Paying a visit to the US Patent website reveals advanced technology does exist and is being withheld from the public. I don't think anyone can get a patent for an idea. I believe it must be proven workable before a patent will be issued, yes? Take a look for yourself at the following link.
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7709819.PN.&OS=PN/7709819&RS=PN/7709819
I haven't been able to locate any patents for antigravity yet. Perhaps I'm not searching for the correct terms. I'll keep digging.
Peace all.
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=7709819.PN.&OS=PN/7709819&RS=PN/7709819
I haven't been able to locate any patents for antigravity yet. Perhaps I'm not searching for the correct terms. I'll keep digging.
Peace all.