Daniel Kirkwood

IU students will recognize the name Kirkwood from Kirkwood Hall, Kirkwood Avenue, and Kirkwood Observatory, but not many know the story of astronomer and IU professor Dr. Daniel Kirkwood. Known as the "Kepler of his time," Daniel Kirkwood changed astronomy with his discovery of "Kirkwood Gaps" and research on meteors during his time at Indiana University.

1814-1895

Courtesy of IU Archives

1814

Kirkwood is Born

Daniel Kirkwood was born on September 27,1814 in Hartford County, Maryland into an agrarian family.(1)

Courtesy of IU Archives

1833

Kirkwood Begins Teaching

He began his career as a teacher in Hopewell, Pennsylvania at the age of 19 when one of his students introduced him to algebra, inspiring him to enroll in York County Academy in 1834. After graduationin1838,he was appointed mathematical instructor at York County Academy (2)

Courtesy of York Daily Record

1845

Skeptical of Asteroid Theory

In an 1845 publication of the Journal of the Linnaean Association of Pennsylvania College, Kirkwood voiced his skepticism of the astronomical theory Bode's Law that theorized asteroids had a catastrophic origin, which would shape his own theories on asteroids. This initial skepticism would later influence his theory on asteroid gaps over the next two decades. (3)

1849

First Publication Mentioning Planets

After presenting at the annual meeting of the American Association for the Advancement of Science in Cambridge, Massachusetts in 1849, Kirkwood published his formula for the rotation periods of the planets in the proceedings of the American Association for the Advancement of Science. (4) His theory, which became known as Kirkwood's Law, stated the square of the number of rotations made by a planet during one revolution around the sunis proportional to the cube of the diameter of its sphere of attraction. (5)

Courtesy of Robert Aley

1851-1856

Professor of Mathematics in Delaware College

Kirkwood taught at Delaware College in Newark from 1851-1856. (6)

Courtesy of IU Archives

1856

Kirkwood at IU

In 1856, he joined the IU faculty. (7) During his 30-year tenure, he published 98 papers and two books.(8)

1857

Asteroid Research Develops

Kirkwood continued his work on asteroids; he turned his focus to the orbital periods of asteroids orbiting Jupiter. (9) He then decided he must study each asteroid to prove his hypothesis; at that time only 50 asteroids had been identified. (10)

1862

Kirkwood Suggests Meteor Shower Origins

Building off of his research from the previous two decades, Kirkwood surmised that meteor showers were in fact debris from comets. (11)

1866

88 Asteroids, 1 Theory

In 1866, Kirkwood pointed out the consistent gaps at the orbital periods between asteroids and Jupiter, illustrating they were not as chaotic or random as previously believed. These gaps were actually a result of "periodic perturbations" by Jupiter. Kirkwood identified what is now known as "Kirkwood Gaps" in the orbits or minor planets and asteroids.This theory stated “that in those spaces were simple commensurability of motion with that of Jupiter occurs, there must, be gaps in the asteroid zone." This theory of Jupiter’s influence on the orbital periods of asteroids still holds true today. (12, 13)

Kirkwood Gaps

1866-1867

Kirkwood Leaves IU for a Year

Kirkwood left IU for a year to teach at Washington and Jefferson College from 1866-1867. (14)

1870

More Presentations by Kirkwood

In the 19th century, historian Robert Aley wrote about Daniel Kirkwood and how esteemed British Astronomer Richard A. Proctor admired him: "When about fifty asteroids were known Dr. Kirkwood announced the theory that in those spaces were simple commensurability of motion with that of Jupiter occurs, there must, be gaps in the asteroid zone. The theory was based on mathematical and physical facts. It was at once received with favor and in 1870 Proctor spoke of it in the highest terms." (15)

1875

146 Asteroids, 1 Theory

Kirkwood presented his findings to the The American Association for the Advancement of Science on almost double the asteroid gaps and Jupiter measurements, earning notable British Astronomer Richard A. Proctor to refer to Kirkwood as the "Kepler of our day." Proctor also noted that he came to America specifically to see Daniel Kirkwood. (16) This compliment is astounding as 17th century astronomer Johannes Kepler revolutionized Astronomy with his laws of planetary motion, which provided foundation for future scientists like Isaac Newton. In this same way, Kirkwood's Gaps and Kirkwood's Law became the foundation for future scientists' discoveries.

