Economist GMAT Reading Comprehension Challenge #26
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Article: A lot of the periodic table is a result of neutron stars colliding
Link: https://www.economist.com/science-and-technology/2019/02/23/a-lot-of-the-periodic-table-is-a-result-of-neutron-stars-colliding
Living things are star…
Other than hydrogen from the big bang, elements from which life is composed came from the nuclear fusion that powers stars but that process has its limits and can’t produce elements heavier than iron.
To synthesise…
Some of the elements heavier than iron have been produced by supernova but supernova can’t account for the abundance of the heaviest metals which it is now confirmed are the products of collisions between ultra dense objects called neutron stars.
The neutron-star…
Neutron stars are the collapsed leftovers of particular types of supernova.
A single neutron…
Although a single neutron star cannot create new elements, two neutron stars orbiting each other might as they collide, creating an explosion called a kilonova that throws neutrons in all directions.
On Earth one …
On Earth one established way of making heavy elements from light ones is by neutron bombardment.
In effect…
Neutron bombardment is a small-scale version of what happens after a neutron-star collision but although the theory was reasonable until recently no one had seen a kilonova and so could prove its existence.
In the wake…
Scientists used optical telescopes to scan the recent kilonova to collect spectra from the explosion and thus determine which elements were created.
Kilonovae are rare events…
Kilonovae are rare events although they were more common in the past.
Future observations…
More refined analysis is forthcoming but it is confirmed that heavy metals at least in part originated from Kilonova.
Main Idea
It is now confirmed that Kilonovae are responsible for heavy metals present on earth that can’t be explained by supernovae.
Primary Purpose
To discuss a theory that has recently been confirmed by data.