A Warp Drive Could Shine Brighter than the Sun in the Earth’s Atmosphere
Trustworthy military pilots report about Unidentified Aerial Phenomena (UAP) that exceed the performance envelope of human-made technologies. In a testimony before Congress, the Retired Navy Commander David Fravor reported seeing in 2004 white `Tic-Tac’ shaped objects that are of order 10-meter long , descending about 30 kilometers in less than a second.
Some interpreters were quick to suggest that UAP might be warp drives invented by magical thinking in science fiction narratives.
But there is also a scientific counterpart to this concept. By warping space inside a bubble, a spacecraft inside the bubble could be propelled to a spatial speed faster than light. This possibility is manifested in the Alcubierre drive, a theoretical steady-state solution to Einstein’s equations of General Relativity. The Alcubierre metric in the time (t) and space (x,y,z) coordinates can be written as:
where v_s is the speed of the warp bubble, f(r_s) is the shape function of the bubble and r_s is the radial distance from the bubble center. The creation of such a bubble requires an exotic substance with negative energy density, in violation of the Weak Energy Condition of Einstein’s General Relativity. We do not know if such a substance exists. If it exists, it might be possible to create a time machine out of it and go back in time.
In a warp bubble moving at a speed comparable to the speed of light, the distortion of spacetime is large — of order unity. When such a spacetime structure moves through air, it would move around air molecules at roughly the speed of light during a period of order the light crossing time of the bubble. The inevitable collisions of these molecules with each other will heat up the air around the bubble to an extremely high temperature, triggering the formation of a fireball more powerful than those seen around meteors or atomic explosions.
The supersonic motion of the air would inevitably lead to dissipation of heat and an outward moving blast wave that would cool through the emission of radiation. How bright might the fireball be?
Assuming energy conservation, the heat deposited in air would eventually be radiated away. For a bubble that moves molecules around near the speed of light, the dissipated power could be at most of order the rest mass energy of the air within the bubble volume divided by the light crossing time of the bubble. For an object of 10 meters in size, this corresponds to a maximum radiation power of roughly ten times the luminosity of the Sun. An Alcubierre Warp Drive on the length scale of the `Tic-Tac’ objects reported by Navy Commander David Fravor could shine brighter than the Sun. Clearly, this was not observed in 2004.
In reality, the radiative luminosity would be somewhat smaller because the reduced cross-section for molecular collisions at relativistic velocities but not enough to make the fireball faint enough to be consistent with Fravor’s testimony. Even though the luminosity scales with the area of the warp bubble, it could still approach a tenth of the Sun’s luminosity for a meter-size bubble. The luminosity scales with the air speed cubed, but that speed cannot be smaller than 10 kilometers per second based on Fravor’s testimony. At that minimum speed, a meter-size bubble would still shine with a power of 30 terawatts, ten times larger than the average electric power consumption throughout the globe. Surely, such a bright source of light was not seen in 2004.
Of course, we can always imagine new physics that avoids this conclusion but any such physics should be contemplated only if it is suggested by indisputable evidence from exquisite scientific instrumentation.
Is there a caveat to Fravor’s report? When driving in a highway, we might see a black car behind us in the rearview mirror and then shortly thereafter notice the same type of black car in front of us. Without verifying that the license plates are identical, our eyewitness testimony does not imply conclusively that we saw the same car moving at an extraordinary speed. Our two data points might be associated with two independent cars coming in and out of our view.
This caveat calls for a rigorous scientific study of UAP — triggered by Fravor’s report, which is precisely the goal of the Galileo Project that I am leading. As of now, the Galileo research team is able to measure distances to objects in the sky through the method of triangulation from multiple observing units (as discussed here). This allows us to unambiguously measure the velocity and acceleration of objects with well-calibrated scientific instrumentation.
Recently, we invited here the public to get engaged in our data analysis as a way of establishing the ground truth for our machine-learning software in searching for UAP.
Here’s hoping that in the coming months and years, the Galileo research team will shed new light on the origin of the unusual `Tic-Tac’ objects reported by Navy Commander David Fravor.
ABOUT THE AUTHOR
Avi Loeb is the head of the Galileo Project, founding director of Harvard University’s — Black Hole Initiative, director of the Institute for Theory and Computation at the Harvard-Smithsonian Center for Astrophysics, and the former chair of the astronomy department at Harvard University (2011–2020). He is a former member of the President’s Council of Advisors on Science and Technology and a former chair of the Board on Physics and Astronomy of the National Academies. He is the bestselling author of “Extraterrestrial: The First Sign of Intelligent Life Beyond Earth” and a co-author of the textbook “Life in the Cosmos”, both published in 2021. The paperback edition of his new book, titled “Interstellar”, was published in August 2024.
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