Scientists Solve Century-Old Optics Mystery 265
evan_arrrr! writes "From the article:
Since the early 20th century physicists have known that light carries momentum, but the way this momentum changes as light passes through different media is much less clear. Two rival theories of the time predicted precisely the opposite effect for light incident on a dielectric: one suggesting it pushes the surface in the direction light is traveling; the other suggesting it drags the surface backwards towards the source of light. After 100 years of conflicting experimental results, a team of experimentalists from China believe they have finally found a resolution."
"Experimentalist" (Score:4, Insightful)
What happened to good old "Scientist"? It's a nice, nine letters long, and respected. "Experimentalist"... It sounds like what a social deviant might call themselves. Like some weird cult that was rejected by the mainstream sect of Scientist, so they had to add an extra six letters to their name to make up for their lack of membership. Maybe more letters makes it sounds more smart? -_-
Slashdot Effect (Score:2, Insightful)
We need to get these guys working on the Slashdot Effect, next.
Push me Pull me (Score:2, Insightful)
Re:Relativity (Score:3, Insightful)
I think it all depends from which side you look at it. From the light's perspective, or from the surface.
So you're saying that from one perspective a surface will be attracted to the direction from which the light came, and from another perspective it will be repelled? That is *not* a relativistically viable effect :)
Re:"Experimentalist" (Score:5, Insightful)
What happened to good old "Scientist"? It's a nice, nine letters long, and respected. "Experimentalist"... It sounds like what a social deviant might call themselves. ...
Of course, the more common term is "experimental scientist", as opposed to someone like Albert Einstein or Stephen Hawking, who were/are mostly known as theoretical scientists.
But "experimentalist" is a valid English word, makes sense in context, and has fewer syllables than "experimental scientist" while still emphasizing the experimental nature of their work.
Re:First Post AND Slashdotted Already (Score:0, Insightful)
Re:Slashdotted already (Score:3, Insightful)
Re:Mirrored (Score:3, Insightful)
i read 'text only mirror' and my first thought was 'how in hell do they choose what gets reflected?'
Re:No physics background here (Score:3, Insightful)
are you mad??? if light had infinite mass, then every torch would act like the Half-Life 2 gravity gun.
no... if you turned the torch on, you would be instantly destroyed.
there is no such thing as "infinite" in reality - every case where "infinity" turns up is a case where the existing maths is not quite up to describing reality.
Re:No physics background here (Score:3, Insightful)
It's a nice way of thinking about it. Almost by _definition_, heat is simply energy for which we don't bother to quantify momentum.
Re:No physics background here (Score:2, Insightful)
paraphrased: "nothing == everything"
you are an idiot.
Re:A little background is apropos me thinks... (Score:4, Insightful)
For those with a large monitor, the GP was doing us all a favor. It gets difficult for the human brain to read text with overly long lines: the optimal width is about 65 characters. Longer than that and the eye gets lost when traveling back to the left for the next line. Basic usability/readability knowledge.
Re:First Post AND Slashdotted Already (Score:4, Insightful)
Re:No physics background here (Score:3, Insightful)
Perhaps you'd like to define what you mean by 'mass'. What exactly is 'mass'?
If you say that mass is the stuff that makes objects solid, then what's 'solid'? If you say 'solid' means that nothing can penetrate it, then that's obviously wrong - neutrinos penetrate massive objects. Or do you think that there is some infinitesimally small little sized thing that can't be made any smaller, that nothing can penetrate, and that you'd call 'mass'?
Let me give you my take on mass. Mass is:
- a point from which gravitational forces are exerted
Mass is nothing more than a coordinate in space - a coordinate in space from which we can define gravitational effects originating. If something 'has mass' then it has a coordinate point that we can use in gravitational equations to determine how much gravitational force is being exerted from that point.
That's it. That's all mass is. It's the coordinates from which gravitational forces are exerted.
Light doesn't exert gravitational force on anything. It has no coordinates from which one would calculate the exertion of gravitational forces on other objects. Ergo, light has no mass.
Once again, if you are so hung up on this concept of 'mass' and insistent that objects must have it in order to 'push' other objects, then please define exactly what 'mass' is. If I were to build a microscope capable of magnifying to an infinite degree, what exactly would I see when I "zoomed in" on 'mass'?