The eLoran system adds a data capability, so encription is an issue.

I just viewed a description of eLoran at: www.ursanav.com/ sites/ default/ files/ pdfs/ news/ UrsaNav%20ILA-40%20eLoran%20System%20Definition%20%26%20Signal%20Spec ification%20Tutorial.pdf and scaned for the words: security, encription, jam. Nothing. Looks like there's no provision for these...true?

I placed a program on Slashdot.net that does this. Its called 'jcblock'. Just enter its name in the Search window. I also placed a similar program for an Android 2.2 smartphone on there. Its called 'JCBloc'. Unfortunately the Andoid folks blocked a needed permission in versions of Android after 2.2. There have been over 150 downloads of jcblock and over 30 of JCBloc. For further details read the README files for the programs.

Employers are getting a college trained employee at no up front cost to them. If they want something different, they can pay for it. For example they could write a contract with an entering freshman to pay for four year's college in exchange for four year's of employment at a reduced salary -- like the Navy does.

Humm... it seems like we are seeing an increase in earthquakes and now a volcano. I wonder if it has anything to do with melting glaciers and polar ice caps. Seems like, as the ice melts its weight is shifted from the ice to the oceans. As sea levels rise, increased weight is applied to continental shelves and tectonic plates and weight is decreased where the ice was. I wonder if this could cause the plates to shift. Also, if volcanoes spew more sulfur, etc. into the atmosphere there could be a cooling effect. I don't recall hearing anyone mention that global warming might cause geologic shifts. Maybe that will be the most immediate consequence? What do you think??

Point one: GPS, since the plane's antenna is semi-omnidirectional, is easily jammed. GPS signal strengths are weak. Point Two: Radar is not easily jammed. A jammer can only jam one radial -- and he gives away his angular position when he does. Point Three: Radar can skin track a plane even when the plane's transponder is turned off.

The obvious solution is to add a motion detection circuit to these devices. When they move faster than, say five mph, they turn off or go blank until their motion drops below the threshold. Detecting motion could be done in several ways: (1)doppler shift of the tower signals, (2)triangulation shift of the phone location, (3) GPS location shift, etc. This is a no-brainer.

Humm... seems like those inventions could have been designed without the expense of going to the moon. Nice info on Tang and Velcro though... I just used them to make a point. Thanks...

I assume you are kidding... ...funds would be better spent on saving Earth. The manned space station is a project without a purpose. So far as I know it has yielded no substantial science. NASA is offering free time on it in a desperate attempt to find a use for the thing!

Once again, besides Velcro and Tang, what have we gotten from manned space flight?

Put a cell phone jamer in each car -- that turns on when the car moves. Then people would have to stop to use the phone...

First, a satellite system is easier to jam. The signals are weak and the antenna on the aircraft is semi-omnidirectional so a jammer signal can get in. By contrast, its harder to jam a radar since it has a pencil or fan beam. Second, since the system is 'dependent' on aircraft cooperation, a terrorist can turn the on-board equipment off and become untrackable. By contrast, radars have a 'skin mode' where they depend only on reflections from the skin of the plane to track. This is not the normal transponder mode, but will defeat the attempts of a terrorist to avoid being tracked.