forces. also, more protests outside of st. louis as racial tension increase between police and civilians. and torrential rain in the northeast. we have more coming up at 6:00. "techknow" >> announcer: this is "techknow", a show about innovation, we explore humanity, and we'll do if in a unique way. this is a show about science by scientists. tonight military technology in the e.r. >> night vision goggles show surgeons something they could never see before.

brighter. >> dr shini somara is a mechanical engineer. kyle hill is an engineer. and i, phil torres, am an ento meteorologist. tonight - los angeles builds for the future, but discovers a secret deep under a subway line. >> i was the first person to ever see that. >> reporter: ever see what? >> a rare fossil. see. >> that's our team, now, let's do some science. [ ♪ music ] hello, welcome to "techknow". i'm phil torres.

joining me today is kyle hill, dr shini somara, and dr crystal dilworth. we have great stuff coming up. we'll start with you crystal dilworth - you have a new look at cancer. >> all of us know one person affected by cancer. i had a chance to go into the operating room and look at a new technique allowing surgeons to request

once something like this is dyed with the technology, would it carry with it, to see where the cancer spread to. is it something you'd have to reapply? >> it would be something you do have to constantly reapply. i don't think the life-time of the label in the body would be long enough to do that study. now, they are only doing surgeries for cancer that has not metastasized. >> fascinating. hopefully it will be standard in

operating rooms in the next 20 years. >> next, 10 miles away from here, in the heart of l.a. they are constructing a subway system. it will be great. they can celebrate. scientists are digging in, they are uncovering mysteries that are tens of thousands of years old. we'll check it out after the break. >> we want to hear what you think about these stories. join the conversation by following us on twitter and at

[ ♪ music ] >> hey, welcome back to "techknow". i wept 10 miles away from here. there's a place called la brea tar pits, and you may have smelt it, that is methane gas. besides the smell it's a gold mine for scientists. the fossils they are uncovering in the area are unlike any other place in north america, and they are uncovering mysteries of the past and giving us an idea of our global warming future. it's all from digging out a subway in l.a. let's check it out. [ ♪ music ] . >> reporter: it's called the miracle mile, a stretch of los angeles defined by deco cool and modern museums.

now its future is defining it's prehistory orric past. >> we've gone down 70 feet, 330,000 years. >> from the sub way to the sea - a treasure trove of ancient goodies has been uncovered, proving the sea was here. >> 300,000 years ago this was all ocean, and it had flooded a forest and it was cool and it was nice - much nicer than 100 degrees today jim scott is the palliantologist on the site. >> these fossils are 180 years old. there's a lot of cold water clams. on the right is a gooey duck and washington clams - we have them off the coast of california, but further north. the presence of these cold-water clams tells us that we had much

cooler waters 300,000 years ago. we are getting amazing things from this shaft. >> reporter: that subway shaft is across the street from the la brea tar pits, the richest ice-age fossil site in the world. a little over a century ago this was an asphalt mine until a shocking discovery was made around where i was standing - thousands and thousands of prehistoric bones, pallian tollogical gold, and they are still taking them out today. >> we have been taking fossils out of the ground, collecting the big bones, small creatures, insects, rodents and plants. >> reporter: john is the chief curator at the museum. >> this is telling us about what the environment was like when los angeles was in the peak of the ice aim. >> reporter: what was the environment like? >> in pit 91, 27,000 years ago, the average yearly temperature was

52 degrees and the rain fall 19, like the conditions in washington d.c. >> reporter: you can see the record. >> you can see them, yes. >> reporter: and this is why they have got such great specimens. this is the tough. this is the magic that made the fossils happen. >> exactly. >> reporter: two inches of this and a giant animal could get stuck in it. >> absolutely. animals. >> there's mammoth, and elephant size and larger. >> reporter: these are giant animals, huge, stuck in 2 inches of this. >> exactly. >> reporter: my question is how sticky is it? >> you could always try. >> reporter: that is thick, i can't get it off my fingers. it's amazing that this is the substance allowing the research to go on. >> isn't it fun to play with?

>> reporter: a little too much fun. what is fun is discovering something new from on old fine, now that technology has caught up with curiosity. it been -- it can be studied with 3d technology. it. >> we are able to look inside is see for the first time, something we would never see with human eyes. >> reporter: how do you pull it off with something small? >> it's a microscanner. it's intensive. >> reporter: two leaf-cutter bugs that can be compared. >> this is a modern bug and this is the fossil contrasted with it. you can see the eye, the eye. here is the wing right there. >> reporter: these things haven't changed in about 40,000 years.

>> i was the first person to ever see it. and then there's an image and we can share and show rare fossils that see. mouth. >> reporter: no trouble seeing this fossil discovered in 2006 during an excavation for a nearby parking garage. >> you guys work on pretty big specimens, including this beast. what is this. >> this is z, a full-grown male columbian mammoth. we radio accommodated him to 35,000 years old. >> z turns out because you had a picture of course model. where you see t. >> we can study lymph proportions of its kind. we found tusks before, but these

or complete tusks that we found. 23. >> project 23 is a large collection of ice-age fossils that were found next door to the construction. >> researchers found 23 crates that they are picking through. >> we found 15 deposits making double our collection discovered in the past 100 years, digging in the ground, on the ground. >> reporter: in the ground, on the ground. >> it's fascinating, it's like digging for treasure. >> reporter: you guys are digging more and better. >> we can't cleanaway the outside, so we save the microfossils, so we focus on the stuff. >> reporter: and you are able to get better apps from the things you -- answers from the things you find.

