00:00:30 The telescope is the astronomer's traditional stock and trade, but as Halley's Comet makes

00:00:44 its reappearance, astronomer Michael Ahern will mainly be eyeing telemetry data from

00:00:49 space probes tracking the comet close up.

00:00:52 For Dr. Ahern is an authority on the makeup of comets, and only from space, he says, before

00:00:57 the comet's molecules are broken down by sunlight, can we hope to get a true picture of the chemistry

00:01:02 of these mile-wide snowballs.

00:01:04 They're thought to be frozen debris from the very formation of the solar system, and come

00:01:09 from what's called the Oort cloud, billions of miles from the sun.

00:01:12 We believe that the comets have been preserved since the time of formation without any changes.

00:01:19 They have been kept in the Oort cloud where they are very cold, not heated by the sun,

00:01:24 they're very small, therefore they have not had any internal processes affecting them,

00:01:28 and therefore if we can go to a comet and study the chemical composition of the snowball

00:01:33 and the structure of the snowball, we will learn what the conditions were like when the

00:01:38 solar system formed.

00:01:39 Theory has it the Oort cloud surrounds the entire solar system and is made up of trillions

00:01:44 of comets.

00:01:45 The cloud is so far from the sun that another passing star can change the orbits of these

00:01:51 comets, and that in fact is what causes a few comets to fall into the sun so that we

00:01:57 can see them.

00:01:58 Halley's comet is one that's been trapped in solar orbit, reappearing every 76 years.

00:02:04 This time in the space age, scientists have the technology to look at its chemistry close-up.

00:02:08 If we can learn the exact chemical nature and the exact physical structure of cometary

00:02:14 nuclei, that will tell us what the conditions were like in the solar system when the planets

00:02:20 formed, therefore we will know much more than we know at present about what conditions

00:02:26 were like when the Earth formed, and ultimately this might tell us something about the way

00:02:33 in which life originated on the Earth.

00:02:36 On the Science Scene, I'm Alan Smepp.

00:02:50 Today in the paint industry, chemists using high-tech science create and match colors

00:03:17 with a precision and in a variety never before possible.

00:03:21 For a commercial customer, they can quickly produce nearly any color without relying on

00:03:26 sometimes imprecise paint chip samples.

00:03:29 Making this possible is the computerized visual color system, or VCS, a color wheel that when

00:03:34 spinning at high speed allows the chemist and a distant client with a companion machine

00:03:39 to see the exact color the other has in mind.

00:03:43 Digital readouts show the portion of each colored disk which produces the desired final

00:03:48 The disks on a color wheel are made up of seven primary colors.

00:03:52 The amount of each disk which is viewed by the operator determines the actual color which

00:03:58 is seen.

00:04:00 The amount or area of these disks are displayed on the LED.

00:04:05 When these numbers are transmitted to a second VCS, the color which is developed in the first

00:04:11 location can be seen exactly in the second location.

00:04:15 For example, a commercial designer in Dallas may deal with a New York paint company.

00:04:20 Using the VCS, the designer creates a wall paint to complement carpeting for an office

00:04:24 building.

00:04:25 When she finds one that goes with the carpet, the numbers or the amounts of each disk which

00:04:32 are exposed can be recorded.

00:04:34 These numbers can be transmitted to the paint company.

00:04:37 They can put the numbers on their VCS and see the color that the stylist would like

00:04:42 to have.

00:04:43 When he takes the same seven numbers and puts them into a computer, the computer will then

00:04:48 formulate a pigment formula for his specific paint which will give that color when the

00:04:55 paint is manufactured.

00:04:57 So now, paint chemists no longer need guess what a customer means when he wants a red

00:05:01 just a bit warmer or a blue more intense.

00:05:05 For in seconds, what's on the client's mind shows up precisely on the VCS screen.

00:05:10 From the science scene, I'm Alan Smith.

00:05:40 Plastic, in its conventional state, is an electrical insulator.

00:05:51 That's why it's used to coat electric wiring.

00:05:53 But at the University of Pennsylvania, chemist Alan McDiarmid turns that all around.

00:05:58 In 1977, he and a colleague, Alan Heeger, were the first to make plastic conduct electricity.

00:06:04 This looks like tinfoil, but it's actually polyacetylene plastic film made from welding

00:06:08 gas.

00:06:09 In order to make this plastic film a conductor of electricity, it's necessary to rearrange

00:06:16 its electrons.

00:06:17 To illustrate, here we have a small piece of the plastic film which is completing an

00:06:23 electric circuit from the battery through the film to the motor.

00:06:28 On treating the film with a small amount of iodine solution, the conductivity is increased

00:06:34 billions of times and the electric circuit is now completed and the motor is turning

00:06:40 the blade.

00:06:41 When first performed, that demonstration touched off chemical research worldwide into various

00:06:46 plastics that might have commercial potential, as batteries and electronics for solar cells.

00:06:51 Many show promise, but most, even the polyacetylene, have been complicated to make and eventually

00:06:56 lose conductivity.

