Six months after the explosions at the Fukushima nuclear plant and the release of radiation there, Professor Jim Al-Khalili sets out to discover whether nuclear power is safe. 　　He begins in Japan, where he meets some of the tens of thousands of people who have been evacuated from the exclusion zone. He travels to an abandoned village just outside the zone to witness a nuclear clean-up operation. 　　Jim draws on the latest scientific findings from Japan and from the previous explosion at Chernobyl to understand how dangerous the release of radiation is likely to be and what that means for our trust in nuclear power.

Six months after the explosions at the Fukushima nuclear plant and the release of radiation there, Professor Jim Al-Khalili sets out to discover whether nuclear power is safe. 　　He begins in Japan, where he meets some of the tens of thousands of people who have been evacuated from the exclusion zone. He travels to an abandoned village just outside the zone to witness a nuclear clean-up operation. 　　Jim draws on the latest scientific findings from Japan and from the previous explosion at Chernobyl to understand how dangerous the release of radiation is likely to be and what that means for our trust in nuclear power.

For centuries we have dreamt of reaching the centre of the Earth. Now scientists are uncovering a bizarre and alien world that lies 4,000 miles beneath our feet, unlike anything we know on the surface. It is a planet buried within the planet we know, where storms rage within a sea of white-hot metal and a giant forest of crystals make up a metal core the size of the Moon. 　　Horizon follows scientists who are conducting experiments to recreate this core within their own laboratories, with surprising results.

For centuries we have dreamt of reaching the centre of the Earth. Now scientists are uncovering a bizarre and alien world that lies 4,000 miles beneath our feet, unlike anything we know on the surface. It is a planet buried within the planet we know, where storms rage within a sea of white-hot metal and a giant forest of crystals make up a metal core the size of the Moon. 　　Horizon follows scientists who are conducting experiments to recreate this core within their own laboratories, with surprising results.

如果你被问到“你知道现在的时间吗”，是否会觉得这是一个太过简单的问题？看看腕上的手表，或是翻出手机，精确到分秒的时间就能被轻易知晓。然而今天，粒子物理学家布莱恩·考克斯教授也如此问到。布莱恩探访了墨西哥的古玛雅金字塔，在那里古玛雅人是靠建神殿来计时的。他惊人地发现，符合地球本身规律的“时间”，从来都不是一天24小时。那么这个我们早已习以为常的“公理”，到底是个物质周期变化的规律，还是我们对于时间和空间认知上的一种错觉呢？ 　　此次BBC地平线系列纪录片的摄制组，将跟随布莱恩教授的脚步，从时间的起点开始入手研究，走访了多个支持“弦理论”的国度，并研究了时间的极限，试图解开这个抽象概念背后的神奇奥秘。

如果你被问到“你知道现在的时间吗”，是否会觉得这是一个太过简单的问题？看看腕上的手表，或是翻出手机，精确到分秒的时间就能被轻易知晓。然而今天，粒子物理学家布莱恩·考克斯教授也如此问到。布莱恩探访了墨西哥的古玛雅金字塔，在那里古玛雅人是靠建神殿来计时的。他惊人地发现，符合地球本身规律的“时间”，从来都不是一天24小时。那么这个我们早已习以为常的“公理”，到底是个物质周期变化的规律，还是我们对于时间和空间认知上的一种错觉呢？ 　　此次BBC地平线系列纪录片的摄制组，将跟随布莱恩教授的脚步，从时间的起点开始入手研究，走访了多个支持“弦理论”的国度，并研究了时间的极限，试图解开这个抽象概念背后的神奇奥秘。

Around the world, a new generation of astronomers are hunting for the most mysterious objects in the universe. Young stars, black holes, even other forms of life. 　　They have created a dazzling new set of super-telescopes that promise to rewrite the story of the heavens. 　　This film follows the men and women who are pushing the limits of science and engineering in some of the most extreme environments on earth. But most strikingly of all, no-one really knows what they will find out there.

Around the world, a new generation of astronomers are hunting for the most mysterious objects in the universe. Young stars, black holes, even other forms of life. 　　They have created a dazzling new set of super-telescopes that promise to rewrite the story of the heavens. 　　This film follows the men and women who are pushing the limits of science and engineering in some of the most extreme environments on earth. But most strikingly of all, no-one really knows what they will find out there.

Horizon is BBC Two's flagship 50-minute science documentary series. In September 2004 it celebrated its 40th anniversary and it continues to enjoy outstanding critical acclaim. Recognised as the world leader in its field, it regularly wins a sweep of international science, medical and environmental film accolades, and has recently won the Royal Television Society Award and the Prix Italia. In 2002, the British Academy of Film & Television Arts presented Horizon with the BAFTA Television Award for Best Factual Series or Strand. In 2003 it won the prestigious Images et Science award for best medical documentary and the Carl von Linne Award at the Living Europe film festival in Sweden. That year, a Horizon co-production with WGBH Boston won the Emmy for best documentary.

Horizon is BBC Two's flagship 50-minute science documentary series. In September 2004 it celebrated its 40th anniversary and it continues to enjoy outstanding critical acclaim. Recognised as the world leader in its field, it regularly wins a sweep of international science, medical and environmental film accolades, and has recently won the Royal Television Society Award and the Prix Italia. In 2002, the British Academy of Film & Television Arts presented Horizon with the BAFTA Television Award for Best Factual Series or Strand. In 2003 it won the prestigious Images et Science award for best medical documentary and the Carl von Linne Award at the Living Europe film festival in Sweden. That year, a Horizon co-production with WGBH Boston won the Emmy for best documentary.