The study on the expansion of the universe by Saul Perlmutter may seem to be beyond this world, but in the eyes of colleagues and family members, the co-winner of this year's Nobel Prize in Physics is a down-to-earth person with a positive attitude and full of fun.

Nobel Prize in Physics winner Saul Perlmutter meets the press in Lawrence Berkeley National Laboratory, Berkeley, the United States, Oct. 4, 2011. Three scientists including Perlmutter shared the 2011 Nobel Prize in Physics. (Xinhua/Mao Lei) 
Perlmutter, a U.S. astrophysicist at the Lawrence Berkeley National Laboratory (LBNL), was awarded the Nobel Prize in Physics with two other scientists "for the discovery of the accelerating expansion of the Universe through observations of distant supernovae," the Royal Swedish Academy of Sciences announced Tuesday.

"He is very inspiring, he is very positive," Alex Kim, a fellow scientist at the LBNL, told Xinhua in an interview later in the day at the Berkeley lab.

Perlmutter co-founded the international Supernova Cosmology Project based at the Berkeley lab in 1988 which led to the discovery of the accelerating expansion of the universe.

Kim, who worked as a graduate student on the project under Perlmutter in the 1990s, recalled that back then, a lot of people saw the project as a mission impossible.

"Despite that, he (Perlmutter) is somebody who forges forward," said Kim, noting that the positive attitude is one of the things he admired most of the Nobel laureate.

"From what I see of him, he never gets discouraged, he is the optimist," Kim said. "I think that's why a lot of the things that he works on succeed."

For Laura Nelson, Perlmutter's wife, the astrophysicist is a " great guy" who is "really funny."

"He is creative about things, he is just a lot of fun," Nelson told Xinhua.

Perlmutter puts their 8-year-old daughter Noa to bed almost every night, she said, and they often sit in the dark talking about topics like science and literature.

The father and daughter have an ongoing series about making up stories of a little girl and her robots, and "it's a lot of fun," Nelson said.

"He is very smart, and 'silly'," said Noa, describing her Nobel Prize-winning father. "He is good at being funny, he makes jokes a lot."

VietNamNet/Xinhuanet