I think it kind of depends on what he means by 16,000x louder? If he's talking in decibels, then it's already a logarithmic scale, so 16,000x times higher output amplitude is about 84db? higher (which is no joke) not quite sure on the maths there. 16,000db higher is basically impossible unless we are talking a supernova or something.

That puts it at over 204db which is apparently the same volume as the Saturn V launch. Which would definitely kill you, but maybe not 8000 times over... I mean once really does the trick.

If he's talking about the energy input, it seems that's a different thing according to wikipedia, and would result in an increase of 42db, which puts it at 162db, which is about the same as a 12-guage.

He may also mean that the sound is that loud at source, but as the guy was probably trying to say as he was squirming, the distance matters. The sound energy will be dissipated over a 2D shell and so I'd guess it drops off proportional to distance squared plus some extra for loss as it goes.

All of that is in air, it's quite a different matter in the water as I think the force is transmitted more efficiently.

Either way, every 10 seconds for months? No thanks.

this was oddly uninformative and misinformative. the names for white and pink noise are related to light but brown noise is named after robert brown.

white noise is equal power (amplitude/"volume") across frequencies (1/1), pink noise equal power per octave (1/frequency), and brown/red noise is -6dB/octave (1/frequency^2). there is also grey noise, blue noise, black noise, violet noise, and others. and no mention of the fletcher-munson curve (how sensitive our ears are across the frequency spectrum).

Well this just made me want to go wire my head unit into my vehicle. Been meaning to do that all winter... and last summer.

I wanna beat this beat at the highest clearest amplitude into my brains.

This just seems too far fetched at the moment. The number of variables and situations to consider, the speed of execution required, the level of reliability ... it just seems too much for today's processing power.

I mean, take something like speech recognition as an example. Computer processing continues to fail at even this. The visual spectrum is much more complex than the auditory, which is largely just wavelength and amplitude.

To jump straight into something like that, with life or death ramifications ... I just don't see them jumping to production any time in the next decade.

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

Both @Chairman_woo and @Rawhead are 100% correct.

Traffic behaves like a wave. Canceling the amplitude (not stopping and going all the time, rather going a constant speed) reduces the chain reaction.

If you really want to know the chain reaction happens because people are no machines. They need time to reaccelerate once stopped. This time adds up.

Here is an example of this: http://videosift.com/video/Traffic-Jam-Simulation

@scheherazade it's not about keeping space in front of you. It's about going a constant speed. You're parking lot theory seems to stem from playing Sim City too much.
I do realize less cars = less traffic. But jams will still occur. You just need two cars.

That was probably a lot like it felt and looked when the meteor came down in Russia. I can't imagine the frequency or amplitude of that wave was much different.

I don't understand why viols aren't more popular.
They imbue that great impression of being overwhelmed when they buzz non-linearly at high amplitudes.
Violins sound so whiny by comparison - like their tears are a plea for attention rather than emotion which has utterly possessed the body. . 2¢

Degassed water helps, too.

We did this as an experiment in undergrad. Degassed water, a container with a simple shape (we just had a rectangular prism), a thing to vibrate it, and a thing to control the amplitude/frequency of vibrations. We usually got three or four nodes, depending on how good we were doing.

It was quite a while ago, but I think we had a piece of equipment we used to tell whether we were getting close to a resonance, and then it was just by feel to actually get sonoluminescence to happen. Cuts down on the amount of patience required, but still takes a bit.

>> ^messenger:

So would two pendulums of the same length hung from the same string (like on the Wikipedia page) be considered in phase, even though they have opposite patterns? What about the Wilberforce pendulum? Is it considered to be in phase?>> ^crotchflame:
You're right: a double pendulum is a coupled oscillator and is a good example. It's a coupled oscillator with multiple normal modes that can give it a complex motion even for small oscillations where it isn't chaotic - some would argue that at larger amplitudes it's no longer a simple oscillator so a lot of the terminology in use here doesn't apply. The point is that it doesn't settle into one coupled mode that is stable against perturbations the way phase locked oscillators would.



The two pendula on a string can be put into motion where they are in phase but they aren't phase locked because they don't have to stay that way. Like the example being shown on the wikipedia entry, they are mode coupling where one oscillates but loses amplitude as the other begins to move - this is the motion it will be in if you start one of them but not the other. If you set them both swinging at the same time from the same height they would be in phase but if you then perturbed them they would go into a more complex modal behavior so you couldn't say they are phase locked.

The Wilberforce is the same - if you just twist the spring, it will be twist back and forth for a while until it loses energy to the pendulum motion; it will eventually stop as the pendulum takes over and then it will start coupling back the other way. You can put the system in phase where the rotations and the swings are aligned in phase but the strong coupling allows them to share energy more rapidly and to take on more complex modal interactions.

So would two pendulums of the same length hung from the same string (like on the Wikipedia page) be considered in phase, even though they have opposite patterns? What about the Wilberforce pendulum? Is it considered to be in phase?>> ^crotchflame:

You're right: a double pendulum is a coupled oscillator and is a good example. It's a coupled oscillator with multiple normal modes that can give it a complex motion even for small oscillations where it isn't chaotic - some would argue that at larger amplitudes it's no longer a simple oscillator so a lot of the terminology in use here doesn't apply. The point is that it doesn't settle into one coupled mode that is stable against perturbations the way phase locked oscillators would.

