BhavinB

in the Hall experiment, both behave differently.

Jacquesl, this is what you should look at if you're interested in learning about Phosphors http://en.wikipedia.org/wiki/Phosphor

In current technology, yes, 1 pixel is 1 detector. In XRay images, yes again, 1 pixel represents a certain number of phospors (detectors).

As a side project, I am working on some small things on a laser display for the US air force. Though I still haven't personally seen the laser display, theoretically, it can provide a wider spectrum of colours and contrasts and ofcourse higher brightness with respect to current technology. Heat is not an issue. Interestingly, a laser's greatest advantage in other fields (its coherence properties) is its greatest disadvantage in displays. Laser displays are plagued with laser speckle issues (speckle is the random noise caused by interference effects from reflection off a rough surface such as a display screen). Speckle is known to hinder resolution and make it uncomfortable for the eyes to watch the screen.

So it looks like I'm joining this debate a little late. I live with an atmospheric environmental scientist. She told me that it is common belief that the ice ages occur due to regular variations in the earths orbit eccentricity. It's interesting to note that data also claims that CO2 levels dip at the same time as the ice ages. Wondering if anyone knows what the connection is here.

Fredrik really has a good knack at conveying his thoughts and providing a unique perspective. Fredrik: I enjoyed reading your posts on this 'observer issue'.

lol, sadly you've mistaken what the system really is. JOURNAL OF THE AUDIO ENGINEERING SOCIETY 47 (9): 726-731 SEP 1999 Author(s): Pompei FJ Abstract: A device known as a parametric array employs the nonlinearity of the air to create audible sound from inaudible ultrasound, resulting in an extremely directive, beamlike wide-band acoustical source. This source can be projected about an area much like a spotlight, and creates an actual spatialized sound distant from the transducer. A basic theoretical analysis of the airborne parametric array is outlined and verified experimentally, and future challenges are discussed. also: http://www.holosonics.com Basically the spotlight is only to identify the direction of the ultrasound beam. This technology has nothing to do with 'transmitting sound with light'...which as far as I know...not possible / discovered.

No...all known matter interacts with light in some way. The concept of refractive index is an assertion of this (ie the light is slower inside the material than in a vacuum). Dark Matter supposedly does not interact with matter in this way and thus should have RI of 1 for all frequencies; the same as vacuum. A block of wood painted black can't say the same thing...lol

There is a stochastic, statistical method of determining a mathematical model of data...though usually restricted in industry to polynomial relationships. This is known as the "Statistical Design of Experiment" originally developed by Fisher. Through appropriate design of factors and experiment settings, one can perform just the required number of experiments (no more) to determine the relationship required (within statistical tolerances). In industry, this method is heavily heavily used to determine optimal conditions. For example, in a chemical production facility or every single semiconductor fab facility in the world. Though not really used for exploration of a system response, I don't see why it can't. There are several books / websites that go over the mathematics behind this method.

Do you have a reference of this? Or maybe a common application? Remember, there is a difference between melting, exciting and ionizing (otherwise known as stripping electrons).

under most normal and abnormal conditions, IR light will not ionize an atom. To use IR detectors as evidence is incorrect since they don't detect through ionization. So although sometimes its nice to have a visual perspective of the universe, its ofcourse better to start off with a lit search to see the current state of knowledge before making massive assertions. For example, there is a very very small amount of iron in a star. Iron is formed in larger quantities only after an explosion or supernova. Showing a cloud in space says nothing. and why iron!?

I can't seem to find any links I distinctly recognize. Sorry dude...been like 4 years. I would imagine there are better designs out.

Hey, interesting project. I had a similar project a few years back and came to a few conclusions. for i) I couldn't find a freeware C compiler anywhere on the web...even a BASIC compiler would have done. So instead I had to use the assembly compiler by Microchip. Its not that bad...you have to be resolved to making your own system for 'functions'. ie where in memory do you store parameters, in what order, and where the returns values go. Also, coding in assembly is MUCH easier when you're not using interrupts. I don't know if this PIC supports that. ii) can't help you much for this as its different for each situation. Just a general warning, a few people I know tried to make a PIC programmer of the net and though some were successful, a few just fried their microcontrollers.

Not just the temperature difference, even assuming we can get that, how can we get 882 W of solar energy absorbed (assuming 100% efficiency..hah)? Whats the surface area of this specific Peltier?

You'd still need a broad wavelength absorbing material to first convert solar energy into thermal energy. I'm sure it's been thought of. After such a material is in place, what is the efficiency and power output? Thats the big question.

Mowgli, I can understand what you are saying and you are correct because the limit says you can't have any signal / information go faster than light. Read this link and provide a reply please. http://en.wikipedia.org/wiki/Faster-than-light#Moving_spot_of_light

........Running virus scan now.....

I don't understand what you mean here. Can you clarify?

Every material in the universe has a RI which varies with frequency, so it goes without saying. And the group velocity is the only important value in determining the speed of optical information...phase velocity is useless. I thought CPL.Luke provided a good enough reason of why it 'appears' to be travelling faster. On a side note, I think that article is meant to mislead (for amazement factor).

CPL.Luke is right, the position of the peak changed making it appear like it was faster than light velocity. Suppose in optical information transfer, you send in a pulse from one side and wait for the pulse to emerge on the other side. In such a case, most people keep track of the peak of the pulse because it is the easiest to observe. As the leading edge goes into the material, it becomes the peak because of the 'special' group velocity dispersion. So while the input peak hasn't even gone into the sample, already there is a peak on the other side. This is the illusion of 'faster than light velocity'.

Maybe what you mean is our angle of view might be minimized. In that sense, yes, we'd notice that we can see less in either direction. But everything will seem larger, even our ruler. So ofcourse everything would still measure to the same values.

The concept of 'size' is based on some reference we hold. So as long as we see the reference and the object in the same proportions, then it doesn't really matter how our eyes magnify / minify.

I remember a professor brought in a piece of the same foam to show in a class. That stuff is ridiculously soft and brittle. No way a netting would help...probably damage it further...plus nylon doesn't have that high a temperature resistance.

nope, thats it. sub the first equation into the second and solve for Y. To be fair...I used matlab to solve for the roots of the resulting fourth order polynomial.