Blog 47: Interstellar the Movie’s Black Hole! How do we know Black Holes exist? by award-winning author, adventurer and scientist Mark Kingston Levin PhD
Evidence of black holes’ existence comes from three diverse experiments: 1. measuring orbits of objects around black holes, 2. measuring gravity waves for collisions and 3. watching mergers of black holes as they collide
Figure 1. The black hole, as illustrated in the movie Interstellar, shows an event horizon fairly accurately for a very specific class of rotating black holes. INTERSTELLAR / R. HURT / CALTECH
Many friends have asked me to explain the movie Interstellar; however, Kip Thorne has written a book to explain the science and I recommend it. He is a great scientist; he is a Noble Prize winner and he writes like an author. See Figure 2 below and buy his book to fully understand what he is saying as a co-producer and science consultant for the film. Having a background in science is helpful but not necessary to understand this well-written book.
This blog will help you to understand how we know black holes exist. There are other ways alongside Einstein’s theory of relativity and computer simulations, watching them feed and burp, and much more.
Figure 2. You can find Interstellar by Kip Thorne on Barnes & Noble, Amazon, and other retailers. He writes very well and wrote another general audience science book in 1994. Credit Amazon
Many astronomers are confident that the Milky Way galaxy has a supermassive black hole at its center, 26,000 light-years from our Solar System. It is named Sagittarius A* according to Ethan Siegel (Forbes 2018) and Mark Henderson. [Henderson, Mark (December 9, 2008). “Astronomers confirm black holes at the heart of the Milky Way”. London: Times Online. Retrieved 2009-05-17.]
Other evidence is the orbits of many stars near the center of galaxies. Specifically, one example is the star designated S2, which follows an elliptical orbit with a period of 15.2 years and a pericenter (closest distance) of 17 light-hours (1.8×1013 m or 120 AU) from the center of the central object, according to R. Schödel at the Max-Planck-Institute for Extraterrestrial Physics. [Schödel, R.; et al. (17 October 2002).
“A star in a 15.2-year orbit around the supermassive black hole at the center of the Milky Way”. Nature. 419 (6908): 694–696.]
History of Research
In 1963, Fred Hoyle and W. A. Fowler proposed the existence of hydrogen burning supermassive stars (SMS) as an explanation for the compact dimensions and high energy output of quasi-stellar objects (quasars). These would have a mass of about 105 to 109 solar masses or the 105 to 109 times the mass of our sun. However, Richard Feynman stated stars above a certain critical mass are dynamically unstable and would collapse into a black hole, at least if they were non-rotating. Fowler then proposed that these supermassive stars would undergo a series of collapse and explosive oscillations, thereby explaining the energy output pattern.
In 1964, Edwin E. Salpeter and Yakov B. Zel’dovich proposed that matter falling onto a massive compact object could explanation what a quasar is and its properties. This was a major mystery for many years. The mass of around 108 solar masses would be needed to match the output of most quasars. In 1969 Donald Lynden-Bell stated that the infalling gas would form a flat disk that spirals into the central “Schwarzschild throat”. If the gases leaving are moving near the speed of light that could account for the high energy photons observed.
In 1971 Martin Rees and Donald Lynden-Bell stated that the Milky Way galaxy should contain a massive black hole at its center. In February 1974 this hypothetical black hole Sagittarius A* was discovered and named by astronomers Bruce Balick and Robert Brown. They used the Green Bank Interferometer of the National Radio Astronomy Observatory. Their evidence included a certain type of radiation known as synchrotron radiation showing it was dense and immobile because of its gravitation.
In 1972 Appenzeller and Fricke constructed computer models to simulate the phenomena, but found that resulting stars would still undergo collapse, concluding that a non-rotating 0.75×106 solar mass “cannot escape collapse to a black hole by burning its hydrogen through the normal fusion cycle” said Appenzeller and Fricke. I could not believe it because our Sun has been stable for over 4 billion years.
In about 1973 Martin Ryle, Malcolm Longair, and Peter Scheuer then proposed that the compact central nucleus could be the original energy source for these relativistic jets. Now that seems to be the correct answer.
Figure 3. Artist view of a feeding quasar emitting powerful jets (burping and shining as bright as an entire galaxy. What a beautiful spectacle) Credit Wikipedia
In 1978, strong evidence for a massive dark object was found at the core of the active elliptical galaxy Messier 87. In 1978, it was initially estimated at 5 billion solar masses. In 1984 discovery was made of similar behavior in other galaxies, including the Andromeda Galaxy. In 1988 the Sombrero Galaxy was discovered.
The Hubble Space Telescope, launched in 1990, provided the resolution needed to perform more refined observations of galactic nuclei. In 1994 the Faint Object Spectrograph on the Hubble was used to study Messier 87, finding that ionized gas was orbiting the central part of the nucleus at extremely high velocity.
In 1995 Miyoshi et al. were able to demonstrate that the emission from an H20 maser (“microwave amplification by stimulated emission of radiation”, a device that produces coherent electromagnetic waves through amplification by stimulated emission) in this galaxy came from a gaseous disk in the nucleus that orbited a black hole with 36 million times the mass of our Sun, providing more evidence of supermassive black holes.
Figure 4. The final stage of a merger between two galactic nuclei are in the galaxy NGC 6240.
