Can We Be Touched by a Star? | Sabrina Savage | TEDxNashville

now when I was writing up my dissertation work I encountered some serious writer's block now granted I had a 12 a 10 a 4 and a 1 year old at the time so it's probably not all that surprising that I had trouble focusing right but daughter number 2 Elida who was 10 at the time wanted to help me out so she wrote up a list of things that she knew about the Sun and as you can see she was a little bit worried about it touching her fair enough but this was a child who has seen lots of pictures of the Sun on my computer in different colours and wavelengths and so she perhaps knew a little bit more than the average 10 or a 30 year old and she went on to write the Sun has spots excellent and the Sun is a star and this is the line that triggered me into writing again if I go into any room and ask what is the nearest star about 99% of the time someone is gonna fire back at me with Alpha Centauri I know some of you were thinking of it it's like free bird I know some of you were thinking about that too but it's not it's the Sun the Sun is a star just like anyone that used to get night in your favorite constellation it's no different and even more than that it is the closest astronomical object to us most of us will go through our days not even realizing that we are living with an astronomical object right next to us and more than that we're living in it in its extended atmosphere it's wind it's whether it's tendrils sure most of us are pretty familiar with the first part of her list it's hot it's bright it causes some burns and we know that it does good things for us like grow food with the photons that were created in its core a few million years ago plus about eight minutes of flight time we all know that part right it is also the source of nearly every bit of energy in your body and in the whole solar system even the Sun brought you here today and you thought it was your lift driver over 100 earths would fit across this diameter and it would take a million more to fill it up and the embarrassing thing is this star the anchor of our solar system which is everything to us isn't special it's actually pretty mediocre if you were at any one of these stars in the Milky Way looking back with your very own Hubble you would not be able to distinguish our wee little system from the background noise sorry our Sun will not even have the dignity to explode once it's done burning all of its fuel in its core in about five billion years however it will go out in a spectacular whimper and take all of these inner planets with it and yes you are sitting on it in your planet such as life now when I first embarked on my career in astrophysics I wanted to study cosmology the universe big things far away things Hitchhiker's Guide to the galaxy things things that you needed a TARDIS to go see I kind of tripped my way down into solar physics and honestly I was a little disappointed at first the Sun after all is only 93 million miles away that is peanuts to space honestly I thought eclipses were as cool as it got now don't get me wrong eclipses like this one that went over Nashville just a couple of summers ago are incredible and I cannot wait until 2024 and you better go ahead and book your hotel for it but I thought that the Sun was boring and flat and that we knew everything we need to know about it it didn't touch me and it probably didn't touch you before you walked into this room let's fix that shall we here is a picture of a planet Venus the entire thing you can even see the atmosphere around its rim and in the background of this is something straight out of a science fiction movie that star in the background it's so massive that you can't even detect its curvature and this is your next-door neighbor now if we zoom out a little bit and focus on its atmosphere instead of its surface using more lights than what our very limited eyes can detect you can see this beast and its entirety and admire how gorgeous and complex it really is and if we sit and stare at it for just a little while well we find is that it is a superheated ball of plasma that is delicately dancing along writhing magnetic fields it is constantly changing on all scales remember what I said we're not just living with this beast we're living in it in its reach so anything that happens at the Sun can have profound consequences at Earth and I'll let you in on the secret stuff happens at the Sun a lot so remember those spots that were on a lightest list those are important that is where the biggest explosions in the solar system occur sunspots are only dark because they're a little bit cooler than their surrounding material but they would still note rocks they look completely static by eye right but if you zoom way in on them they are ridiculously complex and dynamic in this movie at its highest resolution you can pick out features that will fit between Nashville and Huntsville 93 million miles away I love my job but what are these though well to answer that you have to look outside of the visible spectrum and what we find is that underneath they are the locations of the sun's strongest concentration of magnetic fields and above they are regions of intensely hot activity hotter than the surface these are called active regions and they are the source of hazardous space weather and now we have finally arrived at the reason I'm really here which is to give you nightmares about space weather so without further ado let us begin with solar flares you've probably heard of a solar flare right they are the highly energetic bursts of light that can occur at these spots when the magnetic field gets so twisted and sheared that it pops kind of like a rubber band and then it instantly rearranges itself kind of like magic and it releases a ton of energy before settling back down again flare temperatures can reach into the tens of millions of degrees which is hotter than the core of the Sun where nuclear fusion is taking place and yet flares aren't what to keep you up at night it is literally the mountain of ionized plasma that can be ejected with these flares that is the real problem these coronal mass ejections or CMEs can go roaring through interplanetary space at