Dark matter and dark energy are believed to make up the majority of the universe, yet their exact nature remains a mystery.
Despite significant progress in understanding the Big Bang theory and the early stages of the evolution of the universe, the exact origin of the universe remains unknown.
Currently, there are different theories, such as string theory and loop quantum gravity, that attempt to unify these forces, but a complete theory of everything remains elusive.
The question of how subjective experiences arise from the activity of neurons in the brain is still an open question in neuroscience and philosophy.
Despite extensive research and scientific advancements, the exact origin of life on Earth remains uncertain.
The question of whether there is life beyond Earth is one of the most intriguing mysteries in science.
Time is a fundamental aspect of our existence, yet its true nature remains mysterious.
Consciousness, our subjective experience of the world, is still not fully understood.
Despite being one of the most fundamental forces in the universe, gravity is not yet fully understood.
The ultimate fate of the universe, including whether it will continue expanding indefinitely or eventually collapse, is still unknown.