Announcement of the 2020 Nobel Prize in Physics

good morning and welcome to the royal swedish academy of sciences the academy met in session this morning to decide on this year's nobel prize in physics and we are now ready to announce it and it took a little while for us to get in touch with uh belorus therefore we are a few minutes late i apologize for that i'm joran hansen i'm the secretary general of the academy and with me today is on my right professor david havilland who is the chairman of the nobel committee for physics and on my left professor of danielson who is among many other things also a member of the nobel committee before we announce the prize i would like to thank all of you who are here in the session room today and i regret that we have to operate under restrictions imposed by the corona pandemic and i really appreciate that you are complying with these restrictions so thank you i must also apologize to all the journalists who cannot be here in the session room this year normally we are close to 90 people in this group now we must be fewer than 30 persons all together and therefore many representatives of the media will have to follow the press conference over the video link we're really sorry that we could not admit you and we hope for your understanding and we're offering interviews with nobel committee members and other experts immediately after the press conference thank you for your understanding now over to the nobel prize in physics this year's prize is about the darkest secrets of the universe objective intergotten center the royal swedish academy of sciences has today decided to award the 2020 nobel prize in physics with one half to roger penrose for the discovery that black hole formation is a robust prediction of the general theory of relativity and the other half jointly to andrea gis and reinhardt gensel for the discovery of the supermassive compact object at the center of our galaxy the current english vedic academy nobel prize for physique lion roger penrose and you have the pictures of the new nobel auris on the screen behind me roger penrose was born in kolwich in england and got his phd at cambridge university he is now emeritus professor in mathematics at the university of oxford reinhardt cancel was born in bad hamburg for the in germany he got his phd at the university of bonn and his currently director at the max planck institute for extraterrestrial physics in garching in bayern in germany and he's also a professor at the university of california at berkeley in the united states andrea guess finally was born in new york city she got her phd at caltech in pasadena in california and she's currently professor at the university of california los angeles in the united states now we are not requesting that the nobel laureates come to stockholm in december this year to pick up their prices because of the pandemic we plan for digital nobel lectures and the digital prize ceremony with laureus participating over video links we are still working on these events together with the nobel foundation and of course from now on with the laureates themselves and we'll come back with more information as soon as it becomes available but already at this stage i can assure you that the nobel laureates will receive their awards before the end of the year and that they will be invited to stockholm next time we can celebrate the nobel prize in the traditional way here in stockholm in december and with that i like to ask david havilland chairman of the nobel committee for physics to make some remarks david please thank you euron on behalf of the nobel committee for physics i would like to congratulate the laureates in receiving the 2020 nobel prize this year's prize celebrates one of the most the discovery of one of the most exotic objects in our universe the black hole for many years physicists question the very idea of a black hole treating it as a peculiarity in our theory in our theory of gravity roger penrose showed that black holes might really exist forming in a stable and robust process consistent with the theory of general relativity reinhard genzel and andrea goetz led research teams to make precise observations over many years which pointed to the existence of a super massive black hole in the center of our very own galaxy my colleagues in the nobel committee my colleague in the nobel committee for physics professor ulf danielson will tell us more about the contributions of this year's laureates to the discovery of black holes thank you david and now ulf the floor is yours as early as the end of the 18th century the english astronomer john mitchell and the french scientist pierre simon laplace speculated that there might exist objects with a gravity so strong that not even light can escape we now call such objects black holes to create them you would need to compress the sun into a region only a few kilometers across or to squeeze the earth down to the size of a pea but it was only in 1915 when einstein formulated his general theory relativity that we had the mathematical framework powerful enough to describe such objects physicists einstein himself included were confused for decades the mathematics was too complicated could something like that actually occur in a real universe and then in 1965 inspired by the discovery of new violent phenomena in the universe in need of an explanation roger penrose published a remarkable paper he introduced new mathematical tools improved with mathematical rigor that the formation of black holes is an inevitable consequence of general relativity in a universe governed by gender relativity the formation of black holes is a natural and expected process let us study now a black hole a little bit more closely in general relativity there's an intimate relation between gravity and time down at my feet time runs a trillionth of a second slower per hour than it does up in my head and if you have a black hole time even seemed to stand still at the horizon of the black hole now i can point towards the black hole and say there it is there is the center of the black hole my finger is stretched along a direction of space but if i then bring my finger a little bit closer and let the tip of my finger go through the horizon and enter into the interior of the black hole i will make a startling and somewhat worrying discovery the direction inwards is now time and the tip of my finger will be in my fall future and it will be as difficult to pull my finger back out again as it would be to travel backwards in time furthermore my finger will be torn apart and the tip of my finger will be carried by time all the way into the center of the black hole where time itself ends and the known laws of physics cease to apply but if such objects now actually exists in the real universe then how could you find them well actually already in [Music] 1783 john mitchell had an idea what if what if there are other luminous objects such as stars moving around the black hole then one could in fear the existence of