Discussion Overview
The discussion revolves around the application of the small angle formula to measure the physical size of stars, particularly focusing on how to determine the angular size of a star like Betelgeuse, which is located 600 light years away. Participants explore the theoretical and practical aspects of measuring angular size and the challenges associated with distant stars.
Discussion Character
- Exploratory, Technical explanation, Debate/contested
Main Points Raised
- One participant explains that the small angle formula relates the angular size of an object to its physical size and distance from the observer, questioning how to find the angular size of Betelgeuse.
- Another participant suggests using a right triangle to conceptualize the measurement, indicating that the angle at the observer's position is half the angular size and can be calculated using the inverse tangent function.
- This participant notes that if the distance to the star and its angular size are known, the radius of the star can be derived using the tangent of the half-angle.
- A later reply points out the difficulty in measuring the angular size of most stars, stating that they appear as points even with the best telescopes, and mentions that only a few stars are close enough to measure their parallax due to Earth's orbit.
Areas of Agreement / Disagreement
Participants express differing views on the feasibility of measuring the angular size of stars, with some suggesting methods while others highlight the limitations posed by distance.
Contextual Notes
There are unresolved assumptions regarding the measurement techniques and the specific conditions under which angular sizes can be determined for distant stars.