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Robert Wald

Robert Wald is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Robert Wald rather than just read about it. In short: Robert M. Wald (; born June 29, 1947, in New York City) is an American theoretical physicist and professor at the University of Chicago.

Robert Wald — main illustration
Robert Wald — illustration

Key takeaways

  • Robert Wald belongs to physics; place it in that map before memorising details.
  • Learn the definition first, then one example that makes the definition concrete.
  • Connect Robert Wald to a quantity you can measure, compute or draw — that is where exam questions come from.
  • Reproduce the core statement of Robert Wald from memory before moving on to harder problems.

Reference excerpt

Robert M. Wald (; born June 29, 1947, in New York City) is an American theoretical physicist and professor at the University of Chicago. He studies general relativity, black holes, and quantum gravity and has written textbooks on these subjects.

Life and education He is the son of the mathematician and statistician Abraham Wald and great-grandson of the chief rabbi Moshe Shmuel Glasner. Wald's parents died in a plane crash when he was three years old. He earned his bachelor's degree from Columbia University in 1968 and his PhD in physics from Princeton University in 1972, under the supervision of John Archibald Wheeler. His doctoral dissertation was titled Nonspherical Gravitational Collapse and Black Hole Uniqueness.

Career and contributions Between 1972 and 1974, Robert Wald worked as a research associate in physics at the University of Maryland. He then moved to the University of Chicago, spending two years as a postdoctoral fellow before joining the faculty in 1976. He wanted to move to Chicago in order to work with Robert Geroch and other specialists in gravitation. In 1977, Wald published a popular-science book titled Space, Time, and Gravity: The Theory of the Big Bang and Black Holes explaining Albert Einstein's general theory of relativity, and its implications in cosmology and astrophysics. The book also gives a survey of what was then ongoing research on gravitational collapse and black holes. This book grew out of a series of lectures Wald gave as part of the Compton Lectures at the University of Chicago in the spring of 1976. The Compton Lectures, given every Spring and Fall quarter, are intended to explain notable advances in the physical sciences to members of the general public. He published the textbook General Relativity in 1984. Aimed at beginning graduate students, it covers spinors, the variational principles, the initial-value formulation, (exact) gravitational waves, singularities, Penrose diagrams, Hawking radiation, and black-hole thermodynamics. It is well-received, but has become outdated by the early twenty-first century. Wald has taught first-year graduate courses covering a broad range of topics, including classical mechanics, quantum mechanics, statistical mechanics, and electromagnetism. He has also taught courses on general relativity, his specialty, at both introductory and advanced levels. A particularly effective teacher, he received the Graduate Teaching Award from the University of Chicago in 1997. Wald investigates black holes and their thermodynamics, and gravitational radiation-reaction (or self-force). During the early 1970s, Wald and a number of other theoretical physicists studied the external electric field lines of black holes, and subsequently the perturbations of black holes, following the publication of the Teukolsky equations by Saul Teukolsky in 1972. Wald has published over 100 research papers on general relativity and quantum field theory in curved spacetime, many of which have been cited by hundreds of subsequent papers. In 1993, he described the Wald entropy of a black hole, which is dependent simply on the area of the event horizon of the black hole. He organized The Symposium on Black Holes and Relativistic Stars in 1996, in honor of the late Nobel Prize-winning theoretical astrophysicist Subrahmanyan Chandrasekhar. Distinguished speakers of this event included Stephen Hawking, Roger Penrose and Martin Rees. Although the event charged an entrance fee of $100, Wald made sure all University of Chicago students were admitted free of charge. Chandrasekhar founded a research group on general relativity at the University of Chicago, which includes Wald, James Hartle and Robert Geroch. Although Wald and Chandrasekhar never collaborated on any particular research projects, the two developed warm relations. He became a fellow of the American Physical Society (APS) in 1996 and a member of the National Academy of Sciences in 2001. He received the Einstein Prize from the APS Division of Gravitational Physics in 2017 for "the discovery of the general formula for black hole entropy, and for developing a rigorous formulation of quantum field theory in curved spacetime." Wald delivered a public lecture at the University of Alabama on October 27, 2015, titled "The Formulation of General Relativity," celebrating the centennial of Einstein's theory. Wald is a member of the LIGO group at the University of Chicago, headed by astrophysicist Daniel Holz. The Laser Interferometry Gravitational-wave Observatory detected gravitational waves for the first time in 2015, one century after Einstein predicted their existence. In 2025 he received the Albert Einstein Medal from the Albert Einstein Society in Switzerland for his studies of classical and semi-classical gravity. In the same year, Wald, Gary Gibbons, Gary Horowitz, and Roy Kerr were awarded the Dirac Medal from the International Center for Theoretical Physics in Italy for their landmark contributions to the study of gravity, in both the classical and quantum regimes.

Books Wald, Robert M. (1992) [1977]. Space, Time, and Gravity: The Theory of the Big Bang and Black Holes (2nd ed.). Chicago: University of Chicago Press. ISBN 0-226-87029-4. Wald, Robert M. (1984). General Relativity. Chicago: University of Chicago Press. ISBN 0-226-87033-2. Wald, Robert M. (1994). Quantum Field Theory in Curved Spacetime and Black Hole Thermodynamics. Chicago Lectures in Physics. Chicago: The University of Chicago Press. ISBN 0-226-87027-8. Wald, Robert M., ed. (1998). Black Holes and Relativistic Stars. Chicago: University of Chicago Press. ISBN 0-226-87035-9. Wald, Robert M. (2022). Advanced Classical Electromagnetism. Princeton: Princeton University Press. ISBN 978-0-691-22039-0.

See also

List of contributors to general relativity List of books on general relativity Bekenstein–Hawking entropy

References

… excerpt ends here. Continue reading the full article.

Illustrations

Robert Wald illustration

Worked examples

Example 1 — a first encounter with Robert Wald

Start with the simplest possible case. Write down what Robert Wald claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Robert Wald before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Robert Wald ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Robert Wald

In research
Robert Wald appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry
Engineering practice reuses Robert Wald in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom
Robert Wald is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1947 births, 21st-century American Jews, 21st-century American physicists, so understanding it makes those chapters shorter.
In everyday life
Look for Robert Wald outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.
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How to study Robert Wald in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what Robert Wald means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain Robert Wald out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Robert Wald in simple terms?

Robert M. Wald (; born June 29, 1947, in New York City) is an American theoretical physicist and professor at the University of Chicago.

Why does Robert Wald matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Robert Wald?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Robert Wald.

Tags

  • 1947 births
  • 21st-century American Jews
  • 21st-century American physicists
  • American people of Romanian-Jewish descent
  • American relativity theorists
  • Columbia College, Columbia University alumni
  • Fellows of the American Physical Society
  • Jewish American physicists
  • Living people
  • Members of the United States National Academy of Sciences
  • Princeton University alumni
  • Quantum gravity physicists

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