um, it's extremely nerdy and requires at least a minor understanding of recording techniques.

let's see.

dynamics is the difference between the quietest sounds and the loudest by amplitude. recordings with a lot of dynamics generally sound more natural and detailed because it leaves the transients more or less intact.

compression in audio is the reduction of those dynamics which generally has the effect of making the recording sound louder by RMS amplitude or the recording which is at the cost of the transient details.

the "loudness war" is basically the conflict between sound engineers that try to make a recording sound good and producers and labels demanding that the recording sounds loud so that it stands out from other recordings. this is done by compressing the recording and limiting it's dynamic range. to give you an idea of how much recordings are compressed vinyl records have a dynamics range of about 50dB (i believe) and CDs have a dynamics range of 90dB. pop recordings and especially pop rock recordings have a dynamic range of 3dB. jazz and classical records will generally use most of the available dynamic range and will be compressed very little if at all.

the ideal for most music is a well compressed recording that still retains the transient detail. something that is very difficult to do well.

the loudness war started approximately in the early 90s (i believe) and mainstream recordings have gotten more and more compressed to try and stand out from their contemporaries by sounding louder. what you're actually hearing in this video is the difference between a CD recording (with a dynamic range of 90dB, and probably using about 2-4dB) and a DVD quality recording (with a dynamic range of 144dB and probably using about 6-12dB).

i'm a little rusty, but i think that's fairly accurate. if you're interested in further reading i just found out that wiki has a good page on the loudness war. and interestingly enough the album this song is from is listed as an album that has been criticized for sounding like crap for the sake of sounding loud which basically makes this example completely useless and confusing for anyone who's not already familiar with the loudness war. to really understand the differences you need to listen to something that was recorded before the loudness war and a remastered version after.

here's a decent example of what the difference is. you can see how much info is missing by the graphical representation of the sound too.

http://www.youtube.com/watch?v=-v6ML2DsBfA

I know what many atoms look like, from a distance

Two things struck me, the extent of mans first radio signals (can't imagine how weak they would be at that distance) and the areas of the universe we haven't mapped yet. I love that feeling of insignificance, makes you feel all fuzzy insidel

When you think about it though, the first radio signals broadcast would have been very directional at the time, not a sphere at all, instead showing the earth's shadow and spiraling around as the earth rotated and orbited. Not easy to model or represent graphically though. Would love to see how the signals have increased in spectrum and amplitude, you'd see a kind of gas, like our atmosphere, varying density and colour...

I agree with you in basic principle, but I don't think the job-loss to job-replacement is at a one-to-one ratio when true automation and computer technology comes into play. In my mind there's a U-shaped regional employment curve relative to technological growth, with technological progress over time as the independent axis and employment level the dependent. Employment starts at one level along with a given level of technology, some big progress takes place that causes employment to drop, and then over time the region will adjust its educational and business practices in order to bring the employment curve back up to near former levels. And then the process would repeat itself. Sort of a sine wave... but every period the amplitude is reduced unless external factors (mainly political) mitigate the drop-off ratio.

So in the USA manufacturing jobs are going bye-bye, as are many IT jobs, as a consequence of economic and technological change, along with the shrinking disparity in education levels between the USA and mainly BRIC countries. Most of the newly unemployed will find replacement jobs, or be trained to work in off-shoot industries or newly arised industries. But again not all of them will find re-employment before the next drop off, unless the politicians are really doing their jobs.

Correction to the previous comment : extrinsic backgrounds fields certainly are not Schwinger sources for the string excitations in the space-time .No problem by imposing world sheet conformal sigma model invariance and thus evaluating strings scattering amplitudes in higher dimensional critical space-time

Well , it appears to me that string theory is a interesting attempt to "quantize" the space-time manifold (added with suitable supersymmetric structures ).Everything in higher dimensions become reduced to two-dimensional quantum field path integral models "living"on the string chart manifold (the intrinsic two-dimensional "string space-time").However , people impose dipheomorffism invariance on this intrinsic string parameter "space-time" which unfortunatelly get mixed with 2D conformal invariance , when one uses the sigma model Polyakov' action to assign "energy" for these "quantum -fluctuating extrinsic /observable higher dimension space-time process (quite different from the more geometrical Nambu-Goto string action ).In order to solve this problem one thus impose full sigma model conformal invariance by restricting that all strings Schwinger sources (the string higher dimensional field back grounds-including the own extrinsic space time manifold dimension!)to lead to a vanishing beta function for the sigma model Polyakov action at any perturbative order of the new universal coupling constant-the String length scale/Regge parameter.This produces an apparently well defined (?,and about the infrared 2D cut-off remotion on the perturbative Feynman calculationson the intrinsic string space-time ?) 2D Field theory for the extrinsic space-time quantum energy action, besides of fixing the string Schwinger sources to satisfy the usual Einstein-Maxwell-etc field equations at one loop and the extrinsic space-time dimension and the classical manifold topology of the extrinsic space-time to be fixed, when one has supersymmetry (Spin manifold space time structures,etc..).At this point , one has an apparently well defined quantum -mechanical framework to evaluate numerically scattering amplitudes (including quantum gravity!-the old dream ) to compare with the experimental results.That is the problem on this new quantum-mechanical framework : as far as I know nothing has been matched with the usual qed,qcd,etc results!(anomalous particle magnetic momentum, deduction of the asymptotic freedom in QCD ,The Higgs mechanism on the weak sector ,etc.

