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Showing posts from December, 2014

Stalling Aircraft

Modern passenger planes cruise at very high altitude and very close to their stall speed, flying on a knife edge, in order to minimize fuel consumption.  The problem is that when a plane encounters turbulent air due to a storm or a side wind, it can stall unexpectedly, while still traveling at high speed. It appears to me, that in the relentless pursuit of lower drag and lower fuel consumption, the designers have compromised aircraft stability and safety.  The situation now, that a passenger plane can stall at 30,000 feet and then fall out of the sky, with the total loss of aircraft, crew and passengers, unable to recover despite the best efforts of an experienced flight crew, because the plane was designed to save every last drop of fuel, is inexcusable. Aircraft designers should always put stability and safety first and should not be driven by marketing only. Postscript In October 2018, a brand new Boeing 737 Max crashed in Indonesia with great loss of life, because it had


I've been playing with FreeCAD for a few hours, since I need to make little Nylon brackets and things at Shapeways . The program is absolutely amazing for its price - Zero Dollars - which is a nice way to say that there are a few hiccups, but once one knows how to avoid the hiccups, then it works perfectly... :) Antique Radio Ham Speaker Mic, circa 2015 To aid with error checking of CAD files before uploading them to Shapeways, also install the free Meshlab .  Note that uploading a file to Shapeways takes a while, because they also do a conversion and error check, so be patient.  If you checked it with Meshlab, then it should work. I made the above widget by drawing four cubes, resizing them and subtracting  three from the other, then subtracting four cylinders for the mounting holes and finally applying fillets to the edges.  That's all there is to it.  Made out of Nylon, it makes a strong base for a little step motor. In general, I would say that FreeCAD i

Tor Exit Nodes Compromised ExcludeExitNodes node,node,… A list of identity fingerprints, nicknames, country codes and address patterns of nodes to never use when picking an exit node---that is, a node that delivers traffic for you outside the Tor network. Note that any node listed in ExcludeNodes is automatically considered to be part of this list too. See also the caveats on the "ExitNodes" option below.  Tor users should note and temporarily avoid the affected mirrors below: http://globe223ezvh6bps.onion http://atlas777hhh7mcs7.onion http://compass6vpxj32p3.onion


Sony, the company that distributed millions of MS Windows root kits on CD in 2005 , has now been hacked through a Windows SMB exploit . I don't have much sympathy with this crowd, since they cost the IT world an enormous amount of money to clean up their root kit mess and blaming their current disaster on North Korea just doesn't fly with me.  I don't see how someone can download terabytes of data over the North Korean antiquated  internet link.   Clearly the Sony IT staff and management were stupid in 2005 and they are still stupid today. They haven't learned anything. On November 4, 2005.  Thomas Hesse , Sony BMG's Global Digital Business President, told reporter Neda Ulaby , "Most people, I think, don't even know what a rootkit is, so why should they care about it?" Now suddenly, they care deeply... If I apply Occam'

SSH Daemon on a Mac

A Mac is a weird thing that doesn't always know whether it wants to be BSD or Linux. Enable Remote Login You should only need to enable remote login: $ sudo systemsetup -setremotelogin on If the above doesn't work, here is the magical incantation to start a SSH Server: $ sudo launchctl start /System/Library/LaunchDaemons/ssh.plist One can then check it with a Telnet client: $ telnet localhost ssh   Trying ::1...   Connected to localhost. Escape character is '^]'.   SSH-2.0-OpenSSH_6.2 ^]   telnet> q   Connection closed.  Now you can use scp and ssh from another machine on the LAN, but one needs to know what the IP address is: $ ifconfig en0 | grep inet  inet6 fe80::5626:96ff:fece:371f%en0 prefixlen 64 scopeid 0x4  inet netmask 0xffffff00 broadcast Run SSHD On A Different Port If you want to allow internet access to your Mac and don't want to be bothered by script kiddies all the time, then you need to c