>> ^messenger:

I'd imagine very few of them phase lock, no? Most of them result in chaos, I'd think, assuming a double pendulum counts as coupled oscillation.>> ^crotchflame:
>> ^draak13:
Actually, the answer is known as coupled oscillation
http://en.wikipedia.org/wiki/Oscillation#Coupled_oscillations

Oscillators have to be coupled to phase lock but not every coupled oscillator phase locks.




You're right: a double pendulum is a coupled oscillator and is a good example. It's a coupled oscillator with multiple normal modes that can give it a complex motion even for small oscillations where it isn't chaotic - some would argue that at larger amplitudes it's no longer a simple oscillator so a lot of the terminology in use here doesn't apply. The point is that it doesn't settle into one coupled mode that is stable against perturbations the way phase locked oscillators would.

Based on this I just bought the Admiral's edition. 4X games are awesome.
http://endless-space.amplitude-studios.com/

>> ^MaxWilder:

I started tearing up as soon as I realized what he was about to do. How could that be even remotely tolerable???


Strangely, while looking incredibly awkward and tiring it may not be that bad depending on how much he's causing the muscle group(s) to fire compared to typical methods of firing. Also, to what extent is the device causing the muscle group to fire it's nerves in relation to the maximum firing rate for that muscle, and does the electrical impulse have to be "strong"? Is the device simply causing a moderate firing; firing the group of muscles at about the same strength as we do? If it's just a bit less to just a bit more this device may work fairly well. Assuming you don't wear it all day.

The eyelid has (had to look this one up, it's been awhile) different groups to open and close (that's why it feels as though it's at rest when open or closed) the eyelid. There's a third group which helps control the widening of the eyelid. So while it looks odd, it may actually be fairly comfortable (again depending on the amplitude of the electric device versus the speed).

But, I certainly agree it "might" be OK for an hour or so, but long amounts of time will certainly tire the muscle groups no matter what (and probably give you a headache). Neat device, neat concept, but I highly doubt it'll go anywhere in it's current state.

Hopefully, it does force engineers to realize that the body is perhaps the best way to do a lot of these type of things. If someone else knows a lot more about stimulating that muscle group(s) as shown, please fill us in as I'm going off of old knowledge.

>> ^arvana:

The half-life of the transverse waves propagated from that slap indicate a damping factor of: FIRM.


You said exactly what I was going to post! So, instead...

In this new video being created by our highly skilled graduates; the camera speed will be slightly slower at 1000 FPS @1920x1080 (or higher if intended for use with IMAX or a screen over two meters) with a secondary stream containing a duplicate, but separate feed set proportionately two-centimeters apart from the other feed. Then slightly zoomed out at around a 5.7% overall frame increase in size and a slight 2° shift from the vertical, counter-clockwise. Then combine the two feeds to one feed, except beforehand, polarize the frames (or frame frequencies) 90° from the other (relatively). Hand out polarized glasses--that of course have a film matched to the polarized frequency. Then increase the overall playback time, matching with the framerate speed, to give a new perceived 30 minute length (20 seconds is ridiculous).

Then some 1960's or 1970's music can be added in (the beat of the music must match the wave speed; some "human intercourse" period film pieces may have the required music) to further increase the relation of wave propagation seen in the video demonstration. This will help add to the overall immersion and enjoyment of the experience.

Then, we suggest the use of lubrication (Group 5, with a Viscosity of 800cSt is recommended) and then use some transformational waves (many options are available) at a decent amplitude and frequency. One traditional method used is caused by simple human mechanical kinetic manipulation (flexing muscle groups) in a rhythmic horizontal/vertical oppositional motion spread out over a chosen time span. Speed, duration, and intensity are decided by the user or a human/non-human counterpart. Typically, this will propagate a strand of flagellates into a D-glucose polysaccharide chains in a combined structure for simple discontinuation and cleanup; then quickly proceeding on to the web browser and watching the next "sift*".

If "flagellate" reaction is not noticed or possible for you, please follow the yellow strip on the floor. On your way out you may participate in our free clinical study looking for medical problems. You will need to put on a special garment for the study, and you will receive a complimentary lollipop! Do not be disturbed if this reaction is not noticed as it is a well known and documented myth created by the sub-species that is the focus of our demonstration video. Do not be disturbed if you think you look like as said sub-species.

Thank you for watching our dissertation on wave propagation.
We look forward to our next project on fluid dynamics!


*sift, definition below

sift (sift)
verb. sift·ed, sift·ing, sifts
v.tr.
1. To put (flour, for example) through a sieve or other straining device in order to separate the fine from the coarse particles.
2. To distinguish as if separating with a sieve: sifted the candidates for the job.
3. To apply by scattering with or as if with a sieve: sift sugar on a dessert.
4. To examine and sort carefully: sift the evidence.
v.intr.
1. To make use of a sieve.
2. To pass through or as if through a sieve: a meal that sifts easily.
3. To make a careful examination: sifted through back issues of the magazine.

sift (suhifft)
noun. sift·ed, sift·ing, sifts, spelunking
n.wtf.
1. A video on the website called "Videosift™"; sometimes amusing.
2. A video not on the website called "Videosift™", fought over in a mating like ritual to become a sift.