I've never done this, but I have to call bullshit. The strings should be moving near the fundamental with a node at the players fingers and one at the bridge (if that's what it's called), the amplitude is way too high, and the strings are moving in the wrong direction. The only explanation I could think of is that it's some kind of phasing trick with the camera shutter like the lines moving down a CRT monitor, but I doubt that could explain what we're seeing.

More like this:
http://www.youtube.com/watch?v=tZpeAJdD770

The amplitude of the crazy-flake waves radiated by this video is off the charts!

I've taken my upper-end at work before, in a sound proof room, and could follow with good detection accuracy up to 17.4 kHz (labmates typically maxed around 16.8... I win).

The lower end is highly dependent on the speaker, and tactile detection of vibration at very low frequencies can be confused for hearing. The upper end is also speaker and background dependent. If anything I thought this ramp test might show people where they have 'notches' in hearing: frequency ranges where they have hearing damage in one or both ears. BUT, with this poorly compressed recording on my cheap Monsoon pc speakers there were all sorts of fades and rises in amplitude.

I wouldn't use this to test hearing, or even test speakers, but it was fun rumbling around on the low end.

They do pitch noticeably even on calmer seas, but you get used to it. Rougher stuff and maybe you'll be bumping into the walls on the way back to your stateroom, but unless you're in a hurricane I don't think things would be really dangerous if you're belowdecks.

I can only guess that it was rocking with enough amplitude at the right frequency to get the pool going...

The amplitude is only double at the anti-node of a standing wave at nodes the amplitude is 0. So the total energy in the system is constant (conservation of energy). Besides standing waves don't transfer energy.

>> ^Irishman:
This reminds me of the story of the two Russian journalists who cooked an egg using two cellphones...
http://yusuf.asgerally.com/?p=42

Don't wanna scare anyone but...
2 waves of the same frequency create a standing wave (harmonic), DRAMATICALLY increasing the amplitude. Just by doubling the amplitude you will quadruple the energy, quadrupling the amplitude creates a 16-fold increase in the energy carried by the wave - (energy = amplitude squared)
It would require about 100 watts to heat the water enough to pop the corn (NOT 71watts as mentioned above, it takes 150-180 degrees C to pop corn not 100)
So! Who wants to do the math properly , not like that completely wrong mess posted above?
Here's the ratios:
http://en.wikipedia.org/wiki/Standing_wave_ratio
Assume the minimum 0.75 watt magnetron in the cellphone.

There isn't enough power in one cellphone to cook the kernel, the point is that there are two or more phones accumulatively interfering.

It won't work with all phones, it will only work if all the phones transmit on the exact same frequency - the key is the you need 2 transmitters to set up a standing wave harmonic which increases the amplitude many times, in turn increasing the amount of energy exponentially (as a square of the amplitude).

Cellphones need to transmit back to the tower after each packet they recieve.

I found one other person so far who has also realised that this is a standing wave harmonic causing the boost in energy
http://freepage.twoday.net/stories/4969270/

And here are some related studies:
http://www.sciencedaily.com/releases/2008/02/080214144349.htm
http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?tp=&arnumber=934914&isnumber=20229
http://www.content4reprint.com/health/diseases-and-conditions/swedish-study-links-brain-damage-to-cell-phone-radiation.htm
http://www.protectingourhealth.org/newscience/learning/2003/2003-0129salfordetal.htm

There's only one way to prove it and that's to do it! Time to gather up all my old phones...

There are loads of other clips on youtube of this effect...


In reply to this comment by theaceofclubz:
A microwave can range between 500-1000 watts and is specifically designed to transfer as much energy as possible onto a target. It still takes minutes to make a kernel pop. These cell phones are making it happen in about 5 seconds using antennas. They would practically have to be alien death rays for that to be possible.
In reply to this comment by Irishman:
The supernerd hasn't taken the amplitude increase that occurs between waves of the same frequency into account. The amplitude increase can be as much as ten-fold for most standing wave (harmonic) solutions...

I'm pretty certain that this video is geniune... which is a bit scary

In reply to this comment by theaceofclubz:
Choggie's insightful analysis aside, a supernerd at http://forums.gametrailers.com/showthread.php?t=423337 has already applied the science required to debunk it - "Popcorn pops because the water in it turns to steam and a kernel is about 14% water. So, if we assume a kernel of popcorn weighs 1 gram, it has 0.13 grams of water. Heat that water from 30�C to 100�C would take:

(0.14g)*(100�C-3 to turn the water to steam requires he latent heat of vaporization, which is 2259J/g.