the black hole by following the motions of the stars but it would take more than 200 years before this dream would come true and it was reina guenzel andrea gayes and their teams who did it they turned the telescopes towards the center of our galaxy 26 000 light years away where there were suspicions that something strange was going on the heart of our galaxy the heart of the milky way is hidden inside of a dense cloud of dust and you have to look in the infrared to reveal its secrets what they found was incredible they could see several stars moving around something that they couldn't see and it was one star in particular that caught their attention it took the star around 16 years to complete its orbit at closest approach it was no more than 17 light hours away from the invisible object calculations show that 4 million solar masses is hiding there there is no other explanation than a supermassive black hole this year's lords have uncovered secrets in the darkest corner of our universe but this is not just an old adventure coming to its triumphant conclusion it's a new one beginning as we probe ever closer to the horizons of the black holes nature might have new surprises in store thank you very much for that excellent uh introduction and now it's time for questions uh when you ask questions could you please push the button on the microphone stand so that it comes your your voice is picked up uh actually we hope to have one of our new nobel laureates with us on a phone line doctor andrea guezz are you there yes hello this is jordan hansen again i'm the guy who called you about an hour ago to give you the good news and we are now in the middle of our press conference and i wonder if you're ready to take some questions i'll be i'd be delighted who would like to start thomas jones fast as always hello professor guess congratulations i'm just curious this is swedish television public service i'm just curious to hear what went through your mind when you saw that sign that there must be something lurking in the middle of the milky way i think the first thing is doubt um that you have to prove to yourself that you're really seeing um what you think you're seeing so both doubt and excitement um it's it's uh that feeling of being at the frontier of research where you have to always question what you're seeing so it's it's a combination of things more questions yes i think it's david keaton from associated press you'll get a microphone there yes uh david keaton from the associated press thank you professor um at this moment in time the research that is being uh rewarded here uh today dates back uh for decades and like you just mentioned there this uh this disbelief at the beginning beginning the importance of science and the belief in following the facts is quite crucial at this moment in the united states where science is somewhat in doubt what message do you have maybe today oh that science is so important um and uh pursuing um the reality of our physical world is is just a critical to us as human beings uh um i i think today i feel more passionate about um the the teaching side of my job than i um have ever because it's so important to convince the younger generation that their ability to question and their ability to think is just crucial to the future of the world thank you please we have questions [Music] so professor guest did you hear the questions unfortunately i did not hear that question okay could you repeat then okay um you're the fourth woman to receive this prize what do you think about that that was my first question and the other question is do you understand what's happening inside the black hole i mean time is stopping what time is it stopping at is it stopping now or at the end of the time or um well well do you have any way of explaining that so that we can understand it i did hear that those two questions um so let me take that first i'm um i i'm thrilled um to receive the prize and i take very seriously um the responsibility um associated with being i guess as you said the fourth woman to win the nobel prize and [Music] i guess i i hope i can inspire other young women into the field it's a field that has so many pleasures and if you're passionate about the the science there's so much that can be done let me take the easier question which is almost what is the black hole um we don't know we have no idea what uh what's inside the black hole and that's what makes these things such exotic objects and they really represent the breakdown of our physical understanding of the laws of physics so that that's uh that's part of the intrigue is that we we still don't know it really pushes uh forward on our on our understanding of the physical world question over here hello this is johannes poland from tt news agency in swedish new zealand first i want to congratulate of course to the price and then perhaps you just answered it but how would you say that this discovery of a black hole far far away has changed life here on earth well it's it's the it really represents the basic research you don't always know how it's going to affect our lives here on earth but it is pushing the frontier of our knowledge forwards both from the the point of view of pure physics understanding um what a black hole is and then also their astrophysical world in the formation and evolution of galaxies uh and and so today we really we really accept that these objects are are critical to the building blocks of our universe any more questions to professor giz if not thank you very much again professor giz and we'll be in touch about the arrangements for december but thanks so much for being with us at the press conference thank you bye-bye for now now any questions for the panel all crystal clear if there are no further questions thanks so much the now there will be individual interviews taking place here out there and nearly everywhere in the building and our staff will help you find your way please be careful and keep the distance when you exit the room and then of course you're all very welcome back tomorrow for the nobel prize in chemistry thank you ultra nilson can you summarize this year's nobel prize in physics please yeah it consists of two parts uh there is one part which goes to roger penrose for the theoretical understanding or even prediction of the existence of black holes i mean the history of black holes go back way back in time to the end of the 18th century and then of course through einstein's generativity we had the tools to actually start to describe these objects so real but since the mathematics is so complicated it took several decades before one really was able to understand what's what's going on could such objects actually form in the real world and that is what roger penrose did he understood the mathematics he introduced new tools and then could actually prove that this is a process which you naturally can expect to happen that a star or something else collapses and turn into a black hole before penrose that was far from clear many