In light of the recent criticisms of string theory, preeminent physicist Juan Maldacena sheds light on the promise of string theory and how it fits into our current understanding of the universe. In so doing, Maldacena also explains the ideas of holograms, dimensions, and quantum fields in terms everyone can understand.

For more featuring Juan Maldacena, join IAI LIVE: Fantasy, Faith and Physics this July 3rd. Sabine Hossenfelder, Max Tegmark, Michio Kaku, Juan Maldacena, Lisa Randall, and Mary-Jane Rubenstein debate the role of fantasy and unproven belief in modern physics. Book now.

Most people think that physics tells us that everything that exists is made out of particles, like atoms and quarks. Is that right?

Yes, indeed. The current picture of nature posits that all matter is composed of a few elementary particles. More accurately, the theory is that there are several fields that permeate spacetime. The excitations of these fields are quantized, and each elementary excitation quantum represents a particle. For example, the electromagnetic field's unit of excitation is the photon. There is another, the electron field, whose elementary excitation is the electron, and so forth. All electrons are identical because they are excitations of the same underlying field. While popular descriptions often talk about particles, our current foundational theory, the so-called “Standard Model,” relies significantly on the existence of fields.