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Post by silverdragon on Oct 27, 2014 12:32:31 GMT
You can slow down light......
It all depends on Gravity, but, so its reckoned, the higher the gravity the slower the light.
[edit, it doesnt all depend on one thing, see later posts, it can be done by a "Mask" and changing the shape of the proton as well.... edited later to add extra bits....]
But how about super-cooling the light............ can COLD slow light?....
In 1999 Lene Hau of Havard Physicist fame, managed to "Slow" light to 17 meters per second, and in 2001 stopped light completely.
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Post by silverdragon on Oct 27, 2014 12:37:08 GMT
By the way, further watching, this guy sound like a real "Genius"......
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Post by silverdragon on Oct 27, 2014 12:40:41 GMT
Further material for those able to keep up.... and that is just about me, because I had to stop and think several times to understand some of the concepts here.
[Note... its over an hour long... go make a fresh cup of coffee before you start?.....]
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Post by GTCGreg on Oct 27, 2014 13:35:26 GMT
Here's an idiot's explanation coming from a true idiot on the subject. The way I understand it is that a photon of light travels through the material under test and is absorbed by an atom. The photon's energy causes the atoms electrons to jump orbits to a higher energy state (closer orbit) after a short delay, the energy state of the atom then jumps back and releases another photon of the same energy (color) as the one that was absorbed. That photon then continues on until it is absorbed by another atom and the process repeats itself. The photons actually travel at C between atoms but it is the delay in being absorbed and remitted that causes the speed of light to appear slower than C when traveling through the material.
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Post by silverdragon on Oct 27, 2014 13:42:18 GMT
....Yeah, but as I understand that, the travelling between whatever is being done under extreme cold, which slows things down.
It has also called into question "Absolute Zero" as a measurement of Kelvin, and Minus Kelvin values, may go down much further than we ever believed.
To the state where its so cold it can not be measured because no known measuring device "Functions" at that extreme cold.....
Go Figure.
I say extremely plausible?....
We are learning more about what we dont know than we know about what we know.
(I may have to adopt that as a signature?....)
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Post by mrfatso on Oct 30, 2014 22:20:32 GMT
As I understand it we can never measure absolute zero, as it would mean violating the Heisenburgh Uncertainty Principle , as particles at absolute zero have both a known position and momentum .
Though I might have misunderstood that, it might be impossible to ever reach absolute zero for that reason, we can get very close, but never actually get there.
I will have to see which case it is.
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Post by GTCGreg on Oct 30, 2014 22:47:24 GMT
As I understand it we can never measure absolute zero, as it would mean violating the Heisenburgh Uncertainty Principle , as particles at absolute zero have both a known position and momentum . Though I might have misunderstood that, it might be impossible to ever reach absolute zero for that reason, we can get very close, but never actually get there. I will have to see which case it is. At absolute zero, we would know the position but there would be no momentum because all motion would stop. So would that violate Heisenberg? And even if it did, would it matter? |
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Post by silverdragon on Oct 31, 2014 12:14:00 GMT
And then is there colder.
If you take a solid piece of Ice and cool it, it can go colder than zero Celsius....
So is there a true absolute zero, or is it we just havnt been anywhere where that exists already.
What would be the temperature of solid Hydrogen.... if left where it could cool down....
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Post by GTCGreg on Oct 31, 2014 14:59:27 GMT
And then is there colder. If you take a solid piece of Ice and cool it, it can go colder than zero Celsius.... So is there a true absolute zero, or is it we just havnt been anywhere where that exists already. What would be the temperature of solid Hydrogen.... if left where it could cool down.... It depends on how you define absolute zero. If you say absolute zero is the kinetic point where all molecular motion stops, then that's absolute zero. If you use some other criteria, such as the enthalpy of the system, then you could have a different number actually lower than kinetic "absolute zero." For most discussions, the kinetic absolute zero (−459.67°F, −273.15°C) is used. |
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Post by silverdragon on Nov 1, 2014 12:39:03 GMT
Then there is Kelvin scale, which is used by most people to denote absolute zero.
But is it?...
Its based on theoretical and possible temps, but what is not possible is to see the unknown, and if that is dark matter, when we find the absolute of darm matter, will that be lower...
We Just Dont Know.
And this is where theoretical science begins....
I propose that whatever temp you can get to, there will be something lower. Eventually.
