根據《物理評論快報》實驗報道(http://focus.aps.org/story/v22/st20), 當光離開光纖時，給光纖一個推力，而不是拉力。作為揭示一種新的物理現象，這個實驗是很成功的。但如何解釋這種現象，引起了很多爭異。
A series of laser pulses is sent into the fiber, and each causes it to bend. The research team interprets this as a recoil of the fiber as the light gains momentum when it hits the air. This result supports the claim that light's momentum is less in a material than it is in air--one side of a century-old debate on the true momentum of light in transparent materials.
按我的看法，是由於動量守恒引起的，和光在介質中特別是在透明介質中的動量大小沒有什麽關係，就像自來水離開塑料軟管一個道理。
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