>> that's right. the more evidence you have, the better the story you can tell. so i have to say, i visited the la brea tar pits when i was little with my parents. the one thing i wanted to do, that i didn't get a chance to do is touch the tar. i'm jealous. >> playing with the tar. it was sticky, it took my about 10 minutes to get it off my hands, i can see why it would get an animal stuck. >> these tar pits seem to be good at preserving the animals, is that because the tar. >> the asphalt and the bacteria, you don't get feather or hair, so that made it difficult to get d.n.a., but as far as preserving the structure, they can tell a lot about an animal based on the skeletal structure. it's thanks to the asphalt. >> what is amazing is that you really see in the tar pits how much the climate changed.

l.a., essentially, was under water once upon a time, and the tar pits are evidence of that. >> absolutely. the asphalt that you get there comes from marine life in this area a very long time ago. millions of years ago. it's an interesting insight that you get of looking at the old life preserved by older life. i have some goodies, and this is the asphalt, and really old wood from one of the l.a. subway digs. what is interesting is the subways are digging 70 feet down, so they are getting older speaks mums. these are 300,000 years old compared to the ice aim stuff that is tens of thousands. what stands out is how well preserved these are. this is a cyprus tree, 300,000 years old. look at it. you can see the details thing. it. decayed.

>> it's still brain. >> it is still brown. that is nuts. that's the magic of asphalt and why it's such a treasure for the scientists because it preserves things so well. a funny story about these is that they are - i mean, 300,000 years old, these amazing things to look at. when they were in the "techknow" they accidently got thrown out by the cleaning staff. leave it it the hardworking producer to dump into the dumpster to get it out so we can be talking about it now. >> one man's trash is another's scientific treasure. >> absolutely. if you want to see more, check out the website. crime scope investigation coming up. what if you use d.n.a. that a suspect left behind to predict what they look like. that is after the break. >> hundreds of days in detention. >> al jazeera rejects all the charges and demands immediate

release. >> thousands calling for their freedom. >> it's a clear violation of their human rights. >> we have strongly urged the government to release those journalists. >> journalism is not a crime. @

america mobile app, available for your apple and android mobile device. download it now [ ♪ music ]

hey, guy, welcome back to techknow. i'm phil torres, and with me kyle hill, dr crystal dilworth, and dr shini somara. at the scene of a crime a suspect leaves dna behind and maybe that can be used to identify a suspect. they are using it in a new way to predict what the suspect may look like. check it out. can d.n.a. left behind at a crime scene give investigators a mug shot of a suspect. scientists at a university devised a technique to make 3d renderings of a person's face using the genetic cold in d.n.a. 600 volunteers were recruited and they captured 7,000 points on each face using mesh, measuring positions of landmark,

such as the eyeballs and the nose. comparing the map to the code the researchers zeroed in on 24 variants and genes that determined facial features. >> what do you guys think, it seems preliminary and now they have got some good evidence with it. >> i definitely wouldn't trust it yet. but i'm not sure that i would trust a traditional sketch artist rendition either. but it is a step forward. >> having done the report on facial recognition, i identified problems with the technology, and the sense that it's sensitive to the lighting or the cameras that were used, or if the face was not completely straight on. so there are problems with the technology, how will you reconstruct a face from d.n.a. it seems far fetched.

>> at the same time there are general factors that could be beneficial if you never saw the suspect. you could tell if it was a man or a woman, what race the person was, you can get a general idea of the kind of perpetrate scror, and you could apply that in a germ way. >> i think, if anything we can take from this. it's preliminary and interesting. the question is should they pursue it. the whole question comes into play tomorrow when al jazeera airs "flawed forensics", in this forensics gone wrong. joe huffington served 23 years in prison for a crime he may not have committed because of mishandled d.n.a. >> there were two hairs found at the scene, one on the bedsheet and one on the garter belt of the victim.

that was the key evidence of the prosecution. that's what put him at the time and place of the murders. in 1999 an intern report found problems with what michael malone had done in the huffington case much. >> we are looking through a microscope. you don't know how many characteristics to match, you can choose it. it depends upon the person downing the analysis, not fact. standard. we knew that there were problems with the technique. there are many documented cases where numbers, including michael malone, but not limited to michael malone, have matched carpet fibres to head hair. he had excluded hairs, without explaining why he excluded hairs. he matched hairs without explaining why.

he hadn't tape hair samples from all the people who may have been in -- taken hair samples from all of the people that may have been in contact with the body. results. >> absolutely. this is a great example of how scivening process -- scientific process and important, more important when a life hangs in the balance. such a diverse array of subject. we'll be sure to bring you more like it next week on techno. follow our contributors on twitter, facebook, google+ and more. >> on tech know, >> the system is paying attention... >> life saving technology... >> i definitely slowed down as a result... >> transforming the way you drive... >> maybe crashes won't happen any more... >> smart cars of the future... >> whoa...i would have driven

straight through that... >> tech know, every saturday go where science meets humanity. >> this is some of the best driving i've every done, even though i can't see. >> tech know. >> we're here in the vortex. only on al jazeera america. >> this is al jazeera america live from new york city. i'm tony harris with a look at the day's top stories. a new truce israelis and palestinians have agreed to a five-day cease-fire in hopes of finding a solution to a lasting peace. now the white house deciding whether to rescue refugees trapped in a mountain. and protests growing in missouri over the shooting of an unarmed teenager. the police say their priority is now on race relations.