Gupta it all started in 2004 when sal khan was working as a Hedge Fund Analyst in boston and his cousin nadia, a seventh grader in new orleans, was struggling with algebra. He agreed to tutor her remotely, and wound up posting lessons on youtube. But then an odd thing happened total strangers started using them, too. Just like we talked about consumer surplus, this is a producer surplus. Innovation never comes from the established institutions. Its always a graduate student or a crazy person or somebody with a great vision. Sal was that person in education. In my view, he built a platform that could completely change education in america. Logan when he was just 29, jack dorsey invented twitter, a technology that changed the way hundreds of millions of people communicate all over the world, from the president to the pope, celebrities, teens and teachers. You just take the card and swipe it through. Logan seven years later, dorsey heads up a Company Called square, which promises to revolutionize the way we pay for things. You dont even take your phone out of your pocket. It just pops up on the screen . Yes. Logan and did we mention he wants to be mayor of new york city . Im steve kroft. Im lesley stahl. Im bob simon. Im lara logan. Im sanjay gupta. Im scott pelley. Those stories tonight on 60 minutes. Break a leg i used to love hearing that phrase. But not since i learned i have postmenopausal osteoporosis and a high risk for fracture. I want to keep acting but a broken bone could change that. So my doctor and i chose prolia® to reduce my risk of fractures. Prolia® is proven to help make bones stronger. I take prolia®. Its different its two shots a year. Do not take prolia® if you are pregnant, are allergic to it or if you take xgeva®. Prolia® can cause serious side effects, including low blood calcium levels, serious infections, some of which may require hospitalization. And skin inflammation, rash and eczema. Tell your doctor if you develop dental problems. As severe jaw bone problems may happen, or if you develop new or unusual pain in your hip, groin or thigh, as unusual thigh bone fractures have occurred. Whats out there matters to me. So does whats in here. Break a leg ask your doctor if prolia® is right for you. [ camera shutters clicking, crowd groans ] no. Closer. I am a veggie, i am so tasty 2007 called, it wants its camera phone back. And i am filled with vitamins and minerals hows this for a drama shot . La la la la la la why arent we getting closer . [ guy ] with the nokia lumia 1020, weve got the best seats in the house. [ male announcer ] meet the nokia lumia 1020 with 41 megapixels and reinvented zoom. Nothing else comes close. [ male announcer ] hurry in for labor day deals, like 10 off all major appliances 399 and above at lowes. I put in the hourswhere i am today by luck. And built a strong reputation in the industry. I set goals and worked hard to meet them. Ive made my success happen. So when it comes to my investments, im supposed to just hand it over to a broker and back away . Thats not gonna happen. Avo when you work with a schwab financial consultant, youll get the guidance you need with the control you want. Talk to us today. Stahl ever since the wreck of the Costa Concordia a year and a half ago, the huge italian luxury liner has been sitting semisubmerged off the coast of tuscany, looking like a big beached whale. Its the largest Passenger Ship ever capsized, easily surpassing the titanic. And, as we reported last year, removing the ship has turned out to be the most complicated, the most expensive, the most daunting and the riskiest salvage operation ever. The Costa Concordia is a rusting carcass, sitting precariously on two underwater mountain peaks. The swimming pools and jacuzzis where passengers sunbathed and sipped cocktails, now empty and askew. A clock remains frozen in time, marking the hour and minute when the ship lost power. And below, ghostly vestiges of the ships contents litter the ocean floor in what the italian authorities have designated an official crime scene. 30 people died; two are still missing. Nick sloane welcome on board. Stahl thank you. Nick sloane from south africa is the senior salvage master. He took us out to the wreck site. How big is that ship . Sloane shes huge, and what you see at the moment is only 35 of her. So 65 underneath is like an iceberg underneath there. Stahl now the plan is to roll the 60,000ton ship in one piece onto an underwater platform, raise it, and then float it away so it can be cut up for scrap. So, youre planning to rotate a ship that weighs 60,000 tons. Sloane yeah. Stahl so, let me see. Youre going to. This is the ship. You have to do it like. Sloane well roll it up right. Stahl . The whole thing together at once, creaking. Sloane all the way along the three football fields long. Stahl three football fields long . Sloane yeah. And were going to rotate it all at the same time. Stahl it sounds like an experiment in defying the laws of physics. The actual work is being shared by nick sloanes titan salvage, an american wreck removal company, and micoperi, an italian engineering firm. Sergio girotto is the companys project director, in charge of refloating a 60,000ton ship filled with seawater. So you have to create much more buoyancy than even the original weight of the ship because of all the water. Girotto absolutely. Absolutely. Stahl a team of engineers came up with something ingenious to, in effect, weld a new ship onto the shipwreck. It starts here with the construction of towering steel boxes called sponsons. Theyre gigantic. The largest ones weigh 500 tons each and stand 11 stories high, and theyll be outfitted with hoses and sophisticated air pumps to create buoyancy. Heres whats supposed to happen one by one, nine of them will be welded across the exposed side of the ship. Girotto they will be joined together like a big lego, outside in the open. Stahl and they have to be precisely welded, correct . Girotto the space from one sponson to the other, it is less than two inches, so they must be