s*****r
发帖数: 11545 | 1 Scientists discover new form of light
DUBLIN, Ireland, May 17 (UPI) -- Researchers in Ireland have discovered a
new form of light. Their discovery is expected to reshape scientists'
understanding of light's basic nature.
Angular momentum describes the rotation of a light beam around its axis.
Until now, researchers believed the angular momentum was always a multiple
of Planck's constant -- a constant ratio that describes the relationship
between photon energy and frequency, and also sets the scale for quantum
mechanics.
The newly discovered form of light, however, features photons with an
angular momentum of just half the value of Planck's constant. The difference
sounds small, but researchers say the significance of the discovery is
great.
"For a beam of light, although traveling in a straight line it can also be
rotating around its own axis," John Donegan, a professor at Trinity College
Dublin's School of Physics, explained in a news release. "So when light from
the mirror hits your eye in the morning, every photon twists your eye a
little, one way or another."
"Our discovery will have real impacts for the study of light waves in areas
such as secure optical communications," Donegan added.
Researchers made their discovery after passing light through special
crystals to create a light beam with a hollow, screw-like structure. Using
quantum mechanics, the physicists theorized that the beam's twisting photons
were being slowed to a half-integer of Planck's constant.
The team of researchers then designed a device to measure the beam's angular
momentum as it passed through the crystal. As they had predicted, they
registered a shift in the flow of photons caused by quantum effects.
The researchers described their discovery in a paper published this week in
the journal Science Advances.
"What I think is so exciting about this result is that even this fundamental
property of light, that physicists have always thought was fixed, can be
changed," concluded Paul Eastham, assistant professor of physics at Trinity. | r*****2
发帖数: 3513 | | s****Y
发帖数: 1004 | 3 这是典型的灌水式科研，别给记者糊弄了。
【在 s*****r 的大作中提到】
: Scientists discover new form of light
: DUBLIN, Ireland, May 17 (UPI) -- Researchers in Ireland have discovered a
: new form of light. Their discovery is expected to reshape scientists'
: understanding of light's basic nature.
: Angular momentum describes the rotation of a light beam around its axis.
: Until now, researchers believed the angular momentum was always a multiple
: of Planck's constant -- a constant ratio that describes the relationship
: between photon energy and frequency, and also sets the scale for quantum
: mechanics.
: The newly discovered form of light, however, features photons with an
| h*h
发帖数: 27852 | 4 绝对不是
这个发现还是很重要的
【在 s****Y 的大作中提到】
: 这是典型的灌水式科研，别给记者糊弄了。
| s*****r
发帖数: 11545 | | s****Y
发帖数: 1004 | 6 错，一点都不重要，谢谢。
【在 h*h 的大作中提到】
: 绝对不是
: 这个发现还是很重要的
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