The black holes at the cores are growing quickly, devouring the merger’s gas and dust. Credit: M. Koss (Eureka Scientific, Inc.)/NASA/ESA/W.M. Keck Observatory, Pan-STARRS
Astronomers recently observed the final phase of several galactic mergers by peering through thick walls of gas and dust to see pairs of supermassive black holes coming very close, in fact in extremely tight orbits spiraling into one.
During these galactic mergers supermassive black holes have opportunities to feed and burp. The burp is the massive release of extraordinary amounts of light and mass, which in many scientist’s opinions create what we call the quasars. Quasars are the brightest objects since the big bang. These collisions show black holes can emit light and matter when they feed. Another myth bites the dust.
At the centers of all galaxies are supermassive black holes with masses that are millions to billions of times that of Earth’s sun. At the center of our Milky Way galaxy lies Sagittarius A* as discussed earlier. Sagittarius A*’s mass is approximately 4.5 million times the Sun’s mass.
In conclusion, I have highlighted just a small portion of the evidence for black holes. I believe, and so did Dirac in 1982. Previous work found that mergers of galaxies might help fuel the growth of supermassive black holes. That research is solid evidence that black holes merge to become even larger black holes of larger galaxies. How will our universe evolve? Stay tuned for more information.
Figure 5. The black hole stands out only because it is feeding. The light the artist cleverly placed in shows what is happening from the speed of the atoms and molecules, which are accelerated to near the speed of light before entering the event horizon. Credit: David Powell Sithsomium.com from an article about Stephen Hawking
The messy cores of these colliding galaxies are more evidence to those who are still skeptical about the existence of black holes. Top: NGC 6240, as imagined by Hubble’s Wide Field Camera 3, paired with a close up of the galactic cores in infrared light by the Keck Observatory in Hawaii. The other four galaxies are imagined by the Panoramic Survey telescope and Rapid Response System (Pan-STARRS) as well as Keck: Credit M. Kiss (Eureka Scientoific, Inc.) W.M. Keck Observatory; Pan-STARRS images: M. Koss (Eureka Scientific, Inc.) Panoramic Survey Telescope and Rapid Response System
Figure 5 There is great beauty in the eye of artists; see Paul Gauguin’s famous “When will you Marry?” which is the most expensive painting in the world today.
Can an artist top the beauty of quasars? I leave that judgment to you. I love his painting, but I also love nature; after all, the artist is a part of nature.
All in all, the scientists analyzed 96 galaxies observed with the Keck Observatory and 385 galaxies from the Hubble archive. All of these galaxies are located an average of 330 million light-years from Earth, which is not far for astronomers, with many galaxies being similar in size to the Milky Way.
The researchers found that more than 17 percent of these galaxies hosted a pair of black holes at their centers. Many show signs of the late stage of a galactic merger. These findings matched the researchers’ computer simulations, which suggested that highly active mergers may be heavily obscured black holes hidden within gas and dust-rich galaxies, which are responsible for many mergers of supermassive black holes. There are about 100 million ordinary black holes in every galaxy and more forming every year.
Schmidt Maarten (1963). “3C 273: a star-like object with large red-shift”. Nature. 197 (4872): 1040–1040. Bibcode:1963Natur.197.1040S. doi:10.1038/1971040a0.
Award-winning author, adventurer and scientist Mark Kingston Levin PhD.
Astronomy was always what I wanted to study, but it was hard for me to stay awake all night and sleep in the day time. I tried “all-nighters,” it was too rough for me. I became a theoretical scientist for a while and then started my first of two companies and started doing experiments, quality control, and developing products as well as processes to make them. Then became CEO and got into sales and marketing.
Mark Kingston Levin PhD author of 30th Century series book 2 30th Century: Revived, which was release on Amazon April 29, 2018.
Dr. Levin won the IRWIN for the Best Science Fiction Book of 2017 for the first book in the series, 30th Century: Escape. To read the first three chapters, see www.markkingstonlevin.com.
For questions and comments write to Dr. Levin email@example.com
Dr. Levin was born and grew up in Vermont with many winters spent in Florida as a child. As a teenager he wrote poetry, served as a lifeguard and played football. He currently enjoys sailing, exploring underwater caves, snorkeling, writing science fiction and other pursuits. After working on the Apollo and Mars projects, he returned to school to study under Nobel Laureate Paul Dirac, obtaining his PhD in 2.5 years. Dr. Levin founded two companies and served the science policy apparatus in President Ford’s administration. He has been published over 44 times in scientific literature and was awarded over 32 US patents. The science fiction writer is now emerging with his first work, a trilogy titled 30th Century.
The first award-winning book, 30th Century: Escape, is currently available on Amazon both in its original erotic form BUY HERE and the new, toned-down General Audience Edition in both Kindle and in full-color print BUY PRINT HERE. Book two in the series, 30th Century: Revived, is available HERE in both e-book and print. Look for book 3 in the series, 30th Century: Contact, by early 2019!
NEW: Your opportunity to be part of the process! If you sign up to be a Beta Reader, I will email you an Advanced Reader Copy (ARC) of Book 3, 30th Century: Contact, in either PDF or Kindle. You read and tell me how you would make it stronger by sending an email to Dr. Levin firstname.lastname@example.org