[00:11.60]WARMING UP
[00:16.04]"How many new uses can you think of for the folowing items?"
[00:36.49]reminds us of the appearance of nanotechnology,
[00:53.76]according to which nothing is useless and
[01:04.91]no garbage or waste material to speak of
[01:13.17]Everything can be broken up into very small things
[01:23.80]and be made use of.
[01:31.25]The word nano is a scientific term for anything one billionth of a meter long.
[01:49.58]The idea behind it was
[01:54.34]first proposed by Nobel Prize winning scientist Richard Feynman
[02:02.10]in 1959.It was later developed in more detail by Eric Drexler,
[02:10.85]a scientist at the Massachusetts Institute of Technology(MIT)
[02:50.79]He now heads the Foresight Institute,
[02:57.74]a group tormed to encourage research and regulation of all aspects of nanotechnology
[03:24.49]for eric drexler,the benefits of nano technology are literally universal.
[04:00.04]They include space exploration vehicles,which will be cheap to produce because they will only
[04:09.50]need very small rockets.
[04:24.33]More generally,
[04:29.06]humans will be finally able to understand how things really work
[04:37.24]how atoms combine to produce materials with certain qualities.
[05:13.68]"Nanotechnology is expected to touch almost every aspect of our lives,"he says
[05:23.63]"Once we have the ability to structure a molecule,
[05:29.38]we should be able to create systems that will scrub the toxins
[05:37.03](=poisonous things)from the air or remove
[05:42.80]hazardous organisms for the water we drink.

[06:14.86]We should be able to begin the long process of cleaning up our environment.
[06:29.83]However,everything has its dark side as well as its bright side.
[06:44.38]Despite all those benefits.
[06:51.14]environmentalists are worried about it getting out of control,
[06:57.70]which reminds of reading D in 2003 NMET
[07:06.06](for shanghai only.) Can you do it on your own?
[07:32.02]nanotech
[07:40.07]molecular
[07:54.02]microscopic self-replicating machines that put atoms together
[08:14.08]to create copies of anything alive in the world
[08:36.44]In fact,the scientific community is deeply divided over
[08:43.81]whether self-replicating machines are possible.
[09:03.06]If they are,major dangers could exist.
[09:14.71]Mr.Drexler himself thought
[09:24.66]that self-replicating machines could probably go out of control.
[09:38.12]He writes in his book that man-made "plants" with leaves no more efficient
[09:46.19]than today's solar cells could win over real plants
[10:01.94]crowding the earth with leaves that are not suitable to be eaten.
[10:18.19]Tough 'bacteria'
[10:32.14]could be more competitive than the real bacteria:
[10:43.50]They could spread everywhere,
[10:50.06]replicate swiftly,and reduce the earth to dust in a matter of days."
[11:07.61] Cities of nanotech have made use of such images,
[11:13.96]calling for a delay on commercial nanotech until regulations are established
[12:02.83]"In a way,calling for bans on research into molecular manufacturingis
[12:10.88]like calling for a delay on faster-than-light travel because no one is doing it.
[13:22.25]Listening
[13:30.01]1.Listen to the tape.
[13:35.65]What is being described?
[13:39.80]What can the things be used for?
[13:44.35]1.Object described: Chopsticks
[13:56.49]Possible uses:Eating,opening a bottle.You can think of more creative uses
[14:17.52]2.Object described:Cellphone
[14:41.68]Possible uses:Making phone calls,sending pictures,Sending e-mails.
[14:54.35]3.Object described: Refrigerator
[15:19.20]Possible uses:keeping food fresh,keeping drinks cool.Students think of more.