December 21, 2011 at 11:59 am
Steve Jones - SSC Editor (12/21/2011)
GilaMonster (12/21/2011)
Slow motion photography anyone?http://scienceblogs.com/startswithabang/2011/12/how_to_make_the_slowest_slow-m.php
Interesting, kind-a. The second video didn't seem all that amazing to me. Either I don't understand, or I'm not enough of a science geek to get it.
To me, the first video seemed fairly old hat (maybe the original frame rate was higher than previous times I've seen something like that, but it didn't seem enormously different) and the second video was absolutely amazing, almost incredible until I read the explanation of how the built it line by line, in a way that required some real precision stuff.
Tom
December 21, 2011 at 12:39 pm
GilaMonster (12/21/2011)
jcrawf02 (12/21/2011)
I think it's similar to this explanation of photos taken of plane propellers[/url], we're really seeing layered snapshots of a photon pulse moving through the target, recreated as a composite video shot, not truly seeing one pulse, because that can't be captured.Yup, same kind of principal.
It's impossible to create a camera that can take frames at the trillions/sec that would be required to see a single pulse of light move, so they take multiple pulses at regular intervals and take one frame per pulse, slightly offset. Still looks pretty astounding.
I dunno. If you have the source of the lightpulse and the target to be illuminated completely surrounded by something in which light is rather slow (carefully choose the light frequency and a medium with a high group speed refractive index - not what we normally call refractive index, which is the phase speed refractive index, although that obviously also has to be high - at that frequency) and the imaging aparatus is outside that medium (preferably in a vacuum) what will happen? I don't know anything with a high enough group index to be interesting (and maybe any such medium will do enough scattering to make a difference big enough to invalidate the experiment), for example using germanium as the high group index medium and infra red light the (phase speed) refractive index is about 4 (I looked that up - didn't remember it), and I think the group index is a bit higher (but it might be lower - I either never knew or have forgotten whether the first derivative of refractive index as a function of the wavelength is going to be positive or negative at a useful frequency, but I think from basic principles that it should be negative which means the group index is higher at that frequency) - and a factor of about 4 is far too low a reduction in light speed to allow us to do anything useful. But there may be an alternative medium that does better than germanium (and if it's a factor of a couple of hundred better than germanioum that might crack it, because we can build gear that does things in nanoseconds. Personally I doubt we'll find anthing with a high enough group index that doesn't do so much scattering that we don't see anything, but I wouldn't say it's impossible unless I saw some physics to demonstrate that we can't get a longer time interval by looking a something that happens in a medium with high group index.
Tom
December 21, 2011 at 1:27 pm
L' Eomot Inversé (12/21/2011)
GilaMonster (12/21/2011)
jcrawf02 (12/21/2011)
I think it's similar to this explanation of photos taken of plane propellers[/url], we're really seeing layered snapshots of a photon pulse moving through the target, recreated as a composite video shot, not truly seeing one pulse, because that can't be captured.Yup, same kind of principal.
It's impossible to create a camera that can take frames at the trillions/sec that would be required to see a single pulse of light move, so they take multiple pulses at regular intervals and take one frame per pulse, slightly offset. Still looks pretty astounding.
I dunno. If you have the source of the lightpulse and the target to be illuminated completely surrounded by something in which light is rather slow (carefully choose the light frequency and a medium with a high group speed refractive index - not what we normally call refractive index, which is the phase speed refractive index, although that obviously also has to be high - at that frequency) and the imaging aparatus is outside that medium (preferably in a vacuum) what will happen? I don't know anything with a high enough group index to be interesting (and maybe any such medium will do enough scattering to make a difference big enough to invalidate the experiment), for example using germanium as the high group index medium and infra red light the (phase speed) refractive index is about 4 (I looked that up - didn't remember it), and I think the group index is a bit higher (but it might be lower - I either never knew or have forgotten whether the first derivative of refractive index as a function of the wavelength is going to be positive or negative at a useful frequency, but I think from basic principles that it should be negative which means the group index is higher at that frequency) - and a factor of about 4 is far too low a reduction in light speed to allow us to do anything useful. But there may be an alternative medium that does better than germanium (and if it's a factor of a couple of hundred better than germanioum that might crack it, because we can build gear that does things in nanoseconds. Personally I doubt we'll find anthing with a high enough group index that doesn't do so much scattering that we don't see anything, but I wouldn't say it's impossible unless I saw some physics to demonstrate that we can't get a longer time interval by looking a something that happens in a medium with high group index.
