英國開發“量子羅盤”欲取代GPS

英國開發“量子羅盤”欲取代GPS

英國《金融時報》防務與安全記者 薩姆•瓊斯 報道

 

英國國防部(Ministry of Defence)正投資數百萬英鎊於一種新型導航技術。這種不會受到數據篡改和信號干擾影響的全球定位設備，可謂是導航技術的“聖杯”。

英國國防科學與技術實驗室(Defence Science and Technology Laboratory)和英國國家物理實驗室(National Physical Laboratory)的科學家們相信，再有3到5年，他們就能開發出一種“量子羅盤”，它能夠利用地磁場的亞原子效應定位自身。
這種定位技術將不再需要衛星，也不再需要無線電天線發射塔這類固定的參考點。全球軍方都對這種新技術十分感興趣，因為目前廣泛使用的“天基導航”系統存在種種限制。
今年2月，美國全球定位系統(GPS)的發明人曾警告說，GPS目前不堪重負，極易受到故意破壞或攻擊。
英國國防部尤其希望在核潛艇內運用新的定位技術，因為核潛艇的航行需要極大的隱蔽性及精確性，航行期間也很少能與外界通信。
如果不作定期校正，現有的即使最精密的定位系統每天產生的誤差也可能高達1公里。
多國政府的戰略規劃部門都迫切地希望開發出衛星定位系統的替代品。
英國正在建造陸基天線陣列，以作為GPS的備用系統。韓國也在建造類似天線陣列，以防止朝鮮的阻塞式攻擊。
英國國家物理實驗室的鮑勃•科克肖特(Bob Cockshott)表示：“據我們所知，目前物理上還不存在能乾擾這種（新）設備的方法。”
科學家表示，英國國防部這種技術有可能像GPS那樣被用於民用用途，最終也許會被用在智能手機上。
這種技術的基本原理是，通過把一些離子囚禁在過冷狀態，並減少外部電波造成的影響，使被囚禁離子僅僅對地球產生的電磁擾動敏感。通過測量地球產生的電磁擾動對這些離子的影響，科學家就能以極高精度跟蹤含有被俘離子的芯片的運動狀況。
盡管其他國家——尤其是美國——也在開展這類研究，英國在這方面卻是全球領先。英國國防科學與技術實驗室科技與創新主管尼爾•斯坦斯菲爾德 (Neil Stansfield)表示：“我們這方面的技術在英國是最先進的。我個人的猜測是，第一臺原型機3到5年內就能成型。對我們來說，關鍵在於我們要開發的 是一種不依賴於天基的設備。這種設備在軍事上有一系列用途。”
斯坦斯菲爾德表示，目前英國國防科學與技術實驗室已開發出的量子定位系統已經小到了3英尺見方。目前，科學家把主要精力用於將該設備最小化，以便用於戰場上，而不是只能裝在核潛艇和軍艦的甲板上。
譯者/簡易

The beauty of mathematics – in pictures

The book 50 Visions of Mathematics is a collection of 50 short essays by 50 maths writers and a foreword by Dara O Briain. Launched on Wednesday to celebrate the 50th anniversary of the Institute of Mathematics and its Applications, it also contains 50 images supplied in response to an open call from the worldwide maths community. Here are my favourites

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• Alex Bellos
• theguardian.com, Wednesday 14 May 2014 07.00 BST

The Brillouin zones of a square crystal lattice in two dimensions, which underlie the analysis of waves propagating through the crystal. Image: R R Hogan, University of Cambridge

A trefoil knot combining four parallel Möbius strips and a spiral tube running continuously round. Drawn freehand by Tom Holliday, inspired by M C Escher

A 3D print of the tesseract, which is the four dimensional analogue of the cube. Sculpture by Saul Schleimer and Henry Segerman. Photograph: Henry Segerman

The Mandelbox is a 3D fractal object that represents the points in space that do not move to infinity under the action of a set of geometric transformations. Image: Jos Leys

A much-magnified detail of the Mandelbrot set, revealing what appears to be a procession of elephants. Image by Philip Dawd, using the program winCIG Chaos Image Generator developed by Thomas Hvel. Copyright: Darwin College, University of Cambridge

Bat country, a 22ft tall Sierpinski tetrahedron composed of 384 softball bats, 130 balls, and a couple of thousand pounds of steel. Designed by Gwen Fisher, engineered by Paul Brown. Photograph: Gwen Fisher

A representation of 3,000 seeds on a sunflower with spirals occuring a Fibonacci number of times: 1, 1, 2,3, 5, 8, ... Image: Ron Knott

A crocheted model of the hyperbolic plane. Photograph: Daina Taimina

Map showing areas around Cambridge accessible via public transport, visualised in time bands of ten minutes, with a departure time of 9am. Image: Mapumental

A quaternion Julia set fractal. With the advent of 3-D printing, mathematical constructs like this can now be printed as physical objects, like the one below. Image: Rob Hocking

A model of the Julia set in gold-plated brass. Photograph: Rob Hocking

A hybrid 3-D fractal object, obtained using a combination of two sets of geometric transformations. Image: Jos Leys

The complex folding patterns that arise when a layered material (paper) is put into a test machine and squashed. Created by Timothy Dodwell and Andrew Rhead, University of Bath

A demonstration of the mathematical principles of the original Forth Bridge in Scotland performed at Imperial College in 1887. The central 'weight' is Kaichi Watanabe, one of the first Japanese engineers to study in the UK, while Sir John Fowler and Benjamin Baker provide the supports. Photograph: Imperial College

Long-exposure photograph of a double pendulum exhibiting chaotic motion. Photograph: Michael G Devereux

The proof is in the pudding: cake illustration of Pythagoras's theorem, baked by Emiko Dupont. Photograph: University of Bath