Given the CURRENT laws of physics.........................
For the past one hundred years all sorts of people, some quite brillant, have tried to disprove Einstein’s core theories of relativity. None have. However Einstein who famously said that imagination is the most important trait a scientist can have also had a great sense of humor. He had great fun postulating about unproven theories. Still press any imaginative but credible physicist and they will admit that physical and biological UFOs are not real.Yet as long as people say “Never say never” or “always”, the fun will continue.