Which of the following is an informal presentation of a physicist's scientific findings?

published scientific paper in print

lecture at a scientific meeting

published scientific paper online

poster presentation at a scientific meeting

poster presentation at a scientific meeting

The correct answer is: "poster presentation at a scientific meeting."

The informal presentation of a physicist's scientific findings is usually done through a poster presentation at a scientific meeting.

To arrive at this answer, let's briefly analyze the given options:

1. Published scientific paper in print: This is typically considered a formal way of presenting scientific findings. Scientists publish their research in peer-reviewed journals, which undergo a rigorous process of review by experts in the field.

2. Lecture at a scientific meeting: While lectures are a common way of disseminating scientific knowledge, they are usually considered more formal than an informal presentation.

3. Published scientific paper online: Similar to the first option, publishing scientific papers online is still considered a formal method of sharing research findings.

4. Poster presentation at a scientific meeting: Poster presentations are often seen as a more informal and interactive way for scientists to present their research. It involves creating a visual display summarizing the research on a poster board and engaging with attendees at a scientific meeting.

Given the options, the most informal presentation of a physicist's scientific findings is a poster presentation at a scientific meeting.