- Munroe, Randall.
What If?
New York: Houghton Mifflin, 2014.
ISBN 978-0-544-27299-6.
-
As a child, the author would constantly ask his parents odd
questions. They indulged and encouraged him, setting him on
a lifetime path of curiosity, using the mathematics and physics
he learned in the course of obtaining a degree in physics
and working in robotics at NASA to answer whatever popped into
his head. After creating the tremendously successful Web comic
xkcd.com, readers began to ask him
the kinds of questions he'd mused about himself. He began a
feature on xkcd.com: “What
If?” to explore answers to these questions. This book is
a collection of these questions, some previously published on-line
(where you can continue to read them at the previous link), and
some only published here. The answers to questions are interspersed
with “Weird (and Worrying) Questions from the What If? Inbox”,
some of which are reminiscent of my own
Titanium
Cranium mailbox. The book abounds with the author's
delightful illustrations. Here is a sample of the questions
dealt with. I've linked the first to the online article to give
you a taste of what's in store for you in the book.
- Is it possible to build a
jetpack using downward firing machine guns?
- What would happen if you tried to hit a baseball pitched at
90% the speed of light?
- In the movie 300 they shoot arrows up into the
sky and they seemingly blot out the sun. Is this possible, and
how many arrows would it take?
- How high can a human throw something?
- If every person on Earth aimed a laser pointer at the Moon at
the same time, would it change color?
- How much Force power can Yoda output?
- How fast can you hit a speed bump while driving and live?
Main belt asteroid
4942 Munroe
is named after the author.
While the hardcover edition is expensive for material most of which
can be read on the Web for free, the
Kindle edition is free to
Kindle Unlimited
subscribers.
- Outzen, James D., ed.
The
Dorian Files Revealed.
Chantilly, VA: Center for the Study of National Reconnaissance, 2015.
ISBN 978-1-937219-18-5.
-
We often think of the 1960s as a “can do” time, when
technological progress, societal self-confidence, and burgeoning
economic growth allowed attempting and achieving great things: from
landing on the Moon, global communications by satellite, and mass
continental and intercontinental transportation by air. But the
1960s were also a time, not just of conflict and the dissolution of
the postwar consensus, but also of some grand-scale technological
boondoggles and disasters. There was the
XB-70 bomber and its companion
F-108 fighter plane,
the
Boeing 2707
supersonic passenger airplane,
the NERVA nuclear rocket,
the TFX/F-111
swing-wing hangar queen aircraft, and plans for military manned space
programs. Each consumed billions of taxpayer dollars with little or
nothing to show for the expenditure of money and effort lavished upon
them. The present volume, consisting of previously secret information
declassified in July 2015, chronicles the history of the
Manned
Orbiting Laboratory, the U.S. Air Force's second attempt to launch its
own astronauts into space to do military tasks there.
The creation of NASA in 1958 took the wind out of the sails of the U.S.
military services, who had assumed it would be they who would lead
on the road into space and in exploiting space-based assets in the
interest of national security. The designation of NASA as a civilian
aerospace agency did not preclude military efforts in space, and the
Air Force continued with its
X-20 Dyna-Soar,
a spaceplane intended to be launched on a
Titan
rocket which would
return to Earth and land on a conventional runway. Simultaneous with
the cancellation of Dyna-Soar in December 1963, a new military space
program, the Manned Orbiting Laboratory (MOL) was announced.
MOL would use a modified version of NASA's
Gemini spacecraft to carry
two military astronauts into orbit atop a laboratory facility which they
could occupy for up to 60 days before returning to Earth in the Gemini
capsule. The Gemini and laboratory would be launched by a Titan III
booster, requiring only a single launch and no orbital rendezvous or
docking to accomplish the mission. The purpose of the program was
stated as to “evaluate the utility of manned space flight for
military purposes”. This was a cover story or, if you like, a
bald-faced lie.
In fact, MOL was a manned spy satellite, intended to produce reconnaissance
imagery of targets in the Soviet Union, China, and the communist bloc in
the visual, infrared, and radar bands, plus electronic information in
much higher resolution than contemporary unmanned spy satellites.
Spy satellites operating in the visual spectrum lost on the order of
half their images to cloud cover. With a man on board, exposures would
be taken only when skies were clear, and images could be compensated
for motion of the spacecraft, largely eliminating motion blur. Further,
the pilots could scan for “interesting” targets and
photograph them as they appeared, and conduct wide-area ocean
surveillance.
None of the contemporary drawings showed the internal structure of
the MOL, and most people assumed it was a large pressurised structure
for various experiments. In fact, most of it was an enormous telescope
aimed at the ground, with a 72 inch (1.83 metre) mirror and secondary
optics capable of very high resolution photography of targets on the ground. When
this document was declassified in 2015, all references to its resolution
capability were replaced with statements such as {better than 1 foot}.
It is, in fact, a simple
geometrical optics
calculation to determine that the
diffraction-limited
resolution of a 1.83 metre mirror in the visual
band is around 0.066 arc seconds. In a low orbit suited to imaging in
detail, this would yield a resolution of around 4 cm (1.6 inches) as
a theoretical maximum. Taking optical imperfections, atmospheric
seeing, film resolution, and imperfect motion compensation into account,
the actual delivered resolution would be about half this (8 cm, 3.2 inches).
Once they state the aperture of the primary mirror, this is easy to
work out, so they wasted a lot of black redaction ink in this document.
And then, on page 102, they note (not redacted), “During times
of crisis the MOL could be transferred from its nominal 80-mile orbit
to one of approximately 200–300 miles. In this higher orbit the system
would have access to all targets in the Soviet Bloc approximately once
every three days and be able to take photographs at resolutions of
about one foot.” All right, if they have one foot (12 inch)
resolution at 200 miles, then they have 4.8 inch (12 cm) resolution at
80 miles (or, if we take 250 miles altitude, 3.8 inches [9.7 cm]),
entirely consistent with my calculation from mirror aperture.
This document is a management, financial, and political history of
the MOL program, with relatively little engineering detail. Many
of the technological developments of the optical system were later
used in unmanned reconnaissance satellite programs and remain secret.
What comes across in the sorry history of this program, which,
between December 1963 and its cancellation in June of 1969 burned
through billions of taxpayer dollars, is that the budgeting,
project management, and definition and pursuit of well-defined project
goals was just as incompetent as the redaction of technical details
discussed in the previous paragraph. There are almost Marx brothers
episodes where Florida politicians attempted to keep jobs in their
constituencies by blocking launches into polar orbit from Vandenberg
Air Force Base while the Air Force could not disclose that polar
orbits were essential to overflying targets in the Soviet Union because
the reconnaissance mission of MOL was a black program.
Along with this history, a
large collection of documents
and pictures,
all previously secret (and many soporifically boring) has been released.
As a publication of the U.S. government, this work is in the public
domain.