Strangelet - Debate About The Strange Matter Hypothesis

Debate About The Strange Matter Hypothesis

The strange matter hypothesis remains unproven. No direct search for strangelets in cosmic rays or particle accelerators has seen a strangelet (see references in earlier sections). If any of the objects we call neutron stars could be shown to have a surface made of strange matter, this would indicate that strange matter is stable at zero pressure, which would vindicate the strange matter hypothesis. But there is no strong evidence for strange matter surfaces on neutron stars (see below).

Another argument against the hypothesis is that if it were true, all neutron stars should be made of strange matter, and otherwise none should be. Even if there were only a few strange stars initially, violent events such as collisions would soon create many strangelets flying around the universe. Because one strangelet will convert a neutron star to strange matter, by now all neutron stars would have been converted. This argument is still debated, but if it is correct then showing that one neutron star has a conventional nuclear matter crust would disprove the strange matter hypothesis.

Because of its importance for the strange matter hypothesis, there is an ongoing effort to determine whether the surfaces of neutron stars are made of strange matter or nuclear matter. The evidence currently favors nuclear matter. This comes from the phenomenology of X-ray bursts, which is well-explained in terms of a nuclear matter crust, and from measurement of seismic vibrations in magnetars.