Understanding Time & Gravity
We doubt even physicists really understand how time and gravity work. These sites, however, give you a glimpse into it all, appropriate for students.
Thomas Kitching, a cosmologist and astrophysics lecturer, looks at questions like: Does time have a beginning? Time's arrow? Will time end?
Written in non-technical language, this post gives you an idea of the questions scientists are looking at.
This on-line essay on the history of timekeeping was conceived and written by Kent Higgins and illustrated by Darwin Miner, of the Program Information Office of the National Bureau of Standards (now NIST). Originally penned in 1975, it has been updated numerous times over the years.
This site provides an overview of Time Zones, what are they and why we have so many of them.
Who knew the International Date Line created 3 extra time zones.
Strangely, although we feel as if we sweep through time on the knife-edge between the fixed past and the open future, that edge – the present – appears nowhere in the existing laws of physics. Albert Einstein wrote in 1955, "... the distinction between past, present and future is only a stubbornly persistent illusion." And yet, at the quantum level, outcomes are random and unpredictable, even as particle behavior collectively follows statistical patterns.
A Swiss physicist, Nicolas Gisin posits that the problem is in the math. If you reject existence of numbers with infinitely many digits (i.e., infinite precision) and use what's called intuitionist math, the strict determinism implied by Einstein's equations gives way to a quantum-like unpredictability. If numbers are finite and limited in their precision, then nature itself is inherently imprecise, and thus unpredictable.
How Gravity Makes Things Fall
A demonstration of gravity, featuring the "Spacetime Stretcher," built mostly out of materials from the garage and hardware store. Click on the YouTube logo to view the About section containing additional details. Would make a great classroom or science fair project.
- YouTube URL
Strangest Time Zones of the World
This video looks at some of the world's strangest time zones, including: China, Kiribati, Nepal, Australia and more.
- YouTube URL
You've heard the phrase, "8 bells and all is well." This resource shows you where that saying originated.
Not everyone uses a display to tell the time.
Telling Time for Young Children
There are a number of videos helping kids learn to tell time. This is one of our favorites.
- YouTube URL
Major concepts and a history of time-keeping can be found at the NIST site.
Like other resources in this library, these sites advances traditional curriculum by asking a meta-questions: Who sets the time on our globe? How was the time set in history? What is global time (rather than a student's local time)? In other words, students can go beyond the descriptive to the analytical.