Comment from CAITLIN WITT

[200.202(e), 200.220] To Whom it May Concern: I am an assistant professor in physics and astronomy. I am writing in my personal capacity to oppose the proposed revisions to sections 200.202(e) and 200.220 that would restrict international scientific collaboration and isolate American scientists. I am a member of the International Pulsar Timing Array collaborations, which has had a fundamental impact on gravitational wave astronomy. Under Section 200.220, our collaboration would not be able to operate, and our decades of effort and past funding would go to waste. The US has significantly invested in us and other large collaborations (LIGO, LISA, etc). Bans on collaborations with particular countries would cut off access to their telescopes and scientists. I have significant concerns about Section 200.220, as it will significantly degrade our efforts to create a global astronomy community, which furthers efforts in many fields. Without these communities, our previous efforts will be wasted, and scientific advancement will become competitive rather than collaborative.