Categories: Space | Tech | Sci
I spent twelve years standing on a museum floor, explaining the Apollo Guidance Computer to school groups who were more interested in the vending machine. One thing you learn quickly: people love the *myth* of science, but they despise the *constraints* of science. When I see people conflating astronomy with astrology, I don't just see a hobby; I see a total breakdown of the logic that keeps our satellites in orbit and our astronauts from suffocating in deep space.
In 1975, the scientific community reached a breaking point. They published a statement in The Humanist titled Objections to Astrology. It wasn’t a manifesto; it was a cry for help. If you want to understand the history of skepticism—the kind that isn't just "being a contrarian" but actually requires an understanding of thermodynamics and mission architecture—you need to read the primary source documents. But before we get to the reading list, we have to talk about why these arguments happen in the first place.
The Propulsion Problem: Or, Why "Game-Changing" is a Dangerous Word
Whenever I see a pitch for a "game-changing" new Mars propulsion system, I cringe. There is no such thing as a "game-changing" engine in physics; there is only a trade-off between mass, time, and complexity. If someone tells you a new thruster will revolutionize space travel, check their math. Are they ignoring the radiator mass? Are they ignoring the shielding? They usually are.
Let’s pause for a second. I know this gets technical, so let’s define Specific Impulse (Isp). Think of Isp as the "miles per gallon" of a rocket. It measures how much thrust you get out of a specific amount of propellant. A high Isp means you are very efficient, but it rarely means you are fast. You can have an engine that is incredibly efficient, but if the thrust is so low that it takes you three years to leave Earth’s gravity well, you’ve just committed your crew to a massive radiation dose. That is a waste of human life.
This is exactly the type of intellectual laziness that the 1975 letter authors were fighting against. They weren't just debating the stars; they were debating the standards of evidence. Whether you are building a nuclear thermal rocket or using chemical combustion, you are bound by the same boring, non-negotiable laws of physics.
Comparison of Propulsion Architectures
Propulsion Type Pro: Efficiency Con: Mass/Complexity Verdict Chemical Low (The "brute force" method) Low (Mature, predictable) Good for launches, bad for deep space. Nuclear Thermal Medium-High High (Heavy shielding/reactors) Fastest, but high risk/cost. Electric (Ion) Extremely High Extreme (Requires massive power) Good for cargo, bad for humans.Apollo Architecture: Why We Argue About Docking
I once had an engineer scream at me in the museum archives because I suggested the Lunar Orbit Rendezvous (LOR) was just as much about saving mass as it was about mission safety. He wanted to talk about the "boldness" of Apollo. I wanted to talk about the mass of the fuel tanks.
The 1975 Objections to Astrology text mirrors this exact conflict. One side (the scientists) is looking at the mass of the evidence; the other side (the astrologers) is looking for a narrative that feels good. You can’t build a rocket out of narrative, and you certainly can’t navigate the solar system with a horoscope. Apollo succeeded precisely because engineers stopped trying to make the mission look "cool" and started making it survive the constraints of gravity.
When you read the history of the 1975 letter, keep this in mind: the signatories—including 18 Nobel Prize winners—were trying to establish a baseline of reality. It’s the spacecraft docking waste same baseline an engineer uses when they decide to dock a command module rather than landing the whole stack on the moon. It’s not about ego; it’s about math.
Where to Start Your Reading
If you want to understand why these people were so annoyed in 1975, you need to read these documents in this order. Do not skip the boring introductions; that’s where the methodology is hidden.
"Objections to Astrology: A Statement by 186 Leading Scientists" (Published in The Humanist, 1975). This is the foundation. It focuses on the lack of empirical evidence and the psychological crutch that astrology provides. "The History of Skepticism" by Richard Popkin. You need to understand that this didn't start in 1975. This is an age-old battle between people who want the universe to care about them, and people who know the universe is indifferent. "Apollo: The Race to the Moon" (Murray & Cox). Read this to understand what real problem-solving looks like. Notice how many "big ideas" were discarded because they wasted too much mass or created too much complexity.The Cost of Vague Thinking
The reason I get so annoyed when astrology is treated as a form of astronomy is that it treats our curiosity as a free resource. It isn’t. Every hour you spend calculating your sun sign is an hour you aren’t learning about the actual physics of transit. Every time a mission concept ignores the "boring" constraints—like the radiation belts, or the delta-v requirements for a Mars injection, or the sheer mass of the thermal protection system—we lose time, money, and potentially lives.
The 1975 letter wasn't about suppressing freedom of thought; it was about protecting the integrity of the data. We live in a world where technology is advanced enough that we can land a car-sized robot on Mars, but we still have people who won't read a thermometer because they prefer a mystic’s interpretation of their birth chart.
Stop looking for "game-changing" narratives. Start looking for the boring, heavy, complex math that actually makes things happen. Read the 1975 letter, but don't just read it to be right. Read it to understand the cost of ignoring reality.
Recommended Reading Paths
- For those interested in the philosophy of science: Check our Science category for critiques of pseudoscience. For those interested in the hard engineering constraints: Browse our Space history archives for breakdowns on mission architecture. For those wanting to understand modern tech skepticism: Visit our Technology blog.
And for heaven's sake, if you're writing a mission proposal, stop using the phrase "game-changing." Tell me how much your heat shield weighs, or how you’re handling the specific impulse degradation over time. I’m waiting.
