OT: Heisenberg Uncertainty Principle, hacked.
Atoms make up molecules, but even smaller, elementary particles make up atoms:
At this level, things start to get weird. You can't examine a quantum particle without changing its state. And there's a phenomenon called 'quantum entanglement' where one particle's change will cause also another particle to change, no matter how far away it is, what Einstein called "spooky action at a distance".
This makes quantum particles hard to examine because they're jiggling all around -- and this is what the Heisenberg Uncertainty Principle means. You can't examine with certainty.
Now, we want to understand the nature of the Space-Time Fabric, don't we. A large object like a star deflects the STF like a ball rolling around in a depression, and the depth of that depression is proportional to the gravity of that star. Being able to measure changes in the STF allows us to see things happening in the universe that there is no other way to see, and it exposes characteristics that there is no other way to understand.
So they've built two LIGO observatories. ('Laser Interferometer Gravitational-Wave Observatory") These consist of two legs, 4km long, one on the X-axis and one on the Y-axis. Each shoots a laser beam which is reflected back by mirrors many times, until the end of the beam is compared with the other axis.
This comparison is done by 'interferometry', an 'interference pattern', which clearly shows the difference between the two beams:
Why? Because these LIGOs are so exquisitely isolated that they can detect deviations which are less than ten-thousanth the diameter of a proton! Now, a proton is a large atom, but come on!
The LIGOs make it possible to measure warpages in the fabric of Space-Time -- meaning gravity waves resulting from events; gravity is the weakest force in physics believe it or not. These LIGOs can see destruction of neutron stars which are unfathomable distances away, or massive collisions, and after calibrations were completed they almost immediately began receiving observations, about two per month. The location of the event in the Universe could be estimated by comparing the timing of the two observatories. If there were three observatories, location would be much more accurate, and if we just could stop the frickin' rotation and movement of Earth, much more so...
But the observations were fuzzy... due to the jittering about of the laser photons (quantum particles) which is what the Heisenberg Uncertainty Principle is about. Astoundingly, now this has been hacked!
LIGO is so sensitive it shudders with the quantum noise of light
"... the uncertainty limits the combined values of these properties. (my emphasis) If you accept a lot of noise in one of the properties, you can get a lot more precision in your measurements of the other. Famously, this applies to location and momentum: if you want to know more precisely where a particle is, you can do so by sacrificing precision about its momentum.
"But location and momentum aren't the only properties that can be correlated. In this case, the researchers relied on correlations between the amplitude of the light waves and their phase. (my emphasis) By manipulating one, they could decrease the uncertainty in the other."
"This has a couple of interesting consequences. For one, this is the first time that researchers have managed to escape the limit placed on a system by quantum uncertainty in a setup like this. It also means that the researchers have altered the quantum properties of light without destroying the information it contains.
"This is one of the factors that has allowed Advanced LIGO to go from detecting roughly one astrophysical event per month in observing runs 1 and 2 to about one astrophysical trigger per week in the third observing run of LIGO/Virgo."
Carl A. Cook