本帖最后由 positron 于 2009-5-31 13:27 编辑
Vacuum Energy
Quantum physics tells us that contrary to appearances, empty space is a bubbling brew of "virtual" subatomic particles that are constantly being created and destroyed. The fleeting particles endow every cubic centimeter of space with a certain energy that, according to general relativity, produces an anti-gravitational force that pushes space apart. Nobody knows what's really causing the accelerated expansion of the universe, however.
Credit: NASA-JSC-ES&IA
真空能
量子物理告诉我们，和表面看起来不同，真空是由亚原子虚粒子组成的泡沫，这些虚粒子不断地产生又湮灭。这些转瞬即逝的粒子赋予了每立方厘米真空一定量的能量，根据广义相对论，这些能量提供了形成空间膨胀的反引力。然而，现在还没有人知道到底是什么原因造成了宇宙的加速膨胀。
Quasars
These bright beacons shine to us from the edges of the visible universe and are reminders to scientists of our universe's chaotic infancy. Quasars release more energy than hundreds of galaxies combined. The general consensus is that they are monstrous black holes in the hearts of distant galaxies. This image is of quasar 3C 273, photographed in 1979.
Credit: NASA-MSFC
类星体
这些明亮的灯塔从可见宇宙的边缘照向我们，它们向科学家暗示我们的宇宙在早期是多么混乱。类星体向外释放的能量超过数百个星系能量的总和。一般认为它们是遥远星系中心的巨大黑洞。这张是类星体3C 273的照片，拍摄于1979年。
Neutrinos
Neutrinos are electrically neutral, virtually mass-less elementary particles that can pass through miles of lead unhindered. Some are passing through your body as you read this. These "phantom" particles are produced in the inner fires of burning, healthy stars as well as in the supernova explosions of dying stars. Detectors are being embedded underground, beneath the sea, or into a large chunk of ice as part of IceCube, a neutrino-detecting project.
Credit: Jeff Miller/NSF/U. of Wisconsin-Madison
中微子
中微子是电中性的、实际上无质量的基本粒子（最新的研究表明，中微子有很小的质量，译注），它们可以不受阻碍地穿过数英里的铅。在你阅读这段话时，就有大量中微子穿过你的身体。这些“幽灵”般的粒子来自于恒星内部的燃烧（核反应可以产生中微子，基本粒子的反应也可以产生中微子，译注），包括壮年恒星以及死亡恒星的超新星爆炸。中微子探测器被深埋在地下以及海洋中，或者置于大块的冰中，冰块是被称为冰立方的中微子探测器的一部分。
Antimatter
Like Superman's alter-ego, Bizzaro, the particles making up normal matter also have opposite versions of themselves. An electron has a negative charge, for example, but its anti-matter equivalent, the positron, is positive. Matter and anti-matter annihilate each other when they collide and their mass is converted into pure energy by Einstein's equation E=mc2. Some futuristic spacecraft designs incorporate anti-matter engines.
Credit: Penn State U. /NASA-MSFC
反物质
就像超人还有与其相反的一面，Bizzaro，组成通常物质的基本粒子也有相反的一面。例如，电子带有负电荷，而它的反粒子，即正电子，带正电荷。物质和反物质碰到一块儿后会碰撞湮灭，同时它们的质量会转变为纯能量，此过程遵守爱因斯坦质能方程E=mc[sup]2[/sup].一些未来主义的太空船就是靠反物质引擎推动的。
Galactic Cannibalism
Like life on Earth, galaxies can "eat" each other and evolve over time. The Milky Way's neighbor, Andromeda, is currently dining on one of its satellites. More than a dozen star clusters are scattered throughout Andromeda, the cosmic remains of past meals. The image above is from a simulation of Andromeda and our galaxy colliding, an event that will take place in about 3 billion years.
