Original sentence: Even so, vigorous research is being conducted at prestigious Universities throughout the United States, and Europe.However, useful, real world, applications won't be realized for, at least, several decades.In other words, stealth capability is limited by strategizing with physical materials.The design flexibility includes governing ɛ & µ at arbitrarily selected points within the material, and at arbitrary scales of gradient.The future of stealth technology is to, instead, manipulate the electromagnetic spectrum, so as to envelope the object, rather than depend on physical materials, so that the object of interest cannot be seen or detected
Edited sentence: Even so, vigorous research is being conducted at universities throughout the United States, and Europe.One development of stealth technology is to manipulate the electromagnetic spectrum, to envelope the object so that it cannot be seen or detected.Real world applications are unlikely for several decades.The design flexibility includes governing ɛ and µ at arbitrarily selected points within the material, and at arbitrary scales of gradient