Re: Expedition to Europa

On 7/1/2024 8:43 AM, Martin Brown wrote:

On 29/06/2024 18:11, Don Y wrote:

On 6/29/2024 8:35 AM, Joe Gwinn wrote:

On Sat, 29 Jun 2024 04:04:11 -0700, Don Y
<blockedofcourse@foo.invalid> wrote:
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On 6/28/2024 10:08 PM, bitrex wrote:

On 6/27/2024 5:17 PM, Don Y wrote:
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Most big librarys carry AW.
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.<https://europa.nasa.gov/mission/about/>
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If it turns out that there is life in the ocean of Europa, which has
existed for something like four billion years, it supports the general
idea of "random but inevitable" theories of Abiogenesis.

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_Remembrance of Earth's Past_ has an interesting take on the whole
notion behind an "empty" universe.  It's a tedious read (mainly for
me coming from a non-chinese culture... just keeping track of the
characters is difficult) but has some good ideas to chew on at its core.

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My guess: The Universe is mammoth, the technological and energy requirements of
even short-distance interstellar travel are immense, the lifespan of
technological civilizations is highly time-limited before such a civilization
destroys itself, technological civilizations are very rare to begin with, and
no technological civilization ever survives long enough to attempt it.

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That wouldn't explain why there are no *signs* of intelligent life.
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*We* can't (yet) travel interstellar distances in single lifetimes
but I'm sure anyone with technology comparable to ours would be able to
*detect* our presence (given that we seem to make no attempt at "hiding")
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_If the Universe Is Teeming with Aliens ... WHERE IS EVERYBODY?_ gives some
interesting takes on the Fermi paradox.

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That's a bit self-important.
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If the universe is teaming with life, but alien civilizations capable
of interstellar travel are exceedingly rare, there would be little
reason for those spacefaring aliens to visit any but the other
advanced alien civilizations.
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We might get the equivalent of an anthropologist ever few million
year, and they would do whatever needed to prevent detection by that
which they study.

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Why does an alien race have to VISIT in order to EXIST?
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*We* can't visit anything beyond lunar orbit (perhaps Mars, soon)
yet we expend considerable effort "looking".
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What techniques have our deep space probes used /to prevent detection/?

 Being small insignificant and with feeble radio transmitters. The only reason we are still in contact with the most remote ones is that ground based low noise amplifiers have improved enormously since their launch.

Wouldn't you expect other civilizations to also understand the issues
involved, if they were interested in searching?  We spot bits of
space debris, comets, etc. and they aren't trying to signal their
presence...

When it was operating and doing radar range imaging the EPR of the Arecibo dish was phenomenal along the direction it was pointing. Anyone in the beam would see a very distinctive flash potentially with obviously digital patterns in it if they were lucky.

But they don't have to see a pattern; just an unexpected "event" that
attracts their attention.  There's a wide field to examine so it seems
they would focus their attentions on anything "unexpected" rather than
systematically trying to canvas the entire space.
Assuming "others" have the same technological limits (or abilities!)
as we do is naive.
And, assuming they abandon older technologies to concentrate on
newer ones also seems specious; if lost while hiking, I can signal
with a whistle or a mirror -- I don't have to rely on a cell phone to
get help!

There have been the odd WOW signal detected on Earth but nothing that stood up to detailed analysis or was reproducible. The pulsar trace was originally marked LGM in the margins since it's very precise repetitive signal looked artificial at first glance.