Living forever has been a pipe dream for many scientists. Now some scientists are researching ways to extend the human lifespan and they think immortality is possible for people living today.

"The first person to live to be 1,000 years old is certainly alive today ...whether they realize it or not, barring accidents and suicide, most people now 40 years or younger can expect to live for centuries," said Aubrey de Grey, a leading longevity researcher.

De Grey, a scientist at Cambridge University is well known in academic circles as one of the leading proponents of anti-aging. He believes he has identified the biological process that is responsible for aging.

"It depends on the tissue. In the eye, there is a type of junk that accumulates in the back of the retina that eventually causes us to go blind. It's called age-related macular degeneration. In the arteries, you have a different type of cell which accumulates a different type of junk that eventually causes arteriosclerosis," he says.

Another method being researched is an anti-aging drug called SRT-1720 which reduces the amount of fat in the liver and increasing sensitivity to insulin. When the drug was tested on obese mice, the mice lived 44 percent longer. The findings "demonstrate for the first time the feasibility of designing novel molecules that are safe and effective in promoting longevity and preventing multiple age-related diseases in mammals," Dr. Rafael de Cabo, a gerontologist at the National Institute on Aging wrote in the journal Scientific Reports. De Cabo and his colleagues are testing drugs related to SRT-1720 in humans.

While genetic research has produced many intriguing results that could prevent aging there are other fields that may hold the fountain of youth.

"There are many, many different components of ageing and we are chipping away at all of them," said Robert Freitas at the Institute for Molecular Manufacturing, a non-profit, nanotech group in Palo Alto, California. "It will take time and, if you put it in terms of the big developments of modern technology, say the telephone, we are still about 10 years off from Alexander Graham Bell shouting to his assistant through that first device. Still, in the near future, say the next two to four decades, the disease of ageing will be cured."

De Grey also believes that humans will soon be able to live forever. With the rapid advance of technology scientists could soon design smart drugs specifically tailored for individuals and gene therapies could soon cure hereditary diseases. Nanotechnology is also a developing field that could provide nanobots that can travel through bloodstreams to fix the ailing human body.