I read:
We're animaniacs
We have pay or play contracts
We're zany to the max
There's baloney in our slacks
We're animany
Totally insaney
Here's the shows name-y
Animaniacs
---------------------------------------------------------
How best to post your question[/url]
How to post performance problems[/url]
Tally Table:What it is and how it replaces a loop[/url]
"stewsterl 80804 (10/16/2009)I guess when you stop and try to understand the solution provided you not only learn, but save yourself some headaches when you need to make any slight changes."
December 21, 2011 at 1:31 pm
jcrawf02 (12/21/2011)
L' Eomot Inversé (12/21/2011)
GilaMonster (12/21/2011)
jcrawf02 (12/21/2011)
I think it's similar to this explanation of photos taken of plane propellers[/url], we're really seeing layered snapshots of a photon pulse moving through the target, recreated as a composite video shot, not truly seeing one pulse, because that can't be captured.Yup, same kind of principal.
It's impossible to create a camera that can take frames at the trillions/sec that would be required to see a single pulse of light move, so they take multiple pulses at regular intervals and take one frame per pulse, slightly offset. Still looks pretty astounding.
I dunno. If you have the source of the lightpulse and the target to be illuminated completely surrounded by something in which light is rather slow (carefully choose the light frequency and a medium with a high group speed refractive index - not what we normally call refractive index, which is the phase speed refractive index, although that obviously also has to be high - at that frequency) and the imaging aparatus is outside that medium (preferably in a vacuum) what will happen? I don't know anything with a high enough group index to be interesting (and maybe any such medium will do enough scattering to make a difference big enough to invalidate the experiment), for example using germanium as the high group index medium and infra red light the (phase speed) refractive index is about 4 (I looked that up - didn't remember it), and I think the group index is a bit higher (but it might be lower - I either never knew or have forgotten whether the first derivative of refractive index as a function of the wavelength is going to be positive or negative at a useful frequency, but I think from basic principles that it should be negative which means the group index is higher at that frequency) - and a factor of about 4 is far too low a reduction in light speed to allow us to do anything useful. But there may be an alternative medium that does better than germanium (and if it's a factor of a couple of hundred better than germanioum that might crack it, because we can build gear that does things in nanoseconds. Personally I doubt we'll find anthing with a high enough group index that doesn't do so much scattering that we don't see anything, but I wouldn't say it's impossible unless I saw some physics to demonstrate that we can't get a longer time interval by looking a something that happens in a medium with high group index.
I read:
We're animaniacs
We have pay or play contracts
We're zany to the max
There's baloney in our slacks
We're animany
Totally insaney
Here's the shows name-y
Animaniacs
You may need new glasses....
--------------------------------------
When you encounter a problem, if the solution isn't readily evident go back to the start and check your assumptions.
--------------------------------------
It’s unpleasantly like being drunk.
What’s so unpleasant about being drunk?
You ask a glass of water. -- Douglas Adams
December 21, 2011 at 1:37 pm
L' Eomot Inversé (12/21/2011)
GilaMonster (12/21/2011)
jcrawf02 (12/21/2011)
I think it's similar to this explanation of photos taken of plane propellers[/url], we're really seeing layered snapshots of a photon pulse moving through the target, recreated as a composite video shot, not truly seeing one pulse, because that can't be captured.Yup, same kind of principal.
It's impossible to create a camera that can take frames at the trillions/sec that would be required to see a single pulse of light move, so they take multiple pulses at regular intervals and take one frame per pulse, slightly offset. Still looks pretty astounding.
I dunno. If you have the source of the lightpulse and the target to be illuminated completely surrounded by something in which light is rather slow...
Yeas, that would at least theoretically work, dunno if such a material exists. I was only thinking of light in air.
Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability
December 21, 2011 at 1:50 pm
GilaMonster (12/21/2011)
L' Eomot Inversé (12/21/2011)
GilaMonster (12/21/2011)
jcrawf02 (12/21/2011)
I think it's similar to this explanation of photos taken of plane propellers[/url], we're really seeing layered snapshots of a photon pulse moving through the target, recreated as a composite video shot, not truly seeing one pulse, because that can't be captured.Yup, same kind of principal.
It's impossible to create a camera that can take frames at the trillions/sec that would be required to see a single pulse of light move, so they take multiple pulses at regular intervals and take one frame per pulse, slightly offset. Still looks pretty astounding.
I dunno. If you have the source of the lightpulse and the target to be illuminated completely surrounded by something in which light is rather slow...
Yeas, that would at least theoretically work, dunno if such a material exists. I was only thinking of light in air.
US Berkeley guys slowed the light to 9.7 km/s. about 6 miles per sec. The medium was a seminconductor. Unless I am mistaken, the exact composition is classified.
