The Whitney sum formula for the total Chern class implies that it is a map of H-spaces from BU to the space of units of HZ[t] (|t|=2). It was a question of G. Segal from the 70's whether this could be lifted to a map of spectra. V. Snaith quickly showed that was not possible. Later B. Lawson et al constructed a theory of ``algebraic cycles" which produced a spectral lift with a different target. In this talk I will outline a new construction, joint with S. Carmeli and L. Yanovski, which provides a spectral lift with target gl_1 HZ^{tS^1}, the units of the Tate construction. As a result of our construction we obtain a proof that the ``sharp" construction of Ando-French-Ganter preserves E_infty orientations. As a corollary we establish that``two-variable elliptic genera," and their conglomerate, the "Jacobi orientation," admit E_infty lifts. With this knowledge, one is motivated to run the Ando-Hopkins-Rezk obstruction on the Jacobi orientation, which produces power series that satisfy nontrivial congruence conditions that may be of number theoretic interest. I will present some computational beginnings of this program, joint with E. Peterson.