calbiterol

I'm almost positive that a CRT won't work for the experiment I intend on performing with the array.

Externet:

I forgot to mention that I would like it to be scalable. But yeah, 1 square mm is fine.

Vertical and horizontal cells? I'm not really sure. I wouldn't think that would be too large of an issue - just put more rows/columns in, I would think... At least, under most circumstances.

The laser is backlighting the entire array - not individual cells (at least, that's what I'd prefer).

Intercell gap... well, I don't really know, it all depends. Probably 1/10th of the cell size or smaller.

As far as transparency range goes, I want closed to be pretty much CLOSED (opaque) and open to be pretty much transparent.

Shutter speeds/refresh rate? Right now, I don't care, but 'twould be nice if this could be changed later on.

Richard, its purpose is for relatively complex experimentation with the emission of fluorescence at atomic level after infrared excitation. More specifically, it is being applied to the display technology field.

why would you bother? you would be burning momentum going up instead of forward.

Island hopping. Just kidding!

So, in all of my spare time (which is like, nothing... ), I'm undertaking a rather ambitious project, and I'd like some help as to where I should start. The long and short of the project is to create a grid, similar to an LCD display, that:

1. Controls the "status" (on or off) of infrared light
   
2. Is backlit by an infrared laser
   
3. Can control areas smaller than the size of the laser beam (in other words, multiple cells in the grid per laser beam - with preferrably only ONE laser beam - just like the many pixels in an LCD screen to the one backlight)
   
4. Is controlled, whether directly or indirectly, through electric current, preferrably distributed in some type of grid
   
5. Contains nothing that will interfere with the transfer of infrared light in the control area (just like there isn't a big green blob in the middle of an LCD computer screen)
   
6. Is prefferably in the off state with no power applied ("none" of the infrared light passes through the grid when no power is applied)
   
7. Does not necessarily use liquid crystals (in fact, I would prefer that it didn't)
   

So, more or less, I am creating a kind of light projector with the functional qualities of an LCD, with an infrared laser as a backlight, that does not necessarily use liquid crystals, and I want some help getting started.

Anyone that wants to chip in will be greatly appreciated. Right now, I just need somewhere to start, but if you want to help out until I'm done, feel free - I sure could use an extra brain or two. Please be prepared to explain any advanced concepts - I'm a quick study (if I do say so myself), but I'm still only in high school. Note that as of yet, this project is unrelated to school.

Thanks in advance.

Water tunnels, I never even thought of that... How might one go about making the flow visible, though? I could think of some ways, but noting practical.

It's much more efficient to use graphite electrodes... Well, efficient isn't the right word, but it's a lot faster in the long run than nails, because the nails will corrode. Just carve the wood off of a pencil with an XACTO knife, or any other sharp knife. The core (in other words, the lead) is really graphite, which makes for a fine electrode. The lead tubes are actually surprisingly strong.

My best guess would be that it's some form of corrosion of the nail, but that would go against getting that result with graphite electrodes.

I've never had that problem with my nice graphite rods (out of a pencil, true to form) and have been bubbling away hydrogen when I feel like amusement. My next project with hydrogen is to create a solar "hookup" that will keep it running without batteries, "producing" clean, free (aside from water bills) hydrogen for... "experimentation..." (Insert evil laugh) Yes, I said create, as in, from scratch.

There's another problem here that I see though - there should be much more bubbling on the negative electrode (the anode, the one bubbling hydrogen) because water is, quite simply, H₂O, two parts hydrogen to one part oxygen. Perhaps you are forming a diluted form of an acid (like, hydrochloric... something with H and Cl).

There is a group in New York that believes it already has. But nobody is sure - because they have to check for Hawkind radiation, etc, to confirm that it was, in fact, a black hole. Check it out at http://www.thisislondon.co.uk/news/articles/17315265?source=Evening%20Standard.

Note: This is VERY recent, as in, the article is from the 17th of March 2005. Yep, I said March 17, 2005. That's only 4 days ago.

So let's say I want to make a double parabolic mirror (like the one at http://www.optigone.com/ ) that recreates a virtual image of a three dimensional object. That in itself wouldn't be too incredibly challenging. It's also entirely possible to do so.

While I'm at it, can someone explain to me the physics behind these?

Unfortunately, I don't think that's how it works...

