About Blue

Blue is the ocean wing of Truth Sleuth. Every question comes from real science, like NOAA, the Smithsonian, and marine research groups around the world, with a link to the source so you can go deeper. It works for curious minds of any age. The reasoning is what counts here, not how much you already know about sea creatures.

The thinking skills you practice

Claim Check

Pin down what a claim really says, and what it leaves out.

Cause or Coincidence?

Tell a real cause from two things that just happen together.

Observed or Inferred?

Separate what someone measured from what they concluded.

How Do We Know?

Ask how we know something, and how sure the evidence lets us be.

How Would You Test It?

Pick the experiment or measurement that would answer the question.

Magnitude

Judge whether a number makes sense at the scale involved.

Estimate It

Estimate an unknown number by reasoning from things you already know.

How scoring works

Each question is worth up to 3 points. Multiple-choice questions give 3 for a correct answer. Estimation questions score by how close you get: within 2× of the true value is a bullseye (3), within 10× earns 2, within 100× earns 1. Five questions make a daily dive, for up to 15 points.

Take today's dive

The thinking skills you practice

How scoring works

Where the facts come from