Physics Department Colloquium

Scaling towards AGI

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Abstract: In this talk, I will take you on a tour of large language models, tracing their evolution from Recurrent Neural Networks (RNNs) to the Transformer architecture. We will explore how Transformers elegantly sidestep the vanishing and exploding gradient issues that plagued RNNs. I will introduce neural scaling laws—empirical relationships reminiscent of scaling behaviors common in physics—that predict how model performance improves with increased computational investment.

From Mars Sample Return to Enceladus plume missions: finding habitable environments and life across the solar system

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Abstract:  Planetary exploration has unveiled environments that could support life today, or in the past, or contain the ingredients of life. Mars was once habitable; Enceladus’ ocean is today, Europa is a question mark, and Bennu contains most of the basic key monomers of life in abiotic form. I will discuss how this all fits together. 
 

Closing the Loop in Early Universe Cosmology

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Abstract: Inflationary cosmology has been widely accepted for decades. Yet there are persistent debates about inflation which raise central questions in philosophy of science. Skeptics have often expressed doubt regarding whether inflation is "testable" or "falsifiable," due to the flexibility of inflationary models. This is an instance of a general question in philosophy of science: to what extent does phenomenological success support the claim that a theory gets the physics right?

Tabletop X-Ray Lasers: From Star Wars to Quantum Sculpting

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Abstract:   Ever since the invention of the laser over 60 years ago, scientists have been striving to create x-ray lasers. In the same way that visible lasers can concentrate light energy far better than a light bulb, a directed beam of x-rays would have many useful applications. The problem was that until recently, ridiculously high powers were needed to make an x-ray laser.