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<blockquote data-quote="freyar" data-source="post: 6258775" data-attributes="member: 40227">Right.&nbsp; While there are processes that can create or destroy photons (like those in the laser!), the light propagation you see in that video is all just scattering.&nbsp; Each pulse has many, many photons, and they are bouncing off the water (in the coke bottle), or, in daily experience, dust particles.&nbsp; The &quot;exploding&quot; photons in the cartoon about looking around the corner is their way of illustrating that the single &quot;light bullet&quot; has tons of photons in it.&nbsp; Each photon will hit a slightly different part of the wall and therefore bounce in different directions.&nbsp; But anyway, you only see photons that go directly into your eye, so seeing a light beam &quot;from the side&quot; really means that some of the light is being scattered out of the beam toward you.By the way, that video is really cool, but I have to point out a bit of &quot;false advertising&quot; or something in it that really bugs me.&nbsp; Notice that the camera takes a frame every 1 trillionth of a second.&nbsp; That's a picosecond, not a femtosecond, which is 1000 times smaller than a picosecond.&nbsp; So calling it &quot;femto-photography&quot; is, well, misleading.&nbsp; I mean, it's hard enough to explain science in a simple but reasonably correct way, so someone intentionally goofing up scientific notation is hard to take.&nbsp; (And I'll eat my hat if no one in his lab knows the difference between &quot;pico&quot; and &quot;femto.&quot;)I'll make a separate post in a bit about the &quot;wrap-around.&quot;</blockquote>

[QUOTE="freyar, post: 6258775, member: 40227"] Right. While there are processes that can create or destroy photons (like those in the laser!), the light propagation you see in that video is all just scattering. Each pulse has many, many photons, and they are bouncing off the water (in the coke bottle), or, in daily experience, dust particles. The "exploding" photons in the cartoon about looking around the corner is their way of illustrating that the single "light bullet" has tons of photons in it. Each photon will hit a slightly different part of the wall and therefore bounce in different directions. But anyway, you only see photons that go directly into your eye, so seeing a light beam "from the side" really means that some of the light is being scattered out of the beam toward you. By the way, that video is really cool, but I have to point out a bit of "false advertising" or something in it that really bugs me. Notice that the camera takes a frame every 1 trillionth of a second. That's a [I]picosecond[/I], not a [I]femtosecond[/I], which is 1000 times smaller than a picosecond. So calling it "femto-photography" is, well, misleading. I mean, it's hard enough to explain science in a simple but reasonably correct way, so someone intentionally goofing up scientific notation is hard to take. (And I'll eat my hat if no one in his lab knows the difference between "pico" and "femto.") I'll make a separate post in a bit about the "wrap-around." [/QUOTE]

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