Researchers develop way to control speed of light, send it backward

[beenherebeforeagain]

Okay...finally read through the original article...not that I understand it...pretty much at all...

What I did notice as I searched for more information is that so far there haven't been any responses...just repetition of the press release story...so I don't have any idea of whether this is controversial in the field...

Personally, I don't understand the faster than light part...one would think that being able to make photons travel faster than c would be something that many more people would be commenting on...

 

[Shadow Wolf]

OK...thanks...I think. I have no idea what you just said. "Negative speed?" Would that not involve time? I have to tell you that this is a concept I'm not grokking.

Einstein was much better at explaining stuff. Couldn't you put that 'ball' or particle of light, on a train with lightening bolts and explain it?

I'm not sure if I could, but basically they shine this light of negative speed, and it reaches the end of the medium it's shined through almost instantaneously (it's allegedly faster than the normal speed of light). Or a car, perhaps, as when it goes backwards it's trajectory is not being changed through a bounce or reflection but a change in mechanical applications.

 

[dianaiad]

I'm not sure if I could, but basically they shine this light of negative speed, and it reaches the end of the medium it's shined through almost instantaneously (it's allegedly faster than the normal speed of light). Or a car, perhaps, as when it goes backwards it's trajectory is not being changed through a bounce or reflection but a change in mechanical applications.

uh huh.

(thinking) nope. Still not getting it. Frustrating. What I see is that they are talking about taking the same specific particle (or wave...perhaps that makes a difference, whether light is acting as a particle or a wave) and simply changing the trajectory. Whether that trajectory is precisely the same as the one it arrived on, only going the other direction, or whether it is deflected onto another trajectory, it's still the same bit of light bouncing around like it has done since it got created at the sun's core. We have been manipulating light like this since man first figured out that some things glittered in the sun. What's different about this? What the heck is 'negative speed?"

...and what is a 'mechanical application,' if it's not a simple matter of a 'bounce?"

OK, I see I'm going to have to put the authors of that article on Einstein's elevator and give it a good tug. Or let go, and see which direction is 'negative speed.'

Gahhhhhh.

I wonder if math COULD explain this. Doubt it, but it's worth a wonder.

So...it's the elevator. I'm going to the original article, published in "Nature Communications," to see what they actually did.

....and y'know, I'm only in four paragraphs and I'm learning stuff. Cool. One thing I'm learning is that the article posted in the OP wasn't exactly accurate....er,

give me a bit. I need to read this.....

 

[dianaiad]

OK, I read it.

Well, I didn't read it. I skimmed it and skipped over all the math and most of the terms that I didn't have immediate definitions for. I'm going back.

However, I did find out a few things. First, I was right; time is indeed an important factor. These people were discussing how to change the velocity of light in free space, without reflecting it. They weren't talking about using any reflective surface at all, but acting directly on 'wave packets.'

They are using light acting as a wave, mostly, and discussed how individual waves are not remotely confined to the established 'c' or speed of light. Light can go slightly slower, or faster; they were working with 'synthesized' (in other words, they made the light, it wasn't 'free range' (my term, not theirs) so that their 'light packets' contained waves that all went at the same speed.

They never did define 'negative speed.'' Or they did and I didn't see it. They DID refer to 'negative speed' once, but only tangentially. I could have missed that, though. What they claimed to be able to do is to use their 'spatial light moderator' to affect light as it travels through 'free space.' They included charts, illustrations and graphs to demonstrate how the thing works. They spoke about reshaping the light packet using spacial-temporal (see? I knew time had to be in there somewhere) methods, and then sending the reshaped packet elsewhere, faster--or slower--but oddly enough, they didn't have as much success slowing things down as they did in speeding things up.

I THINK...though I'm going to have to plow through this some more, that 'negative speed' is something like a "0"...a mathematical placeholder/construct that is useful to make the math work, but doesn't actually mean anything in 'real life.'

Again, I could be wrong. Probably am. I DID tell you that I was mathematically challenged, didn't I?

 

[Shadow Wolf]

(thinking) nope. Still not getting it. Frustrating. What I see is that they are talking about taking the same specific particle (or wave...perhaps that makes a difference, whether light is acting as a particle or a wave) and simply changing the trajectory. Whether that trajectory is precisely the same as the one it arrived on, only going the other direction, or whether it is deflected onto another trajectory, it's still the same bit of light bouncing around like it has done since it got created at the sun's core. We have been manipulating light like this since man first figured out that some things glittered in the sun. What's different about this? What the heck is 'negative speed?"

Honestly, I had a hard time with it all pouring over articles from this site and that. It's very counter intuitive, difficult to image in your head, and makes sense without making sense. It's like someone threw a baseball and it suddenly went backwards without being hit by the stick, and went fast backwards than it did forward. Not really, but kind of.

 

[Shadow Wolf]

I also think my searches are turning up older articles than everyone elses, because what I'm finding is a bit older and isn't exactly matching what everyone else is talking about.

