Logical Reasoning

PT135 · S4 · Q7 The ruins of the prehistoric Bolivian

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The ruins of the prehistoric Bolivian city of Tiwanaku feature green andacite stones weighing up to 40 tons.

Hypothesis

These huge 40 ton stones were transported from Copacabana to Tiwanaku, 90 km away and across a lake, on reed boats.

Evidence

We transported some 9-ton stones from C to T using a reed boat built with locally available materials and techniques traditional to the area.

Evaluate

Since we're dealing with the word 'hypothesis', we can use our Curious Fact / Explanation mindset.

CURIOUS FACT - how did these prehistoric people get 40 ton stones from C to T?! AUTHOR'S EXPLANATION - they used reed boats

There are two different ways to affect this sort of argument: - Alternate Explanations for the curious fact. - the Plausibility of the Author's Explanation

What could be a different way that they got the 40 ton stones that far? Maybe the stones float? Maybe they broke them apart into smaller chunks and glued them back together?

How plausible is the hypothesis that they used reed boats? Well, I wouldn't usually think of reeds as being strong enough to hold 40 tons. We can see from the experiment that the reed boats the experimenters made can carry 9 ton stones, but that's only 20% as heavy. Could the reed boats really handle 40 tons?

In general, we have to wonder if the "proof of concept" voyage that the experimenters took with their 9 ton stones was relevantly similar to the reed boat voyage that the prehistoric people would have taken. If there are significant differences about terrain / weather / locally available materials, that might break down the comparability of the analogy.

Goal

Look for an answer that could be answered in a way that would sound like an Alternate Explanation for how the prehistoric people moved 40 ton stones 90km from C to T, or for an answer that could be answered in a way that would damage the plausibility of the Author's Explanation.

Which one of the following would be most useful to know in order to evaluate the support for the archaeologists' hypothesis?

Correct
whether the traditional techniques for
Why this is right
If the traditional techniques the experimenters used to build their reed boats weren't in use at the time Tiwanaku would have been building their reed boats, then the evidence the experimenters have offered is total garbage. They made a boat using techniques that didn't exist with the Tiwanaku and carried much lighter stones ... that does not show that it's possible the Tiwanaku carried 40 ton stones with their style of reed boats.
Skill tested: Evaluate · how this choice captures the argument's function is the move to repeat next time.
89% picked this
whether green andacite stones quarried
Irrelevant
Whether these big stones were also used near the quarry or not used near the quarry doesn't illuminate anything about whether the Tiwanaku were able to move 40 ton stones across a lake on reed boats.
6% picked this
whether reed boats are commonly
Irrelevant
Whether reed boats are commonly used today or rarely / never used today doesn't illuminate anything about whether the prehistoric Tiwanaku people were able to move 40 ton stones across a lake on reed boats.
1% picked this
whether the green andacite stones
Irrelevant
Whether the 40 ton stones were the largest stones or the 2nd largest or 3rd largest doesn't tell us anything about whether the prehistoric Tiwanaku people were able to move 40 ton stones across a lake on reed boats.
3% picked this
whether the reed boat built
Irrelevant
This is the most tempting trap answer, but whether the reed boats built by the experimenters are now usable for several years or whether they only last one year doesn't really affect the plausibility of the hypothesis. There was nothing in the prehistoric storyline that required that the reed boats the Tiwanaku built would last for several years, only that they were capable of a one-time move of 40 ton stones across a lake.
2% picked this

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