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Too Hard For Science? A Black Hole Life Preserver

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


Can one prolong survival near a black hole, even for an instant?

In "Too Hard For Science?" I interview scientists about ideas they would love to explore that they don't think could be investigated. For instance, they might involve machines beyond the realm of possibility, such as devices as big as galaxies, or they might be completely unethical, such as experimenting on children like lab rats. This feature aims to look at the impossible dreams, the seemingly intractable problems in science. However, the question mark at the end of "Too Hard For Science?" suggests that nothing might be impossible.

The scientist:J. Richard Gott, professor of astrophysical sciences at Princeton University.


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The idea: A black hole's gravity can rip apart anybody tumbling into one. However, might it be possible to counteract its gravity to prolong survival? Gott and his colleagues say it is.

Let's say you were to fall toward a large black hole, one more than 13,000 times the mass of the sun, and assume for simplicity's sake that it's neither rotating nor electrically charged. If you were to plummet feet first, "it's like being pulled apart on a rack and being crushed in an iron maiden at the same time," Gott explains — your feet experience a stronger pull than your head while your sides get mashed together. Although "spaghettification" with such a black hole would take less than 0.1 seconds, "that's just long enough for a pain signal to get from your waist to your head as you rip apart," he says.

Is there an invention a prospective diver can use to resist spaghettification? Gott and his colleague Deborah Freedman Woods calculated that a giant ring might do. If this "life preserver" encircles your waist as you fall, its gravity counteracts the black hole's, pulling your sides apart while pulling your head and feet together.

The problem: Although this life preserver would prolong survival, it would not ultimately save your life — it would merely shorten the time of suffering by a factor of about 26. That, at least, "is so fast you really wouldn't know what hit you," Gott says.

Moreover, such a buoy would have a mass of more than 12,800 trillion tonnes, about two-millionths the mass of Earth, roughly equal to an asteroid 100 miles wide. "That's somewhat beyond the current NASA budget," Gott says.

The solution? Instead of just delaying a death one would experience from diving into a black hole, such a life preserver could enable daredevils or probes to venture closer to neutron stars or small black holes than would otherwise have been the case and still return safely home from the adventure.

"Hero of Alexandria invented a steam engine before 100 AD, and people back then looked at this and said, 'Good job, that's fun, isn't that nice,' and nobody looked at it and said 'Wait, this can change the world.' We waited about 1,700 years for the Industrial Revolution," Gott notes. "You can never tell — concepts for inventions that might seem like toys now might have unrealized promise."

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If you have a scientist you would like to recommend I question, or you are a scientist with an idea you think might be too hard for science, email me at toohardforscience@gmail.com.

Charles Q. Choi is a frequent contributor to Scientific American. His work has also appeared in The New York Times, Science, Nature, Wired, and LiveScience, among others. In his spare time, he has traveled to all seven continents.

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