fabricated with a very strict tolerance. Stahl this row of hydraulic pulleys will tighten a string of 36 cables attached to the sponsons, slowly rolling the ship upright. Then, other steel boxes will be welded to the other side of the vessel, and, eventually, the hollow, airfilled sponsons will act like waterwings so the Costa Concordia can be floated and towed away. Has this ever been done before . Girotto no, no. Stahl this is brand new . Girotto the brand new technology, brand new methodology. To lift a vessel in this way, it is the first time ever. Stahl and no ones 100 sure lifting a vessel this gigantic in one piece is going to work. Its the biggest Passenger Ship ever wrecked, twice the size of the titanic. Before the accident, it was a 15story floating palace big enough to house a small town of 4,000 people. As this promotional video shows, it had 1,500 luxury cabins, 18 restaurants and bars, four swimming pools, five jacuzzis, and a casino. The accident occurred in january of last year, ominously on the night of friday the 13th. Nervous passengers crowded together as water gushed in. Sailing too close to shore, the ship had struck a huge boulder hidden just beneath the surface. You can see that it just tore the pipes apart. Sloane yeah, the momentum of a large ship like this hitting that rock, she had no chance. Stahl almost like a shark eating the belly of a whale or something, it just ate into that. Sloane yeah, it was a big rock, about 96 tons. Stahl the wrecks an eyesore right off the beaches of tiny giglio island that has been overrun by an armada of support vessels and an army of welders, crane operators, and marine engineers. Because of the angle of the ship, the workers have to take a fourday course in mountain climbing. Here, theyre working on the strong cables that are keeping the ship in place. Much of the work is being done underwater by specially trained salvage divers, 111 in all. Ebano, whos from brazil, is being geared up and safety checked by other divers on his team. Sloane hes got communication for talking. Hes got the air. Hes got backup air. Hes got a camera and a light. Stahl every one who goes in has a support team of at least five up on deck. Once suited up, ebano is lowered down in a cage. The day we were there, the divers were ratcheting, tightening, measuring those massive steel cables that run under and around the ship to tie it down so it doesnt slide off the mountain peaks and sink. Its an exacting and dangerous job, so teammates stand by on deck in case of an emergency, and a dive supervisor monitors and directs the action. Duane morsner do you want to move back on your. On your camera and give us a wide shot of exactly whats going on down there. Stahl duane monster morsner oversees a dive team. So youre just watching everything he does, listening to him . Morsner and explaining to him exactly where to go because sometimes when you go past 30 meters, you can get narcosis and it sort of affects your your thinking. And obviously, if hes in trouble, i can see what the problems are and help him out and check his depth, that sort of thing. Stahl theres a salvage divers camaraderie. They live in close quarters in floating barracks next to the ship. And while they come from eight different countries, speaking different languages, theyre like soldiers in combat they have each others back. Morsner move towards the bow of the Costa Concordia, please. Stahl though these divers are in the water round the clock, each one can stay under no longer than 45 minutes at a time. They have five minutes to get from a depth of 40 feet into a decompression chamber. When a diver surfaces, its a race to strip off his gear and get into the chamber. The divers and everyone else work round the clock, seven days and nights a week, in a race against time. They have to remove the ship before storms like this one last winter break it apart. Sloane every storm weakens the structure, and there will be a certain point where the structure. And she will just say, ive had enough. Stahl so is that what has you worried the most, the weather . Sloane yeah, yeah. When you have bad weather, you dont sleep. Stahl neither do the Insurance Companies that are footing the bill. So, how much is this operation costing . Sloane well, basically, its going to be around about 400 million, plus or minus, and thats a lot of money. Stahl did your company ever consider proposing just blowing it up . Because i know a lot of salvage operations, they just dynamite. Sloane yeah, some places in the world, that would be a solution. In this scenario, i dont think it would ever be allowed. Stahl is the reason because this is such a tourist area . Sloane oh, the environment is the number one priority. Stahl number one. Thats because the ship settled in a nationally protected marine park and coral reef thats home to dolphins, exotic fish, these huge rare mussels, and more than 700 other botanical and animal species. Sergio girotto hi, lesley. Stahl Sergio Girotto took us to one of six shipyards in italy that have been pressed into action. At this one north of venice, theyre building this huge steel platform. Its one of six platforms thatll be lowered into the water, its legs anchored into the hard granite sea floor. When the ship is rolled upright, it will roll onto them. So the ship is over there . And what, its going to roll. . Girotto yeah, its going to rotate, and rotate slowly to rest on this platform, exactly the same area where we are standing. Stahl the platforms are necessary to keep the 60,000ton ship from sliding off its mountain peaks, down into the abyss. But getting the platforms to the wreck site is an operation in and of itself. Girotto and we make the tour of italy. Stahl they will be floated by barge from the shipyard to the shipwreck off giglio island. Around the heel, around the toe and up to giglio. Girotto up to giglio. It is a long trip. Stahl how long . Girotto its going to take. Its going to take 15 days. I tell you, it is a gigantic project. If you simply think of the quantity of