[Edit: Plus, even if it worked, and I'm not saying it would, when you opened the box, you would get a flash of light so fast that you couldn't see it anyway.]

There is also some speculation that he had designed a VERY powerful energy weapon based on his various other inventions.

What is clear quartz's refractive index?

[Edit: as far as what band, I'm not entirely sure. As soon as I find out, I'll let you guys know. By the way, what are Cuvetes?]

Bump.

Are mirrors transparent to the IR spectrum?

It would be more practical to pull Titan to Mars.

But while you're at it, why don't you just crash Titan into Mars to give it some water?

Just kidding.

Let's say I don't care about how dim it gets... Then, would it be possible?

I have three questions on materials:

1. What common materials are opaque to the infrared and/or the UV spectrum?
   
2. What common materials reflect all visible light except infrared and/or UV light?
   
3. What common materials are completely transparent to infrared and/or UV light?
   

They're all similar, so I thought I'd bundle 'em up in one post.

Note: By common, I mean available cheaply.

How does an electric camera shutter work? I'd like some serious detail here - I want to reconstruct the electric open/shut action that makes the shutter work. Also, how are the shutters so fast?

Thanks in advance.

YT, what are "roofing lead sheets?" And could you give me a rough idea of the amount of power these will store?

Solar insolation average for Bangladesh = 4.78kWh/m^2/day (http://www.sdnbd.org)

Average Sunshine Hours = 7.55

 

4.78/7.55 = 0.63311

Solar Innsolation per hour = 633Whm^2

 

Solar Refelection systems max efficiency 30%' date=' a figure of 10% is used.

Energy Reflected = 633 x 0.10 = 63.3J/hm^2[/quote'] I'm not sure if this is correct - but I think it is. The meters squared would be the problem, if there is one. I have no idea where this efficiency fiure is coming from, though. I can't help you out any there.

 

Energy Required to Heat 0.5m^3 of air to 900C.

Q = mc(change in T)

m = 0.5kg

c(Specific Heat Capacity) = 1.005

Change in T = 900 - 20 = 880

Q = 0.5 x 1.005 x 880

Q = 442J

First off, it's C_p. Do that using [sub ][/sub ] tags (without the spaces).

 

Second, double-check your conversions. If your specific heat is in J/(g*c) then you have a problem - a kG is a thousand grams, a meter is 100 centimeters, and neither the jules or the centigrade numbers are increased. So, for simplicity and security, convert the meters cubed to centimeters cubed (and kilos to grams). Note that this results in 50^3 = 125000 centimeters cubed, because it is converting cubed units - meaning you need to cube the conversion rate. kG, however, is straight-up: a half-kilogram is 500 grams. That would give you 500g * 1.005 J/(g*C) * 880 or 500g* 1.005 J/(g*K) * 880, which is your number times one thousand. That would seem to be a MUCH more reasonable figure. But that's the only problem I see with your math.

 

 

Therefore the surface area of the solar reflector to focus enough energy to heat 0.5m^3 of air to 900C

= 442/63.3

=6.982622

=7m^2.

Remember that this is not the surface area of the reflector, it is the area of the aperature of the reflector. Double-check your maths and conversions.

 

Is this correct? Do I need to take other variables into consideration such as the angle of incidence of the sun etc? Any help would be much appreciated.

Well, it depends on conversions and the figures you got. Angle of incidence should be taken into consideration.

How many of these could be used (hypothetically ) to refrigerate to liquid-nitrogen temperatures?

A vortex refrigerator? What is that?

While I'm at it, can a stirling cycle engine (in reverse, or something like that) be used to refrigerate?

Meths? As in, methanol, etc?

I've searched the forums.

I've searched online.

I've searched high and low.

I understand the principle behind them (for the most part - but any in-depth explanations would be cool.)

But I can't find what I want.

So, HOW can I make a refrigerator from parts readily available (like, go to hardware store, etc) that is reasonably safe and (probly) legal?

P.S.: I did find one design, but it didn't really show me what I wanted.

Aha. Picture Posted.

Fake - I'm using the windtunnel to test propellers/impellers, aerodynamics in body design, and airfoil efficiency, among other things, in order to build a very efficient hovercraft.

[EDIT: It's NOT for a school project - it's something I work on in my "free time," which, seeing as today is a semi-regular school day and I just got home for the first time after 15 hours of being at school, is NOT MUCH.]