Right now, the main Stack Exchange documentation says that five votes are required to close a question, except for a list of networks that does not include Physics SE. But this Physics Meta SE post seems to suggest that there is currently a test ongoing that lowers the threshold to 3 votes. But the latter post is long, heavy on analytics and so hard to read, and does not highlight the policy change very clearly. Moreover, the title makes it seem like it could just be an idea for discussion.
If 3 votes is indeed the current threshold to close a question on Physics SE, then I would suggest that someone clarify the main SE Meta answer to state that, and also rewrite the Physics SE question to make it clearer that this test is in fact in effect. (Perhaps add "Announcement:" in the title, add a bold sentence right up top announcing the new policy, and clarifying how long the test will last and what will happen after it ends.)