Observations and the

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Observations and the Fermi Paradox We now
turn to the top down approach and explore what
we know as a result of looking directly for
extraterrestrial life and/or civilization. The
short description is that there is no Direct
evidence of any kind of extraterrestrial life,
civilized or not. However, people have been
looking and we will consider three aspects of
this UFO reports SETI searches NASA probes
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UFO reports Though they are frequently reported
in the media, no reports of unidentified flying
objects are regarded as evidence of
extraterrestrial life by scientists. To
understand why not, we digress to briefly discuss
the nature of scientific inquiry. (This
discussion follows the ideas of Popper
approximately). We may divide the practise of
science into two parts The determination of
scientific facts (experiment) The formulation
and testing of theories , also called
hypotheses (theory)
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Determination of scientific facts
(experiment) Observations are regarded as facts
when they are publicly and transparently
reported and when they are REPEATABLE by
others. Observations which are not reported in
a way which allows them to be repeated or
observations which are not confirmed by
repetition are not regarded as scientifically esta
blished facts.
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Theories (hypotheses) Theories and hypotheses
make predictions about future observations and
experiments. Scientific theories are required to
be FALSIFIABLE. That is, it must be
possible for the predictions not to be confirmed
by the experiment, thereby falsifying
thet theory. Falsifiable theories which have not
been falsified are the best knowledge we have
for use in scientific prediction. They are
always subject to test and hence are always
tentative. CAUTION Falsifiable is NOT THE SAME
as false.
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A few examples Repeatable experiment The
discovery of high temperature
superconductivity (1984). Not predicted and
still not fully explained but
repeatable. Unrepeatable experiment The
claimed discovery of cold fusion (about
1986). Widely ballyhooed but not repeatable.
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Examples of falsifiable theories
Falsified Newtons theory of gravity.
All predictions were successful for nearly
300 years but some predictions, including
details concerning the orbit of Mercury,
were falsified in the twentieth century.
The theory has been supplanted by the
still unfalsified general theory of
relativity, which agrees with Newtonian
theory under most circumstances. Unfalsified
Quantum electrodynamics, which reduces to
Maxwells earlier theory under many
circumstances and has made many
successful predictions. Many physicists
expect it to be eventually supplanted because
of some peculiar features.
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• In these cases, the theory made
• numerical predictions and the experiments
• either gave the predicted number or they
• did not. In fact, some judgment and knowledge
• of experimental details will be required to
  decide
• if a given experiment came close enough
• More qualitative theories can also be described
• in the same framework. Let A be extraterrestrial
• life. Consider the two hypotheses
• A exists
• A does not exist.
• Which one is most readily falsifiable?

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• Any observation of A will falsify 2.
• Is much harder to falsify
• Therefore 2 is the better hypothesis.
• For A extraterrestrial life or intelligence,
• one can regard the efforts of SETI and
• NASA on this question as testing hypothesis
• 2.

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Returning to UFO reports. There are thousands of
reports of unidentified flying objects. The
vast majority of these are quite easily explained
in terms of optical effects, fraud,
psychological disorders, etc. There is a residue
of reports which are unexplained and/or
uninvestigated some of which involve physical
effects on the ground, apparent damage to
witnesses, radar anomalies and vehicle
malfunctions. None of these observations has
proved to be repeatable and in the vast majority
of cases, quantitative measurements are lacking.
By the criteria discussed, this information does
not establish any facts in the scientific sense
described above.
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Thus there are no scientific facts in the UFO
data which might be used to formulate a
hypothesis. In view of this situation, the
most scientifically appropriate hypothesis is
that the events are not evidence of
extraterrestrial life or civillization.
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Conspiracy theories There is a school of
thought that contends that the government
is hiding evidence that UFOs are caused by
extraterrestrials. Is this idea a falsifiable
hypothesis?
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Guessing the thinking patterns of ET The
contemplation hypothesis ET civilizations are
not interested in exploring or communicating
with other biospheres and thats why we dont
see them. The zoo hypothesis Advanced ETs
leave us alone because we are being nurtured as
a developing biosphere. Are these hypotheses
falsifiable?