astronomy

James Freeman Gilbert

James Freeman Gilbert is a astronomy 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 James Freeman Gilbert rather than just read about it. In short: James Freeman Gilbert (August 9, 1931 – August 15, 2014) was an American geophysicist, best known for his work with George E. Backus on inverting geophysical data, and also for his role in establishing an international network of long-period seismometers.

Key takeaways

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

Reference excerpt

James Freeman Gilbert (August 9, 1931 – August 15, 2014) was an American geophysicist, best known for his work with George E. Backus on inverting geophysical data, and also for his role in establishing an international network of long-period seismometers. Gilbert was born in Vincennes, Indiana. A 1949 graduate of Lawrenceburg High School (Kentucky), his undergraduate and graduate degrees were earned from MIT (B.S., 1953, and Ph.D. in geophysics, 1956), and he continued at MIT as a postdoctoral fellow until 1957, when he moved to the University of California, Los Angeles. At UCLA he was an assistant, then associate, professor, but left to take an appointment as a senior researcher at Texas Instruments. In 1961, he was recruited by Walter Munk to the Institute of Geophysics and Planetary Physics (IGPP) at the Scripps Institution of Oceanography, also becoming a professor of geophysics at the University of California, San Diego. He remained at UCSD through the remainder of his career, and became an emeritus professor. In his later years, Gilbert enjoyed extensive world travel with his wife, Sally Gilbert. He died due to complications resulting from a car accident in Southern Oregon on August 15, 2014. He was 83 years old.

Contributions Gilbert was among the first to recognize that the free oscillations of the Earth (so-called bell-ringing modes) could be measured immediately following large earthquakes, and could be used to produce structural models of the inner earth. In collaboration with Adam Dziewonski, he applied these ideas first to seismic records from the 1964 Alaska earthquake and then to records from the 1970 Colombia earthquake. In this context he and Backus developed robust methods for inverting seismic data. By the early 1970s it was clear that better data from long-period seismometers was needed for this kind of work. Gilbert convinced geophysicist/philanthropist Cecil Green to fund a network of seismometers designed to provide data for global studies of the Earth. The first of 40 stations of this International Deployment of Accelerometers (IDA) array (the acronym also commemorating co-philanthropist Ida Green) was installed in 1974, and it continues in operation to this day.

Awards Gilbert had received many honors, including the Gold Medal of the Royal Astronomical Society in 1981; the William Bowie Medal of American Geophysical Union in 1999; and the Harry Fielding Reid Medal of the Seismological Society of America in 2004. In 1990, Freeman was awarded the Balzan Prize for Geophysics (solid earth) for his outstanding contribution to our knowledge of the Earth's deep interior.

See also Backus–Gilbert method List of geophysicists

References

External links J. Freeman Gilbert Biography Archived 2016-03-04 at the Wayback Machine Project IDA (International Deployment of Accelerometers) Archived 2023-12-31 at the Wayback Machine 1981 The Gold Medal (A) The Society's highest honour 1985 The Arthur L. Day Medal 1990 Balzan Prize Winner J. Freeman Gilbert Receives 1999 William Bowie Medal 2004 The Harry Fielding Reid Medal of the Seismological Society of America Archived 2015-07-20 at the Wayback Machine Obituary

Illustrations

Worked examples

Example 1 — a first encounter with James Freeman Gilbert

Start with the simplest possible case. Write down what James Freeman Gilbert claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, 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 James Freeman Gilbert 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 James Freeman Gilbert 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 James Freeman Gilbert

In research: James Freeman Gilbert appears in astronomy 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 James Freeman Gilbert 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: James Freeman Gilbert is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1931 births, 2014 deaths, American geophysicists, so understanding it makes those chapters shorter.
In everyday life: Look for James Freeman Gilbert 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 James Freeman Gilbert in 20 minutes

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

Frequently asked questions

What is James Freeman Gilbert in simple terms?

Why does James Freeman Gilbert matter?

Because it connects several astronomy 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 James Freeman Gilbert?

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 James Freeman Gilbert.