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timothy

cylonlover writes "A team of scientists at Nanyang Technological University (NTU) in Singapore has developed a new image sensor from graphene that promises to improve the quality of images captured in low light conditions. In tests, it has proved to be 1,000 times more sensitive to light than existing complementary metal-oxide-semiconductor (CMOS) or charge-coupled device (CCD) camera sensors in addition to operating at much lower voltages, consequently using 10 times less energy."

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Landsat 7

The US Geological Survey will soon shut down Landsat 5, an observational satellite that has been running since 1984. Landsat 5 was designed for a three-year run, but it's now orbited the Earth over 150,000 times and transmitted 2.5 million images in nearly three decades, making it the longest-running Earth-observing satellite, though not the oldest satellite still in orbit. "Any major event since 1984 that left a mark on this Earth larger than a football field was likely recorded by Landsat 5, whether it was a hurricane, a tsunami, a wildfire, deforestation, or an oil spill," says USGS Director Marcia McNutt.

It's also malfunctioned several times in the past, sometimes temporarily going out of commission while being stabilized. On...

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Is it worth bluffing if you're playing cards against a computer? Most of us go through the day reading subtle (and some not-so-subtle) social cues, like tone of voice, body language, and facial expressions, to figure out what an appropriate course of action should be. To look into how humans read some of these social cues, researchers have put subjects into an MRI tube and asked them to play a simplified form of poker (just one card) against both computerized and human opponents.

The participants kept track of their opponents' behavior on previous trials when determining whether to bluff with a given card, but were more careful to pay attention to what their human opponents did. The researchers then used MRI images of brain activity to look for areas of the brain that might mediate this difference. One area stood out: the temporal-parietal junction, or TPJ.

(Functional MRI studies have come in for some criticism because the researchers often focus imaging on areas they expect to see involved. In this case, the researchers imaged the whole brain, divided it up evenly, and repeated the search for elevated activity. The TPJ still stood out.)

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Lately I've been trying to rid my life of as many physical artifacts as possible. I'm with Merlin Mann on CDs:

Can't believe how quickly CDs went from something I hate storing to something I hate buying to something I hate merely existing.

Although I'd extend that line of thinking to DVDs as well. The death of physical media has some definite downsides, but after owning certain movies once on VHS, then on DVD, and finally on Blu-Ray, I think I'm now at peace with the idea of not owning any physical media ever again, if I can help it.

My current strategy of wishing my physical media collection into a cornfield involves shipping all our DVDs to Second Spin via media mail, and paying our nephew $1 per CD to rip our CD collection using Exact Audio Copy and LAME as a summer project. The point of this exercise is absolutely not piracy; I have no interest in keeping both digital and physical copies of the media I paid for the privilege of owningtemporarily licensing. Note that I didn't bother ripping any of the DVDs because I hardly ever watched them; mostly they just collected dust. But I continue to love music and listen to my music collection on a daily basis. I'll donate all the ripped CDs to some charity or library, and if I can't pull that off, I'll just destroy them outright. Stupid atoms!

CDs, unlike DVDs or even Blu-Rays, are considered reference quality. That is, the uncompressed digital audio data contained on a CD is a nearly perfect representation of the original studio master, for most reasonable people's interpretation of "perfect", at least back in 1980. So if you paid for a CD, you might be worried that ripping it to a compressed digital audio format would result in an inferior listening experience.

I'm not exactly an audiophile, but I like to think I have pretty good ears. I've recommended buying $200+ headphones and headphone amps for quite a while now. By the way: still a good investment! Go do it! Anyhow, previous research and my own experiments led me to write Getting the Best Bang for Your Byte seven years ago. I concluded that nobody could really hear the difference between a raw CD track and an MP3 using a decent encoder at a variable bit rate averaging around 160kbps. Any bit rate higher than that was just wasting space on your device and your bandwidth for no rational reason. So-called "high resolution audio" was recently thoroughly debunked for very similar reasons.

Articles last month revealed that musician Neil Young and Apple's Steve Jobs discussed offering digital music downloads of 'uncompromised studio quality'. Much of the press and user commentary was particularly enthusiastic about the prospect of uncompressed 24 bit 192kHz downloads. 24/192 featured prominently in my own conversations with Mr. Young's group several months ago.

Unfortunately, there is no point to distributing music in 24-bit/192kHz format. Its playback fidelity is slightly inferior to 16/44.1 or 16/48, and it takes up 6 times the space.

There are a few real problems with the audio quality and 'experience' of digitally distributed music today. 24/192 solves none of them. While everyone fixates on 24/192 as a magic bullet, we're not going to see any actual improvement.

The authors of LAME must have agreed with me, because the typical, standard, recommended, default way of encoding any old audio input to MP3 …

lame --preset standard "cd-track-raw.wav" "cd-track-encoded.mp3"

… now produces variable bit rate MP3 tracks at a bitrate of around 192kbps on average.

Encspot-omigod-disc-3

(Going down one level to the "medium" preset produces nearly exactly 160kbps average, my 2005 recommendation on the nose.)

Encoders have only gotten better since the good old days of 2005. Given the many orders of magnitude improvement in performance and storage since then, I'm totally comfortable with throwing an additional 32kbps in there, going from 160kbps average to 192kbps average just to be totally safe. That's still a miniscule file size compared to the enormous amount of data required for mythical, aurally perfect raw audio. For a particular 4 minute and 56 second music track, that'd be:

Uncompressed raw CD format51 mb
Lossless FLAC compression36 mb
LAME insane encoded MP3 (320kbps)11.6 mb
LAME standard encoded MP3 (192kbps avg)7.1 mb

Ripping to uncompressed audio is a non-starter. I don't care how much of an ultra audio quality nerd you are, spending 7× or 5× the bandwidth and storage for completely inaudible "quality" improvements is a dagger directly in the heart of this efficiency-loving nerd, at least. Maybe if you're planning to do a lot of remixing and manipulation it might make sense to retain the raw source audio, but for typical listening, never.

