In the Alimony Reform Act of 2011, St. 2011, c. 124 ("the Act"), "alimony" is defined as "the payment of support from a spouse, who has the ability to pay, to a spouse in need of support for a reasonable length of time . . . ." G. L. c. 208, § 48. However, because neither "ability to pay" nor "need of support" are defined in the Act, Probate and Family Court judges are given the discretion to balance numerous other factors, such as the parties' ages, health, incomes, and economic and non-economic contributions to the marriage, in order to arrive at a fair alimony award. See G. L. c. 208, § 53 (a).