Sam Fletcher, a sixth year graduate student in LPS, has been awarded an NSF Doctoral Dissertation Improvement Grant, worth $11,669. Fletcher's dissertation concerns the role of the mathematical field of topology in traditional philosophical debates concerning the relations between different physical theories, such as general relativity and Newtonian gravitation. The funds will enable Fletcher to travel to the Universities of Washington and Pittsburgh to discuss his dissertation research with renowned experts in his field of study. This is Fletcher's second award from the NSF; in 2009, he won a prestigious NSF Graduate Research Fellowship, which supported three years of his graduate studies.