December 21, 2011 at 2:00 pm
Revenant (12/21/2011)
GilaMonster (12/21/2011)
L' Eomot Inversé (12/21/2011)
GilaMonster (12/21/2011)
jcrawf02 (12/21/2011)
I think it's similar to this explanation of photos taken of plane propellers[/url], we're really seeing layered snapshots of a photon pulse moving through the target, recreated as a composite video shot, not truly seeing one pulse, because that can't be captured.Yup, same kind of principal.
It's impossible to create a camera that can take frames at the trillions/sec that would be required to see a single pulse of light move, so they take multiple pulses at regular intervals and take one frame per pulse, slightly offset. Still looks pretty astounding.
I dunno. If you have the source of the lightpulse and the target to be illuminated completely surrounded by something in which light is rather slow...
Yeas, that would at least theoretically work, dunno if such a material exists. I was only thinking of light in air.
US Berkeley guys slowed the light to 9.7 km/s. about 6 miles per sec. The medium was a seminconductor. Unless I am mistaken, the exact composition is classified.
I don't know that that kind of material would be useful in illumination for photography.
--------------------------------------
When you encounter a problem, if the solution isn't readily evident go back to the start and check your assumptions.
--------------------------------------
It’s unpleasantly like being drunk.
What’s so unpleasant about being drunk?
You ask a glass of water. -- Douglas Adams
December 21, 2011 at 4:54 pm
Revenant (12/21/2011)
butUS Berkeley guys slowed the light to 9.7 km/s. about 6 miles per sec. The medium was a seminconductor. Unless I am mistaken, the exact composition is classified.
Oh YG&LF. I wished I'd stayed an applied mathematician instead of becoming a computer man. That (group index about 30100) is absolutely fantabulous, I want in on that work, but I'm damned sure computer nerds with math background like me won't be permitted to see any of that stuff if government (whether US, UK, Russian, or Chinese - or anywhere else I can think of) has any say, despite there being very little chance at all of being able to do anything sensible/useful with it without math (and computationally competent) input. And I'm also damned sure the scientists wouldn't want me in - I've completely forgotten physics, and forgotten almost all applied maths that doesn't have instant application to computing, so I'd be no use to them at all.
Tom
December 22, 2011 at 10:39 am
Since it's doubtful I'll be around for the next four days...
Happy Holidays to anyone who celebrates. And happy long weekend to those who don't celebrate but take advantage of the long weekend. @=)
I wish you all the best.
December 22, 2011 at 10:58 am
Brandie Tarvin (12/22/2011)
Since it's doubtful I'll be around for the next four days...Happy Holidays to anyone who celebrates. And happy long weekend to those who don't celebrate but take advantage of the long weekend. @=)
I wish you all the best.
Happy holidays to you too and to everyone else here.
--------------------------------------
When you encounter a problem, if the solution isn't readily evident go back to the start and check your assumptions.
--------------------------------------
It’s unpleasantly like being drunk.
What’s so unpleasant about being drunk?
You ask a glass of water. -- Douglas Adams
December 22, 2011 at 11:27 am
Happy Holidays!
December 22, 2011 at 11:53 am
Brandie Tarvin (12/22/2011)
Since it's doubtful I'll be around for the next four days...Happy Holidays to anyone who celebrates. And happy long weekend to those who don't celebrate but take advantage of the long weekend. @=)
I wish you all the best.
And now I have Audra and the Antidote "We Wish You..." song going through my head.
http://www.lyricstime.com/audra-and-the-antidote-we-wish-you-a-lyrics.html
- Gus "GSquared", RSVP, OODA, MAP, NMVP, FAQ, SAT, SQL, DNA, RNA, UOI, IOU, AM, PM, AD, BC, BCE, USA, UN, CF, ROFL, LOL, ETC
Property of The Thread
"Nobody knows the age of the human race, but everyone agrees it's old enough to know better." - Anon
December 22, 2011 at 11:54 am
Happy Holidays, Steve, and thanks for keeping this great Web site humming!
December 22, 2011 at 12:03 pm
You're all SQL heroes in my books!
Thank you for the help and the knowledge.
Happy Holidays
Steve
December 22, 2011 at 10:48 pm
Happy Holidays to one and all.
And to others, 10 SSC points for this reference:
Why would I want anything with a mind of its own bobbing about between my legs?
Jason...AKA CirqueDeSQLeil
_______________________________________________
I have given a name to my pain...MCM SQL Server, MVP
SQL RNNR
Posting Performance Based Questions - Gail Shaw[/url]
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