Verification reference notes

Delayed reveal: Open these notes during Step 6 only after making your predictions, recording the AI responses, and attempting an independent source check.

These notes provide source locators, not a substitute for reading the sources. A page can change, a statement can be narrower than your claim, and an authoritative source can still leave uncertainty.

1. A day on Venus is longer than a year on Venus

Finding: Supported when “day” means one rotation relative to the stars. NASA lists a Venus rotation as 243 Earth days and its orbit around the Sun as 225 Earth days. NASA also distinguishes this from sunrise-to-sunset time, which is about 117 Earth days.

Inspect: NASA Science — Venus: Facts, under Orbit and Rotation.

Calibrated wording: Venus takes longer to rotate once relative to the stars than it takes to orbit the Sun once.

2. Octopuses have three hearts

Finding: Supported. Smithsonian Ocean explains that cephalopods have two branchial hearts that move oxygen-depleted blood through the gills and one systemic heart that moves oxygenated blood through the body.

Inspect: Smithsonian Ocean — Cephalopods: Octopus, Squid, Cuttlefish, and Nautilus, under Circulatory System.

Calibrated wording: Octopuses have three hearts: two branchial hearts and one systemic heart.

3. The Great Wall of China is visible from the Moon with the unaided eye

Finding: Disputed by NASA evidence. NASA describes this as a myth and states that the wall is not visible from the Moon. Even from low Earth orbit, it is generally difficult to distinguish without favorable conditions and imaging.

Inspect: NASA — Interesting Fact of the Month 2020, item 10, You can see the Great Wall of China from space.

Calibrated wording: The Great Wall is not visible to the unaided eye from the Moon; identifying it from low Earth orbit is also difficult and condition-dependent.

4. Lightning never strikes the same place twice

Finding: False. NOAA’s National Severe Storms Laboratory says lightning can hit the same or nearly the same spot more than once. Taller objects may be more likely to connect with a developing flash.

Inspect: NOAA National Severe Storms Laboratory — Lightning FAQ, under Can lightning strike the same place twice?

Calibrated wording: Lightning can strike the same or nearly the same place repeatedly.

5. Pure water boils at 100 °C

Finding: Context-dependent. The U.S. Geological Survey states that pure water boils at 100 °C at sea level, where pressure is one atmosphere. At Yellowstone’s higher elevation and lower air pressure, water boils at about 93 °C.

Inspect: U.S. Geological Survey — How hot are Yellowstone’s boiling waters?, beginning with the sea-level comparison.

Calibrated wording: Pure water boils at 100 °C at one atmosphere of pressure; the boiling point changes with pressure.

6. Mount Everest is the tallest mountain on Earth

Finding: Context-dependent because “tallest” needs a measurement. NOAA identifies Everest as the highest point above global mean sea level, Mauna Kea as the tallest from base to peak, and Chimborazo as the farthest summit from Earth’s center.

Inspect: NOAA Ocean Service — What is the highest point on Earth as measured from Earth’s center?, especially the three-measure comparison.

Calibrated wording: Everest has the highest summit above mean sea level; Mauna Kea is taller from base to peak; Chimborazo’s summit is farther from Earth’s center.

What this source set teaches

• A true statement can hide a definition, as with a Venus “day.”
• A familiar fact can be checked against a specific biological explanation.
• A repeated saying can be false.
• A numerical statement can depend on conditions.
• A superlative can change with the measurement.

The point is not to memorize six facts. It is to ask what the words mean, find an appropriate source, inspect the locator, and preserve whatever remains uncertain.

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Source: labs/reality-check-for-ai/materials/verification-reference-notes.md