2259J*0.14g= 316J for a total of 316J 41J = 357J.

Wattage = Joules/seconds. If it took about 5 seconds to turn the water in the popcorn kernel to steam, then the wattage required was:

357J/5sec = 71W assuming all power from the cell phone transmitter went into the kernel.

Cell phones typically have 0.75W-1W transmitters in them. With a 1W transmitter, it would take,

334J/1W = 334secs, if all power is transfered to the kernel.

Conclusion: since the corn is popping in 5 seconds... completely fake.

edit - as pointed out, corn kernels weigh about 0.25g and there are 4 phones which could be up to 2W each. Therefore, the energy hitting the corn could be 16 times greater. But the other assumption (that all the power is focussed into the water content of just 1 kernel) is most likely wrong by a factor of 100 or more." - NOBODY PANIC

A microwave can range between 500-1000 watts and is specifically designed to transfer as much energy as possible onto a target. It still takes minutes to make a kernel pop. These cell phones are making it happen in about 5 seconds using antennas. They would practically have to be alien death rays for that to be possible.
In reply to this comment by Irishman:
The supernerd hasn't taken the amplitude increase that occurs between waves of the same frequency into account. The amplitude increase can be as much as ten-fold for most standing wave (harmonic) solutions...

I'm pretty certain that this video is geniune... which is a bit scary

In reply to this comment by theaceofclubz:
Choggie's insightful analysis aside, a supernerd at http://forums.gametrailers.com/showthread.php?t=423337 has already applied the science required to debunk it - "Popcorn pops because the water in it turns to steam and a kernel is about 14% water. So, if we assume a kernel of popcorn weighs 1 gram, it has 0.13 grams of water. Heat that water from 30�C to 100�C would take:

(0.14g)*(100�C-3 to turn the water to steam requires he latent heat of vaporization, which is 2259J/g.

2259J*0.14g= 316J for a total of 316J 41J = 357J.

Wattage = Joules/seconds. If it took about 5 seconds to turn the water in the popcorn kernel to steam, then the wattage required was:

357J/5sec = 71W assuming all power from the cell phone transmitter went into the kernel.

Cell phones typically have 0.75W-1W transmitters in them. With a 1W transmitter, it would take,

334J/1W = 334secs, if all power is transfered to the kernel.

Conclusion: since the corn is popping in 5 seconds... completely fake.

edit - as pointed out, corn kernels weigh about 0.25g and there are 4 phones which could be up to 2W each. Therefore, the energy hitting the corn could be 16 times greater. But the other assumption (that all the power is focussed into the water content of just 1 kernel) is most likely wrong by a factor of 100 or more." - NOBODY PANIC

The supernerd hasn't taken the amplitude increase that occurs between waves of the same frequency into account. The amplitude increase can be as much as ten-fold for most standing wave (harmonic) solutions...

I'm pretty certain that this video is geniune... which is a bit scary

In reply to this comment by theaceofclubz:
Choggie's insightful analysis aside, a supernerd at http://forums.gametrailers.com/showthread.php?t=423337 has already applied the science required to debunk it - "Popcorn pops because the water in it turns to steam and a kernel is about 14% water. So, if we assume a kernel of popcorn weighs 1 gram, it has 0.13 grams of water. Heat that water from 30�C to 100�C would take:

(0.14g)*(100�C-3 to turn the water to steam requires he latent heat of vaporization, which is 2259J/g.

2259J*0.14g= 316J for a total of 316J 41J = 357J.

Wattage = Joules/seconds. If it took about 5 seconds to turn the water in the popcorn kernel to steam, then the wattage required was:

357J/5sec = 71W assuming all power from the cell phone transmitter went into the kernel.

Cell phones typically have 0.75W-1W transmitters in them. With a 1W transmitter, it would take,

334J/1W = 334secs, if all power is transfered to the kernel.

Conclusion: since the corn is popping in 5 seconds... completely fake.

edit - as pointed out, corn kernels weigh about 0.25g and there are 4 phones which could be up to 2W each. Therefore, the energy hitting the corn could be 16 times greater. But the other assumption (that all the power is focussed into the water content of just 1 kernel) is most likely wrong by a factor of 100 or more." - NOBODY PANIC

This reminds me of the story of the two Russian journalists who cooked an egg using two cellphones...
http://yusuf.asgerally.com/?p=42



Don't wanna scare anyone but...

2 waves of the same frequency create a standing wave (harmonic), DRAMATICALLY increasing the amplitude. Just by doubling the amplitude you will quadruple the energy, quadrupling the amplitude creates a 16-fold increase in the energy carried by the wave - (energy = amplitude squared)

It would require about 100 watts to heat the water enough to pop the corn (NOT 71watts as mentioned above, it takes 150-180 degrees C to pop corn not 100)

So! Who wants to do the math *properly*, not like that completely wrong mess posted above?

Here's the ratios:
http://en.wikipedia.org/wiki/Standing_wave_ratio

Assume the minimum 0.75 watt magnetron in the cellphone.