Sky & Telescope - May 2024 - 7

something rather than being expelled?
Perhaps a universe-size black hole is
beyond visual acquisition?
Walter Prendergast
Reno, Nevada
"
Monica Young replies: You pose
an interesting suggestion, that there
exists some external " attractor " that is accelerating
galaxies away from Earth. The
problem with this scenario is that we can
look in any direction and see the galaxies
speeding away from us. So an external attractor
would need to exist in every direction
at once to explain our observations.
Another, perhaps debatable objection to
your suggestion is that such a hypothesis
isn't testable. Therefore, it's more of a philosophical
hypothesis than a scientific one,
but those can be fun to contemplate, too!
Recreating the Antikythera
Mechanism
I read " A Clockwork Cosmos " by Tony
Flanders (S&T: Nov. 2023, p. 22) with
interest. There is an amazing YouTube
series about building a working reproduction
of the Antikythera mechanism,
https://is.gd/AntikytheraMechanism. A
master craftsman by the name of Chris
Ramsay builds the mechanism, with
side videos on how the ancients might
have made the tools to do so. He shows
how they might have made files (https://
is.gd/handcutfiles) and goes on to show
how the gear teeth could be filed by
hand. The craftsmanship is superb and
the video production excellent.
Bruce Hope
Toronto, Ontario
Deep-Sky TV
As an aging observer, I have started using
a video camera attached to my 12-inch
Meade LX200 ACF telescope to watch
the sky through a 20-inch monitor.
What I enjoy most is the lack of eyepiece
gymnastics: no more eyepieces jabbed
in my eye and no more guessing if I am
actually seeing something.
I view from the San Francisco Bay
Area, and what I can actually see on my
screen is amazing. When I lock onto the
double star Polaris, I can see both stars
easily on my screen. Compared to what
one would see in an eyepiece, I was sold.
After all, the aim of all our efforts is to
see what is out there. If one can do it
comfortably, I think one would actually
see more. The screen makes all my
efforts worthwhile. And, as an added
plus, this setup was made for city skies.
As my old bones start to groan, I can
still view the heavens and ponder the
universe as I sip my hot cocoa while
sitting in an easy chair, warm and
comfortable.
C. J. Fox
Antioch, California
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75, 50 & 25 YEARS AGO by Roger W. Sinnott
The name WAC Corporal, for
1949
1974
1999
º May 1949
New Highs " The scientific world
may well be pleased with Army Ordnance
for recently sending a missile
over 240 miles up into the earth's
atmosphere, where it could obtain
data of great value. The highest
altitude previously reached by a V-2
launched from White Sands was 114
miles. The new record was made
by a two-stage rocket. In place of
the usual warhead of the V-2 was
installed the American-developed
rocket, the WAC Corporal. After the
V-2 had acquired a high velocity,
the WAC was fired. The velocity of
the V-2 boosted the speed the WAC
could achieve independently to a
maximum of nearly a mile and a half
a second. . . .
" This is still far from . . . escaping
from the gravitational hold of the
earth . . . However, had this missile
been launched from the moon it
might have gotten away, for the
moon's velocity of escape is only
about 1½ miles a second. "
America's first sounding rocket, is
still of disputed origin.
º May 1974
Celestial Visionary " Fritz Zwicky
was one of the last of the scientific
individualists, a breed that is
dying out in an age of teamwork.
Aggressively original, outspoken to
the point of abrasion, he seemed
to his contemporaries stubbornly
opinionated. His ideas were so fertile
and his projects so vast that he
could have employed all the facilities
of a great observatory. Looking
back on his rugged determination
and his slightly Renaissance flavor,
one is reminded of Tycho Brahe:
brilliant, opinionated, combative, a
superb observer, and a very human
person. For Zwicky was one of
the kindest of men, with a deep
concern for humanity. To those
who knew him only in the scientific
arena, it may come as a surprise to
learn that he was a former chairman
of the board of trustees of the
Pestalozzi Foundation, devoted to
the support of orphanages. "
It took an astronomer of Cecilia
Payne-Gaposchkin's caliber to
weigh in on the passing of Fritz
Zwicky, discoverer of dark matter.
º May 1999
Cosmic Anchor " Ever on the
prowl for interesting 'what if'
scenarios, planetary dynamicists
have recently come to appreciate
the role Earth plays in stabilizing
the inner solar system.
This new insight came to light
almost by accident when Kimmo
Innanen (York University, Canada)
and Seppo Mikkola (University
of Turku, Finland) were testing
computer routines that perform
long-term simulations of planetary
motions. They found that removing
the Earth-Moon system from their
calculations caused the orbits of
Venus and especially Mercury to
gyrate wildly in eccentricity, with
the likely outcome being Mercury's
ejection by Venus from the
inner-planet region or an outright
collision between the two. "
sk yand tele scope .o r g * MAY 2024
7

https://www.is.gd/AntikytheraMechanism https://is.gd/handcutfiles https://is.gd/handcutfiles http://skyandtelescoper.org

Sky & Telescope - May 2024

Table of Contents for the Digital Edition of Sky & Telescope - May 2024