Wherein a random nerd tries and fails to combine “Supernovae evidence for foundational change to cosmological models” code and data to reproduce research.

Reproducing any research is a project I’ve long wanted to undertake, and this seemed like an ideal candidate:

  • Interesting result in a cool field
  • Python code

Unfortunately, it was not to be.

Unsupported Python

For context:

Python 3.0 […] was released on December 3, 2008

and

In November 2014, it was announced that Python 2.7 would be supported until 2020, but users were encouraged to move to Python 3 as soon as possible.

The initial commit of the research project was in 2022. The readme says that the project requires Python 2.7. There could be legitimate reasons why they did this, but it’s not looking good.

The project must also require some other version of Python, because some of the syntax is not compatible with Python 2.7. But having used Python since the days of 2.4 or so, this is something I would’ve dealt with if other blockers hadn’t come up.

Unknown dependency versions

The project needs Matplotlib, NumPy, pandas, and PyMultinest, but there’s no mention of which versions of any of these were used for the analysis. NumPy 1.16.6 was the last release to support Python 2.7, and nixpkgs 272744825d28f9cea96fe77fe685c8ba2af8eb12 has NumPy 1.16.6 for Python 2.7, so I tried using that version.

Several Python 2.7 package dependencies had broken builds which I had to work around. But once I got far enough through that, the real blocker showed up.

Missing files

They don’t share all the input data, including something called “.FITRES calibration files” which seem to be necessary - the first command, python BuildPP.py, fails because it can’t find Pantheon/calibration_files/FITOPT000_MUOPT000.FITRES.

This was the final nail in the coffin. No files means no point in even trying.

“Updated version”

Since the initial attempt there’s been a new commit to the project:

commit 3caa94c62b10f97fe8c116ccd3f6cda860d55a38 (HEAD -> main, upstream/main, upstream/HEAD)
Author: ZacharyLane1204 <113726903+ZacharyLane1204@users.noreply.github.com>
Date:   2025-01-15 00:17:37 +1300

    Update README.md

diff --git a/README.md b/README.md
index c66117c..ccdcd9e 100644
--- a/README.md
+++ b/README.md
@@ -2,0 +3,2 @@ # SNe-PantheonPlus-Analysis
+For a more updated version look at https://github.com/ZacharyLane1204/SNe-PantheonPlus-Analysis
+

But as of 2026-06-11 that repository does not, in fact, have any updates.

Conclusion

The results of this project can’t be reproduced as is.