On a recent flight, I had an interesting discussion with the man next to me. It turns out his job is to work with airports and airlines to streamline the process of baggage handling to reduce delays and misplaced bags and he told me how the system works. Apparently, there are miles of conveyor belts behind the scenes at airports that begin at the check-in counter and they have multiple sensors all along the way that use lasers to periodically check the barcode on the baggage tags to make sure that the bag gets transferred to the correct belt for the final destination. The sensors also check the times at each checkpoint and predict when it should reach the next checkpoint so that if a bag does not reach it at the expected time, an alert goes off and someone physically goes to see if the bag has mistakenly switched to the wrong belt, fallen off the belt, or has got jammed somewhere. He said that the goal is to have bags spend no more than 20 minutes in transit from one plane to another though they can often do it in 10 minutes.
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One of the features of science is that there is always a tension going on. We have standard paradigms that most scientists work within but on occasion a new result will turn up that seems to be violate the boundaries of that paradigm. What does one do then? Reject the paradigm and its associated underlying theory? Seasoned scientists know not to do that because throwing out a paradigm is not something to be undertaken lightly since good theories are hard to come by. What they do is treat the discrepant event as an anomaly meriting further study.
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The design of the standard passenger airplane seems to be pretty fixed where there is a central fuselage that houses passengers and cargo and the wings that provide the lift. But via David Pescovitz I learn that KLM is funding a new design where the central fuselage is eliminated and passengers and cargo are seated in the wings, as shown below.

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On May 20th, the 26th General Conference on Weights and Measures instituted a new standard for the kilogram mass. A metal block kept in a hermetically sealed vault in Paris had been the mass standard for 130 years. New standards were also introduced for the unit of current (Ampere), temperature (Kelvin), and the mole.

It used to be the case that standards for the basic units used in science had been defined in terms of macroscopic objects like this and thus could be easily understood. But the need for increasingly precise and unvarying standards meant that these were no longer suitable and standards have increasingly shifted to using the fundamental constants of nature and getting from those to the familiar quantities involves quite a long chain of reasoning. The kilogram is the last remaining physical object to be so displaced.
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That is a blatantly clickbait-and-switch post title. Anyone expecting to read about the origins of romantic outings involving two people will have to look elsewhere. What this post is about is how the idea of assigning consecutive numbers to the years originated.

We now routinely assign a numbered year to events in recorded history, so that I can write that Bishop Ussher’s year of the creation of the Earth was 4004 BCE or that the American revolution was in 1776 CE. This sequential numbering of the years enables us to immediately fix an event in relation to other events. The system seems so natural that one feels that it must have always been in place and did not have to be invented at all, let alone have a definite beginning. But classicist Paul J. Kosmin says that there was a time when this system of numbered years did not exist and that events were placed in a historical sequence using various circumlocutions that had only local validity.
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