Welcome to the new home for SIMIODE. Please use the login link on the upper right of the window to create an account, and then click join group.



Modeling Scenario


Author(s): Kurt Bryan

Keywords: astronomy mirror climate change mitigation ocean deacidification optics telescope lens Foucault interpolation

141 total view(s), 92 download(s)


Resource Image This project models the ``Foucault Knife Edge Test,'' an optical test commonly used by amateur astronomers who make their own mirrors for reflecting telescopes. The goal of the test is to estimate the shape of the surface of a mirror from optical reflecti


Researchers should cite this work as follows:

Article Context

Resource Type
Differential Equation Type
Qualitative Analysis
Application Area
Lesson Length
Key Scientific Process Skills
Pedagogical Approaches
Vision and Change Core Competencies - Ability


The model results in a very simple first order nonlinear ordinary differential equation (ODE) that has no closed-form solution. Moreover, one of the components of the ODE is a function that must be estimated from the collected data; some real data from a mirror the author made is included. A computer algebra system can be helpful for performing computations, and sample Maple and Mathematica worksheets are provided.

It is a time-honored tradition among amateur astronomers to build a telescope from scratch, right down to grinding the optical elements.

Building a telescope is an interesting exercise in ``multiple precision'' construction. The telescope's tube and base are often made of wood, which is typically cut to an accuracy of a few hundredths of an inch. Machined metal parts might be accurate within a few ten-thousandths of an inch. But in order to obtain good images, the optical elements themselves must be made to tolerances on the order of a textit{millionth of an inch}. How can such precision be attained at home (or anywhere else)?

Remarkably, this can be done by using only bare human hands, aided by a bit of clever optics and geometry.

Article Files


Author(s): Kurt Bryan



There are no comments on this resource.