Aubrey HilllEinstein had a mind that leapt nimbly from one new idea to the next. His powerful sense of intuition steered him to a safe landing and a new discovery. These leaps make his scientific essays miniature works of art. They are simple and graceful, but reveal a mind dancing among the deepest ideas. One example … Read more
Imagine trying to run if every faster stride made your legs heavier and even sprinting speeds turned them into lead weights. Increasing a body’s speed requires some kind of push or force. Increasing the speed of heavier bodies requires stronger and harder pushes. If a body’s mass approaches infinity, then further increases in speed would … Read more
Energy is the “amount of motion”. Suppose that two identical cars are racing down a road; the faster car has more energy. Suppose that a truck and a small car are travelling side by side along the road and at the same speed; the truck is heavier and therefore has more energy. It is harder … Read more
A few months after Einstein published his first paper on relativity in 1905, he sent in a sort of extended footnote to the same journal. His theory had an odd little consequence. It seemed so strange that he phrased the note’s title as a question: “Does Mass Depend on Energy?” To leaf through the next … Read more
The most famous of the problems prominent in the early controver- sies over relativity was the twin paradox. It is easy to state but exposes some very deep issues, and so hundreds of papers have been written about it over the decades. Now that the dust has settled, it is clear that the paradox does … Read more
Both the majority and minority interpretations agree that measure- ments show that one ship is longer and shorter than the other, or that the car is longer and shorter than the garage, depending on which set of rulers and clocks is used. That is, they agree that appearances are symmetric. They also agree that there … Read more
An illustration will help bring these points home. According to Einstein, length contraction will permit us to house the six-metre Jaguar in a three-metre garage, as mentioned above. By driving at 85 per cent of the speed of light, the car will contract by some 50 per cent. We can drive the car into the … Read more
Set on the Avon River in England’s West Country, Bristol has a real buzz: its docks are tourist honeypots, its galleries and theater are thriving, and the area of Clifton, beside Brunel’s great suspension bridge, is as elegant as ever. Visit Brunel’s SS Great Britain for an insight into how passengers used to have to … Read more
As capital cities go, Vientiane feels little more than a country town. A broad, open community beside the Mekong River, it’s largely on the flat and ideal for walking around (though a tuk tuk will help you through the traffic). The temples and stupas are the highlights, particularly Wat Si Saket and Pha That Luang. … Read more
Surrounded by ski mountains and broad plateaus, Taos is a picturesque town that was a favorite with artists at the beginning of the 20th century. They were drawn here by the walled adobe Taos Pueblo, which dates back nearly a thousand years and is still inhabited by villagers today. Head for the Harwood Museum of … Read more