There are so many things in life that we just don't know or understand. Here is a list of 6 science questions that you've probably wondered about, and the answers to those tough questions by top scientists.

Question 1 - Does the Universe Have a Purpose?

Answer: Steven Weinberg, theoretical physicist, University of Texas at Austin: Ever since people started thinking systematically about the world, there has been a widespread impression that the universe exists partly to serve the interests of humanity. That is, that nature is arranged to make it possible for human being to be here. Galen, the Greek medical scientist and philosopher, said, "The reason the sun is where it is relative to the Earth is so that the Earth would not be too hot or too cold for us." That is a very crude example, but there is a general impression that we somehow have a special significance built into nature. I don't think that's true.

Question 2 - Is Immortality Possible?

Answer: Cynthia Kenyon, biologist, U.C. San Francisco: I think that it might be possible. I'll tell you why. You can think about the life span of a cell as the integral of two vectors, in a sense: the force of destruction and the force of prevention, maintenance, and repair. In most animals, the force of destruction has still got the edge. But why not bump up the genes just a little bit, the maintenance genes? All you have to do is set the maintenance level a little higher. It doesn't have to be much higher. It just has to be a little higher, so that it counterbalances the force of destruction. And don't forget, the germ lineage is immortal. So it's possible at least in principle. Of course, immortality is impossible if you consider the chance that you could be hit by a car.

Question 3 - What's the Chance Earth Will Get Hit by a Giant Asteroid?

Answer: H. Jay Melosh, planetary scientist, University of Arizona: Impacts have happened in the past. They'll happen in the future. We're doing what we can right now to find all the objects that are greater than a kilometer in diameter. We know that there are probably not 2,000 such objects out there, as we'd previously thought, but more like 1,100, and we've discovered more than 75 percent. None of them at the moment have our name on them, but that doesn't mean that in the future these orbits won't change, putting something on a collision course with Earth. One such example is the asteroid Apophis, which could impact us in 30 years' time.

Question 4 - Will Science Ever Replace Religion?

Answer: Scott Atran, anthropologist, National Center for Scientific Research, Paris: Never. Because it doesn't solve any of the problems that religion solves, like death or deception. There is no society that survives more than a generation or two that isn't religiously based - even the Soviet Union, where half the people were religious. Thomas Jefferson's Unitarian God fell by the wayside. The French Revolution's neutral deity also fell by the wayside. People want a personal God, for obvious reasons, to solve personal problems.

Question 5 - Is it More Important to Explore Space or the Ocean?

Answer: Shirley Pomponi, marine biologist, Harbor Branch Oceanographic Institution: I love space exploration, but I think many people would be amazed to learn that only two human beings have ever gone to the deepest part of the ocean - the Mariana Trench - and that was more than 30 years ago. It's only seven miles deep. We're talking about sending people millions of miles away, but we've yet to explore our own planet. People have been diving around the Florida Keys for over a century, yet we still go five miles offshore and find an entirely new species of sponge [the so-called Rasta sponge] that has anticancer properties. There is some very cool stuff in our own backyard.

Question 6 - Will Robots Ever be Like People?

Answer: Marvin Minsky, computer scientist, MIT: It seems to me that building mechanical robots that look like people so that they evoke emotional reactions is just a waste of time. It hasn't led to any improvement in knowledge about how to do the important things that would make machines really smart. The key problem is how to imbue computers with what [computer scientist] John McCarthy and I call, "commonsense reasoning." There's no robot "alive" today that knows general things, like if you let go of something, it will fall. No robot knows that you can pull something with a string, but that you can't push it with a string. Little things like that. The average 5-year-old knows a few hundred thousand of those things and an adult a few million. Today there are only a handful of people working on commonsense reasoning, so you can't say how long it will take before robots are truly smart.

We don't make most appliances look like people. The new point to me is the idea that we don't want people to learn to order around servants that look like people, because that's catching. If you tell a household robot to do unspeakable, disgusting, or just boring things, you'll get the hang of telling other people to. And most human interactions are rotten already. People lie, cheat, do all sorts of awful things.

Source: Discover Presents Top 75 Questions of Science

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