[BigFreakinToad]

until I can see it and touch it myself, there are no aliens.
I like the idea of it, but the physics of FTL or space folding would require huge energies, construction and materials that can’t and don’t exist.
I will concede that life is hardy and on some exo planet somewhere a primordial slime does exist

[PIF]

require huge energies, construction and materials that can’t and don’t exist.

—
You must know all the possible materials that can exist in the Universe, in which case you must know everything also.

Carbon composite is an example of a material everyone, like you, would have said “that can’t and don’t exist” before the 20th century.

[voicereason]

I like the idea of it, but the physics of FTL or space folding would require huge energies, construction and materials that can’t and don’t exist.

So the Table of Elements is complete and there will be no additions to it? What about the elements added over the last 30-40years? Are they just made up?

I think there are a couple of interestng paths that often come up regarding the potential for aliens:

1) It's not scientifically possible. This assumes that already know everything there is to know about science, the universe, time...essentially everything. This approach is of course completely false from the start.

Or

2) On the religious side, the belief that aliens can't possibly exist. But they'll hold onto the belief of winged angels, thank you very much. When there is no actual physical evidence of angels existing either.

Or

3) They don't exist...unless of I've had a six-pack, and there's a late-night radio show I can call into.

[Openurmind]

“the physics of FTL or space folding would require huge energies, construction and materials that can’t and don’t exist.”

As new physics we didn’t know about or understand are discovered weekly. We arrogantly think we know everything about physics when we are actually still infants in the field.