Credit: F. Summers/C. Mihos/L. Hemquist
星系吞食
和地球上的生命一样，星系也会相互吞食并随着时间演化。我们银河系的邻居，仙女座星系，当前就在吞食着它伴星系中的一个。超过一打的星团分散在仙女星系的周围，它们是以前的宇宙大餐的遗体。上方的照片是我们的银河系和仙女星系碰撞的模拟结果，这次碰撞将在30亿年后发生。
Cosmic Microwave Background
Also known as the CMB, this radiation is a primordial leftover from the Big Bang that birthed the universe. It was first detected during the 1960s as a radio noise that seemed to emanate from everywhere in space. The CMB is regarded as one of the best pieces of evidence for the theoretical Big Bang. Recent precise measurements by the WMAP project place the CMB temperature at -455 degrees Fahrenheit (-270 Celsius).
Credit: NASA/WMAP Science Team
宇宙微波背景辐射
即所谓的CMB，这个辐射是创造宇宙的大爆炸的遗迹。1960年代第一次探测到CMB，当时被当做是无线电噪声，而且似乎是从宇宙所有方向发射出来的。CMB被当做是大爆炸理论最强有力的证据之一。当前由WMAP工程做出的精确测量给出CMB辐射温度是-455华氏度，或者-270摄氏度。
Gravity Waves
Gravity waves are distortions in the fabric of space-time predicted by Albert Einstein's theory of general relativity. The waves travel at the speed of light, but they are so weak that scientists expect to detect only those created during colossal cosmic events, such as black hole mergers like the one shown above. LIGO and LISA are two detectors designed to spot the elusive waves.
Credit: Henze/NASA
引力波
引力波是根据爱因斯坦的广义相对论预言的时空结构的变形。引力波以光速传播，但是引力波的强度是如此微弱，以至于科学家仅仅期望于探测被强烈宇宙事件制造的引力波，如上面图片显示的黑洞合并。LIGO和LISA是两个用于探测这种难以捉摸的波动的探测器。
Dark Matter
Scientists think it makes up the bulk of matter in the universe, but it can neither be seen nor detected directly using current technologies. Candidates range from light-weight neutrinos to invisible black holes. Some scientists question whether dark matter is even real, and suggest that the mysteries it was conjured to solve could be explained by a better understanding of gravity.
Credit: Andrey Kravtsov
暗物质
科学家相信暗物质组成了宇宙的大部分物质，但是利用当前的技术，既无法看到也无法探测到暗物质。暗物质的候选者包括极轻的中微子到看不到的黑洞。但有些科学家质疑暗物质是否真的存在，建议这种神秘的现象有可能通过对引力的更好理解所解决。
Exoplanets
Until about the early 1990s, the only known planets in the universe were the familiar ones in our solar system. Astronomers have since identified more than 190 extrasolar planets (as of June 2006). They range from gargantuan gas worlds whose masses are just shy of being stars to small, rocky ones orbiting dim, red dwarfs. Searches for a second Earth, however, have so far turned up empty. Astronomers generally believe that better technology is likely to eventually reveal several worlds similar to our own.
Credit: ESO
系外行星
一直到1990年代早期，宇宙中仅知的行星就是在我们太阳系中很熟悉的那几个。截止2006年6月，天文学家已经确认了超过190个系外行星。包括巨大的类木行星，它们的质量只比形成恒星的要求小一些，还有围绕暗淡红矮星转动的类地行星。然而，寻找第二个地球的努力，迄今为止仍然毫无所获。天文学家普遍相信更好的技术有望最终发现一些类似于我们的世界。
Mini-Black Holes
If a radical new "braneworld" theory of gravity is correct, then scattered throughout our solar system are thousands of tiny black holes, each about the size of an atomic nucleus. Unlike their larger brethren, these mini-black holes are primordial leftovers from the Big Bang and affect space-time differently because of their close association with a fifth dimension.
Credit: NASA-MSFC
迷你黑洞
如果关于引力的一个新的激进理论“膜理论”是对的，那么会有数千个微小的黑洞分散在我们的太阳系，这些小黑洞都只有原子核的大小。和它们的大个同胞不同，这些迷你黑洞是大爆炸产生的，并且对时空的影响不同，因为它们和第五维时空密切相关。 |
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