 

[beenherebeforeagain]

I also think my searches are turning up older articles than everyone elses, because what I'm finding is a bit older and isn't exactly matching what everyone else is talking about.

well, it appears to me that this article is the latest in a series of articles on the 'problem' ...I used to be able to get a pretty good idea of what they are talking about in such articles, but it's too dense for me to understand anymore.

One thing that kind of stood out is that they talk of affecting light in free space, but then they say they got this effect by using a device...sheesh...I'd have to go back to find the name again...and the one illustration in the article basically showed the arrangement of the device, detectors, etc.

Edit: my point was that they talk about modifying space-time, but I've never heard of anyone successfully modifying space-time before, except through use of mass...

 

[dianaiad]

well, it appears to me that this article is the latest in a series of articles on the 'problem' ...I used to be able to get a pretty good idea of what they are talking about in such articles, but it's too dense for me to understand anymore.

One thing that kind of stood out is that they talk of affecting light in free space, but then they say they got this effect by using a device...sheesh...I'd have to go back to find the name again..

"Spatial light moderator." Sounds like something out of Dr. Who, doesn't it? Or "Back to the Future?" it definitely has a "Flux capacitor" vibe. I, personally, approve.

.and the one illustration in the article basically showed the arrangement of the device, detectors, etc.

Edit: my point was that they talk about modifying space-time, but I've never heard of anyone successfully modifying space-time before, except through use of mass...

I'll admit to major confusion. However, I'm an English major for a reason.

On the other hand, I handled MATH in school just fine; that is, I understood equations in Algebra and Geometry: they were, after all, languages. I could not, however, solve them worth a darn because one actually has to plug in numbers to do that, and arithmetic has always escaped me. I felt a lot better about myself and my intellect when I read about how Einstein worked. HIM, I followed. At least, I followed his thought experiments.

It looks like I'll need translations for most of this stuff.

 

[dianaiad]

well, it appears to me that this article is the latest in a series of articles on the 'problem' ...I used to be able to get a pretty good idea of what they are talking about in such articles, but it's too dense for me to understand anymore.

One thing that kind of stood out is that they talk of affecting light in free space, but then they say they got this effect by using a device...sheesh...I'd have to go back to find the name again...and the one illustration in the article basically showed the arrangement of the device, detectors, etc.

Edit: my point was that they talk about modifying space-time, but I've never heard of anyone successfully modifying space-time before, except through use of mass...

I wonder...do they call it a difference when they claim to be affecting light waves directly, rather than using a reflective or refractive surface/item/mass/whatever? Is that what they claim to be doing? I think they are, but...

dang. I'm out of my educational league. I don't care, though. I'm now terminally curious.

 

[Twilight Hue]

The light moving thing is just an illusion it's a trick. Still fascinating but light does not travel in reverse.

I prefer actual science journals and magazines. Not embellished 'journalism'.

Faster Than Light! Incredible Illusion Makes Images 'Time Travel'

 

[dianaiad]

The light moving thing is just an illusion it's a trick. Still fascinating but light does not travel in reverse.

I prefer actual science journals and magazines. Not embellished 'journalism'.

Faster Than Light! Incredible Illusion Makes Images 'Time Travel'

Y'know, while this article was most interesting, and may indeed be accurate and have some great information, in lieu of your claim that you would rather go with established science journals and magazines rather than 'embellished journalism,' I would point out that the article you linked us to has no references for us to check...

And the article under discussion in this thread did. As well, those discussing the issue (me, actually) chased down the reference to find a peer reviewed science journal with lots of references.

Not that I'm arguing with the content of the article you are giving us; as I have often mentioned, I'm out of my educational league here. I'm just sayin' that before you slam the origin of information others link to by calling them 'embellished journalism,' you check the references to make sure that they are NOT 'science journals and magazines,' especially properly peer reviewed journals and magazines.

That said, do you have anything else...like a peer reviewed journal or other equally respected source...that enlarges upon what is said in your link? I'd really like to see it. Not an argument against it; I can't. I don't know enough to argue. I really would like to see it.

Thanks.

edited: oh, having reread that Live Science article, I see that it is not an attempt to debunk anything, but is actually a 'proof' of some other claim that has nothing to do with what we are talking about here.

 

[beenherebeforeagain]

"Spatial light moderator." Sounds like something out of Dr. Who, doesn't it? Or "Back to the Future?" it definitely has a "Flux capacitor" vibe. I, personally, approve.



I'll admit to major confusion. However, I'm an English major for a reason.

On the other hand, I handled MATH in school just fine; that is, I understood equations in Algebra and Geometry: they were, after all, languages. I could not, however, solve them worth a darn because one actually has to plug in numbers to do that, and arithmetic has always escaped me. I felt a lot better about myself and my intellect when I read about how Einstein worked. HIM, I followed. At least, I followed his thought experiments.

It looks like I'll need translations for most of this stuff.

Yeah, that thingy...here's a document about those...

https://www.hamamatsu.com/resources/pdf/ssd/e12_handbook_lcos_slm.pdf