1. Critical Technology Giant leaps Near-term steps Non-IFO methods
Keith Thorne, Katherine Rawlins
Giant leaps
Near-term steps
Non-IFO methods
One vs. many
Sociological aspects
Confusion limit
Imagining the Future: Technology summary

2. Near-term (“known”) steps
To beat down low-frequency limits (mechanical)
Move underground (int-term)
Cryogenic (int-term)
Seismic isolation
Gravity gradient compensation
To beat down quantum limit (optical)
Detuning (narrowbanding)
Mirror reflectivity
Squeezing
Laser Frequency
Speed meter
Probe masses
Next generation of bars: dual acoustic
Broadband, high-frequency, R&D funded!
Imagining the Future: Technology summary

3. Adv LIGO Detector Performance
Zones to improve?
Suspension thermal noise
Internal thermal noise
Newtonian background, estimate for LIGO sites
Seismic ‘cutoff’ at 10 Hz
Unified quantum noise dominates at most frequencies for full power, broadband tuning
10-22
Initial LIGO
10-23
10-24
10-25
1 Hz
10 Hz
100 Hz
1 kHz
D. Shoemaker

4. Sub-quantum-limited interferometerX+ X-
Quantum correlations (Buonanno and Chen)
Input squeezing
Imagining the Future: Technology summary

5. Imagining the Future: Technology summary
Giant Leaps
To leap forward a factor of 100 or more, will need to go beyond groundbased
LIGO-in-space (LIGO frequency)
Big Bang Observer (frequencies between LIGO and LISA)
Discussion of space logistics (orbit, other planets, station-keeping)
Imagining the Future: Technology summary

6. Non-IFO, non-bar methods
Pulsar timing (progress)
Precision clocks in space (getting there)
Matter-wave interferometers (atoms too slow, too few, arms too short)
Very high f lasers (optics technology not there yet)
Magnetic/gyroscopic
Imagining the Future: Technology summary

7. Imagining the Future: Technology summary
Sociological aspects
Science must sometimes push for new technology itself (i.e. large superconducting magnets in HEP); is this one of those cases?
Not in a position yet to choose something to push.
Better to have “100 pairs of eyes” looking for useful advances by others
How much long-term R&D? How much speculative vs. directed?
MORE! 5-10% (1% is too little) of total investment
What is the right balance (short-, long-term)
Imagining the Future: Technology summary

8. Imagining the Future: Technology summary
Many or one?
Many bandwidths or one bandwidth?
One versatile instrument likely to be cheaper?
Going to build a versatile instrument first, then build many facilities?
Many instruments or one instrument?
Pointing resolution will demand many instruments
Conclusion: with a constellation of instruments, can be used either individually or as an array (a la radio astronomy)
Imagining the Future: Technology summary

9. Computation and confusion limit
Is computing a vital technology we should push? Instrument itself more likely to be limiting factor.
When LISA becomes confusion-limited, position resolution will be even more important
Without position resolution, can still do “population astronomy”
Groundbased will hit this limit 100x better than Adv. LIGO, can borrow techniques
Imagining the Future: Technology summary

10. Off-topic: theoretical crisis
What if we detect nothing (when we should see lots)?
What if MOND is correct?
What if some yet-unknown physics converts gravitons?
Situation may be similar to “solar neutrino problem” -- the key is to achieve certainty that the detector is performing as expected.
Imagining the Future: Technology summary

11. Off-topic: the 30-sec sound byte
How do we sell GWA to the guy in the elevator?
SKA criteria: unique science, appealing to funding agency, appealing to the public
People like black holes
Some people like supernovae (others don’t)
The big bang is cool too
30-minute pitch just as important
Everything will change after the first detection
Imagining the Future: Technology summary