The Nobel Prize in Physics 2020 | Proving that the centre of the Milky Way is a BLACK HOLE!

so it was announced today that the nobel prize in physics for 2020 has been awarded to sir roger penrose professor andrea guezz and professor reinhard genzel for their research on black holes so you can imagine that someone like me who does research in this area in this field of supermassive black holes i was absolutely elated at the news i was so excited and it really is just a win that's being claimed by the entirety of the astronomy and astrophysics community because it's been a long-running joke in astronomy over the past decade that nobel prize you know they're not bothered about astronomy because the last one was sort of in 2006 or something and then bam two years in a row 2019 astronomy for exoplanets and now 2020 astronomy for black holes all right so this prize is shared between the theoretical and the observational side of things and that's becoming quite commonplace for the nobel prize you know someone would do the mathematics and the theory back in the 20th century in this case all the way back in the 60s and then as our technology improves into the 21st century we can then do the observations or the experiment that then proves that mass in that theory the prediction that was made back in the 20th century and that's exactly what happened here so sir roger penrose has been awarded the nobel prize for work he did back in the 60s and 70s with none other than stephen hawking they used einstein's theory of general relativity i.e a mathematical description for how we think gravity behaves in our universe and they used it to predict that black hole should exist i.e a point in space where the gravity of an object was so strong that it collapsed in on itself to give you this point of infinite density it's something that's called a singularity now back then the idea of a black hole you know an object so dense that not even light is traveling fast enough to escape was just sort of a theoretical curiosity or a mathematical curiosity you know it wasn't considered a real object but what penrose and hawking did was essentially show that mathematically they were inevitable in our universe and if we had the mass of gravity right then we should expect to see these things well you might be wondering why hawking and penrose didn't win the prize sooner since we've known of the existence of black holes now for a very long time well as i said the nobel prize committee likes his theory to be observationally or experimentally confirmed before awarding the prize so for example einstein in 1916 predicted gravitational waves and it wasn't until 2017 that the award was made for the detection of those gravitational waves another example is peter higgs predicting the higgs boson back in the 60s and the nobel prize wasn't awarded again until the 21st century when that detection was actually made what i think has triggered the nobel prize committee this year to award it to black holes was that incredible image we had last year in 2019 the first ever image of a supermassive black hole in the center of the messier 87 galaxy this image was made possible by a huge team of people worldwide bringing together a huge array of radio telescopes to see something so far away and you might be wondering then why did the event horizon collaboration team not win the nobel prize why was it not split between penrose and the eht team this is one of these very archaic properties of the nobel prize it can only actually be shared by three people which isn't exactly in line with how modern physics is done today in these huge collaborations and also it wasn't the eht image that necessarily proved the existence of black holes it was the first image we had sure which was incredible but we definitely knew about supermassive black holes before then even if that was sort of like the nail in the coffin to confirm yep that is definitely what we see in the center of these galaxies instead that proof came thanks to the work of professor reinhard genzel from the max plaque institute in munich and to professor andrea guess from ucla throughout the 90s and the 2000s now the big question in astrophysics back at the beginning of the 90s was what is at the center of the milky way there's a lot of suspicions that it was a black hole no one knew if it was or how big it was and so that needed proving now both gensel and getz were involved in observing the stars at the very center of our galaxy specifically using infrared telescopes so infrared light has a much longer wavelength than the visible light we see with our eyes which means it's not blocked by the tiny particles of dust that we find very concentrated in the center of our galaxy so we can't actually see the center of our galaxy with visible light but we can with infrared light that thankfully manages to make its way through with that you can then observe the positions and the speed that stars are moving around the center over many many years and with that data you can then work out the orbits of those stars with our knowledge then of how gravity works we can then work out how big the object is that those stars are orbiting around and therefore work out the mass of the object in the center and therefore if it is a black hole so this was first done in 1996 by eckhart and genzel with the new technology telescope or the ntt in chile they observed the positions and the motions of 10 stars over four years from 1992 to 1996. they used that data to then model the orbits of those stars around the center of the milky way and derive a mass for the thing at the center of 2.45 million times the mass of the sun give or take about 400 000 times the mass of the sun this was an incredible result it was a proof of concept first of all and it also showed that there was clearly a very massive and dark object a very small space in the center of the milky way but this is science one result does not a theory make so in steps professor andrea guez and her team at the ucla galactic center group to do this much more precisely with the more high-resolution keck telescopes on mauna kea hawaii these use lasers to record the turbulence in the atmosphere i.e the turbulence that you fly through on a plane which is going to disrupt all the light from the object that you're observing they then subtract that turbulence from what they're trying to observe kind of like noise cancelling headphones for a telescope they observed over 500 stars over 12 years from 1995 to 2007 to get a mass for the black hole in the center of 4.5 million times the mass of the sun give or take 400 000 times the mass of the sun or so now they're still observing the stars in the center of the milky way with the keck telescope to this day we've now actually seen one star s0-2 make a full orbit of the center in just 16 years it's observations like this that left no shadow of a doubt in physicist minds that what was at the center of the milky way was a supermassive black hole and it fit in with the theory that at the center of every single galaxy in the universe there's a supermassive black hole that's what my research is on right now i'm researching how big are the supermassive black holes in galaxies of different shapes and can the shapes of those galaxies tell us the evolutionary history they've had have they merged with another galaxy or they've been left alone their entire life and how is that affected how big the black hole can grow to but it's thanks to work by the likes of penrose gensel and getz that i can say this so casually as if we have always known this fact it's why i love making my history of science videos to help people understand where an idea has come from over the years so if you want the full story on how we know that there is a supermassive black hole at the center of every galaxy which includes the work that was honored by the nobel prize committee today i will link it for you up here you can check out if you want to all right i am now off to raise the glass in toast to every single person over the past 60 years that has made these nobel prize winning results possible okay so the nobel prize was announced at 11 a.m this morning by 12 30 i decided let's just film a video in a day we could totally do it i've just finished editing now it's 5 p.m i think this is the quickest turnaround ever on one of my videos and i definitely need that drink now you

Channel: Dr. Becky

Views: 137,449

Keywords: blackholes, supermassive black holes, Nobel prize, physics, 2020, nobel prize announcement, science, astrophysics, astronomy, cosmology, theoretical physics, Stephen Hawking, Roger Penrose, Reinhard Genzel, Andrea Ghez, UCLA galactic centre group, Oxford, max Planck institute, MPE, sagittarius a*, SO-2, galactic centre, Milky Way, centre of Milky Way, galaxies, research, academic, experiment, observation, dr becky, dr Becky Smethurst, women in stem, women in science, female physicist, UCLA

Id: Pv8eKhryAbM

Length: 9min 9sec (549 seconds)

Published: Tue Oct 06 2020