Courtesy of IU Archives

1885

Kirkwood Avenue

In 1885 Kirkwood was honored with the renaming of the street between the Courthouse and University previously known as 5th Street, as Kirkwood Avenue in Bloomington, Indiana, because of his impact during his time at IU and his work in astronomy. (17)

Kirkwood Avenue in 1909

1885

Kirkwood Presents to the American Philosophical Society

Kirkwood attains one of the highest honors in his profession by presenting his speech on the comet of 1866 to the American Philosophical Society. (18)

1886

Kirkwood named Professor Emeritus

Upon his retirement in 1886, Kirkwood was named Professor Emeritus.The IU Board of Trustees resolved: "We hereby tender to Dr. Daniel Kirkwood the sincere gratitude of the Board of Trustees for his nearly thirty years of patient, successful and renowned labors in Indiana University...In his intercourse with the Faculty of the University his upright conduct and scholarly bearing have at all times won the entire confidence and respect and by the students he has ever been held in affectionate reservation." (19) Kirkwood was loved by students and faculty alike, as evidenced in his reviews in Beta Theta Pi's newsletter The Dagger, which reviewed faculty and often gave Kirkwood glowing evaluations. (20).

Courtesy of IU Archives

1886

The Passing of the Kirkwood Bell

Kirkwood was known for using a bell to call students to his classroom. Upon retirement, Kirkwood gave the bell to Joseph A. Miller, a former student of Kirkwood who also became a professor of astronomy at IU. (21)

1889

Kirkwood Moves West

After his retirement from Indiana University, Kirkwood and his wife moved to Riverside, California. (22)

Courtesy of IU Archives

1890

Kirkwood Inducted into the Astronomical Society of the Pacific

EEven though Kirkwood conducted most of his research outside of California, Kirkwood was welcomed and inducted into the Astronomical Society of the Pacific and published three papers. (23)

1895

Kirkwood Hall

After multiple building fires on the original campus (one in 1854 which destroyed the chapel and library and another major fire in 1883), combined with the need for more space, new buildings were constructed on the current Dunn’s Woods campus. One new building was dedicated as Daniel Kirkwood Hall. This was the first building dedicated to a living man on IU’s campus. (24)

Courtesy of IU Archives

June 11, 1895

A Loss to the Astronomical World

In June of 1895, Kirkwood passed away at his home in Riverside, California. His death was preceded by the death of Theophilus Wylie, his long-time friend and colleague who was often mentioned in Kirkwood’s letters and journals. The funeral service was held in Bloomington, IN at the Walnut Street Church. (25)

Courtesy of Indianapolis Journal, Wednesday June 12, 1895 page 2

1895

President Swain Proposes Astronomy Department

Three days after Kirkwood's death, the IU Board of Trustees approved the creation of an astronomy department. (26)

1901

Kirkwood Observatory is Dedicated

After construction in 1900, in 1901 the Kirkwood Observatory was posthumously dedicated in his honor. One should note Daniel Kirkwood’s findings resulted from mathematical calculations and not his own telescope observations. (26).

Courtesy of IU Astronomy Department

2018

Works Cited Part 1

1) Robert J. Aley, "Biography: Daniel Kirkwood," The American Mathematical Monthly 1, no. 5 (May 1894): 141, https://www.jstor.org/stable/2969702 

2) San Francisco Chronicle, Obituaries, published June 14, 1895 

3) Frank Edmonson, “Dean of American Astronomers,” Mercury Magazine, 2000, page 28 

4) Frank Edmonson, “Dean of American Astronomers,” Mercury Magazine, 2000, page 28 

5) Aley, page 142 

6) Board of Trustees Minutes, September 5, 1865 

7) Board of Trustees Minutes, September 5, 1865 

8) Frank Edmonson, “Dean of American Astronomers,” Mercury Magazine, 2000, page 33 

9) Frank Edmonson, “Dean of American Astronomers,” Mercury Magazine, 2000, page 31 

10) Interview with Cathy Pilachowski 

11) Frank Edmonson, “Dean of American Astronomers,” Mercury Magazine, 2000, page 31 

12) Frank Edmonson, “Dean of American Astronomers,” Mercury Magazine, 2000, page 31 

13) Frank Edmonson, Alumni Talk, June 7, 1968 

14) History of IU, Page 269, Box 1, C83 

15) Aley, 143

2018

Works Cited Part 2

16) Frank Edmonson, “Dean of American Astronomers,” Mercury Magazine, 2000, page 31 

17) Frank Edmonson, “Dean of American Astronomers,” Mercury Magazine, 2000, page 32 

18) Box 1, C52 

19) Board of Trustees Minutes, June 6, 1886 

20) Box 1, C591 

21) Frank Edmonson, Alumni Talk, June 7, 1968 

22) Frank Edmonson, “Dean of American Astronomers,” Mercury Magazine, 2000, page 32 

23) Frank Edmonson, “Dean of American Astronomers,” Mercury Magazine, 2000, page 32 

24) Aley, page 140 

25) San Francisco Chronicle, Obituaries, published June 14, 1895 

26) Frank Edmonson, “Dean of American Astronomers,” Mercury Magazine, 2000, page 33