steel, it is three times the weight of the tower eiffel. Stahl of the eiffel tower . Girotto exactly. Three times the weight of the tower. Stahl out at the wreck site, theyre lowering giant pipes that are used to drill holes in the seabed for the legs of those massive platforms. So these are these big pipes that youre putting down. To protect the environment, the drill bit will be enclosed in the pipe in order to contain any debris from the digging. Wow, look how huge sloane as you can see, this is about eight feet. Stahl eight feet is the diameter of the legs of those platforms, and the holes for the legs have to line up almost perfectly. When you put the platforms down, whats your margin of error . Sloane the error that we can allow is less than six inches between them. So, if we are more than six inches out, the platforms arent going to fit. Stahl has there ever been a salvage project this big . Sloane no, this is with the complexities and the amount of engineering, the scale of the equipment that were bringing in, the size of the teams, this is by far the largest thats ever been done. Stahl in the history of salvage . Sloane in the history of salvage. Stahl lets talk about the day that you are going to rotate the ship onto the platforms. If somethings not going right, can you stop it . Sloane no, you cant stop it. You have one chance. Stahl one chance . Sloane one chance. Once you start, you have to finish. Stahl weve spoken to arine engineers. They think you have a 50 50 chance. Sloane no, its more than 50 50, for sure. Stahl it is . Sloane basically, weve got a large engineering team. We have over 200 engineering documents, and everything proves that it can be done, so. Stahl on a computer . Sloane yeah, on a computer. Some parts of the ship will collapse internally. Its going to be very noisy. Theres going to be a lot of creaking, groaning, steel snapping. But shell come upright. Stahl steel snapping . Sloane yeah. Stahl that doesnt sound good. Sloane yeah, well, there will be smaller bits of steel, but the larger structure will take it. Stahl is there a plan b . Sloane we have plan b and c, but we dont want to get there. Stahl there is cutting up the ship in place, which would be an environmental catastrophe. Theyll put plan a into effect later this month, when they attempt to raise the ship, under the watchful eyes of the Insurance Companies, the italian authorities, and camera crews from around the world should they succeed, the Costa Concordia will then be towed to a dry dock and cut up for scrap. Theres so much ship, that process will take two years. And now, the price tag is approaching 900 million. Go to 60minutesovertime. Com to see how the 60 minutes team managed to get these shots of the Costa Concordia. Sponsored by viagra. [ alarm sound for malfunctioning printer ] [ male announcer ] youve reached the age where youve learned a thing or two. [ metal clanks ] this is the age of knowing what youre made of. So why let erectile dysfunction get in your way . [ gears whirring ] talk to your doctor about viagra. 20 million men already have. Ask your doctor if your heart is healthy enough for sex. 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As we first reported last year, thats exactly what sal khan is doing on his web site, khan academy. With digital lessons and simple exercises, he is determined to transform how we learn at every level. One of his most famous pupils, bill gates, says khan this teacher to the world is giving us all a glimpse of the future of education. 36yearold sal khan may look like a bicycle messenger, but with three degrees from m. I. T. And an m. B. A. From harvard, his errand is intensely intellectual. In his tiny office above a tea shop in Silicon Valley, he settles in to do what hes done thousands of times before. Sal khan weve talked a lot now about the demand curve and consumer surplus. Now, lets think about the supply curve. Gupta hes recording a ten minute economics lesson. Its so simple all you hear is his voice, and all you see is his colorful sketches on a digital blackboard. Khan in this video, we are going to talk about the law of demand. Gupta when khan finishes the lecture, he uploads it to his web site, where it joins the more than 3,000 other lessons hes done. In just a couple of years, hes gone from having a few hundred pupils to more than six million every month. Has it sunk in to you that you are probably the most watched teacher in the world now . Khan i. You know, i try not to say things like that to myself. You dont want to think about it too much because it can, i think, paralyze you a little bit. So, if we get rid of the percent sign, we move the decimal over. Gupta hes amassed a library of math lectures. Khan 12 4 is 16. Gupta . Starting with basic addition, and building all the way through advanced calculus. Khan we are taking limited delta x approach to zero. Its the exact same thing. Gupta but hes not just a math wiz he has this uncanny ability to break down even the most complicated subjects, including physics, biology, astronomy, history, medicine. How much reading do you do ahead of time . Khan it depends what im doing. If im doing something that i havent visited for a long time, you know, since high school, ill go buy five textbooks in it, and ill try to read every textbook. Ill read whatever i can find on the internet. Lets talk about one of the most important biological processes. Gupta sal khan has tackled so many subjects that, if you watched just one of his lectures a day, it would take over eight years to cover it all. Khan these are huge time scales. Magnetic north is kind of the geographical. And lets say this is point x is equal to. Basic introduction. Light. If this does not blow your mind, you have no emotion. Gupta did you ever think about putting yourself visually in the video . Khan look, if theres a human face there, especially a funnylooking human face, then its actually hard to focus on the math. 4,000 is 2,000 x 3 is 6,000. I dont have to shave, i dont have to comb my hair. I just press reco