"echo" <echo@otc.cab> wrote in message 
news:11b8kl75e02k977@corp.supernews.com...

  I don't think anyone could understand aliens' technology if they were
more than 100 or 200 years 'ahead' of us. Could a guy living in 1805
understand the sientific theory and technology of today?

Probably.
Isaac Newton understood a lot of scientific principles and died in 1727.
I suppose it would depend on whether they had any scientific background or 
not.
Please don't make the mistake that people living in 1805 were less 
intelligent than we are.
They were just as equally intelligent then as we are now, as were the 
Ancient Egyptians, and were capable of understanding many scientific 
principles.
The only differences related to technology, not intelligence.
In fact, if you plucked a primitive child from , say, 50,000 years ago, and 
placed him in a modern environment, it could grow up to be indistinguishable 
from any modern human being, and as far as intelligence is concerned, it 
could become a doctor, physicist or anything.

What if some aliens
are a billion years ahead of us?

Unlikely.
If the universe has been around for about 14 billion years, give or take a 
billion or two, and it took intelligent life on this planet around 14 
billion years to get where it is today, it's unlikely that there are any 
aliens billions of years ahead of us.
Not enough time.

Most likely all our scientific concepts
would be obsolete; so might the very ideas of science and theory. The 
aliens
would probably be completely incomprehensible to us. Maybe some are.

Some people on this newsgroup are incomrehensible to me, but they're not 
aliens, so you could be right