It’s always fun to read about dissension at the top: Vatican cardinals divided over the next pope, the White House split on health care reform. Now, an entertaining paper that shows surprising fissures among some of the world’s top physicists. The authors asked 33
researchers for their opinions about 16 foundational questions in quantum mechanics. The results showed they differ widely on most topics, except for one: Einstein. No fewer than 64 percent of respondents felt comfortable saying his views on quantum mechanics were wrong.
Nabbed by the buzz
Forensic evidence is a powerful courtroom tool with a worrisome Achilles’ heel: Technology is constantly making it easier to falsify pictures, videos, and sounds.
But fraud detection is also improving, and in England, the Metropolitan Police forensic lab has been working for seven years to develop a remarkable system for guaranteeing that audio recordings are genuine and not doctored. As the BBC reports, the lab’s technique relies on a background fact about our world of which most of us are totally unaware.
That fact is the “all pervasive hum,” as the BBC calls it, emitted by any kind of electrical power source. Outlets, lights, and transmission towers are constantly producing a buzz that registers outside the range of human hearing but is picked up in the background of any nearby audio recording. And because this buzz varies randomly over time—the result of tiny fluctuations in the frequency of the power grid—it functions like a “digital watermark” that specifies the exact date and time a recording was made.
The British system is a massive database—essentially, a complete record of the past 7 years’ worth of those frequency variations. Police can compare the profile of the buzz as logged in their database with the profile of the buzz in a recording, and if the two don’t match—if there are breaks, interruptions, gaps—authorities know the audio has been spliced.
The technique is relatively simple to implement in Britain, which has a single national power grid. As you might guess, things are slightly trickier in the United States. We have three power grids—the Western Interconnect, Eastern Interconnect, and Texas Interconnect—which would all need to be logged in databases for a similar validation system to work here. And as far as I’ve been able to tell, nothing like that is imminent.
The Civil War, letter by letter
To mark the Civil War sesquicentennial, the University of North Carolina’s Louis Round Wilson Special Collections Library is publishing one piece of Civil War-era correspondence a day, 150 years to the day after it was written. The series features a diverse range of voices:
correspondence between sisters trading gifts, letters from soldiers at the front, business transactions between Southern men hiring out slaves. The letters show a nation preoccupied, even as everyday life goes on, and they also occasionally touch on some of the horrors of war we might not think about today. On Dec. 28, 1862, Lieutenant Thomas W. Patton of North Carolina wrote to his aunt in Asheville with news about 11 deserters:
It is said that on Friday last eleven men were shot in and around this place for desertion. I do not know how true that is but I know there was one executed from our Regt. The poor fellows name was Littrell. He deserted while our Regiment was stationed at Greenville and was arrested & brought back here about a month ago by Tom Stevens, and in company with two others (one of them Spain) was tried by court-martial and all three sentenced to suffer death. The other two were pardoned by Genl Bragg and he was shot in the presence of all the troops in his brigade. It was an awful sight, but I am convinced it was necessary for the good of the service and will put a stop to our men running away.
The series is a unique way to experience the inexorability of the war, and the varying impact it had on people’s lives. It will run through April 9, 2015—the 150th anniversary of Appomattox— at www.lib.unc.edu/blogs/civilwar.