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.

82
To
experience
a
looming
mirage, the
observer's
eye
must
be
located in
the
atmos-
pheric
layer
wherein
the temperature anomalously
increases
with
.
height
(in-
version
layer),
and
the
miraged
target
in
the
object
-field
must
also
he
in
or
near
the
inversion
layer.
Inversion
layers
are
essentially
horizontally,
and
the
actually-
encountered
values
of the
inversion
lapse
rates
are
such
that
refraction
anoma-
lies
are
confined to
very
small
departures
from
the
horizontal,
as
noted
above
under
remarks on
mirages.
All
of
these
points
are
well
-understood
principles
of
meteorological
optics.
However,
Menzel
has
attempted
to
account
for
such
UFOs
as
Dr.
Clyde
Tombaugh saw
overhead
at
Las
Cruces
in
August
1949
in
terms
of
"inversion"
refraction
or
reflection
effects.
Since
I
have
discussed
the
quantita-
tive
unreasonableness of
this
contention
elsewhere,
I
will
not
here
elaborate
the
point,
except
to
say
that
if
inversions
were
capable
of producing the
optical
disturbances
that
Menzel
has
assumed,
astronomers
would
long
since
have
given
up any
attempt
to
study
the
stars
by
looking
at
them
through
our
atmosphere.
Other
atmospheric
-optical
anomalies
have
been
adduced
by
Menzel
in
his
UFO
discussions.
He
has
repeatedly
suggested that
layers
of
haze
or mist
cause
remarkable enlargement
of the
apparent
images
of
stars
and
planets.
By
enlarge-
ment, he
makes
very
clear
that
he
means
radial
enlargements
in
all
directions
such
that
the eye
sees
not
a
vertical
streak
of the
sort
well-known
to
astronomers
as
resulting
from
near
-horizon refraction
effects,
but
rather
a
circular
image
of
very
large
angular
size.
Menzel
even
describes
a
sighting
that
he
himself
made,
over
Arctic
regions
in
an
Air
Force
aircraft,
in
which
the
image
of
Sirius
was
enlarged
to
an
angular
size
of over
ten
minutes
of arc
(one-third
of
lunardiameter).
I
have
discussed
that
sighting
with
a
number
of astronomers,
and
not
one
is
aware
of
anything
that
has
ever been
seen
by any
astronomer
that approxi-
mates
such
an
instance.
In
fact,
it
would
require
such
a
peculiar
axially
-
symmetric
distribution
of
refractive
index,
which
miraculously followed the
speeding
aircraft
along
as
it
moved
through
the atmosphere,
that
it
seems
quite
hopeless
to
explain
what
Menzel has
reported seeing
in
terms
of
refraction
effects.
Since
Dr.
Menzel's writings
on
UFO's
have
evidently
had,
in
some
quarters,
a
marked
effect
on
attitudes
towards
UFOs,
I
regard that
effect
as
deleterious.
If
I
felt
that
we
were
dealing
here with
just
a
slight difference
of
opinion
about
rather
controversial
scientific
matters
on
the
edge
of
present
knowledge.
I
would
withhold strong
comment. However,
I
wish
to
say
for the
record,
that
I
regard
the majority
of
Dr.
Menzel's
purported
meteorological
-optical
UFO
explanations
as
simply
scientifically
incorrect.
I
could,
but
shall
not
here, enlarge
upon
similar
critique
of
official
explanations that
have
invoked such arguments.
3.
Atmospheric
electricity
One
phenomenon
in
the area of atmospheric
electricity
to
which
appeal
has
been
made
from
the
earliest
years of
investigations
of the
UFO
phenomena
is
that of
ball
lightning.
For
example,
a
fairly
extensive
discussion
of
ball
lightning
was
prepared
by
the U.S.
Weather Bureau
for
inclusion
in
the 1949
Project
Grudge
report
(Ref. 6).
It
was
concluded
in
that
report
that
ball
light-
ning
was
most
unlikely
as
an
explanation for
any
of the cases
which were
considered in
that report
(about
250).
Periodically, in
succeeding
years,
one
Or
another
writer
has
come up
with that
same
idea that
maybe
people
who
report
UFOs
are
really
seeing
ball lightning.
No
one
ever
tried
to
pursue
this
idea very
far,
until
P.
J.
Klass began
writing
on
it.
Although
his
ideas
have
received
some
attention
in
magazines,
there
is
little
enough
scientific
backup
to his contentions
that they are
quite unlikely to
have
the
same
measure
of
effect
that Menzel's previous writings
have
had.
For
that reason,
I
shall
nothere elaborate
on
my
strong
objections
to Klass'
arguments.
I
spelled
them
out
in considerable
detail in
a
talk
presented
last
March
at
a
UFO
Symposium
in
Montreal
held
by the
Canadian
Aeronautics
and Space
Institute.
Klass hag
ignored
most
of
what
is
known
about
ball lightning
and most
of
what
is
known
about plasmas and
also
most
of
what
is
known
about
interesting
UFOs
in
developing his curious
thesis.
It cannot be regarded
as a
scientifically
significant
contribution to illumination
of the
UFO
problem.
4.
Radar
propagation anomalies
In the past
twenty
years, there
have been
many
instances in
which
unidenti-fied
objects
have been tracked
on radar,
many
of
them with concurrent visual
observations.
Some
examples have been
cited
above. It
is
always necessary to
approach a radar
unidentified
with
full
knowledge of the numerous ways
in
which
false returns can be produced on radar
sets.
The
physics of "ducting"