Here's why:

* Erratic boulders are a common geological feature: They are large rocks transported by glaciers and deposited far from their original source. This is a well-understood process within glacial geology.

* Glaciers are powerful forces: Glaciers can move massive amounts of rock and sediment over long distances, explaining the presence of erratics in seemingly unlikely locations.

* Flood geology lacks scientific support: The idea of a global flood that deposited erratic boulders is not supported by scientific evidence. There is no geological evidence for a global flood of the scale described in the biblical story.

Here's how a single erratic boulder can be interpreted in a scientific context:

* Glacial history: The boulder is a testament to past glacial activity in the area, indicating the presence of a glacier at some point in history.

* Glacial transport: The boulder's composition and origin can be studied to understand where it originated and the path the glacier took.

* Geological timeline: By analyzing the boulder and other geological features in the area, scientists can build a timeline of past glacial events.

In conclusion, an erratic boulder is a fascinating geological feature that tells us about the power of glaciers and the history of the Earth's climate. It does not provide evidence for a global flood, which is not supported by scientific evidence.