Dark matter places limit on how massive and lethal these particles could be, the fact that no one seems to have been killed by rushing to it
Physicists suppose the invisible darkish matter should exist as a result of they will see its gravitational results on the understood subject all through the cosmos. However, nobody is aware of what it’s genuinely made. Among the many primary candidates are weakly interacting large particles, or WIMPs, however, scientists have hunted for them for decades with no success.
Starkman and colleagues focused on macroscopic dark matter, or macros, first proposed by physicist Edward Witten within 1980. If they exist, macros can be made up of subatomic particles referred to as quarks, identical to ordinary matter, however, mixed in a method by no means earlier than noticed.
Theoretically, macros might have nearly any dimension and mass. And since darkish matter doesn’t interact with ordinary matter, there can be nothing to stop these particles from zipping around unimpeded.
If a macro as small as a square micrometer zipped by way of your body at hypersonic speed, it might deposit about as a lot of power in your physique as a typical metal bullet, the group calculated. However, the injury it brought about could be different from that of a round: A macro would heat the cylinder of tissue in its wake to approximately 10,000,000° Celsius — vaporizing the tissue and leaving a path of plasma.
There can be nothing you might do to protect yourself from such a macro strike. Still, there’s no motive to worry, Starkman says. Considering there have been no stories of anybody instantly struggling a mysterious lightsaber wound, the researchers concluded that if macros exist, they must be smaller than a micrometer and lighter than about 50 kilograms.
Physicist Katherine Freese thought these calculations had been price doing. “This examines fun,” says Freese of the University of Michigan in Ann Arbor. “In search of macros in already current detectors, such because the human physique, is a good suggestion.” Although she wasn’t concerned within the macro analysis, she and colleagues did the same thought experiment with WIMPs in 2012. “However weak interactions are so weak as to be innocent” to human bodies.