Srijay Kasturi, 13, found a way to center his camera and get the perfect picture. (Sudhita Kasturi)

You may have heard the saying “Necessity is the mother of invention.” That means that people get creative when they realize that they need something that isn’t available or doesn’t exist.

Four local kids who recently became finalists in two national science contests came up with their ideas by looking around their schools and homes.

Solutions for every day

“My project is called the camera-centering tripod mount. It uses a distant sensor to scan the room. It finds the closest object and then aligns the camera in front of it to take a picture,” said Srijay Kasturi, 13, one of 10 finalists in the Discovery Education 3M Young Scientist Challenge, which asked kids to find a solution to an everyday problem and then make a video about it.

Hundreds of kids across the nation in grades five through eight entered.

For Srijay, who is a photographer and videographer, his invention could help him take photos.

“It makes it easier to center a picture because oftentimes when the camera is on a tripod, it’s hard to move around the camera to get the object in the center of the frame,” said Srijay, who lives in Reston and is home-schooled. He wants to go into computer science or filmmaking when he grows up.

Another finalist in the young scientist challenge, Tim DeMember, 12, lives in Frederick County and is a seventh-grader at Windsor Knolls Middle School. He invented the Piezo Electric Gear Assisted Sustainable Utility System, or Pegasus for short.

That sounds pretty complicated, but the idea itself is simple.

“I was thinking about hybrid vehicles because my dad has a long commute, so I was looking into hybrid to save gas,” Tim said. (A hybrid car uses two or more power sources, such as gasoline and electricity.)

Tim, who wants to be a mechanical engineer when he grows up, used special disks to generate energy when they are hit by rotating hammers.

Tim, Srijay and the other finalists will head to St. Paul, Minnesota, to compete October 6-8 for the grand prize of $25,000.

As the competition draws near, both Srijay and Tim are still perfecting their inventions.

“I’m really nervous,” Tim said. “There are a lot of kids who are really smart and can think up pretty interesting things, so this is going to be challenging.”

Asking a question

Nathaniel Sperry, 14, who goes to Mary Ellen Henderson Middle School in Falls Church, had an unusual question he wanted to answer with his school science project.

“My family, we have a history of making carrot cakes to celebrate birthdays, and every year there’s always been one green carrot in the carrot cake, and these carrots, we don’t know why they’re turning green,” Nathaniel said. “I thought it was a good opportunity to find out why this is happening.”

Nathaniel decided to see if the amount of baking powder in the cake made a difference. He baked nine cakes using different amounts of baking powder. After the cakes were baked, he took the carrots out of the cake, rinsed them and tested the intensity of color with a colorimeter that he made out of Lego Mindstorms. Nathaniel’s project earned him a spot as one of 30 finalists in grades six through eight in the Broadcom MASTERS science and engineering competition. The amount of baking powder did make a difference.

“I found out that there is a pigment in carrots called anthocyanins. It can change color,” said Nathaniel, who wants to be an inventor or a computer programmer.

Katherine Wu, 13, is an eighth-grader at Takoma Park Middle School, where her science fair project also earned her a spot as a Broadcom finalist. She wondered if there were more obese, or very overweight, kids in schools where sweets were sold.

“My mom’s cousin in her 20s suffers from obesity,” Katherine said. Using school system data along with a computer program and language called RStudio, she was able to break down large amounts of data. She concluded that the number of obese kids in school does not relate to sweets sold in the schools.

Katherine hopes to be a scientist or computer programmer. Meanwhile, she and Nathaniel — along with 28 other students — will head to Washington on Friday to see if their everyday-science projects will win a not-so-everyday prize: $25,000.

Talk to young scientists

The 30 Broadcom MASTERS science and engineering competition finalists from across the country will discuss their projects Saturday, September 28, from 1 to 4 p.m. at the National Geographic Society, 1145 17th Street NW in Washington. The event is free.

Moira E. McLaughlin