The Technical Challenges of Measuring Gravitational Waves - Rana Adhikari of LIGO

[@DrTune]

My dad worked on this for many years when I was a kid; he built several detectors (at the University of Bristol, UK). He's 86 now, he's very happy they were measured in his lifetime. I was always kinda sad for him when he retired that he didn't achieve it during his career, but I don't think he saw it that way. I do remember one dark day (when I was.. maybe 8 years old?) that my dad discovered there was an error in his math and the latest version of a detector he's spent the last year or three working on definitely _wasn't_ going to be sensitive enough. Rana describing (at 2:30) what a long struggle it was for people working in the field resonates with my family..

[@gauravkumarastroboy]

Wow... That feeling

[@kamarimarley617]

i know it's quite off topic but does anyone know of a good place to watch newly released movies online?

[@everetttobias7086]

@Kamari Marley Ehh atm I've been using flixportal. You can find it on google:P -everett

[@kamarimarley617]

@Everett Tobias Thank you, I went there and it seems like they got a lot of movies there =) Appreciate it !

[@everetttobias7086]

@Kamari Marley Happy to help xD

[@sinkuabhi1]

Given the chance, Rana Adhikari can explain all the concepts of known physics by using just that cup. He is just brilliant.

[@govindnarasimman6819]

man this guy is so honest. I was always in search of instrumentation. u can explain new theories as long as it satisfies existing phenomena and experiments. this guy beautifully explains all problems staring from power line fluctuation.

[@Raptorman0909]

If I were studying Physics at Caltech I would really love to have Rana as my professor.

[@NK-vp4xt]

Amazing discussion. Other than the topic being discussed, the humility of Rana Adhikari come out striking !

[@albertgerard4639]

the humanity aswell! I like the ghost story analogy when talking about troubleshooting such a huge system

[@Jay-my4mi]

52:08 - 52:57 Apart from being absolutely mind-blowing this in principle sounds similar to seismic wave propagation

[@augre-app]

he reminds me of ycombinator ceo michael seibel.. super chilled and down to earth and densely packed information without any cruft...

[@mscir]

GREAT talk, thank you for posting this. Please consider doing a whole physics series.

[@siwalder1618]

Man,. I wish Rana had been my science teacher at school. Goodness knows what I'd be doing now.

[@mscir]

Regarding the mirror movement, what about hitting the back of the mirror with the same amount of radiation as the front of the mirror at the same time, to cancel the movement? His description of the tea in his mug transferring sound to the other side of the glass, so it didn't have to travel there in the glass itself and followed a shorter path, was the simplest analogy for a so far hidden curled up small dimension that enables entangled particles to communicate in a way that appears to be faster than light speed. When the gravitational wave passes through a quartz crystal, does it deform the crystal enough to create voltage?

[@paublusamericanus292]

because the light is bounced back and forth, it is like having a tuned antenna. the tuned length may be the same length, but does not equal the, say same length antenna at the correct length, just as an antenna with a tuning coil does not equal the antenna of the proper length. so a light cavity 8 kilometers long, is much better than bouncing the light back and forth a bunch of times, but seems diminishing returns, and probably why they don't just extend the antenna's length by another 4 kilometers, because the return isn't quit double sensitivity, but a portion of that.

[@Tadesan]

19:20 smart people

[@jakobzupanec2764]

49:53

[@TayneAmericaUSA50states]

They should measure the back of the mirror to check if it's the front of the mirror being warped by spacetime. 👍

[@saulo5216]

22:17 "Who knows what pounds mean?" Right? XD

[@jeanvanrooyen6004]

22:10 Thank you Mr. scientist.... metric FTW

[@doctorpanigrahi9975]

Football per bald eagle 🦅

[@chissssssss]

Can someone explain to me how it is that the interference of the two waves can tell us whether time or space has been distorted? Because I thought that spacetime was one thing and that an increase in space automatically yields a decrease in time for c to remain constant. So if a laser were to travel through half the distance because of shrinkage of space, wouldn't that mean time would go by half as fast so that the light still travels at light speed? So how do we know that anything has been distorted at all? I'm not a flat earther or anything, I just can't really wrap my head around the spacetime thing.

[@zeitgeistx5239]

The pulses of photons is measured in waves and the mirror splits the laser beam is two beams and bounce it back. There's two sensors that measure the return signal from the split beams. The difference is the effects of gravity once other causes are ruled out. The result is verified by the second LIGO, plus the delay in timing between the two LIGOs since there thousands of miles apart also helps to verify the gravitational waves and helps to triangulate it as well.

[@kaushalvyas1142]

I can't get my head wrap around the concept of gravity even.

[@rishabhpant1559]

Interference of waves depend on the distance traveled, not speed of wave or time. The formulae is (Delta length)= d sin theta. I would suggest you to read the double slit experiment. And please check it maths too. It explains why interference happen and what parameters interference depend on. P.s- I'm sorry I couldn't explain it better here.

[@phasematerialsresearch9319]

I have a question, has anyone invented space-based gravitational wave detectors. I could just ask ChatGPT but my comments support YC’s channel lol

[@albertgerard4639]

Y Combinator should do an interview with that cup

[@breakingdownthewalloflies7812]

subscribed ;-)

[@breakingdownthewalloflies7812]

what a clown .. this guys in charge at ligo .. funny ;-)