Horizon - Life On Mars 火星生命 - 1

In 2001 a new NASA probe was launched. Called Odyssey, it was sent to Mars to carry out the most detailed analysis ever of the planet’s surface. What it has discovered may be about to answer one of

FBI - 揭密联邦调查局 - 8

The FBI agents race in from every direction. Thanks to the FBI's use of a secret informant, the bombing conspiracy is foiled and the suspects are put behind bars. Bob Spence has refused the witness pr

The Great Wall 万里长城 - 8

So when they left the sheltering walls of Dunhuang(敦煌), heading for the desert that local people referred to as

FBI - 揭密联邦调查局 - 2

Atlanta, Georgia, a terrorist bomb explodes in Centennial Olympic Park, killing one woman and injuring hundreds. North Caldwell, New Jersey, an advertising executive is killed when he opens a mysterio

FBI - 揭密联邦调查局 - 3

Back at the explosives lab, examiners use a high-tech instrument called a Raman spectrometer, a device that determines if a package contains explosive material. With the Raman, what we are doing is th

FBI - 揭密联邦调查局 - 4

Unlike the fertilizer bomb used in Oklahoma City, device analysis reveals that the New Jersey bomb is made from common household items. The problem is that there are so many things that can be used to

FBI - 揭密联邦调查局 - 5

If threw these nails out into the crowd, extremely deadly shrapnel. Once the FBI knows what materials were used to build the bomb and how it was concealed, agents make a public appeal for information

Horizon - Life On Mars 火星生命 - 2

I think it is exciting. Because it would imply that if life arose independently on Mars. The implication is that life is pervasive throughout the universe. This is why Mars has so obsessed scientists.

Horizon - Life On Mars 火星生命 - 4

These discoveries raised the stakes. Here was a planet similar to our own. Mars might not have cities or civilizations. But it could be home to other smaller life forms like microbes. Chris McKay is N

Horizon - Life On Mars 火星生命 - 3

Conditions on Mars were so harsh that it was hard to imagine any life surviving there. The idea of sophisticated aliens was wiped out. We know that conditions on Mars today are not very good for life.

The Great Wall 万里长城 - 6

It is a staggering 2,700 miles longer than the first Great Wall of the Emperor Qin. There is no wood, water or stone in the desert. But the Han managed to build a wall that has resisted 2,000 years of

The Great Wall 万里长城 - 5

In the heart of a harsh winter, Meng Jiangnu(孟姜女) decided to visit her husband who had been sent to work on the construction of the wall. Bringing warm clothes for her beloved husband, she went

The Ghost In Your Genes - 4 基因外遗传现象

...lead to the end of diseases like cancer... Alzheimer's , Parkinson's , diabetes. The list is endless. We were thinking of genes in a very mechanical way. We were thinking of them just in terms of t

The Ghost In Your Genes - 5 基因外遗传现象

It showed that there was clearly more to inheritance than simply the coded sequence of DNA. We then realized that we were dealing with what is now known as genomic imprinting. What genomic imprinting

The Ghost In Your Genes - 6 基因外遗传现象

If inheritance was not just about DNA, if these gene switches were so important, just what could turn them on or off? Stephanie and Emend Mullins have two children, Karen and Charlotte. When we were t

The Ghost In Your Genes - 7 基因外遗传现象

After we had seen how relatively easy it was to change the switches in mouse embryos, we thought that perhaps the same could be true of human embryos. In IVF, you also have the embryo for a brief peri

The Ghost In Your Genes - 8 基因外遗传现象

No body had had seen this kind of thing before, so this was the first time and all the people looking at the gel and saying

The Ghost In Your Genes - 2 基因外遗传现象

Marcus Pembrey is one of a select band of scientists, a band of scientists who are daring to challenge an orthodoxy . They believe the lives of our parents, grandparents, and even our great grandparen

FBI - 揭密联邦调查局 - 6

How does the bureau use informants to bring dangerous criminals to justice? They have several top-secret strategies which we are about to reveal. FBI inspector Bob Garrity says the first step is to fi

The Great Wall 万里长城 - 2

Often, the only clue he has, is from some ancient text. And it is up to him to puzzle out the arcane references and make them fit the modern landscape. Armed only with a walking stick to fend off snak