On Monday, January 1, 2018 at 9:19:09 AM UTC-7, Phillip Helbig (undress to reply) wrote:

In article , Gary
Harnagel writes:

It is quite unreasonable to assume that in all the universe we are the
first. In fact, it is unreasonable to assume that a civilization like
ours didn't develop billions of years ago.

How does this in any way contradict any worldview?

The existence of a benevolent civilization billions of years older than
ours wouldn't change YOUR worldview? Come ON!

Not in the least. Why should it? I wouldn't be surprised. The Earth
is about 4.6 billion years old, the universe about three times as old.
Civilization developed here, so I wouldn't be surprised if it did
elsewhere, but I don't know how likely it is; perhaps there is some
difficult bottlenect. It would be an interesting event, yes, but it
wouldn't change my basic worldview.

It WOULD change that of 99% of the world's population just if an advanced
civilization wore confirmed to exist on a planet around Tabby's star.

The odds of spontaneous life could be arbitrarily close to zero.
That we are here (necessary for this discussion to take place) has zero
commentary on the odds of spontaneous life anywhere else.

That's likely to be quite irrelevant:

https://en.wikipedia.org/wiki/Panspermia

Panspermia is a hypothesis, by no means proven.

I think it's pretty solid given evidence for extra-solar comets and asteroid
impact.

It
seems to me that we should be arguing intelligent life developed long
ago in the universe until refuted by evidence to the contrary.

Why should we assume anything?

Because we're human. It's what we DO.

Also, there is no way to disprove the existence of extraterrestrial
intelligence.

But there IS a way to confirm it, which was the mission of Kepler and will
be the mission of the Webb telescope.

Yes, the universe is older than the Earth, but since civilization developed
only recently on Earth, it in no way follows that it must have developed
earlier elsewhere.

"Must" implies 100% probability. I prefer a strong "may" :-)

At only 0.1% the speed of light, generation ships could cross the
entire galaxy in a mere 0.1 billion years.

There is no evidence that this has happened.

Perhaps WE are the evidence :-)