A nation and grapes of wrath and the third man. A film called citizen kanee on any many reels. Keep them flat. Dry. Cold. Having the analog storage version. The best thing. Lets me sleep at night. Knowing we have this. Old posters . Posters, ephemera. Moma also archives those. These are all from the atlanta premiere of gone with the wind. Reporter like the studio scrapbook of press clippings from gone with the winds 1939 premiere which includes a page on the black actors in the film. Awe momas work of restoring rosita in all will take two years. It will bring back a major Mary Pickford film also the first am director, ernst lubich. Head of film preservation at moma. How does the film like that disappear . Mary apparently took a personal dislike to it. For reasons that are still not completely clear. It seems she deliberately allowed the film to deteriorate. Didnt renew the copy right on the film. The museum discovered a copy in the soviet union in the 1970s. In horrible condition. Just too much for the technology of the time to handle. Reporter now rositas time has the finally come. And kerr wishes more films could be restored to the quality of Douglas Fairbanks final movie, the iron mask made in 1929. This is a copy made directly from the original camera negative. Actual film passed through the camera on the sets. Reporter even showing the films will become challenging. Longer manufactured. And spare parts will keep projectors going only for another decade. But after that. We have to start dij gitizing this massive collection, a huge understaking. Make is my head explode. You feel like you are in a race . It is getting there. Dont think the seriousness of this has settled in, even in the archival. Movies are what america did best in the 20th century. Thats our defining art form. I dont want i did everything i could to make her party perfect. Almost everything. You know, 1 i n 10 houses could get hit by an expensive septic disaster. 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See how much coverage you can get for just 9. 95 a month. Call now enough pressure in here for ya . Im gonna take mucinex sinusmax. Too late, were about to take off. These dissolve fast. Theyre new liquid gels. And youre coming with me. You realize i have gold status . Mucinex sinusmax liquid gels. Dissolves fast to unleash max strength medicine. Lets end this. Today you can do everything in just one click, even keep your toilet clean and fresh. Introducing lysol click gel. Click it in to enjoy clean freshness lysol. Start healthing. Yeah, click yesterday was leap day. If you missed it you are not alone. February 29th comes around one every four years. Most of the time. Jamie wax has the confusing story of the extra day. Every four years we have to squeeze an extra day into february. Except we dont add an extra day every four years if that year is evenly divisible by 100 and also divisible by 400. If that sound confusing, it is. We decided to dig into what leap years are all about. Started with one special leap day birthday girl. Daisy bell ward appeared in sun days finest for her Birthday Party this weekend. Isnt she beautiful . 1916, making her americas oldest living leap baby. You made it. Yeah. Reporter the bash complete with an 80piece marching band was celebration of her 100 years. According to the calendar her 25th birthday. Daisy seemed to embrace the latter. Why does daisys birthday only come around once every four years . Do you know why we have a leap year . No. No. Probably something about the sun. The seasons and, global warming. I dont know. El nino. Reporter we decided might be best to consult an expert. Theoretical physicist. Why do we need a leap year . Mother nature has a sense of humor. Did not make a calendar when you what we learn in school. No, Mother Nature made it so every 365 days plus 5 49 and few odd seconds. That means that every year we have to compensate for one quarter of a day. After four years we have to add one more day. So when did we figure out the need for this extra day it . Was bay back in 46 bc. Julius caesar realized the calendar wasnt working. Consulted with an astronomer. They realized what the egyptians discover. We need an extra day every four years to stay on track. He in to theed the julian calendar. Even that wasnt quite right. The solar year is. 242 longer, not even. 25. When we add a full day every four years we are left with that can start to add up. Finally in 1582, pope gregory 17th. Instituted the gregorian calendar we follow today. How is it different . I will let michio kaku explain. 11 minutes difference in one year, builds up. The pope had to intervene the calendar one more time. So for example in the year 1600. Divisible by 400. A leap year. In 1700. 1800. 1900. No lope year. Year 2000 there was again a leap year. Lot of tweaking. Thats right. Luck we he have digital watches to keep track. It turns out, accounting for leap years is difficult for traditional watches. This watch has a wheel that turns one revolution every four some body engineer a wheel. Many of us have to adjust the gauges, end of february. Protect the leap, perpetual calendar does that for you. To see how it works. We looked at one under a microscope. It is a cycle of 48 months for the leap year. We have a 48. 