Symposium on unidentified flying objects: hearings before the Committee on Science and Astronautics, U.S. House of Representatives, Ninetieth Congress, second session, July 29, 1968.

83
or
"trapping"
is
generally quite
well understood.
As
with
mirages,
the
allowed
angle
of
elevation
of the
radar
beam
can
only
depart
from
zero
by
a
few
tens
of minutes of
arc for
typically
occurring
inversions
and
humidity
gradients.
Ducting
with
beam
angles in excess
of
a
degree or
so woulld
require
unheard
of
atmospheric temperature
or
humidity
gradients.
Care
must
be
taken
in
inter-
preting
that statement,
since
beam
-angles
have
to
be
distinguished
from
angles
of
elevation
of
the
beam
axis.
For
the
latter
reason,
a
beam
-axis elevation
of,
say,
two
degrees
still
involves
emission
of
some
radar energy at
angles
so
low
that
some
may
be
trapped,
yielding
"ground
returns"
despite
the higher
eleva-
tion
of the
axis.
All
such
points
are
well
described in
an
extensive
literature
of
radar
propagation
physics.
In
addition to
trapping
and
ground
return
effects,
spurious returns
can
come
from
insects,
birds,
and
atmospheric
refractive
-index
anomalies
that generate
radar
echoes
termed
"angels".
These
are
low
-intensity
returns
that
no
experi-
enced
operator
would
be
likely
to
confuse
with
the
strong return
from
an
air-
craft
or other large
metallic
object.
Also,
other
peculiar
radar
effects
such as
interference
with
other
nearby
sets,
forward
scatter
from
weak
tropospheric
discontinuities
(see
work
of
Atlas
and
others),
and
odd
secondary
reflections
from
ground
targets
need
to
be
kept
in
mind.
When
one
analyzes
some
of
the
famous
radar
-tracking
cases
in
the
UFO
literature,
none
of
these
propagation
anomalies
seem
typical
as
accounting
for
the
more
interesting cases.
(Several
examples have
already
been
discussed,
(cases
32,35,36,
37,
38,
and
39).)
SUMMARY
AND
RECOMMENDATIONS
In
summary,
I
wish
to
emphasize
that
my
own
study
of
the
UFO
problem
has
convinced
me
that
we
must
rapidly
escalate
serious
scientific
attention tothis
extraordinarily intriguing puzzle.
I
believe
that the
scientific
community
has
been
seriously
misinformed
for
twenty
years
about
the
potential
importance
of
UFOs. I
do
not
wish
here
to
elaborate
on
my
own
interpretation
of
the
history
behind that long
period
ofmisinformation
I
only
wish
to
urge
the
Committee on
Science
and
Astronauticsto
take
whatever
steps
are
within
their
power
to
alter this situation
withoutfurther
delay.
The
present
Symposium
is
an
excellent
step in
the
latter direction.
I
strongly
urge your
Committee
that further
efforts
in
the
same
direction
be
made
in
the near
future.
I
believe
that
extensive
hearings
before
your Committee, as
well
as
before other Congressional
committees having
concern with
this
problem,
are
needed.
The
possibility
that the
Earth might
be
under
surveillance
by
some
high
civilization
in
command
of
a
technology
far beyond
ours
must
not
be overlookedin
weighing the
UFO
problem.
I
am
one
of
those
who
lean
strongly
towards
the
extraterrestrial
hypothesis.
I
arrived
at that
point
by
a
process of
elimination
of
other
alternative
hypotheses,
not
by
arguments
based
on
what
I
could
call
"irrefutable proof."
I
am
convinced that the recurrent observations
by
reliable
citizens
here
and
abroad
over the past
twenty
years
cannot be brushed
aside
as
nonsense,
but
rather
need
to
be taken extremely
seriously
as
evidence that
somephenomenon
is
going
on
which
we
simply
do
not understand. Although
there
is
no
current
basis
for
concluding that
hostility
and
grave hazard
lie
behind the
UFO
phenomenology,
we
cannot be
entirely
sure of
that.
For
all
of
these reasons,
greatly
expanded
scientific
and
public attention to
the
UFO
problem
is
urgently
needed.
The
proposal that
serious attention
be
given
to the
hypothesis
of
an
extrater-restrial
origin
of
UFOs
raises
many
intriguing questions,
only
a few
of which
can be
discussed meaningfully.
A
very standard
question of skepticism
is
"Why
no
contact?"
Here,
the best
answer
is
merely
a
cautionary
remark
that
one would
certainly
be
unjustified
in extrapolating
all
human
motives
and
reasons to
any
other
intelligent civilization.
It
is
conceivable that
an
avoidance of prematurecontact
would be one
of the
characteristic
features of
surveillance
of
a
less
ad-
vanced
civilization;
other conceivable rationales
can be
suggested. All
are specula-tive,
however; what
is urgently
needed
is
a
far
more
vigorous
scientific
investiga-
tion
of the
full
spectrum of
UFO
phenomena, and
the
House Committee
on
Science
and
Astronautics could perform
a
very
significant service
by taking
steps
aimed
in that direction.