THE SOUTHWORTH PLANETARIUM
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70 Falmouth Street Portland, Maine 04103
43.6667° N 70.2667° W
Altitude: 10 feet below sea level
Founded January 1970
Julian Date: 245884.16
2019-2020: XCIX
"“Genius is an exceedingly common human quality, probably
natural to most of us.”
-John Taylor Gatto
THE DAILY ASTRONOMER
Wednesday, February 5, 2020
On the Golden Record
A great friend of mine from the SMA (Southern Maine Astronomers) contacted
me the other day in reference to the Voyager's Billion Year Voyaging
article. He wrote the following:
"I was re-reading this article and reminded myself about the travels and
the "Info-in-a-bottle". The directions on the space-ships, V1 and V2, will
be of little use to anyone who may chance grabbing it. The Milky Way is
rotating and everything in it is rotating. In 40,000 years, those
directions will be useless, for references, (in my opinion...but I could be
wrong), and Earth would forever remain "lost". Just a thought."
Dear Great Friend of Mine from the SMA,
First, let's look at the Golden Record that is current careening through
space aboard the Voyager probe:
[image: record-diagram.jpg]
Contained therein (or, in this case, thereon) is as much information as
they could possibly inscribe on its surface. The crafters of these
messages faced the daunting challenge of trying to communicate information
to a race of beings that wouldn't have any knowledge of any of our
languages. (Aliens only speak the Queen's English in Star Trek movies.)
Even to us, these symbols seem quite perplexing. They offer
instructions about how to play the record, a notion that even confounds
most millennials, let alone extra terrestrials. At the lower left corner
one will find a pulsar map, the "directions" to finding us.
The theory is that an alien race will capture the probe at some point,
perhaps in tens of thousands, millions or possibly billions of years in
the future. Provided it doesn't crash into anything, the Voyager probe
will continue moving inexorably through the galaxy indefinitely. If they
do find it, they could learn of the probe' origin by examining this "map,"
which indicates the locations of proximate pulars to our solar system.
Pulsars are rapidly spinning neutron stars produced by the supernova
explosions of some highly massive stars. Each pulsar is distinctive by
is spin rate: no two pulsars rotate at exactly the same speed. Therefore,
each spin rate serves to identify a particular pulsar.
Think of it this way: Let's say we wanted to help people find the
Southworth Planetarium. They would need a lot of help. Portland is so
proud of this institution it is buried seven leagues underground.
Instead of using an address, we list our distances from various known
points. 10,129.34 miles from the Sydney Opera House; 279.8 miles from the
Statue of Liberty; et cetera. By specifying enough locations, we can
truly pinpoint our location. (We might be well advised to use closer
points of interest, however.) Of course, tectonic shrugs apart, these
locations are not moving relative to each other. The pulsars and our
solar system are moving constantly at different speeds. Consequently, the
configuration of pulsars relative to the Sun and Earth will change slowly
over time.
Another issue is how to communicate the timing. Not only will other
beings not be conversant in English, they'll have no knowledge of seconds,
minutes or hours: time units we devised based originally- on Earth's
rotation. It is possible they will know about the transition periods
of atoms, particularly that of hydrogen. Each pulsar's rotation speed
is measured in units of 0.7 billionths of a second, the time period
associated with the fundamental transition of the hydrogen atom. This
atom has also been etched on the record to give the aliens who will
eventually decipher the symbols a time reference.
So, My Great Friend from the SMA, we have provided a way for other beings
to find Earth. The more time that elapses, the less likely it will be
that they'll find us. The pulsars will move on, their rotation rate will
slow down and, if too much time passses, the galactic motions will shift us
far away from these pulsars to much the map will be rendered useless. It
was the best of all possible maps to offer to beings who don't know our
language or location. However, Earth will never be lost....not
entirely....somebody somewhere at some time will find us. Whether this
discovery will be to our benefit remains to be seen.
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