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convex lens 凸透鏡。

convex mirror

The gravitation field of star b bends the light from star a as a convex lens does and we can observe a sudden brightening of star a . much brighter than the total brightness of star a and b . this phenomenon is called microlensing 根據國際天文學聯會international astronomical union于2006年8月24日通過的行星定義,冥王星的行星資格被取消,并被界定為一類稱為矮行星的新天體。

Analysis showed this might be due to the fact that a black hole passed in front of the star . the gravitation of a black hole can function as a convex lens and focus starlight , resulting in transience increase of apparent brightness of the star 分析顯示,這很可能是因為有一個黑洞在恒星前面經過,黑洞的引力會聚了星光,就像凸透鏡把光線聚焦一樣,使恒星的視亮度增加。

Since lenticular clouds look like one or more convex lens , they could sometimes be misinterpreted as flying saucers or unidentified flying objects , and so they are commonly known as “ flying saucer clouds “ 由于這類莢狀云形狀像一塊或多塊凸透鏡,有時候被誤會為飛碟或不明飛行物體,所以亦俗稱飛碟云。

However , spectacles are made of thick convex lens . skills and precautions are needed to wear contact lens properly . both are not suitable for the elderly 不過,這些眼鏡片有相當的厚度,配戴隱形眼鏡亦需要一些特別技巧,對于年紀較大的患者未必適合。