Question
Mathcad Community Challenge January 2023 - Black Holes
This month’s challenge is on black holes! Create a worksheet that:
- Calculates the event horizon (Schwarzschild radius), last photon orbit, last stable particle orbit, and temperature if the Sun, Moon, and planets of our solar system were to become black holes. (You can choose whether to include Pluto.)
- Uses the Chart Component to depict the event horizon and temperature as a function of mass up to the size of UY Scuti, the largest known star in the Milky Way galaxy (which may become a black hole “soon” on a cosmic timescale).

Image courtesy of NASA Goddard Space Flight Center / Jeremy Schnittman used under CC BY-SA 4.0.
Considerations:
- How do you provide the inputs? Matrix, table, combo box input control, or other?
- When creating the Chart Component, does it make sense to use a log scale anywhere?
- The equations can be found here (hint: most are on page 36).
- Documentation (text blocks, text boxes, and images) for this challenge is critical! The math is actually not that complicated so presentation matters. Someone should be able to understand the worksheet without someone explaining it to them.
Are you up to the challenge?
Be sure to consult the PTC Mathcad Community Challenge Guidelines.