hundreds of miles per second that is thousands of times faster than an f-18 jet now the sun's activity cycles over about a dozen years right now we are very near solar minimum very merit it's kind of boring and we will ramp back up to solar maximum in about 2025 give or take which just might coincide with our next trips to the moon and I want you to remember that in just a second at the peak of the cycle CME's are thrown out at a rate of about several per day some are bigger than others and most of them are not aimed directly at us because when they are they can cause a bit of a mess at earth fortunately earth has a strong deflector shield much like the Starship Enterprise [Laughter] called the magnetosphere which protects us from these highly energetic particles it redirects them towards the poles and in so doing energizes the aurora now this consequence of a cataclysmic explosion in space right on your front porch isn't too shabby although it does take hundreds of tons of atmosphere along with it it's okay earth can cope but they're not all this gentle in 1859 there was an event so huge the biggest one ever recorded in fact in observed by eye that it set telegraph poles on fire due to the tremendous induced currents at the ground now when you look up what a telegraph is what you'll find is that 160 years ago we did not have a whole lot of technology compared to today so that we were lucky that that was really the first or the worst of the damage that occurred if that event had happened today damages to the US alone could reach into the trillions of dollars and that's because major US cities are sitting on top of nicely conducted bedrock a more recent example occurred in 1989 when one of these space storms knocked out power to millions of people for nine hours in Canada costing the Canadian economy about six billion dollars six billion dollars for nine hours and that was 30 years ago and it's all because of these pesky charged particles that are moving at tremendous speeds towards the earth they can disrupt GPS fry electronics blow transformers interfere with satellite communications and that's just to name a few and it's only going to get worse as become more and more dependent on space technology right so no power no internet no social media no GPS for planes near the polls it's hard to pick out which ones worse now I don't know about you but when I'm flying to Japan for work I find a degree of comfort and knowing that the pilots are not using the Stars to navigate by so I'm gonna choose that one and if we cannot protect equipment and humans yes that's me and humans on the moon are on the way to and at Mars then we may as well forget about deep space travel in fact there was an event that occurred in 1972 between two Apollo missions that could have killed all of the astronauts on the moon surface in a fairly horrific way through radiation poisoning even in their spacesuits now remember what I said about possibly going back to the moon during the next solar maximum does that get your attention yeah I hope so by the way NASA if you're listening I still totally go I have my David Bowie playlists already picked out ready now as bad as all that sounds we're only mostly helpless there are groups are agencies across the globe that are working fairly tirelessly at trying to improve space weather predictions so that satellite industries and other industries can be prepared as just one example a NASA led probe named Parker which just hurdled towards the Sun this past summer I was lucky enough to be at the launch it was incredible and it was sent out there to help us understand how the sun's wind connects the entire solar system and also how the sun's temperature or that the atmosphere is heated to temperatures that seemed to defy physics this is something that's been keeping us going for decades now an honest way Nonna's journey park we'll become the closest man-made object to a star ever so if earth was out at Los Angeles and the Sun was here in Nashville Parker will get closer than Memphis and there are many other groups across the country and across the globe that are working to find new ways of looking at the Sun to fill in the missing pieces because there are so many like the group that I'm part of in Huntsville Aetna Marshall Space Flight Center where we develop instrumentation first for testing on sounding rockets and on the International Space Station and on spacecraft this one is going to launch again in less than a month actually this is an exciting time for for solar physics we're in this sweet spot where technology is finally starting to catch up to our questions and I encourage students and your kids come join us this is a spectacular job right and you don't even have to be a scientist to do this so please ask me how to get involved there's a lot of job satisfaction that goes along with you know protecting the planet and enabling spaceflight I feel like a superhero sometimes now Aveda who is now in college and where they listen to a lot of TED Talks and she's one of my four favorite children she's not my favorite wherever she is she's out there she put together a little presentation for me when she heard that I was doing this because she was super excited right and it was titled hot knowledge and it had lots of cool graphics in it because that's what you learn in high school in college now and here is her updated list of Sun facts and she has grown quite a bit over the past decade and so has her understanding of our relationship with the Sun as I hope yours has as well in the past 15 minutes the Sun isn't just a big light bulb in the sky it is where science fiction meets our reality it is the best laboratory to the universe that we have and it is just right there it gives us a reason to look up every day and to work together for a very common cause human survival and progress and all and above all that it is beautiful and it's terrifying and it touches us all thank you [Applause]

Channel: TEDx Talks

Views: 12,466

Rating: 4.5247526 out of 5

Keywords: TEDxTalks, English, Science (hard), Astronomy, Big problems, Exploration, Rocket science, Society, Space, Weather

Id: oAyCEVWcErc

Length: 16min 2sec (962 seconds)

Published: Fri Jun 07 2019