experience. Computation
Challenges: Cloud computing, Grid computing, new hardware and
software tools for computational innovation.
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- Home ground advantage !!! Once in a generation opportunity
Threshold of discovery and launch of a new observational window in
human history !! Century after Einstein GR, 40 yrs of Herculean
global effort Cooperative, not competitive science India at the
forefront of GW science with 2 nd generation of detectors: Intl.
shared science risks and credit Low project risk: commit to
established tech. yet are able to take on challenges of advLIGO
(opportunity without primary responsibility) Attain high technology
gains for Indian labs & industries India pays true tribute to
fulfilling Chandrasekhars legacy: Astronomy is the natural home of
general relativity An unique once-in-a-generation opportunity for
India. India could play a key role in Intl. Science by hosting
LIGO-India. Deserves National mega-science project status
Concluding remarks on LIGO India Every single technology theyre
touching theyre pushing, and theres a lot of different technologies
theyre touching. (Beverly Berger, National Science Foundation
Program director for gravitational physics. ) Thank you !!!
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- Rewards and spinoffs Detection of GW is the epitome of
breakthrough science!!! LIGO-India India could become a partner in
international science of Nobel Prize significance GW detection is
an instrument technology intensive field pushing frontiers
simultaneously in a number of fields like lasers and photonics.
Impact allied areas and smart industries. The imperative need to
work closely with industry and other end users will lead to
spinoffs as GW scientists further develop optical sensor
technology. Presence of LIGO-India will lead to pushing
technologies and greater innovation in the future. Increase number
of research groups performing at world class levels and produce
skilled researchers.
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- India leads high visibility, fundamental science expt. that has
huge (international) public appeal !!! Indian academia and industry
would be working together The project provides high-technology
goals that sharpen & showcase the abilities of Indian
institutions and industry. The project will lead to significant
human resources development (HRD@home) in academic, technical and
industrial spheres. Produce highly skilled S & T workforce for
India Jobs at all levels for region hosting LIGO-India. Proximity
to world class science Why is LIGO-India such an Attractive Indian
Science Project?