I agree with others that there should not be limits on scientific knowledge. But it is sometimes hard to disentangle the methods of arriving at that knowledge from the knowledge. What I'm saying is, there are some experiments that are unethical or impractical to carry out. On the ethical side, there are rules put in place to preserve the health and well-being of human and animal subjects in experiments. The Institutional Review Board at colleges and universities, for example, are required to ensure that subjects of studies are treated ethically.
Some kinds of knowledge are simply impractical. Climatologists can gather data, but must use models to predict how climates will behave. One can't so easily just change variables in a region and see what affects it would have on the weather - and I doubt one would want to do that for the likely inadvertent consequences such an experiment would have.
Don't read me as saying we shouldn't study and learn about the universe. I think we should learn all that we can, as much as we can. I'm in favor of robust funding of scientific research in all areas. But there are limits to the way that knowledge can be obtained.