Lecture: Are We Really Made of Stardust?

Introduction

• Main Idea: Humans are made up of elements created in stars.
• Key Speaker: Dr. Ashley King, Planetary Scientist and Stardust Expert.

Formation of Elements in Stars

• Supernovae: Responsible for creating many elements in the periodic table.
• Human Elements: Nearly all elements in the human body originated in stars, often through multiple supernovae.

The First Generation of Stars

• Universe Beginnings: Began 13-14 billion years ago with only light elements (hydrogen, helium, lithium).
• Element Formation: Initial stars formed from gas lumps and initiated nuclear reactions.
• Star Size: First stars were more than 50 times the size of our Sun.
• Nucleosynthesis: Process of element creation within stars.
• Supernova Impact: Early supernovae spread elements to form subsequent stars.

The Life Cycle of Stars

• Fuel and Energy: Stars burn fuel to produce energy, maintaining a balance with gravity.
• End of Stars: Large stars end in spectacular supernovae, while smaller stars like our Sun do not.
• Galactic Chemical Evolution: Continuous reprocessing of elements leading to formation of planets and life.

Observing Stars and Stardust

• Star Observation: Stars can only be observed indirectly due to time lag in light travel.
• Rare Observations: Example of supernova in 1987 allowing direct observation of material ejection.

Studying Stardust

• Cosmic Dust: Studied through electron microscopy to understand star life cycles.
• Pre-solar Grains: Original stardust particles older than our Sun found in meteorites.

Conclusion: Are We Made of Stardust?

• Element Formation: Most elements in our bodies formed in stars, while some light elements originated from the Big Bang.

Additional Topics

• Questions and Engagement: Invitation to ask questions and engage with scientific inquiries.
• Call to Action: Encouragement to support the Natural History Museum's efforts in scientific discovery and environmental protection.

Further Exploration

• Space Exploration: Links to resources and courses about space and cosmic phenomena.