Sky & Telescope - May 2020 - 84

FOCAL POINT by C. Frank Ridolfo

A Night of Déjà Vu
A curious sensation while observing the Great Cluster in
Hercules triggers back-to-back familiar memories.
SOMETIMES A NIGHT OF casual

While enjoying this spectacle, I
suddenly realized that I'd seen these
"dancing lights" before, sans telescope.
But where?
It then came to me that I'd witnessed
a remarkably similar sight many years
ago while using a spinthariscope to
observe radioactive decay. This device
consists of a ﬂuorescent screen that
produces a momentary point of light
wherever an atomic particle impacts
its surface. Placed near a radioactive
source, it displays a signiﬁcant number
of continuous ﬂashes, each caused by
interaction with a single emitted alpha
particle. The resulting display is nearly
identical to the one M13 provided
through my telescope.
I'd no sooner made this connection between visual perceptions at the
atomic and astronomical levels when I
was struck by another moment of déjà
vu. I recalled that I'd seen the same

¢ FRANK RIDOLFO is a retired nuclear
engineer who lives in Bloomfield, Connecticut.

JEFF DAI / SCIENCE SOURCE

observing can lead to unexpected revelations.
Recently, while observing the
globular cluster M13 with my modest
telescope, I noticed an interesting phenomenon as I increased the magniﬁcation. Within the eyepiece, the cluster
became a lively assemblage of tiny ﬂashing lights. It was as if the lights from a
dozen Christmas trees blinked on and
off for my amusement.
The ﬂashing lights came from faint
stars within the cluster that shone at
the very boundary of my perception.
These stars appeared to continuously
jump in and out of view as my eye/
brain brieﬂy recognized them and then
lost them again to background "noise."
Such a dramatic visual show is well
known to deep-sky observers. In fact,
Sue French often noted this effect in
her "Deep-Sky Wonders" column.

"dancing lights" at yet another level of
human perception.
I live near a wetland dominated by
a large open ﬁeld. During summer evenings this ﬁeld comes alive with ﬂashing lights, each generated by a solitary
ﬁreﬂy seeking a mate. Some summers,
conditions are just right for the ﬁreﬂy
population to explode. At such times,
thousands of "dancing lights" are visible
at any given moment.
The display is so mesmerizing that
I've often spent hours watching this
natural light show. It's as if I'm observing a boundless multiverse, with endless
numbers of local universes magically
popping into existence from some
cosmic Neverland, each announcing its
arrival via a mini "Big Bang."
My overactive imagination aside,
I'm amazed that unrelated phenomena,
occurring in three different domains of
existence - atomic, macro, and astronomical - can appear so similar to an
anonymous observer.
Is the universe trying to tell us something?

M AY 2 0 2 0 * S K Y & T E L E S C O P E

Sky & Telescope - May 2020

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