Is the difficulty of space travel the worst evidence against space aliens?
No. The worst evidence is that the statistics of the sightings aren’t right. During any given period a given number of UFO reports are made. Investigators (most of them friendly to the concept of UFOs but wanting to weed out the incorrect cases) declare most of them IFOs, or Identified Flying Objects after some questions are asked. The number of UFOs compared to IFOs is approximately a constant over the short haul. It varies some over the long haul with the varying individual zeal of investigators, of course. Then a UFO flap hits; suddenly it becomes popular to report UFOs. What direction do you expect the ratio of UFOs to IFOs to change? Even the most avid UFO believer expect most of the additional reports during a flap to be just copycat, me-too, garbage. You would expect the true UFOs to be a constant low level beneath the current fad, so the ratio should drop considerably. In fact, you might expect the aliens to lay low for awhile, avoiding attention; this drops it even farther. Bu
