Experimental science requires reproducible empirical evidence

Science studies the natural world.

Here logical proof alone is insufficient.

Scientists require observations and experiments.

Even more importantly,

other researchers should be able to obtain similar results.

That is reproducibility.

Example 1

A chemist claims:

This chemical kills bacteria.

Reviewer asks:

Show the experiment.

The scientist provides:

laboratory method

measurements

statistical analysis

Other laboratories repeat the experiment.

If they obtain similar results,

confidence increases.

Example 2

A physicist claims:

This particle exists.

Other laboratories attempt to detect it.

If nobody can reproduce the observation,

scientists remain skeptical.

What counts as justification?

observations

experiments

measurements

reproducibility

statistical analysis

peer review

Not enough:

"I saw it once."