Opinion
Adhikari: LIGO could probably double its detected signals from existing data
“I think in our data there must be, probably we could double the number of signals we have right now if we were to, I mean, that's my guess. It could be much more.”
Assertion Not checkable as stated
Adhikari: 40-kilometer interferometers could detect collapsing first stars
“We would be able to find signals from Basically, the, all the way back. I mean, it would have. We would find the first stars in the universe, and they were collapsing, if they exist, which I think they do.”
What-if
Adhikari: Decades of required effort would have deterred early gravitational wave researchers
“If they, I think if they had known how tough it would be, or that it was going to take fifties, five years to have success, probably no one would have started.”
Assertion Supported
Adhikari: LIGO stabilizes lasers ten million times beyond commercial models
“So we take the best laser in the world that we can find, and then we stabilize it and make it about ten million times more stable than what you can buy, and then it's kind of just barely good enough, and we're gonna have to do better if we want to do better.”
Assertion Supported
Adhikari: Laser radiation pressure physically moves LIGO's 40-kilogram mirrors
“There's so much laser power that when you, it's weird to think about, but there's so much laser power when we hit the mirror, it moves the mirror. And the mirror, if you, to imagine it, is about this big. And it is 40 kilograms”
Insight
Adhikari: LIGO noise reduction has reached linear limits, needs nonlinear regression
“Now we've reached the limit of what you can do with linear noise subtraction, and we need some better ideas on how to do the next thing. And the next thing involves nonlinear regression.”
Prediction Open · timeframe Sep 2117
Adhikari: Michelson interferometers won't be used for gravitational waves in a century
“If you ask in a hundred years from now, will people still build Michelson laser interferometers and do the same thing? Right. I have a hard time believing that's true.”
Assertion Supported
Adhikari: LIGO laser only costs around $100,000
“The laser itself is cheaper. You can do, probably you could do the whole thing with a 100,000 dollar laser. That's about the laser cost.”
Assertion Supported
Adhikari: LIGO's detectable gravitational waves fall into human audio band
“It happens to be that the waves that we're detecting and the waves which are easiest to detect are exactly in the human audio band. So the waves that you and I can hear with our ears, that's the whole frequency range for gravitational waves that we can detect.”
Assertion Supported
Adhikari: LIGO has not seen another signal matching its first detection
“We've not seen anything of that size since then, since that first one.”
Assertion Supported
Adhikari: LIGO's first black hole detection measured a 10^-18 meter displacement
“About 10 to the -18 meters, which means one billionth of a, about the size of a atom.”
Assertion Supported
Adhikari: LIGO cannot detect the largest black holes due to environmental noise
“So the biggest black holes we can't find right now, because This kind of technical noise feedback and the vibrations from the environment are bigger than the fundamental quantum physics limits of measurement.”
Assertion Supported
Adhikari: LIGO mirrors store vibrational energy 10,000 times longer than glass
“The mirrors we have are more like They store the energy better, something like. About 10,000 times longer. So if I were to ping one of those would last for, you know, hours. They would just keep ringing and ringing.”
Assertion Supported
Adhikari: Welder's glass effectively absorbs LIGO's one-micron infrared laser light
“It has a wavelength of one micron, and so for it some of the things that look black don't work, but if you have a special kind of welder's glass, it really works. Welder's glass is good as, good at absorbing pretty much everything with a longer wavelength than…”
Assertion Not checkable as stated
Adhikari: Upgraded LIGO could detect signals from ten billion years ago
“With the current systems, you know, as big as they are, if we put in like our best technical hacks into them that we can imagine, we could maybe get to the place where the universe was about a one fifth or one sixth of its current age. So we could look back so…”
Assertion Supported
Adhikari: Earth's vibrations limit ground detectors to frequencies above 5-10 Hz
“On the ground, kind of, we're limited to measure things that are that have a signal frequency, which is more than five or 10 hertz or something like that, so we can go a little bit below the human audio band, but not much, and the reason for that is that the e…”
Assertion Supported
Adhikari: The LISA space interferometer aims to launch in 16-17 years
“There's a project called LISA, which is aimed to launch in 16 years, 1617 years from now, and that will put a system, a triangular interferometer in space, which is several interferometers, and that will measure gravitational waves at around a millihertz”
Assertion Supported
Adhikari: An Alpha Centauri black hole merger would overwhelm LIGO electronics
“Like the ones we detected were at, let's say several hundred million light years, and Alpha Centauri is only four light years, I believe, so it would be stronger by that factor of a hundred million. And, which sounds like a lot, it is a lot, but that means tha…”
Rana Adhikari