This is the same as calling an image through a magnifying glass an optical illusion. It's no more an optical illusion than the light bending through the lenses in your eyeballs.

Incidentally, this also has got nothing to do with the brain, and isn't art.

*nochannel

*Music
*Time Shift
*Water

I'm in total agreement with @MichaelL. Strictly speaking, this is definitely not an optical illusion by virtue of the fact that it is not an illusion.

You're just seeing objective reality the way nature is presenting it to the universe and the same way everyone else sees it. It would only be an optical illusion if it physically existed one way but your eyes/brain perceived it a different way.


It'd be like turning on a light in a dark room and declaring it an optical illusion that everything is illuminated because the photons from the light source are making everything look bright, but in reality it's all dark, so: optical illusion. "The room is being incorrectly perceived because it's actually dark, but you're perceiving it as bright."

Yeah, no.

From Wikipedia:
An optical illusion (also called a visual illusion) is characterized by visually perceived images that differ from objective reality.

That means when you stare at an object DIRECTLY, you are tricked into believing that it has different qualities than it does.

In this example, you aren't starting at the arrows... you are staring at a diffracted image of the arrows. The diffracted arrows REALLY do point in the opposite direction. There's no illusion here.

Consider this...

If I put a rose-tinted pane of glass in front of the arrows, would you consider that an optical illusion?

Would you think "Hey, those arrows were on white paper before, NOW the paper is pink! Mind blown! Optical illusion!'?

No, you understand that you are seeing the colour pink because that's the property of the pane of glass IN FRONT OF the white sheet.

If you put a white sheet in front of the arrows, would you think: "Hey, the arrows have disappeared? Optical illusion!"?

No, that's the property of the sheet in front of the arrows.

And so on...

Hopefully, that clarifies it for you...

WAIT A MINUTE--

Light BENDS when you look at it through water, especially water inside a cylindrical object???

I wouldn't have believed it if I hadn't seen this optical illusion in action.

Mind. Blown.

Next thing you'll tell me is magnets work through some kind of force other than magic.

Indeed, boo to anyone with a grasp of both the English language AND science.


Seriously, hoping your joking Ching, Mike's post was exactly my first thought watching the clip. Optical illusions are supposed to be things that trick your brain into misinterpreting a scene. In this case, the scene is being interpreted completely correctly, and the trick is in the physics, not in the brain. It's not a trivial or even obscure distinction to many.

Your video, Reversing Arrow Optical Illusion, has made it into the Top 15 New Videos listing. Congratulations on your achievement. For your contribution you have been awarded 1 Power Point.

Not really the definition of optical illusion... this is just a demo of the optical properties of water.

Tags for this video have been changed from 'beer, small, large, optical illusion, oakland, ballpark, baseball, cup, size' to 'beer, small, large, optical illusion, oakland, ballpark, cup, size, scam, rip off, volume' - edited by lucky760

Optical illusion, sadly. As noted up above, that little itty bitty top part is more than likely 4 oz. Considering the small cup is about to overflow (which you'd be ever so lucky to have them fill it that high mind you) and the large one isn't. Obviously, they are NOT the same volume. What they need to do is actually measure. I know, I'm going all weird and sciency here, but I'd wager that there's at least 2oz still to go.

Not to mention, where doe the manufacturer say 20oz is at? Is that small beer holding 18oz? or 16oz?

Plus, if you're buying beer at a game, you're getting ripped off in the first place. It's like people who buy iPhones for $400 but then complain when an app costs $1. Get over it.

You are thinking about QAM, Quadrature Amplitude Modulation. Thats an interesting question because QAM essentially produces the same results that the prof talks about in this video. By using interesting ways to change the beat and phase of a single carrier, one can represent a whole array of numbers greater than just a 1 or a zero with a single pulse, case in point.

In QAM, lets just use the easy example of QAM, QPSK (4QAM), where there are 4 possible binary positions for any given 'carrier' signal at a known frequency.

By shifting both phase and amplitude, you can get a 0, 1, 2 or 3, where each position represents a power of 2, up to a total value of 16 unique numbers.

Rather than just a 0 or a 1, you can have 0 through to 15. However doing this requires both a timeslot, and a known carrier window.

The fastest the QAM transmitter can encode onto a carrier is limited by the nyquist rate, that is, less than half the frequency which the receiver can sample at its fastest rate (on the remote end). As you increase the speed of the encoding, you also increase the error rate, and introduce more noise into the base carrier signal, in turn, reducing your effective available bandwidth.

So it then becomes a balancing act, do I want to encode faster, or do I want to increase my constellation density? The obvious answer is the one we went with, increase in constellation density.

There are much more dense variants, I think the highest ive heard of was 1024 QAM, where a single carrier of 8MHz wide could represent 1024 bits (1,050,625 unique values for a given 'pulse' within a carrier).

I actually had a lot more typed out here, but the maths that goes into this gets very ugly, and you have to account for noise products that are introduced as you increase both your transmission speed, and your receiver sensitivty, thus lowering your SNR, reducing your effective bandwidth for a given QAM scheme.

So rather than bore you with the details, the Shannon Hartley theorem is the hard wired physical limitation.

Think of it as an asymptote, that QAM is one method of trying to milk the available space of.

You can send encoded pulses very fast, but you are limited by nyquist, and your receivers ability to determine noise from signal.

The faster you encode, the more noise, the less effective bandwidth....and so begins the ritule of increasing constellation density, and receivers that can decode them....etc....

There is also the aspect of having carriers too close to one another that you must consider. If you do not have enough of a dead band between your receivers cut off for top end, and the NEXT carrier alongs cutoff for deadband at its LOW end, you can induce what is known as a heterodyne. These are nasty, especially so when talking about fibre, as the wavelengths used can cause a WIDE BAND noise product that results in your effective RF noise floor to jump SUBSTANTIALLY, destroying your entire network in the process.

