Science fact and Science fiction

[Ibrahim]

One would assume, however, that if they have mastered interstellar travel they would have figured out cloaking, or at least stealth of some kind.

You'd be surprised:

For a less speculative example: the Chinese were pretty sophisticated--in general they were way ahead of the west till the Early Modern Period, but it never occurred to them the Earth was a Spheroid till relatively recently (possibly the 11th century AD, definitely by the 17th century). For comparison, everyone knew the correct shape in the West and Near East since the 3rd century BC; Columbus for example wasn't criticized because he thought the Earth was round, but because he believed the Earth's circumference was lower than calculated--his critics were in fact correct.

It's not quite like figuring out how to shut off the lights; this is a far more complex topic--how to make a person or (in this case) craft invisible. Just as the technology (and thinking) needed to figure out the Earth's shape differs from that of mixing chemicals to make them go boom (or using a magnet to find your way around), so will cloaking and making space-craft. Afterall, technology and science aren't discovered neatly.

Besides, I am not convinced we have not figured out cloaking. Who knows what technologies are being implemented that we don't know about?

Well, I only said the aliens (hypothetically) may not have developed it--at least for space-craft. I didn't say anything about humanity. Mostly because, cloaking tech has been around for a while, and is public knowledge:

https://www.youtube.com/watch?v=PD83dqSfC0Y

But no, they can't do this for airplanes--not yet. Stealth for craft (and even tanks) at this time is really about radar stealth, so as not to be detected by enemy fighters and radar installations. This technology has been common since the late 1980's, and gained attention during the Persian Gulf War.

Personally, my take on most UFO sightings near military bases are more likely tests of such craft, and not aliens. This doesn't discount an alien visit, nor that there are aliens in the first place, nor can you make an argument that it is impossible for them to have paid a visit: we simply don't know. This is especially as once again, we simply don't really know what to expect. For example, we don't know if they even feel the need to shut off the lights...

[Agent Miles]

Most of the cool scientists at SETI and in the Exobiology departments will tell your children that 100,000 intelligent alien races may inhabit the universe. Even if they have an extraordinary understanding of the Drake equation, that might be a very lonely place. The "Hubble Bubble" with the volume of the observable universe centered on the Earth contains about 300,000 billion, billion, billion cubic light years of space. So if we are statistically lucky, we may have an intelligent neighbor within our 3 billion, billion, billion cubic light year zone. Yaaay (sarcasm off).

That may seem daunting, however, time is on our side. The universe is 13.72 billion years old. Galaxies formed within a half billion years after the Big Bang. Giant stars in those galaxies were rapidly fusing hydrogen into heavier elements. After only a few million years these stars with hundreds of times the mass of the Sun were going super nova. The heavier elements that make up life were created in the explosions and spread throughout the surrounding hydrogen clouds. The shock waves created smaller stars like our's. If some of these stars evolved like ours (physics led to chemistry led to biology), then intelligent creatures might have populated them by 5 billion years after the BB. So beings like us should statistically have existed 8 billion years ago. That would give them time enough to colonize everything in that 3 bn, bn, bn cubic light year space. Either interstellar space travel is totally impossible or they should have found us. They wouldn't be visitors. The Sun would be part of their turf. Our ancestors would have been able to look up and see the alien's Dyson ring around the Sun.

Perhaps, the most intelligent members of any advanced species eventually discover technology that the most foolish members of their species use to cause their extinction.