To vaccinate or not? TL;DR: Current vaccination rates against COVID-19 seem to decrease and there are indications that the vaccination coverage among adults could be less than 85 percent in a number of European countries. Why would a significant number of people not want to vaccinate themselves, especially now that millions of Europeans have already done so (mostly) without any serious complications? It is important to realize that there can be very valid personal reasons for this!
Copyright for scientists TL;DR: Copyright protects creative forms of expressions, not the content. In particular, facts or ideas cannot be copyrighted. On the side, we note that therefore mathematical proofs are not copyrightable. Even if something is copyrighted, it is usually possible to use quotations (including images) from such works in your own scientific publications. If in doubt, it is best to get permission from the copyright holder. Otherwise, one needs to check national copyright law - usually quotations are allowed in one’s own creative works, but only if this is necessary for the discussion and the copied amount is not larger than necessary.
Background Julia is a high-level programming language that is exceptionally well suited for scientific and mathematical applications. If you are not familiar with it, you should give it a try! Last year, Julia 1.0 was finally released. Among other important changes, it introduced a different set of scoping rules. For the unwary, these can lead to quite unexpected behavior, and in some cases subtle but embarassing errors (I am speaking out of personal experience here!
Introducing Julia Julia is a powerful language for scientific computing. It is a high-level language that is a lot about performance. Its main feature is the use of a just-in-time compiler to achieve a speed for numerical calculations that is close to C or Fortran code. The learning curve can be a bit steep, especially since one needs to have a good understanding of the type system to work efficiently in Julia.