Just as three dimensions of space are combined with one dimension of time, so we can combine three dimensions of time with one dimension of space. The place to start is the Lorentz transformation. Let’s take a common approach, that of spherical wavefronts of light but instead of taking three length coordinates and converting time […]
“Time is that which is measured by a clock” wrote Hermann Bondi in Relativity and Common Sense (p.65), though the idea goes back to Albert Einstein, and ultimately to Aristotle. “A space is that which is measured by a ruler; time is that which is measured by a clock.” (George Lundberg, quoted in Abrahamson, 1981:
The question is how to interpret the Lorentz transformation. In a previous post, Lorentz generalized, a modest generalization of the Lorentz transform was derived. Absolute reference speeds were combined with a relative actual speed. Let’s step back and look at a map of space and time: This map of nodes and links on the U.S.
Aristotle’s four explanatory factors (aka four causes) provide a template for a full explanation of anything. However in attempting to explain the natural world (and many other things) it is impossible for us to know all the final causes involved. We may have an idea about some purpose or function of some aspect of things,
The four explanatory factors (aka four causes) Aristotle described can be used to explain marriage in a time in which people have forgotten what marriage is. The ancient book of Genesis provides the explanation, so it’s not a recent attempt to promote an agenda. Societies through the ages have implicitly followed the explanation, which may
In some ways transportation is more general than physics, which is surprising. In terms of extent, from the microscopic to the astronomical, from extremes of temperature, etc., physics is the more general subject. But because transportation includes people, there are some additional possibilities. Let’s look at one transportation situation in which this is the case.
Theoretical physics has been applied to a variety of disciplines such as economics and traffic flow theory. Here we are returning the favor by considering transportation as a model for physics; in other words, physics is like a transportation system. Consider the space-time continuum as an infinitely dense transportation network. The spatial extent of the
It may seem an exaggeration at this point to speak of “spacetime” while focusing on examples from everyday life rather than the physics laboratory. Yet after all we live in a physical world so physics should include that, too. But we’ve put off considerations such as the constant speed of light until we have a
We interrupt this series of blog posts to address education in a democracy, especially in America where the public education system is deplorable — beyond reform and beyond revival — so it’s ready for replacement. Another reason for replacement is the right of the people to control their own education, rather than the state and
Galileo was the first to see clearly that someone traveling in uniform motion would not be able to discern any difference from being at rest (without looking out the window). He imagined someone on a ship eating peas, and if a few dropped off their fork, there would be no difference from what would happen