So not only can you not have a contiguous RF bandwidth of carriers, one directly after another...if you try and get them close, you end up ruining everyones day.

I am sure there will be newer more fancy ways to fill that spectrum with useable numbers, but I seriously doubt they will ever go faster than the limit I proposed earlier (unless they can get better SNR, again that was just a stab in the dark).

It gives you a good idea of how it works though.

If you want to read more on this, I suggest checking wikipedia for the following;

Shannon Hartley theorem.
Nyquist Rate
Quadrature Phase Shift Key
Quadrature Amplitude Modulation
Fibre Optic Communication Wavelengths
Stimulated Brillouin Scattering
Ebrium Doped Fibre Amplifiers

Fibre can go a pretty long distance before it affects the signal though...

Fibre is comprised mainly of silicone, the more pure the fibre, the less dispersion issues occur at or around 1550nm (one of the main wavelengths used for long distance transmission, as we can easily and cheaply amplify this using ebrium doped segments and some pumps!)

Any impurities in the fibre will absorb the 1550 at a greater rate than other wavelengths, causing linear distortions in the received carrier along greater distances. This is called Brillouin scattering.

In the context of the above video, consider a paralell cable sending data over 100m. If one of those lines is 98m, then every bit that is sent down that line, will be out of order.

Same deal with Brillouin scattering, only on the optical level. Thats one of the main issues we gotta deal with at distance, however it only ever occurs at or around 1550nm, and only ever when you are driving that carrier at high powers (i.e. launching into the fibre directy from an ebrium doped amplifier at +15 dBm)

Theres some fancy ways of getting around that, but its not cheap.

Anywhere from say around 1260 to 1675nm is the typical bandwidth window we use today.

So, say 415nm of available bandwidth.
If we want that in frequency to figure out the theoritcal bits/sec value from the shannon-hartley theory, then we just take the inverse of the wavelength and times it by the speed of light.

7.2239e+14 hz is the available spectrum.

...thats 7.2239e+5 terahertz....

Assume typical signal to noise on fibre carrier of +6dB (haha, not a chance in hell it would be this good across this much bandwidth, but whatever..)

For a single fibre you would be looking at an average peak bandwidth of around 20280051221451.9 mbps.

Thats 19,340,564 Terabits per second, or 18,887.3 Petabits per second.

You can fudge that +/- a couple of million Tbps based on what the actual SnR would be, but thats your average figure.....thats a lot of Terabits.

On one fibre.

Source: Im a telecoms engineer

Very interesting video, but a pity he went in to all that detail to end with a figure as vague as "1 terabyte in a few hundredths of a second".

If "a few" is 5 we'd get 20 Tbytes/s, if a few is 50 we'd get 2 Tbytes/s.

From wikipedia it seems optical fibre bandwidth is also limited by distance, due to dispersion, but current experimental research results are approaching 100 Terabit/s over a single channel.
(26Tbit/s in 2011, 73.7 Tbit/s in 2013)
http://en.wikipedia.org/wiki/Fiber-optic_communication#Parameters

100 Terabit/s is 12.5 Terabyte/s, which is 1 Terabyte in 0.08 seconds.

So while it still doesn't tell us what the theoretical limit is, for our currently achievable maximum speeds "a few" is 8.

Well, it has been confirmed: GHCQ is indiscriminatly vacuuming webcam footage as well.

Remember when folks said that meta data doesn't bother them, it's not as if they were being spied upon when they're at home, naked? It's not as if they'll mind this time...

Ironically, being naked in front of your webcam might be the way to avoid ending up in their database.

"The documents also chronicle GCHQ's sustained struggle to keep the large store of sexually explicit imagery collected by Optic Nerve away from the eyes of its staff"

Peeping toms and wankers, the lot of 'em. So in order to have a private video chat, just use the chatroulette method and focus the camera on your genitals.

It is pure infrared. The installed filter blocks out all visible light.
The LED Headlights were on the whole time for example, but they appear off because those wavelengths did not hit the cameras sensor.

The glowing effect has nothing to do with thermal radiation.
We thought so too at first and hoped for "hot" surfaces to glow.

It is an optical effect that has to do with the wavelength of infrared light. The trees glow white due to the contained chlorophyll which reflects those wavelenghts very well.

People hear that the flicker fusion threshold is about 16hz, and that movies play at 24hz so they assume that there must be no benefit to higher framerates. Ofc, movies have a lot of motion blur to make the movement appear more smooth and quite often a TV will have sophisticated tech to make the lower framerates on TV shows appear smoother than they actually are. Computer monitors, for the most part, show sharp images and we sit closer to them so low frame rates are much more noticeable. The rods and cones in our eyes might have a "fresh rate" of 16hz (I think rods actually respond much faster, but w.e) but they aren't synchronised like a camera. Our eyes will detect light, or any changes in it pretty much instantaneously. You don't have to wait for the next refresh. At what point our brain, or the variance in latency of the optic nerve, become the limiting factors I don't know. I'd like to think we wouldn't have evolved such advanced optical receptors only to be bottle necked by our brains. In short: 120hz ftw.

My absolute greatest peeve with console ports is mouse settings though. The number of times I've had to delve into the .ini to disable mouse acceleration or set my sensitivity to something sensible. Sometimes even the .ini doesn't have the answer. I fucking hate it when you get a sensitivity slider with 10 arbitrary notches. "Don't worry gamers, I'm sure you'll find a setting you like. As long as your preference is for a mm of mouse movement to spin you between 360 and 720 degrees. Ps. you do have a gamepad rite?"

As you say, "Fuck you" indeed.