thought that such objects were only mathematical artifacts they couldn't form in in the real world so roger penrose he laid the foundation the theoretical foundation so we could say that yes these objects exist we can expect to find them if we go out and look for them and this was sort of a journey that started in the mid 60s and what reiner gansel andrea gears have done is to to prove really that such objects exist and they found one a super massive black hole in the center of our milky way and the way they did that was that they monitored stars which were orbiting around something that they couldn't really see and that of course required very sophisticated equipment to be able to to do this and make these observations so it took several years and then this work has continued and one has been able to to look further and further in and closer and closer to the black hole to start to test general relativity so what is a black hole well so far i mean what the the current understanding of the black hole is that it it's sort of a it's a region in space where gravity is so strong that not even light can can leave it i mean if you think about the earth the surface of the earth we have a what's called an escape velocity which is equal to 11 kilometers per second that means that if something is is is is directed upwards with that speed then it will leave the gravitational field of the earth and never come back again now a black hole that certain object you would say where the escape velocities like the speed of light now in fact what turns the structure of a black hole in generativity turns out to be very much related to the structure of space and time so it's it's it's like a reading in space and time which is so warped and curved that it's impossible to find your way out again in fact what happens is that when you reach the the boundary the horizon of the black hole time i mean we always carried on by time we cannot [Music] compete with time i mean there's no way to stop time or go back in time but the point is that when you go inside of the horizon the direction of time is pointing inwards towards the center of the black hole where it actually ends because you in the middle that's sort of where the direction inwards ends and and that means that the the way that you are that you're caught by the by the black hole it's as powerful as the flow of time itself so it's as difficult to get out of a black hole as moving backwards in time that's our current understanding of black hole that is what generativity predicts and everything that we have seen so far is compatible with that picture still and that is of course why one continues to do all these observations and measurements is that it could be that there is something else something different that you will be able to discover when you move really close into the horizon so we cannot say for sure what's going on but we know that these objects exist but we're not quite sure about their real properties there could be new physics there could be surprises there have been a lot of black holes in science fiction actually and there the end of time is also a beginning of something else inside the black hole you cut the time and go or travel out in another time past time for example would that be possible you think it's not very likely actually i mean the the most likely possibility is in fact that it's a one-way it's a one-way road and there is no escape there's no way to come out somewhere else of course i mean who knows but according to the current theories our current understanding uh if once you're in to a black hole i mean that's that's the end of it basically but uh well who knows i mean it's sort of it certainly marks the the bounded limits of our knowledge and you can you can start to speculate in various ways but but but a good guess is that once inside the black hole there is no there is no way out just the end but you mentioned that there are black holes actually out in the space so where are they well there are probably lots of black holes the one which is awarded this year's prize the discovery of the black hole at the central milky way but probably that many similar examples all through the universe or every big galaxy every galaxy is probably hosting a big black hole in its center many which are much larger than the one in our milky way and then furthermore we expect that to be lots of smaller black holes uh sprinkled across the milky way which are other products of the supernova i mean stars which have run out of fuel and explode and then giving rise to these black holes so black holes all over the place so how dangerous are they if we come close well not not especially dangerous or at all really because the the likelihood for us to encounter a black hole is really very small and it might very well be that there are black holes among the stars black holes that we cannot see but i mean remember i mean it's it's it's very rare that you would collide with another star right another star would collide with our solar system that doesn't really happen and there is no difference with the stellar like stellar mass black holes which are moving around in the milky way they will not just come and hit us that's the probability for that to happen is very very small but what would happen if you come close to a supermassive black hole okay now let's say that you were able to travel on purpose and and wanted to to examine such a black hole then it's actually the better the bigger it is because if it's a really big black hole like the one in the center of the milky way then you can without really getting hurt in any way you can travel all the way towards the horizon and even cross the horizon and enter into the black hole without being being stretched by gravity if the black hole is small like the the ones with just a few solar masses then you cannot even get close before gravity will pull you apart if you if you jump in with the feet first then gravity will be stronger in your feet and in your head and you will be just torn apart but for a big black hole you could actually imagine such such a journey into it then of course it's a dangerous place still because there might be lots of other stuff happening i mean there might be hot gases and plasma which is swirling around the black hole and dangerous radiation but as far as gravity is concerned a big black hole is not really that dangerous of course i mean once in you cannot get out again but otherwise it's okay it's just the end it's just the end otherwise it's fine reinhard gancil and andrea guest came actually quite close by observations they did yes did they expect this place so they did they expect the nobel prize i have no idea what did they say they were very they were very very happy obviously clearly and that was there was a very pleasant experience i mean to share that moment with them thank you very much you

Channel: Nobel Prize

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Length: 36min 46sec (2206 seconds)

Published: Tue Oct 06 2020