追尋科技足跡：你所不了解的那些天文地理 (雙語組圖)

It's not easy to create a controlled nuclear reaction in power plants, but the nature had created the world's first nuclear reactor two billion years before humankind, beneath the surface of Oklo in Gabon, Africa. This natural reactor formed when a uranium-rich mineral deposit came in contact with groundwater, which slowed the neutrons ejected from the uranium so that they could interact with and split other atoms. Heat was produced, turning the water to steam, thus temporarily slowing the chain reaction. The environment cooled, water returned, and the process repeated. Scientists estimate that this prehistoric reactor ran for a hundreds of thousands of years, producing the various isotopes expected from such reactions.

In 1938, while in Baghdad, German archeologist Wilhelm K?nig discovered a five-inch-long (13 cm) clay jar containing a copper cylinder that surrounded an iron rod. The jar showed signs of corrosion and seemed to have once contained a mild acid, such as vinegar or wine. K?nig believed these vessels to be?galvanic cells, or parts of batteries, possibly used for electroplating gold onto sliver objects. The dates of the artifacts are obscure. K?nig dated them to around 250 BC to AD 224, while others have suggested a range of AD 225-640. Of course, even if the vessels did produce electric currents, this does not imply that ancient people understood how the objects worked.

The Antikythera mechanism is an ancient geared computing device that was used to calculate astronomical positions and that mystified scientists for over a century.

A dial on the front of the device probably carried at least three hands, one indicating the date and the other two indicating the positions of the Sun and the Moon. The device was also probably used to predict solar eclipses and indicate other planetary motions.

In 1610, Galileo Galilei became the first person to observe Saturn's rings; however, he described them as "ears." It was not until 1655 that Christian Huygens was able to use his higher-quality telescope to become the first person to describe the feature as an actual ring surrounding Saturn. Finally, in 1675, Giovanni Cassini determined that Saturn's "ring" was actually composed of subrings with gaps between them.

Astronomers may not believe in Hell, but most believe in black regions of space. These cosmological hells truly exist in the centers of many galaxies. Such galactic black holes are collapsed objects having millions or even billions of times the mass of our sun crammed into a space no larger than our Solar System. According to classical black hole theory, the gravitational field around such objects is so great that nothing, not even light, can escape from their tenacious grip. The actual concept of an object so massive that light could not escape was suggested in 1783 by the geologist John Michell.

Neptune is the only planet in our Solar System whose existence and location was mathematically predicted before the planet was actually observed. French astronomer Urbain Le Verrier and British astronomer John Couch Adams both performed calculations to locate a possible new planet. In 1846, Le Verrir told German astronomer Johann Galle where to point Galle's telescope based on Le Verrier's calculations, and in about half an hour Galle found Neptune within one degree of its actual position--a dramatic confirmation of Newton's Law of Universal Gravitation.