

British scientists claimed to have found first evidence of alien life  - nigekelly
http://www.irishtimes.com/news/world/uk/british-scientists-claim-to-find-first-evidence-of-alien-life-1.1533442

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danmaz74
"In the absence of a mechanism by which large particles like these can be
transported to the stratosphere, we can only conclude that the biological
entities originated from space" so, just because we don't KNOW of any
mechanism by which large particles could be transported to the stratosphere,
we conclude that the particles originated from space - even if we obviously
don't KNOW of any mechanism by which life could originate from space and fall
on Earth? This looks like very very weak reasoning.

~~~
bayesianhorse
The mechanism to get these particles there would both have to be very powerful
and very not obvious.

The scientists don't say that these particles must be from space, it's just
possible, or even very likely.

~~~
danmaz74
Possible, yes. Very likely... from your handle, you should know about Bayesan
reasoning. Considering that we know for sure that there is life on Earth
(p=1), while having free-floating life in outer space is a very remote
hypothesis (0<p<<1), what of the following three are more likely using
Bayesian inference?

a) the sample was contaminated, or there was some other error in the
experiement

b) those life forms originated from Earth

c) those life forms originated from outer space

~~~
bayesianhorse
Setting p=1 is sort of frowned upon in the bayesian methodology. Bayesian
inference has nothing to do with this discussion, because the results can only
be explained by speculation, and have not been externally verified etc.

Constructing priors from the knowledge of what has not been seen before seems
to me like an abuse of the methodology. You might as well say "It's impossible
because it's impossible."

I do tend towards a terrestrial origin, but it's certainly a good thing to
investigate further how these organisms got there, what are they doing and
what sequences do they have...

~~~
danmaz74
Actually, to me, this seems like a perfect situation to apply Bayesian
inference: we need to update the probability estimate of a hypothesis (there
is life in outer space) based on new evidence (they found those particles
through their experiment).

Anyway, I completely agree with your last sentence: It's certainly a good
thing to investigate, I'm not saying they're charlatans. It's the "very
likely" that I didn't agree with :)

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anigbrowl
Paper:
[http://journalofcosmology.com/JOC22/milton_diatom.pdf](http://journalofcosmology.com/JOC22/milton_diatom.pdf)

The journal of Cosmology is regarded as a low-quality publication by many
scientists. I can't judge the assertions in the paper but the methodology
seems good.

~~~
lolcraft
That is a well known crackpot article, already debunked by biologists and
astronomers alike:
[http://scienceblogs.com/pharyngula/2013/01/16/diatomsiiiiin-...](http://scienceblogs.com/pharyngula/2013/01/16/diatomsiiiiin-
spaaaaaaaaaaace/)

~~~
anigbrowl
Please read your link. That addresses deficiencies in a paper about a
meteorite. This paper is about samples collected from a weather balloon. And
while the criticisms in your link are well-founded, I feel sure you can find
equally well-founded criticisms without all the distracting ad-hominem
insults.

------
lutusp
> On its return they found organisms that were too large to have originated
> from Earth.

Too large? They had two choices -- too large and too small.

To be "too large", the organism would have had to be larger than an ostrich
egg yolk, the single-cell record-holder for size.

To be "too small", the cells would have to be very small indeed -- the
smallest earthly cells are extremely small.

In any case, if the cell has DNA, it's from here, so first run the test, find
the DNA, then don't publish this ridiculous claim.

"Extraordinary claims require extraordinary evidence." \-- Carl Sagan

------
alphaBetaGamma
If they have protein in their samples and find amino acids of both chirality,
then get exited. If they only find the chirality naturally occurring in earth
based life: forgetaboutit

My bet is on the latter.

~~~
bayesianhorse
If our aminoacids came from space, you would sort of expect them to be in
"incoming" organisms also.

Bioinformatics might be able to bring further light into this problem. If they
do find DNA/RNA then they can tell when terrestrial life and whatever this is
parted ways. If this root can be pinpointed after known mutations from fossil
records, then this must be terrestrial life.

------
_of
Until they do more rigorous analysis of this it is not convincing.

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strictfp
One possible mechanism would be a weather balloon.

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BoppreH
Published on the Journal of Cosmology:
[http://journalofcosmology.com/](http://journalofcosmology.com/)

Wikipedia lists no less than 6 references questioning the credibility of this
journal
([https://en.wikipedia.org/wiki/Journal_of_Cosmology#Reliabili...](https://en.wikipedia.org/wiki/Journal_of_Cosmology#Reliability)).

I think this discovery should be taken with a very large grain of salt.

------
nerfhammer
Meanwhile, a more reputable report against life on Mars:

[http://www.nytimes.com/2013/09/20/science/space/mars-
rover-c...](http://www.nytimes.com/2013/09/20/science/space/mars-rover-comes-
up-empty-in-search-for-methane.html?hp)

------
bayesianhorse
They should do sequencing and metagenomics on this alleged alien life.

Strands, sequences, twisting, separating, joining. Abathur would be pleased...

Honk if you played Heart of The Swarm...

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fleitz
Life is constantly surprising us, it's well known that there is bacteria on
the outside of the ISS, it could well be that life is falling down rather than
up.

I'd like to see a DNA sample that doesn't point to existing earth life, for me
just seeing diatoms seems a little too early to reach this conclusion.

~~~
mathattack
I was thinking the same thing. Of course if life is falling down to earth, it
may be hard to tell apart, but there should be some hints of life optimized
for earth versus optimized for elsewhere.

I find the bacteria on the ISS fascinating. Can you point me to a good
article?

~~~
Someone
I don't know specifically about the ISS, but I found
[http://en.wikipedia.org/wiki/Tardigrade](http://en.wikipedia.org/wiki/Tardigrade)
fascinating. Multicellular, and _" can withstand temperatures from just above
absolute zero to well above the boiling point of water, pressures about 6
times stronger than pressures found in the deepest ocean trenches, ionizing
radiation at doses hundreds of times higher than would kill a person, and the
vacuum of outer space. They can go without food or water for more than 10
years, drying out to the point where they are 3% or less water, only to
rehydrate, forage, and reproduce."_

It's "some of them will survive in outer space", though.

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luscious
I wonder what it smells like. Does it get happy or sad?

~~~
krapp
Will it think our brains taste better with mustard or ketchup?

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bencollier49
It's life, but it doesn't have DNA to test?

~~~
lutusp
If the cell has DNA, that's evidence that it came from the surface, not space.
There may be life out there, but it won't have DNA (an ad hoc solution to a
problem unlikely to be repeated).

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DanielBMarkham
Extraordinary claims require extraordinary proof, but still, this is good to
see.

I imagine this discussion in the scientific community will go on for many
years, perhaps decades. I'm still not convinced that Viking didn't find some
evidence of life on Mars back in the 70s.