The difference between the 320kbps track and the 192kbps track is more rational to argue about. But it's still 1.6 times the size. Yes, we have tons more bandwidth and storage and power today, but storage space on your mobile device will never be free, nor will bandwidth or storage in the cloud, where I think most of this stuff should ultimately reside. And all other things being equal, wouldn't you rather be able to fit 200 songs on your device instead of 100? Wouldn't you rather be able to download 10 tracks in the same time instead of 5? Efficiency, that's where it's at. Particularly when people with dog's ears wouldn't even be able to hear the difference.

But Wait, I Have Dog Ears

Of course you do. On the Internet, nobody knows you're a dog. Personally, I think you're a human being full of crap, but let's drop some science on this and see if you can prove it.

On-the-internet-nobody-knows-youre-a-dog

When someone tells me "Dudes, come on, let's steer clear of the worst song ever written!", I say challenge accepted. Behold The Great MP3 Bitrate Experiment!

As proposed on our very own Audio and Video Production Stack Exchange, we're going to do a blind test of the same 2 minute excerpt of a particular rock audio track at a few different bitrates, ranging from 128kbps CBR MP3 all the way up to raw uncompressed CD audio. Each sample was encoded (if necessary), then exported to WAV so they all have the same file size. Can you tell the difference between any of these audio samples using just your ears?

1. Listen to each two minute audio sample

Limburger
Cheddar
Gouda
Brie
Feta

2. Rate each sample for encoding quality

Once you've given each audio sample a listen – with only your ears please, not analysis softwarefill out this brief form and rate each audio sample from 1 to 5 on encoding quality, where one represents worst and five represents flawless.

Yes, it would be better to use a variety of different audio samples, like SoundExpert does, but I don't have time to do that. Anyway, if the difference in encoding bitrate quality is as profound as certain vocal elements of the community would have you believe it is, that difference should be audible in any music track. To those who might argue that I am trolling audiophiles into listening to one of the worst-slash-best rock songs of all time … over and over and over … to prove a point … I say, how dare you impugn my honor in this manner, sir. How dare you!

I wasn't comfortable making my generous TypePad hosts suffer through the bandwidth demands of multiple 16 megabyte audio samples, so this was a fun opportunity to exercise my long dormant Amazon S3 account, and test out Amazon's on-demand CloudFront CDN. I hope I'm not rubbing any copyright holders the wrong way with this test; I just used a song excerpt for science, man! I'll pull the files entirely after a few weeks just to be sure.

You'll get no argument from me that the old standby of 128kbps constant bit rate encoding is not adequate for most music, even today, and you should be able to hear that in this test. But I also maintain that virtually nobody can reliably tell the difference between a 160kbps variable bit rate MP3 and the raw CD audio, much less 192kbps. If you'd like to prove me wrong, this is your big chance. Like the announcer in Smash TV, I say good luck – you're gonna need it.

So which is it – are you a dog or a man? Give the samples a listen, then rate them. I'll post the results of this experiment in a few days.

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A 27-foot mirror for the Giant Magellan Telescope was cast on Jan. 14 inside a rotating furnace at the University of Arizona’s Steward Observatory Mirror Lab. A round furnace the size of a carousel spinning 21 tons of borosilicate glass heated to 2,140 degrees Fahrenheit slowly melted into a mold to create the giant telescope mirror. The unique fabrication process in the one-of-a-kind furnace results in a lightweight glass structure that can float in water, but is very stiff and able to adjust to changes in the nighttime air. The mirror is one of seven that together will make the largest telescope ever built, the Giant Magellan Telescope, slated to begin observations in 2020 at the Las Campanas Observatory in northern Chile, above the Atacama Desert where there is little to hinder the view into the night sky.

“In this design the outer six mirrors are off-axis paraboloids and represent the greatest optics challenge ever undertaken in astronomical
optics by a large factor,” said Roger Angel, director of the Steward Observatory Mirror Lab. The GMT will allow astronomers to answer some of the most pressing questions about the cosmos including the detection, imaging and characterization of planets orbiting other stars, the nature of dark matter and dark energy, the physics of black holes, and how stars and
galaxies evolved during the earliest phases of the universe.


GMT2 installation of honeycomb columns prior to casting at the University of Arizona’s Steward Observatory Mirror Lab. Ray Bertram/Steward Observatory


GMT2 installation of mold columns–about half way through the installation of more than 1600 individual columns. Ray Bertram/Steward Observatory


Unpacking, inspecting, and sorting Ohara E6 glass. Randy Lutz, Mirror Lab casting team manager, views each piece of glass with polarized light to help evaluate the glass for evidence of internal stress and other imperfections. Ray Bertram/Steward Observatory


Loading the Ohara E6 glass. Each piece of glass has been inspected and graded, then placed into position over the tops of the mold columns according to a predetermined distribution pattern. Ray Bertram/Steward Observatory


Glass loading completed; oven lid is lowered for the final preparations prior to heating and spinning the oven. The oven lid electrical heating coils and thermocouple probes are clearly visible in this view. Ray Bertram/Steward Observatory


The UA’s Steward Mirror Lab makes the world’s only honeycomb mirrors in a process called spin casting inside this spinning furnace built in the 1980s. Patrick McArdle/UANews


GMT1 on LPM (Large Polishing Machine) using small orbital polishing tool for precision zone polishing. Ray Bertram/Steward Observatory

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