AretNCarlsen's comments

AretNCarlsen | 14 years ago | on: CERN pushes storage limits as it probes secrets of universe

I used to be the sysadmin for a high energy physics lab as we prepared for the ATLAS experiment to come online. (It was a long wait, following helium explosions and such.) The reason you see so many different numbers is that they cannot possibly record the full flow of information. CERN has a very large buffer that the collision sensor data is fed into initially, which is analyzed in realtime to determine which chunks of data are likely to contain significant information. Those chunks are kept, and the rest are discarded. This bothered a lot of people, since they are probably throwing away interesting scientific data, but they are limited by current storage technology.

Further preliminary analysis is performed on the retained data, broadly categorizing the energy and other characteristics of the collision. That allows individual physics groups around the world to download only the data that is likely to pertain to their specific research, e.g. the Higgs boson, multiple dimensions, etc.

There was some talk of transferring data via Bittorrent or perhaps a custom protocol involving fountain codes. That never got off the ground. Instead, the Russians were working on a custom peer-to-peer system with a monolithic centralized set of indices, a system which is hopefully working better than it used to.

P.S. - Here's a hummingbird-speed video of building our prototype fileserver node for local physics analysis of ATLAS data [before I learned about electric screwdrivers]: http://www.youtube.com/watch?v=8y6MpPNqxmw

AretNCarlsen | 14 years ago | on: Color, Now Down Two of Three Leaders, Lesson in Lean Startup Philosophy

I haven't used any of them, but you could try arbitrary betting sites. Someone has to be willing to take the bet, which would be an entertaining way of putting one's money where one's forum-mouth is. Betable.com seems like the best fit for non-sports actual-money bets.

Longbets.org would let you make an idealistic point. (They don't let you keep your winnings; they have to go to a charity.)

Smarkets.com plays with real money, but seems targeted towards sports and current events.

AretNCarlsen | 14 years ago | on: Harvard releases archive of student Facebook profiles: unethical?

Includes an entertaining quote from "a postdoctoral fellow at Carnegie Mellon University who studies privacy in social networks" who believes that text content -- tweets, specifically -- can actually be deleted from the internet as long as the Library of Congress doesn't archive them:

"'This is the nature of these systems,' says Mr. Stutzman, who has criticized the Library of Congress's Twitter project. 'Maybe in three years, we'll look at public tweets and say, Oh, my God, those weren't public. A lot of people that are using Twitter nowadays may actually want to go back and delete their accounts or take those things out of the public at a later date, and they no longer can.'"

AretNCarlsen | 14 years ago | on: Google made my son cry

You are exactly right, which is why adults are covered by OPPA (where the C, for Children, is removed): http://en.wikipedia.org/wiki/Online_Privacy_Protection_Act

As in contract and rape law, people below an arbitrary cutoff age are presumed to be unable to give consent (or to even understand what "consent" means). Once beyond that age, the person is considered to be able to give consent, e.g. click "Agree" on a Terms/Conditions form or use a website with a very visible Privacy Policy link.

AretNCarlsen | 14 years ago | on: Google made my son cry

Perhaps we should follow the example set by statutory rape laws: children of age x (where x<13) can only give their personal information to sites run by children whose age is within 24 months of x.

(Yes, I am joking.)

AretNCarlsen | 14 years ago | on: Google made my son cry

If you give a niece or nephew an account on your mailserver, you may need to get parental permission from your sibling to maintain COPPA compliance. :)

P.S. - Verbal authorization won't do! The permission has to be given in the form of a fax, credit card number, digitally signed email, or via a toll-free telephone number.

AretNCarlsen | 14 years ago | on: Google made my son cry

The law is meant to cover this specific situation. The FTC, enforcing COPPA, fined the social network Xanga $1,000,000 for allowing children under 13 to sign up without parental consent.[1] The law is specifically intended to prevent advertising agencies -- like Google -- from gathering information from children.

"Research ... showed that young children cannot understand the potential effects of revealing their personal information; neither can they distinguish between substantive material on websites and the advertisements surrounding it. While some parents tried to monitor their children's use of the Internet services, many of them failed due to lack of time, computer skills, or awareness of risk. ... 'a Los Angeles television station reported that it obtained a detailed computer printout of the ages and addresses of 5,500 children living in Pasadena simply by sending $277 to a Chicago database firm.'"[2]

[1] http://www.msnbc.msn.com/id/14718350 [2] http://epic.org/privacy/kids/#introduction

AretNCarlsen | 14 years ago | on: When was the most history made? A quantified view.

The article defines "making history" as simply existing. That's why they can conclude that disproportionate chunks of history were formed during more recent time periods: human population growth, like that of any other bacteria, is exponential.

It's an interesting perspective. Even if your definition of who "makes history" is more narrow, their results are still accurate if you assume that the history-makers have made up a consistent percentage of the human population throughout history.

AretNCarlsen | 14 years ago | on: 555 Timer footstool

Put an IC socket on top so you can use any DIP8 IC to build GODZILLA CIRCUITS. Though you might have to add active amps in the legs at higher signal frequencies.

AretNCarlsen | 14 years ago | on: Local Food or Less Meat? Data Tells The Real Story

Great article. Scientific analysis is solid.

Understanding of American capitalism is flawed, however.

>> As companies keep discovering, it really helps to run the numbers. As I've written about before, Pepsi discovered...

>> Smart, knowledgeable execs are consistently surprised when good lifecycle data trumps seemingly solid assumptions.

[emphases mine]

That is naive. Pepsi is running a tight ship; they have all the numbers in front of them, all of the time; and they pay a lot of engineers a lot of money to not fall prey to "seemingly solid assumptions". Regardless of when the relevant analyses (like the Tropicana gas-vs-fuel analysis) are performed, companies will announce the "discovery" of such nuances precisely when it becomes good publicity to do so.

In related reading on ignoring surrounding factors when introducing green technology, windmills destroy the environment: http://www.savewesternny.org/environment.html

AretNCarlsen | 14 years ago | on: Researchers create rollerball-pen ink to draw circuits

The existing pens are intended only for minor PCB repairs. They are terribly expensive, as in $100/oz, have high resistance, and cannot be drawn with smoothly (like a pen). They are also not intended for the kind of flexing that you see on a piece of paper.

Example (0.3oz for $30): http://www.amazon.com/gp/aw/d/B000B5YDT8

Historically, you've been better off using conductive silver thread for flexible and on-the-fly circuits. Still expensive and resistive, but tolerably so.

Example (82 ohms/ft, $5/yd): http://www.sparkfun.com/products/8544

AretNCarlsen | 14 years ago | on: TrueCrypt User Held in Contempt of Court

You're right, I butchered the jargon there. By "hidden volume" I meant the volume that is hidden during normal use, whereas the conventional meaning of that term is the volume that is hidden when you give the false password. Exact opposites.

> I recommend creating a hidden volume in any encrypted container...

Do you not want the recommendees to enjoy plausible deniability? After all, if they always create a hidden volume, they could reasonably be held in contempt for refusing to give two passwords for every volume.

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