Question

Decide whether the statement makes sense (or is clearly true) or does not make sense (or is clearly false). Explain clearly; not all of these have definitive answers, so your explanation is more important than your chosen answer. The gold in my wedding band was made by the merger of two neutron stars.

Short answer

The statement makes sense because neutron star mergers can create gold, though individual events cannot be traced.

Step-by-step solution

Understanding the Statement

The statement suggests that the gold in the wedding band was formed from the collision of two neutron stars. Neutron stars are the remnants of massive stars that have exploded in supernovae and are extremely dense regions composed mostly of neutrons.

Research on Gold Formation

In astrophysics, it is understood that heavy elements like gold are formed in two primary ways: during supernova explosions and through the process of neutron star mergers. Both processes involve high-energy environments where neutron capture can occur at rates necessary to form heavy elements.

Analyzing the Feasibility

Given that neutron star mergers are extremely rare but significant cosmic events capable of producing gold, it is plausible that the gold could have originated from such an event, followed by its incorporation into planet-forming materials and eventually becoming part of Earth.

Conclusion on the Plausibility

The statement makes sense in a broader cosmic context. While it is practically impossible to trace the origin of a specific atom of gold to a particular cosmic event, the general scientific understanding supports the possibility that gold could have been formed in neutron star mergers.

Key concepts

Neutron Star Mergers

Neutron star mergers are cosmic events where two incredibly dense stars, known as neutron stars, collide with each other. These stars are remnants of massive stars that have undergone supernova explosions, leaving behind a core purely made of neutrons. When two of these stellar remnants orbit each other and eventually crash together, they create an event that produces enormous amounts of energy.
These mergers are of great interest to scientists because they are rare yet powerful happenings that can be detected through gravitational waves, ripples in spacetime caused by massive bodies in motion. Such events are not just fascinating; they play a crucial role in enriching the universe with heavy elements.
The collision process creates conditions where rapid neutron capture, known as the r-process, occurs. This leads to the formation of heavy elements, such as gold and platinum, dramatically impacting cosmic nucleosynthesis.

Gold Formation

Gold is a heavy element that requires extreme environments for its creation, environments that involve high-energy events in space. Two main phenomena are known to forge gold: supernovae and neutron star mergers.
In both cases, the process involves the r-process, a series of rapid neutron captures by atomic nuclei.

• In a supernova, the explosion provides the energy and free neutrons needed for these interactions.
• In neutron star mergers, the sheer density and collision dynamics provide an ideal breeding ground for transforming simpler atoms into heavy metals like gold.

Although it's not possible to trace the gold in a piece of jewelry back to a specific cosmic event, understanding that such rare and dramatic events have produced the atoms in precious metals adds to their allure.
Each piece of gold tells a story of cosmic events that occurred long before the formation of our solar system.

Supernovae

Supernovae mark the violent end of a star's lifecycle. These explosions are among the universe's most energetic events and can outshine entire galaxies for a brief time.
During a supernova, the star rapidly ejects most of its mass into space, enriching the interstellar medium with heavy elements and creating an intense site for nucleosynthesis.
The forceful expulsion originating from these explosions facilitates the spread of elements across the galaxy. Through the r-process during a supernova, heavier elements, some as heavy as uranium, can be forged.

• The core-collapse type of supernovae involves massive stars that have burnt through their nuclear fuel, leading to an unstoppable gravitational collapse and resultant explosion.
• Supernovae leave behind neutron stars or black holes and distribute newly formed elements throughout space.

This distributed material eventually becomes part of stellar nurseries where new stars and planetary systems are born.

Heavy Elements

Heavy elements are those found beyond iron on the periodic table and require special cosmic events for their creation. Their formation relies on processes with rapid neutron capture, distinct from those that form lighter elements.
Since regular stellar processes are insufficient for forming elements heavier than iron, unique cosmic events come into play:

• Neutron star mergers allow for a site of intense r-process nucleosynthesis owing to their high density and energy.
• Supernovae, with their colossal energy output and rapid neutron flux, lead to the creation of diverse heavy elements.

These elements spread across the universe and contribute to the material forming new planets and stars. The existence of heavy elements on Earth indicates a rich history of cosmic violence, as these atoms have traveled across galaxies over aeons.
Through the life cycles of stars and the grand events following them, the universe perpetually enriches itself, allowing for the complex chemistry we observe today.