This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
The conversion from long to float is "widening" in terms of range -- not bit size.
A 32-bit float has a much greater range than a 64-bit long, but this is because the float gives up precision. This has to do with the way in which floating-point values are typically stored in computers.