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Post by silverdragon on Jan 28, 2015 9:50:07 GMT
Nay mither?.... What did they do, just give it a full bottle of GlenSomething, and heard it in the right direstion?, honstly ossifer I was just ooot fer a walk....... An-am-nay-kiidin'-ya..... They did what now?... I dont understand this science myself fully yet, but, have a read, I think it makes sense..... www.bbc.co.uk/news/uk-scotland-glasgow-west-30944584This is the bit that makes most sense... Full Kudos to them, they explained it in a way that even a 5-yr-old can grasp?... Any scientist that can do that, speak "Normally", gets my full support.... |
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Post by OziRiS on Jan 31, 2015 20:08:47 GMT
Here's an idiot's explanation coming from a true idiot on the subject. The way I understand it is that a photon of light travels through the material under test and is absorbed by an atom. The photon's energy causes the atoms electrons to jump orbits to a higher energy state (closer orbit) after a short delay, the energy state of the atom then jumps back and releases another photon of the same energy (color) as the one that was absorbed. That photon then continues on until it is absorbed by another atom and the process repeats itself. The photons actually travel at C between atoms but it is the delay in being absorbed and remitted that causes the speed of light to appear slower than C when traveling through the material. Isn't that more or less what happens inside a star from when a photon is "born" during fusion and until it reaches the surface and blasts out into space? It sounds a lot like the same explanation, but the last time I heard that, it was added that the photon loses energy with each absorption and expulsion. As I understand it, a photon born from nuclear fusion has gamma ray energy, but when it finally breaks the surface of the star after millions of years, it's much less energetic, coming out as visible light, UV, IR or X-rays. |
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Post by c64 on Feb 6, 2015 0:46:04 GMT
Here's an idiot's explanation coming from a true idiot on the subject. The way I understand it is that a photon of light travels through the material under test and is absorbed by an atom. The photon's energy causes the atoms electrons to jump orbits to a higher energy state (closer orbit) after a short delay, the energy state of the atom then jumps back and releases another photon of the same energy (color) as the one that was absorbed. That photon then continues on until it is absorbed by another atom and the process repeats itself. The photons actually travel at C between atoms but it is the delay in being absorbed and remitted that causes the speed of light to appear slower than C when traveling through the material. Not at all! Air or glass are transparent, not because the photons are remitted by the molecules, the light can just pass through the atoms because the electrons won't stop them. The atom cores do, but they are so tiny and the space between the cores so vast that most of the light can pass. Expose glass to a great gamma-ray dosage and it turns perfectly black. The gamma rays alter the spin of the electrons so they stop photons passing through the atom. That's why RADAR transmitter vacuum tubes turn semi-black after a long service time, X-Rays also have this effect, but you need a very long time for a significant effect. The presence of the electrons in matter can affect light. Mostly by gravity but also due to various other quantum effects. The denser the material, the slower the light. The problem is to create a material which is really dense but still transparent. Optic refraction partially relies on light speeding up and slowing down in different "optic densities". |
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Post by GTCGreg on Feb 6, 2015 1:06:26 GMT
Optic refraction partially relies on light speeding up and slowing down in different "optic densities". These people aren't talking about slowing light down a little like you would find in a prism or lens. They're talking about slowing it down to, for all practical purposes, a dead stop. And speaking of glass turning dark from X-Rays, the high voltage rectifier tubes in old CRT color TVs used to turn dark from the X-Rays they inadvertently produced. That's why they were always enclosed in metal cages inside the TV. It was to shield the users from X-Rays. |
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Post by silverdragon on Feb 6, 2015 9:22:21 GMT
This raises a question...
In the Colour of Magic, Terry Pratchet said that the air on the Diskworld was so thick, it slowed down light, and refracted in a strange way to produce another colour, Octarine.
So what does he know?...
I guess more than I suspected.
Here is a question....Can a cloud of something be that dense that it would effectively slow down light?....
My guess is that yes it can, because the sun is a burning ball of gas, and according to science, the photons have a hard time getting out of there....?....
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Post by c64 on Feb 6, 2015 10:48:07 GMT
And speaking of glass turning dark from X-Rays, the high voltage rectifier tubes in old CRT color TVs used to turn dark from the X-Rays they inadvertently produced. That's why they were always enclosed in metal cages inside the TV. It was to shield the users from X-Rays. And those cages often had a switch to prevent that people without proper training could become exposed to the X-rays. Sadly, most of them were trained enough to bypass a switch... Wasn't it the "HV ballast" to regulate the HV by eating up the energy darker pictures won't spend that made that much X-rays? The rectifiers had a thick metal pipe as the anode with the X-rays appearing in the inside. Well at least this was true for the models I used to fix. I am one of 4 people who can replace the ballast tubes in their oil filled tin can. You need to solder the can shut but if there is one tiny bubble inside, the glass of the tube shatters when the oil turns hot. Also this is the origin of the myth that RADAR emissions cause cancer. It was not from the operators looking into their dishes, it was sitting next to the transmitter tubes. |
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Post by silverdragon on Feb 6, 2015 10:50:43 GMT
There was a Myth in the forces that the "new" microwave transmitters could cook a chicken.....
Busted, wasnt it?...
Hey, did Mythbusters try that one?...
I remember seeing someone try it on the TV, cant remember who it was though.
(If not MB, it could have been Braniac Science abuse)
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Post by c64 on Feb 6, 2015 10:58:23 GMT
This raises a question... In the Colour of Magic, Terry Pratchet said that the air on the Diskworld was so thick, it slowed down light, and refracted in a strange way to produce another colour, Octarine. So what does he know?... I guess more than I suspected. Here is a question....Can a cloud of something be that dense that it would effectively slow down light?.... My guess is that yes it can, because the sun is a burning ball of gas, and according to science, the photons have a hard time getting out of there....?.... Correct, the light is bouncing through the corona for years. I think even decades! The main effect is that the corona is extremely loud, there are incredible pressure fluctuations stirring the corona and trapping the light. |
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