The scientific theorist is not to be envied. For nature, or more precisely experiment, is an exorable and not very friendly judge of his work. It never says "yes" to a theory. In the most favorable cases it says "maybe," and in the great majority of cases simply "no." if an experiment agrees with a theory it means for the latter "maybe," and if it does not agree it means "no." probably every theory will some day experience its "no" - most theories, soon after conception.