48 lobes. Each lobe represents a month. Reporter it take is a year and a half to construct one watch. It will set you back around 85,000. You have four years to save up for the next leap year. Around the world, leap year traditions vary. In greece, its bad luck to get married any day of the leap year. Up north. February 29th. The own day a woman can propose marriage to a man. For daisy, her birthday tradition has always been a nice dinner with family and friend. But this year was different. You turn 25. One last thing to think about this leap year morning. If youve havent left for work. Consider just saying home. If you are a salaried,,,, you could have seen this one coming a mile away. Google says it is partially responsible for the crash of one of its driverless cars. Last month in mountain view. A driverless lexus tried to maneuver sandbags and side swiped a bus when it reentered its lane. No one was hurt. Damage was minimal. Peter greenberg got a look at the state of the technology. Reporter to see where drivers cars are heading. We went for a ride with profess professor raj kumara at carnegie university, where the technology was created over 30 years age for all the people telling us we driverless car tomorrow, you say . Just wait. The magic all happens in here. Reporter right. Keep waiting. Because despite all the technology and decades of research, the driverless car has a long way to go. The biggest nightmare that people like me who work on the car is that somebody dough ploiz this technology prematurely and it kaus s causes an accident and some child dies. Reporter as disturbing as unlikely, a scenario on the mind of researchers and slowing momentum of Autonomous Vehicles. We as human beings are much less tolerant of an error a machine makes. Gill pratt heads the research institute. Global initiative from the manufacture the driverless car. How do you Program Decisions what you are really talking about in Artificial Intelligence is called planning. Planning for near in fi that number of ethical scenarios like this. Suppose your car is approaching a headon collision. To avoid the vehicle, your car can move right because crossing the yellow line on the left is illegal. What is there is a person. Or group of people to your right . These machines have ability to understand what is happening in the world much better than a human can. Every time . The leading tow yo ta research at mit. Whatever time it is reasonable. Self driving can be used to day. And used at low speeds perhaps where we dont about whether there is catastrophic collision. Back on the road oot carnegie melon, our driverless car takes a detour. Decided to take over. Yes, the system has been professor raj kumar takes the wheel. Evidence of the Autonomous Vehicle has miles to go. Thats the cbs overnight news. For some the news continues. For others check back with morning news. And krs cbs this morning. From the Broadcast Center in new york city. Im demarco moore. On the eve of super tuesday, trump clashes with black lives matters protesters. Get them out. Get them out. Out. Out. Out. Out. Also tonight, a cop is gunned down on her first day on the job. The big cheese at a food Company Pleads Guilty to selling parmesan that had no parmesan. And david martin with an american hero. Thats five bronze stars, two purple hearts. Thats correct. And now the highest military honor of all. Announcer this is the cbs overnight news. Nomination today, but super tuesday may generate irreversible momentum for Hillary Clinton and donald trump. Theyre favored in most of the 12 state primaries and caucuses. For democrats, a step towards certainty. For republicans, another jolt in the partys identity crisis. Polls show trump leading in at least six states. He is trailing ted cruz in cruzs home state of texas. The republican race, petty, profane and unprecedented now has prominent republicans talking of an independent candidate if trump wins the nomination. Race became the weapon of choice today. Major garrett is with the republicans. Reporter following the news that former kkk leader david duke was supporting donald trump, black lives matters protesters interrupted a trump rally in virginia. A Time Magazine photographer tried to leave the press area to shoot the protesters as escorted from the venue. Secret service agent. Photographer chris morris admitted to cursing at the agent before the confrontation became physical. Morris said the agent grabbed him by the neck and put him in a chokehold. I am dealing with some real sleaze bags up here. Believe me. Im telling you. Politicians. Criticizing reporters and makes it clear protesters are out. Get out. Out. Trumps momentum towards the gop nomination brought a sharper edge to his already raucous marco rubio complained that what an indictment on the state of political debate in the reporter yesterday, rubio himself dove into the mud. You know what they say about men with small hands. You cant trust them. You cant trust them. Reporter rubio is hoping for Strong Enough finishes tomorrow delegate count. Ted cruz is banking on a victory in his home state of texas. And we are i believe going to have a big chunk of delegates. I think everyone else will be way, way, way behind. At that point it will become abundantly clear this is a two man race. Reporter secret service interviewed the agent involved in the altercation at the trump rally. Agency policy to protect the candidate. The photographer involved, chris morris said he will not press charges. Specially not after the way he provoked the agent. Major garrett reporting for us. Major, thank you. All of this followed trumps responses to support he is getting wanted or not from the ku klux klan to. Day, mitt romney said trump has been disqualified. Here is Dean Reynolds. Reporter campaigning in virginia today, donald trump was boasting