It really hurts to see this happening. CMB-S4, stands for stage 4, is a huge collaborative effort that units many CMB scientists and experiments, in a sense that stage 1 to 3 experiments are “converging” towards this.
To put that in context, CMB-S4 being a DOE project has many side effects to other CMB experiments in a lot of ways. For example, a few years ago the LiteBIRD mission led by JAXA from Japan has been gaining momentum, and many international CMB scientists got involved. European scientists got funded by ESA, and US scientists were expecting NASA to fund them too. In the end they denied the proposal (despite generally positive impressions when discussing with various people there), partly because they think the satellite based CMB experiment LiteBIRD has significant overlap with the goals of the ground based CMB experiment CMB-S4, deeming it unnecessary to support LiteBIRD.
And then CMB scientists used to get generous access to NERSC, a top 10 HPC system in the world. But as CMB-S4 becomes a DOE project, NERSC being DOE funded also, it becomes a bit of conflict there, in the sense that they feel they need to prioritize access for CMB-S4 to guarantee its success. There are many other factors in play but in the end it becomes much more difficult to even get access to the system, not to mention having any sizable allocation.
All these might not be so bad as CMB-S4 is supposed to be our endgame. It would benefits the CMB community as a whole so much. But now? It’s game over.
It also hurts particle physics progress as well. Long story short, the CMB B-mode holds a promising sensitivity to inflationary models, that its discovery may finally makes inflation falsifiable. At the very least, it involves an energy scale so high that no experiments on Earth can reach, and therefore is a good complement, to high energy physics experiments such as LHC.
There is a reason it is deemed so important in both the decadal survey and the Particle Physics Project Prioritization Panel.
Project like this has under heavy scrutiny from both the scientific community and the funding parties around feasibility, risks, costs, etc. It wasn’t a a light decision to have had happened in the beginning. Why would the end come so abruptly without explanation?
To put that in context, CMB-S4 being a DOE project has many side effects to other CMB experiments in a lot of ways. For example, a few years ago the LiteBIRD mission led by JAXA from Japan has been gaining momentum, and many international CMB scientists got involved. European scientists got funded by ESA, and US scientists were expecting NASA to fund them too. In the end they denied the proposal (despite generally positive impressions when discussing with various people there), partly because they think the satellite based CMB experiment LiteBIRD has significant overlap with the goals of the ground based CMB experiment CMB-S4, deeming it unnecessary to support LiteBIRD.
And then CMB scientists used to get generous access to NERSC, a top 10 HPC system in the world. But as CMB-S4 becomes a DOE project, NERSC being DOE funded also, it becomes a bit of conflict there, in the sense that they feel they need to prioritize access for CMB-S4 to guarantee its success. There are many other factors in play but in the end it becomes much more difficult to even get access to the system, not to mention having any sizable allocation.
All these might not be so bad as CMB-S4 is supposed to be our endgame. It would benefits the CMB community as a whole so much. But now? It’s game over.
It also hurts particle physics progress as well. Long story short, the CMB B-mode holds a promising sensitivity to inflationary models, that its discovery may finally makes inflation falsifiable. At the very least, it involves an energy scale so high that no experiments on Earth can reach, and therefore is a good complement, to high energy physics experiments such as LHC.
There is a reason it is deemed so important in both the decadal survey and the Particle Physics Project Prioritization Panel.
Project like this has under heavy scrutiny from both the scientific community and the funding parties around feasibility, risks, costs, etc. It wasn’t a a light decision to have had happened in the beginning. Why would the end come so abruptly without explanation?