Princeton Astrophysicists Uncover the Enigma of Black Hole Jets and Galactic “Lightsabers” Explored by Einstein
Researchers from Princeton University have made a groundbreaking discovery pertaining to the M87* black hole, shedding light on its intriguing energy dynamics and their role in the formation of colossal jets. This revelation, firmly rooted in Einstein’s theory of relativity, challenges conventional wisdom surrounding black holes and presents an exciting prospect for further investigation with advanced telescopic technologies. While this study provides fresh insights into black hole mechanics, it stops short of definitively elucidating the source of the jets’ immense power.
One of the most widely accepted beliefs about black holes is their voracious appetite, devouring anything that ventures too close.
However, it appears that there are exceptions to this rule.
Eliot Quataert, an astrophysicist at Princeton and the Charles A. Young Professor of Astronomy on the Class of 1897 Foundation, explains, “Despite being defined as celestial objects from which nothing can escape, one of the astonishing predictions of Einstein’s theory of relativity is that black holes can, in fact, lose energy. Similar to how a spinning top gradually decelerates and dissipates its rotational energy, a rotating black hole can also shed energy into its surroundings.”
This conceptual framework has been widely embraced by scientists since the 1970s. It posits that magnetic fields are likely responsible for siphoning energy from spinning black holes, although the precise mechanism has remained a puzzle.
In a definitive breakthrough, a team of Princeton astrophysicists has now confirmed that energy in proximity to the event horizon of the M87* black hole is indeed being expelled outward, counter to conventional assumptions that energy flows inward. (The designation M87* corresponds to the black hole at the heart of the galaxy Messier 87, commonly known as M87.) Furthermore, these researchers have devised a method to empirically verify the notion that black holes undergo rotational energy loss, a phenomenon directly responsible for the creation of the awe-inspiring outflows colloquially referred to as “jets.”
In the words of former Princeton postdoc Alexandru Lupsasca, these energy outflow jets resemble “million-light-year-long Jedi lightsabers” and can extend an astounding ten times the length of our Milky Way galaxy.
Their groundbreaking findings have been published in The Astrophysical Journal, with Andrew Chael serving as the paper’s first author. Chael and his co-author, George Wong, are both members of the Event Horizon Telescope team and have played pivotal roles in developing models crucial for interpreting black hole phenomena. Chael, Wong, Lupsasca, and Quataert are all theoretical scientists affiliated with the Princeton Gravity Initiative.
Chael’s pivotal insight at the core of this study was that the spiraling direction of magnetic field lines reveals the orientation of energy flow. This revelation served as the linchpin for the team’s research.
M87* catapulted to global attention when it was first observed by the Event Horizon Telescope. Princeton astrophysicists subsequently unveiled that the twisting magnetic field surrounding a black hole determines the distinctive polarization spiral observed in black hole images. Notably, the direction of energy transfer—whether it originates from the black hole or is directed toward it—dictates the nature of the polarization twist. By scrutinizing the spiral’s orientation, one can infer whether the magnetic field extracts spin energy from the black hole or injects spin energy into it.
George Wong, an associate research scholar affiliated with the Princeton Gravity Initiative and the Institute for Advanced Study, vividly illustrates the scale of this energy transfer, likening it to “if you took the Earth, turned it all into TNT, and detonated it 1,000 times a second for millions and millions of years.”
For decades, scientists have recognized that as a black hole begins to rotate, it imparts a rotational influence on the fabric of spacetime surrounding it. Magnetic field lines intertwined with the black hole are also entrained, contributing to the deceleration of its rotation and, in turn, generating the energy release.
Lupsasca, who now serves as an assistant professor of physics and mathematics at Vanderbilt University and received the 2024 New Horizons in Physics Prize from the Breakthrough Prize Foundation for his black hole research, notes the revolutionary nature of their discovery. He asserts, “Our new, precise prediction posits that whenever one scrutinizes an astrophysical black hole intertwined with magnetic field lines, there will be substantial energy transfer—of truly astronomical proportions.”
While their study unequivocally demonstrates the outwards flow of energy near M87*’s event horizon, the researchers acknowledge the theoretical possibility of an inward energy flow in different black holes. Their confidence in the relationship between energy flow and the orientation of magnetic field lines will soon be put to the test with the hypothetical “next-generation” Event Horizon Telescope.
Over the past year and a half, the global community of black hole researchers has been actively proposing specifications for this future instrument. George Wong anticipates, “Papers like ours can play a pivotal role in shaping these specifications. It is an extraordinarily exciting era.”
It is worth noting that the researchers, while their model strongly supports the notion that the black hole’s spin fuels the extragalactic jet, refrain from making a definitive claim. The energy levels revealed by their model align with the energy requirements of the observed jets, but they concede the possibility that the jet might be powered by rotating plasma located outside the black hole. As Lupsasca puts it, “I believe it is highly probable that the black hole powers the jet, but we cannot provide irrefutable proof at this juncture.”
Reference: “Black Hole Polarimetry I. A Signature of Electromagnetic Energy Extraction” by Andrew Chael, Alexandru Lupsasca, George N. Wong, and Eliot Quataert, 14 November 2023, The Astrophysical Journal.
This research received support from the Princeton Gravity Initiative, the Taplin Fellowship, the National Science Foundation (grant 2307888), and a Simons Foundation Investigator award.
Frequently Asked Questions (FAQs) about Black Hole Energy Dynamics
What did the Princeton astrophysicists discover about black holes?
The Princeton astrophysicists discovered that energy near the event horizon of the M87* black hole is expelled outward, challenging the common belief that energy flows inward.
How does this discovery relate to Einstein’s theory of relativity?
This discovery is rooted in Einstein’s theory of relativity, which predicts that rotating black holes can lose energy, similar to how a spinning top slows down over time.
What are the implications of this finding for black hole research?
This finding opens new avenues for understanding black hole dynamics and suggests that black holes can be sources of incredibly powerful outflows, known as “jets.”
How do the researchers determine the direction of energy flow?
The direction of energy flow is determined by analyzing the spiral orientation of magnetic field lines near the black hole, providing insights into whether the black hole extracts or pumps spin energy.
Could this discovery explain the source of the observed jets’ power?
While the study strongly supports the idea that black hole spin powers the extragalactic jets, the researchers do not make a definitive claim, leaving room for the possibility that rotating plasma outside the black hole may play a role.
How will this discovery be further tested?
The prediction that black holes lose rotational energy through energy transfer will be tested with the launch of the theoretical “next generation” Event Horizon Telescope, which will scrutinize more black holes.
What awards and support did the researchers receive for their work?
Alexandru Lupsasca received the 2024 New Horizons in Physics Prize from the Breakthrough Prize Foundation for his black hole research. The research received support from the Princeton Gravity Initiative, the Taplin Fellowship, the National Science Foundation (grant 2307888), and a Simons Foundation Investigator award.
More about Black Hole Energy Dynamics
- The Astrophysical Journal
- Princeton Gravity Initiative
- Event Horizon Telescope
- Breakthrough Prize Foundation
- Einstein’s Theory of Relativity