#startswithabang

Comments of the Week #95: from gravitational waves to the Multiverse

"To someone who’s never done experimental or observational work, this might seem like the ultimate example of fooling yourself. But there’s a good reason for it: there are two types of errors, statistical (where you can improve on your errors by taking more data/doing more experiments), and systematic, where you need to calibrate/account for a variety of effects having to do with your equipment, sources, objects, and experimental setup. Sometimes you get results that aren’t what you expect, and that’s often because of systematic errors. In fact, that’s often how systematic errors get caught. Unfortunately, we (scientists) suffer from the bias that when we’ve identified all the systematic errors we can and we get a result that’s in alignment with our expectations, we stop looking for new systematics. And that’s how this problem — at least in my experience — often self-perpetuates. Erring on the other side, by the way, is what leads to the OPERA faster-than-light neutrinos, where you fail to get all your systematics before publishing!"

Get an autographed copy of Ethan Siegel’s new book, Beyond The Galaxy!

So, I heard you didn't just want my book, but that you wanted a copy *autographed* and shipped anywhere in the world, immediately, for your own consumption? (Or, perhaps, as a gift for the right person in your life?)

Comments of the Week #50: From hot and dense to co-orbiting rocks

"The idea that the Universe could be described by our physical laws, the fundamental particles, and simply knowing the initial conditions and extrapolating forwards in time is at the heart of what cosmology is. From ancient times until perhaps the 1960s, cosmology was more of a hypothesis than a full-blown physical theory, as there were too many uncertainties that were simply too large. But with the discovery of the cosmic microwave background, all of that changed.

For the first time, we knew not only the physical laws governing the Universe (General Relativity was well-established, and the Standard Model was very close to complete), but we learned what the initial state-and-conditions of the Universe were to a reasonably high precision. The idea of a “precision cosmology,” once a pipe dream, has become a reality thanks to the influx of continually superior data. For the first time, we understand the history of the Universe and almost everything in it with errors and uncertainties on almost everything that are no more than a few percent."