Differential equations are fundamental tools in physics: they are used to describe phenomena ranging from fluid dynamics to general relativity. But when these equations become stiff (i.e. they involve ...

Most of what we believe we believe on faith, even those beliefs we hold to be based on scientific fact. This assertion lies at the heart of William James’s essay ‘The Will to Believe’, originally ...

Sometimes, when you apply for a visa to visit Canada, we ask you to give us a letter of invitation from someone in Canada. A letter of invitation doesn’t guarantee that we’ll issue a visa. Visa ...