00:06:58 So continuing his research, Dr. McDiarmid recently broke new ground with a polyaniline

00:07:03 plastic, far simpler to make and whose conductivity holds up.

00:07:07 Using it in the shell of a conventional battery, he's produced a rechargeable plastic-based

00:07:12 battery.

00:07:13 Here then we have an AA battery whose top has been carefully removed and we have taken

00:07:19 out the contents and replaced these by polyaniline powder together with an appropriate water

00:07:24 electrolyte.

00:07:26 This then converts the battery to a rechargeable battery which will run this small electric

00:07:34 motor.

00:07:35 Through this kind of pioneering chemistry, plastic one day may widely substitute for

00:07:39 metal as circuits within the plastic parts of planes and autos and for batteries from

00:07:44 cars to calculators.

00:07:46 On the Science Scene, I'm Alan Smepp.

00:08:26 This is not an x-ray.

00:08:28 It's a picture taken by one of medical science's latest diagnostic devices using a process

00:08:33 based on what's called nuclear magnetic resonance.

00:08:36 Here's the outline of the heart which you can see entirely.

00:08:40 These are the chambers of the heart.

00:08:42 These are the vessels leading from the heart to the neck.

00:08:45 The National Institutes of Health near Washington, D.C. is one of a number of medical centers

00:08:49 recently to go online with nuclear magnetic resonance for imaging the body and its abnormalities.

00:08:56 Scientists have long used an NMR process to get analytical readouts on compounds, but

00:09:01 taking pictures of the body with NMR is a relatively new application.

00:09:05 High radiation and dyes aren't used.

00:09:08 It works by placing a patient in a magnetic chamber.

00:09:11 This orients the magnetic nuclei of certain atoms, hydrogen in this case, toward the chamber's

00:09:16 magnetic field.

00:09:17 What the physician then does is apply a second magnetic field that changes the orientation

00:09:23 of those nuclei by 90 degrees.

00:09:26 In this 90-degree plane, we can then detect the signal from this nucleus, and as it goes

00:09:32 back to its normal position in the magnet, that's the signal that we detect that we use

00:09:37 to make pictures.

00:09:38 The time it takes the nuclei to return to normal position, relaxation time as it's called

00:09:43 by chemists and physicists, plays a key role in the picture-making process.

00:09:47 The nuclei of hydrogen atoms in different body tissues all have different relaxation

00:09:52 times.

00:09:54 It is these differences in the relaxation time of each part of the body that translates

00:10:01 into a high degree of contrast in the NMR picture that's obtained.

00:10:06 That's why the doctors are so excited about this thing.

00:10:09 The doctors are excited because now they have the ability to vividly see, for instance,

00:10:13 a tumor in the brain or an infection in the skull.

00:10:16 This is the normal sinus area, but now you can see there's an area of a fungus infection

00:10:22 which has actually grown into the area of normal bone cartilage.

00:10:26 NMR imaging, a new and valuable tool for improving the diagnosis and treatment of disease.

00:10:33 On the science scene, I'm Alan Smith.

00:10:46 This

00:11:12 jet is road testing a set of new tires.

00:11:15 Tires not made of synthetic rubber, nor from our customary source, the rubber trees of

00:11:19 Malaysia.

00:11:20 Instead, they're tires from a rubber extracted from the Waiouli bush, a shrub that grows

00:11:25 naturally only in the desert areas of the southwestern United States and northern Mexico.

00:11:30 A recent act of Congress concerning critical agricultural materials is now spurring biochemists

00:11:35 to develop Waiouli as a reliable source of homegrown rubber.

00:11:40 It's very important to develop Waiouli as a source of natural rubber within the continental

00:11:45 USA.

00:11:46 This relieves our nation from depending on foreign nations to supply our highly essential

00:11:53 needs.

00:11:54 Dr. Chandra and other scientists are working to develop Waiouli to the point where it can

00:11:59 satisfy our needs for natural rubber without importing it.

00:12:02 Their principal focus is on plant germination, hardiness, and yield.

00:12:06 Presently, too few seeds take root naturally to ensure the size crop necessary to meet

00:12:11 our total rubber needs, so the biochemist and his colleagues are encasing the seeds

00:12:15 in pellets treated with chemical nutrients and seed protectors.

00:12:20 This may make direct field seeding of Waiouli commercially feasible.

00:12:24 Meanwhile, experimental crops in the southwest are undergoing a variety of tests to determine

00:12:29 the best soils and which strains use water most efficiently.

00:12:33 Various growth regulators are being applied to increase the plant's yield of rubber.

00:12:37 It now runs about 5%.

00:12:40 Scientists are confident the yield can be substantially improved through biotechnology.

00:12:44 At the level of 5% level, it's not an economically feasible industry, but at the level of 20%

00:12:50 level, it becomes a very attractive economic proposition.

00:12:54 Dr. Chandra and other biochemists believe that with adequate resources and today's advances

00:12:59 in technology, within 5 to 10 years, homegrown Waiouli could be supplying us with all the

00:13:05 material we need for all our rubber products.

00:13:08 On the Science Scene, I'm Alan Smith.