Australia is the dominant land mass in the Southwest Pacific. Its area of nearly 3,000,000 square miles is small when compared to the Pacific, but it is large in comparison with even the combined land area of all the islands. The continent lies antipodal to the north Atlantic and near the center of the world's water hemisphere. It is the only inhabited continent that lies entirely within the southern hemisphere.
About 6500 miles of ocean lie between Australia and California, and it is approximately 7500 miles from Sydney to the Panama Canal. London is 12,500 miles distant from Sydney by way of Panama, and it is about the same distance from London to Perth around South Africa. These great distances between the main centers of European colonial expansion and Australia contributed not only to its late discovery but also to the lag in its exploration and settlement by Europeans.
Although only about 4000 miles lay between Australia and the great centers of population of India, China, and Japan, no great overseas expansionist movement took place from those comparatively near-by Asiatic countries. As a result of Occidental discovery and settlement, Australia has long been the "isolated" continent to Europeans and Americans.
Air travel has now brought Australia nearer to America and Europe in terms of travel time. It is only 40 hours' travel time between California and Sydney. Eighteen or more days are required between those ports for the usual ocean vessels. Travel between England and Australia involves three to four days by air and several weeks by ship. Thus the degree of isolation and its many effects are being appreciably reduced. Increasing attention is also being paid to the relative "closeness" of Australia to Asiatic countries. Thus the "outpost of Europe" is becoming the "near neighbor" of Orient in many important respects.