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Comment: Re:Reynolds number (Score 1) 163

by Carnildo (#47571329) Attached to: Quiet Cooling With a Copper Foam Heatsink

OTOH, the traditional CPU/mobo setting is a little problematic; first you put the most heat-concentrating element in the middle of everything, and then later you realize it needs cooling.

The theory is that the exhaust air from the CPU heatsink spreads out to parts that are more heat-tolerant but still need active cooling, such as the voltage regulators. A VRM that can operate at 100C without trouble can be cooled just fine with a slow flow of 50C exhaust air from the CPU cooling system.

In practice, people have found that a front-to-back airflow, preferably ducted, is quieter and more effective than a mix of back-to-front, blow-down, and turbulent airflows. It does, however, require actual engineering work, rather than just attaching a bunch of fans to everything.

Comment: Re:Sales flow chart. (Score 1) 96

by Carnildo (#47554511) Attached to: Oracle Offers Custom Intel Chips and Unanticipated Costs

How big is big enough that nothing but Oracle will do? Facebook is on MySQL, Wikipedia is on MariaDB and Google is using Bigtable.

It's more the nature and size of access rather than the sheer volume of data. Facebook and Wikipedia both act on small portions of the overall dataset, Wikipedia additionally is a read-mostly workload, and Google's access patterns aren't suitable for a relational database.

Comment: Re:GOG discovers DOSBOX works on Linux (Score 2) 81

by Carnildo (#47525699) Attached to: GOG.com Announces Linux Support

There was a brief period (roughly 1993 to 1995) when copy protection worked to stop small-scale piracy: around the time when CD-ROM drives first became popular. If you could stuff a CD full of game files, you had a game that could not be economically pirated, because copying the CD required either a dedicated hard drive to store the data (hundreds to thousands of dollars), a hugely expensive CD recorder (tens of thousands of dollars), or a CD stamping facility (millions of dollars).

Comment: Re:Self-justification (Score 2) 49

by Carnildo (#47479953) Attached to: New Map Fingers Future Hot Spots For U.S. Earthquakes

Starting on page 12 of the report is a series of maps showing the changes since the 2008 report. Of note:

* The South Carolina seismic zone has been displaced southward by about 50 miles.
* The New Madrid zone has changed shape, with some areas seeing a substantial reduction in estimated earthquake risk.
* The risk zones in California are more sharply defined.
* The risk for the central Rocky Mountains area is higher, but still relatively low.
* The earthquake risk estimate for coastal Oregon has been reduced.
* A new seismic zone is present in Oklahoma, reflecting whatever is causing the massive increase in earthquake rates there.

Comment: Re:A Century Ago (Score 1) 195

by Carnildo (#47479015) Attached to: The Improbable Story of the 184 MPH Jet Train

The majority of passenger trips in the US are either less than 50 miles, or more than a thousand, with almost nothing in between. At the short end, the flexibility of car travel beats the cost reduction of rail; at the long end, the speed of air travel beats rail.

The only exception to this is the BosWash area, where -- guess what? -- Amtrak is able to provide profitable rail service. It's not motivation that keeps the US from having good passenger rail service, it's geography.

Comment: Re:LibreSSL cannot be different by being the same (Score 5, Informative) 151

by Carnildo (#47472309) Attached to: LibreSSL PRNG Vulnerability Patched

The random number generator should not be seeded only by a PID.

The PID is used as an absolute last-ditch fallback in the case that no other sources of randomness are available. In order for this to happen, /dev/urandom needs to be inaccessible, the KERN_RANDOM sysctl needs to be unavailable, gettimeofday() needs to fail, and clock_gettime() needs to fail.

If you're running on a system that crippled, you've really only got two choices: try seeding using the PID, or use an unseeded RNG. Or follow Theo's advice and get yourself a real operating system.

Comment: Re:And this doesn't seem like a bad idea? (Score 2) 105

by Carnildo (#47411171) Attached to: Mapping a Monster Volcano

Soviets made a safety experiment with a nuclear reactor in Chernobyl. It didn't go wrong at all.

Correct. The 1982, 1984, and 1985 tests of using rotational energy of the turbines to power the emergency pumping system all went just fine. The 1986 disaster happened when the operator ignored the test procedure (specifically, the instruction "Reduce reactor thermal output to between 700MW and 800MW. If reactor thermal power output drops below 700MW, abort test and shut down reactor" -- the operator reduced the power to 30MW, raised it to 200MW, and attempted to perform the test).

Comment: Re:ok (Score 2) 78

More significantly, if you see left-to-right motion and say "forward", what percentage do you get right? I suspect there's a bias in videos towards left-to-right motion of subjects (or conversely, right-to-left motion of backgrounds), and I don't see anything in the paper about controlling for it.

Image

A Physicist Says He Can Tornado-Proof the Midwest With 1,000-Foot Walls 501 Screenshot-sm

Posted by samzenpus
from the up-against-the-wall dept.
meghan elizabeth writes: Temple physicist Rongjia Tao has a utopian proposal to build three massive, 1,000-foot-high, 165-foot-thick walls around the American Midwest, in order to keep the tornadoes out. Building three unfathomably massive anti-tornado walls would count as the infrastructure project of the decade, if not the century. It would be also be exceedingly expensive. "Building such walls is feasible," Tao says. "They are much easier than constructing a skyscraper. For example, in Philadelphia, the newly completed Comcast building has about 300-meter height. The wall with similar height as the Comcast building should be much easier to be constructed." Update: 06/28 04:14 GMT by T : Note: originally, this story said that Tao was at Drexel rather than Temple -- now corrected

Comment: Re:Dishonourable Mentions (Score 1) 133

by Carnildo (#47302371) Attached to: The Revolutionary American Weapons of War That Never Happened

Would it have changed the course of warfare? A bouncing bomb that worked at sea would have rendered virtually all navies obsolete.

You know what else can lift a ship and break its back? A torpedo with a magnetic fuse. Oddly enough, torpedo bombers don't appear to have rendered the world's navies obsolete.

Nobody said computers were going to be polite.

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