Projectiles, pendula, and special relativity

The kind of flat-earth gravity used in introductory physics appears in an accelerated reference system in special relativity. From this viewpoint, we work out the special relativistic description of a ballistic projectile and a simple pendulum, two examples of simple motion driven by earth-surface gravity. The analysis uses only the basic mathematical tools of special relativity typical of a first-year university course.Comment: 9 pages, 5 figures; to appear in American Journal of Physic

Pegmatites of Southern California

For many years the southern California region has attracted the attention of geologists interested in pegmatites and pegmatite deposits, largely because of the well-known gem and lithium occurrences in San Diego and Riverside Counties. These world-famous pegmatites have been so often noted or described in the literature that they commonly are regarded as typical of the pegmatites in the region, even though this actually is far from the case. More than 90 percent of all published contributions on California pegmatites deal with the gem-bearing dikes of San Diego County alone! It is the main purpose of this brief paper to summarize the distribution, occurrence, composition, and structure of all the known pegmatites in southern California, and to discuss several aspects of their geologic and economic significance. Much of the information has been obtained from the published record, a sampling of which is included in the list of references at the end of the paper. In larger part, however, the writer has found it necessary to draw from the results of his own observations, many of which were made in reconnaissance and hence are not wholly satisfactory as a background for generalizations. This qualification with respect to basic data plainly underlies the summary and discussions that follow

Dialetheism, Paradox, and Nāgārjuna’s Way of Thinking

Nāgārjuna’s doctrine of emptiness, his ideas on “two truths” and language, and his general method of arguing are presented clearly by him and can be stated without paradox. That the dialetheists today can restate his beliefs in paradoxical ways does not mean that Nāgārjuna argued that way; in fact, their restatements misrepresent and undercut his arguments

The Federal Government and Interstate Compacts

The recent congressional foray into the affairs of the Port of New York Authority has dramatized a growingly menacing attitude toward interstate compacts and agencies even while they have become increasingly indispensable arms of state government. In asking for a clarification of the nature of Congress\u27 interest in the interstate compacts, Professor Leach urges a greater exercise of federal restraint. Compromise and adjustment, not challenge and counterchallenge, are basic to a strong federal system

On What is Real in Nāgārjuna’s “Middle Way”

It has become popular to portray the Buddhist Nāgārjuna as an ontological nihilist, i.e., that he denies the reality of entities and does not postulate any further reality. A reading of his works does show that he rejects the self-existent reality of entities, but it also shows that he accepts a that-ness (tattva) to phenomenal reality that survives the denial of any distinct, self-contained entities. Thus, he is not a nihilist concerning what is real in the final analysis of things. How Nāgārjuna’s positions impact contemporary discussions of ontological nihilism and deflationism in Western philosophy is also discussed