Tiny Black Hole Passage Through a Human Body: A Physicist Quantifies teh Risks
A theoretical calculation reveals the potential, though remarkably unlikely, effects of a primordial black hole traversing the human body, ranging from undetectable passage to injury akin to a gunshot.
Vanderbilt University physicist Robert Scherrer has modeled the interaction between a human body and a primordial black hole – hypothetical,extremely small black holes formed in the early universe. The research, published in the International Journal of Modern Physics D, explores the consequences of such an event, finding that the outcome depends heavily on the black hole’s size. While larger primordial black holes (asteroid-sized or bigger) would inflict severe, possibly fatal, trauma, smaller ones might pass through unnoticed.
Scherrer’s analysis indicates that a black hole large enough to cause significant damage would exert a gravitational force akin to a high-velocity projectile. “A sufficiently large primordial black hole… would cause serious injury or death if it passed through you. It would behave like a gunshot,” Scherrer explains. However, the threshold for “spaghettification” - the stretching and distortion of tissue due to extreme gravity – is surprisingly high. Only at a certain minimum mass would the black hole’s gravity be strong enough to cause substantial damage, and even then, the resulting supersonic wake could contribute significantly to any injury.
Despite the dramatic possibilities, the probability of such an encounter is vanishingly small. Scherrer estimates a human-black hole collision would occur roughly once every quintillion years – far exceeding the 13.8 billion-year age of the universe. Moreover, the existence of primordial black holes remains unconfirmed. “Primordial black holes are theoretically possible, but they might not even exist,” Scherrer states. Even if they do exist, their low density makes an encounter “essentially never going to happen.” Humanity is unlikely to be around long enough for such an event to occur, and the universe itself may not last that long.
