on hiatus

We are ending the season a little early this semester. The television program is now on winter break. We expect to be back on the air in February. In the meantime, we encourage you to leave us feedback here if you have any comments or suggestions about the program. As budgets tighten for everyone, it is helpful to hear from anyone who benefits from the program!

Last week we unfortunately experienced technical difficulties during our last show of the year and the signal got knocked out at the end of the hour. We apologize for that, hopefully that won't happen again!

We wish everyone a great Thanksgiving and holiday season.

GPS

If you have used a GPS navigation system in a car, you know how valuable it can be. How does that little electronic device know exactly where you are? It relies on a system of satellites orbiting the earth about 12,600 miles up. At any location, the GPS receiver should be able to see at least 6 of these satellites, each of which transmits information about the locations of all the orbiting satellites along with precise time stamps. The GPS receiver is not capable of communicating back to the satellites, so it listens to these signals and, with lots of mathematics, determines its location.

Specifically, the GPS receiver can determine the synchronized time by comparing messages from different satellites. It can then determine precisely how long each signal took to travel from the satellite to the receiver. The signals travel at the speed of light, so a quick computation tells the device how far away it is from each satellite. On the program this week we showed how having only this information--the distances from several satellites--the GPS receiver can determine exactly where it is on the planet using a process called trilateration. How many satellites are needed to make this happen? The more you have the better, but a minimum of 4 is required (3 if you use information about your elevation on earth).

For more information, check out this very detailed Wikipedia entry.

Tricked out Hummers

This week we showed our recent visit to Predator Motor Sports where they retrofit various Hummer vehicles with more powerful engines and upgrades that makes them not only faster and more powerful but also greatly improves their fuel economy. How do they pull this off? As we saw, there is some math behind the scenes. 

As part of the process, they tweak a variety of settings in control modules on a vehicle and then study the interrelated effects on about 150 data tables. A computer helps them with the math between all the variables. One of the most important things they watch is the horsepower of the engine and the vehicle. A dynamometer ("dyno") is used to measure torque and RPM, and a mathematical formula converts this to the horsepower measurement. 

They also have to fit a larger engine with larger components into the original space, so carefully made custom pieces with precise angles and measurements are required that they make themselves. 

You can check out Predator Motor Sports at their website here.

One more link: Wikipedia entry on how dynos work

Feedback wanted!

As we all know, times are tough economically, and Palomar College is getting hit with budget cuts like everyone else. So, some programs may have to unfortunately be cut. If you would like to see the College Mathline continue, please let us know by leaving a comment here! (Click the "comments" link below.) You can also email us at mathline@palomar.edu.

Thanks!

Water treatment

This week we showed our visit to the Encina Wastewater Authority in Carlsbad, CA where they treat wastewater so that it can be returned to the ocean. Perhaps that's something that you haven't given much thought, but it was quite fascinating to see how they accomplished this task and they have a very impressive facility. And yes, mathematics factors in to many of the processes happening there.

Most of the work treating the water is done by bacteria and other microorganisms. The staff must constantly monitor and adjust the ratio of these organisms to the amount of solid "food" coming in. There is a large aeration tank where the organisms consume the waste followed by a secondary tank where the organisms and matter clump to form an "activated sludge." Some of this sludge is directed back to the aeration tank as needed to keep a 0.5 ratio. In the end, 100% of the sludge is used internally or processed into fertilizer.

After the microorganisms have done their work, the water is ready to be returned to the ocean, after being tested of course.

You can find more information on the Encina Water Authority at their website.