Given the laws of physics, radio signals are the only way that aliens, who logically probably exist in a universe with “hundreds of billions of galaxies” to communicate with earth. Earth has been transmitting radio signals in analog for 120 years and in digital for about fifty. Someone has probably heard and a return communication may have arrived or may soon arrive. It is not farfetched to speculate that there are distant civilizations linked by a network of radio communications but alas questions and answers take centuries. Sorry but mechanical and biological entities coming to earth from distant stars is not possible. You either believe Einstein or in the existence of UFOs. You can’t believe in both. You can speculate that a distant alien civilization is using our atmosphere as a giant video screen having “UFOs” appear, do physically impossible tricks and then suddenly disappear. Perhaps aliens have a sense of humor.
Given the CURRENT laws of physics.........................
You mean “Doctor Einstein” and his theory of relativity. Almost to the level of “Doctor Jill Biden” and her theory of relativity: Dr. Biden’s is a bit simpler and summarized, “My relative is the guy who stole the election which should lead to me being the first “First Lady Doctor”.
While Einstein’s testable theories have been experimentally shown to appear correct, I think Alcubierre is on the trail of something, too.