again. We have amazing endorsements, people that really mean, we have hundreds of people now that want reporter praise from david duke, former grand wizard of the ku klux klan may test his following more than ever. Voting for these people, voting against donald trump at this point is treason to your heritage. Reporter last friday, trump seemed to say no thanks. I disavow. Sunday he declined to renounce the k. K. K. , duke or his support. I dont know anything about david duke, okay. I dont know anything about what supremacy or supremacists. Trump tried to clear up any confusion. I disavowed david duke all twitter. He said a bad earpiece made it hard to hear the question about the kkk sunday though he used the same one for several interviews. In any case it is clear some far right groups like what theyre hearing from him. He has won the backing of the neonazi website, daily stormer for example and American National super pac is making calls in super tuesday states. We dont need muslims. White people to assimilate to our culture. Vote trump. Reporter Southern Poverty Law Center which tracks hate groups says the super pac was started by white supremacist American Freedom party, trumps rhetoric is a coded appeal to racists. The idea that any mildly educated person in this country could not know what the ku klux klan was is perhaps one of the most ludicrous statements we have heard in mainstream politics in many years. Reporter the super pac backing marco rubio put it this way. Trump refuses to denounce the kkk. Think about that . For president. Donald trump has been heavily criticized before, scott, and so far, his support for the nomination among voters in the party of Abraham Lincoln has Dean Reynolds reporting for us tonight. Thank you. The polls are pointing for a very good super tuesday for Hillary Clinton. Here is nancy cordes. Thank you. Reporter clinton said the republican candidates were behaving like grade schoolers. Remember the little box that used to be on your kids report cards. Play well with others. I would have to put a big no. Reporter she is poised to make the deans list tomorrow. The latest cbs news Battleground Tracker shows clinton leading sanders by 20 points in virginia, 24 points in texas and 2 points in georgia. Other polls have her up in tennessee, alabama, and massachusetts. And she is the former first lady of arkansas. That leaves sanders hoping for a strong showing in oklahoma. Colorado. Minnesota. And his home state of vermont. No question here in minnesota. If we have a turnout. The two have found common cause in their distaste for donald trump. When sanders called trump a hate mongor online, Clinton Retweeted it. But otherwise she has begun to focus less on him and more on her likely race against the republicans. One advantage i have is they have been after me for 25 years and im still standing. Reporter the state department is releasing its final batch of clintons 30,000 emails tonight. But, scott, that does not mean the saga is over. The fbi is still looking into her use of a private server and a federal judge wants some of her top aide to testify about it. Nancy cordes with the democrats. Thank you. The cbs overnight news will be ,,, john dickerson, cbs news political director at the top of the broadcast we talked about whats going on within the party . Well if there was a wall between the Republican Party and donald trump it is 10 feet taller. In conversations with republican strategists and staffers on the hill theyre at wits end about what it would be look to have donald trump as the party nominee. What they pointed out in his interview is that he seemed to offend anyone and call anyone a bigot when asked about the kkk and White Supremacists. Suddenly he got politically correct. What they think, republicans i talked to, he was trying to not offend any southern voters. So in super tuesday, tomorrow. What house and Senate Leaders are worried about, what is it going to look like in the fall when they and colleagues have to respond to every incendiary thing he says. They were thing how they could take the nomination away. Or put a Third Party Candidate in if he became a nominee. Slip a Third Party Candidate in there. Hard to tell if theyre more unsettled about being tainted by trump or the fact there is not much they can do to stop him from the nomination. Thank you very much, john. In ohio today, a 14yearold boy opened fire on classmates in a School Cafeteria north of cincinnati. Two students were shot. Two others were hit by shrapnel. None of the injuries is life threatening. The suspect ran, but was caught there is no word yet on the motive. In virginia, the funeral is tomorrow for the Prince William county Police Officer who was gunned down on her first day on the job. Today the prosecutor said he may seek the death penalty. Here is justice correspondent jeff pegues. Reporter 28yearold ashley guindon, a decorated marine corps reservist, was just beginning a new career as a Police Officer her first day in uniform would be her last. Hold your traffic. Shots have been fired. Reporter saturday night she and two other officers were responding to a Domestic Violence call at this home. As officers approached the front door they were shot. Guindon rushed to the hospital. Pronounced dead a few hours later. The two other officers are expected to survive. Police say 32yearold Ronald Hamilton opened fire on the officers with a rifle. U. S. Army is also accused of killing his wife, crystal hamilton in the home. The couples 11yearold son managed to run to safety. Accordin