Anything with science is only impossible until someone does it and they have to re-write the laws. Most modern scientists have this know it all attitude that because nothing has been done in their time it will always be impossible. Then you get guys like John Kanzius who accidentally figured out you can break seawater’s hydrogen/oxygen bond with radio waves.
Who’s to say 100 years from now, or even a 1000, we don’t find a mechanical way to break that bond using a nanomachine or something else our generation never dreamed of.
A nice “top 10 scientific impossibilies proved wrong” list:
http://technology.newscientist.com/channel/tech/dn13556-10-impossibilities-conquered-by-science.html