Thousands of the nation's best and brightest young people are competing in Silicon Valley this weekend in everything from bringing history alive to finding a solution for the ginormous mass of discarded plastic floating in the Pacific Ocean.

Even though the events had a common denominator -- lots of bright young minds -- they were all held independently. And none of the youths seemed disappointed.

Ask any of the 950 elementary, middle and high school students who were in the state finals at the National History Day competition at the Doubletree Hotel in San Jose. Many of the students had spent nearly a year preparing for the event and said they look forward to studying more about history over the next year.

"History is just amazing. Having history come alive is even better," said Jasmine Anklesari, 15, of San Diego, part of a four-girl team from Francis Parker High School who wrote and performed a skit called "One War at a Time: Debate & Diplomacy of the Trent Affair."

The girls were so good at depicting the 1861 international diplomatic incident that one of the judges asked at the end if the young women were actors.

Anklesari and team members Gwendolyn Gardiner, Sabrina Devereaux and Michela Rodriguez had done extensive research and also noted the parallels of the Trent affair with one of the burning issues of our time: whether it's wise to fight more than one war at a time.

In addition to the student performances, projects ranged from papers and exhibits to websites and documentary films.

Sara Miller, Briley Haskins, both 13, and Cameron Kjome, 14, from Spring View Middle School in Rocklin, used the competition as a chance to learn more about a subject they all care about: equality in sports. Their skit was called "Anything You Can Do, I Can Do Too."

A handful of state competitors will be declared winners Sunday and will compete in the National History Day Finals at the University of Maryland.

At the Tech Museum on Saturday, an estimated 1,200 students -- nearly half of them girls -- vied for top honors in The Tech Challenge 2011. This year, the Bay Area's largest team-design science competition aimed at solving a real-world problem encouraged the young brains to find a way to get rid of the tens of thousands of abandoned plastic items floating in the central North Pacific that is so big estimates of its size vary widely -- from larger than Texas to larger than Canada.

The Tech Museum folks said the nearly 270 teams of young people came up with ways to "clean up Trash Island: The Great Pacific Gyre." It was the 24th year of the challenge.

At times, the line to the competition area stretched out and around the museum. There were lots of PVC pipes, menacing looking metallic pincers and several brightly colored life preservers.

Students for this event came from as far away as Maharashtra, India, and a team from Quebec, Canada competed via video.

Nupur Garg and Teresa Li, both 16 and juniors at Monta Vista High School in Cupertino, sat in the shade of the building waiting for their turn. Their design to retrieve items from the improvised plastic "masses" inside included two different size PVC pipes "so you can reach all of the bottles and caps," Garg said.

Inside, Wendy Vargas, 17, from East Side College Prep in San Jose, waited with her life preserver as the line inched forward.

"This is part of our costumes," she said. "Our device is two long poles with a dustpan with tape on one end so you can pick up all of the plastic bottles."

The competition areas were about as large as a good-size child's swimming pool, with plastic bottles and caps strewn inside, some placed behind plastic bushes. Some groups added costumes for the competitive edge, and some added humor.

Students were competing for such coveted titles as "Most Spectacular Failure" and "Best Team Name."

More than 300 students are expected at Stanford on Sunday for the Julia Robinson Mathematics Festival. Students in grades six through 12 will have a chance to test their brainpower against that of other bright competitors. For more information, see http://tinyurl.com/JRMFStanford2011.

And the Conrad Foundation's Spirit of Innovation Awards will culminate with the 2011 Innovation Summit at NASA-Ames Research Center in Mountain View. Presented by Lockheed Martin, this weekend's competition invites young scientists from across the country to try to create breakthrough technologies to help deal with the challenges of the 21st century.

On Thursday, 1,400 students age 6 to 18 participated in hands-on space and science demonstrations at the annual Lockheed Martin's "Young Minds at Work Day."