Sentences with phrase «astronomical research during»

Although the United States has been a world leader in astronomical research during much of the 20th century, other countries have advanced rapidly, so that in some cases their facilities are competitive with — and for some purposes, even superior to — U.S. facilities in optical ground - based astronomy.1 The United States can benefit from international collaboration, but only if it brings world - class capabilities to the collaboration.

This statement contradicts results of astronomical research during the past two centuries indicating that some stars now visible to us were in existence millions or billions of years ago, as well as the results of radiometric dating indicating that the age of the earth is about 4 1/2 billion years.