A few days ago I wrote about how different measurements of the Hubble parameter gave results that didn't quite agree. It's not the only example of such an experimental disagreement. In fact, one of ...

A free neutron outside a nucleus is not stable. It undergoes beta decay at a probability. Over time, the number of free neutrons decreases exponentially at a time constant, which is called the neutron ...

The neutron is composed of two down quarks and an up quark and is stable under the strong and electromagnetic interactions. The weak interaction, however, can convert a down quark into an up quark ...