To experience being at the top of the world without the help of bottled oxygen, “Strap a 30 pound bag of potatoes to your back, tie a pillow to your face and run up a hill.” Ed Viesturs, an internationally-known mountain climber, has conquered 10 of the world’s tallest peaks, including Mount Everest, without the aid of bottled oxygen.Viesturs, 38, spoke Sunday at the Fawcett Center for Tomorrow to a sold out crowd of more than 500 people.After conquering smaller peaks such as Mount McKinley, he felt stronger than most climbers and discovered the unique ability to breath without the use of oxygen. For experienced climbers, oxygen use becomes necessary for survival at about 25,000 feet, where the oxygen level is one-third of what it is at sea level.Mount Everest is 29,000 feet and Viesturs has climbed to its peak five times, twice without oxygen. “I wanted to experience mountains for what they are and I made a personal rule that my first ascent would be without oxygen,” he said.The ability to not use oxygen as an aid at such altitudes is partially genetic, but training, technique and desire are required, he said.”I picked the right parents and the right sport.” In 1996, Viesturs was asked to organize the transportation of food and equipment for an expedition to film a world-wide IMAX presentation of climbing Mount Everest. An IMAX frame is 10 times larger than a conventional 35 mm frame and the film is shown on an 80-foot screen. Viesturs showed slides of the expedition and said the film, opening in March, will show the general public that mountaineering is a challenging but good experience, he said. Viesturs is also featured in the television program “NOVA” and “Everest: Mountain Without Mercy,” a book published by National Geographic. Viesturs plans to become the first American and the sixth person in the world to climb 14 of the world’s tallest peaks without the aid of oxygen. He will climb one peak a year for the next four years.Viesturs is also a partner in Mountain Hardwear, a California-based manufacturer of mountaineering equipment. He helps the company develop products such as tents and down-filled suits. “Mountaineering first became a hobby, then a passion, then an obsession and now a profession,” he said. All proceeds from Viesturs’ presentation went to Recreation Unlimited, a camp for physically and mentally disabled children and adults in Delaware County.