Brian Greene

"The arrow of time points from past to future because of entropy—disorder always increases in a closed system."

"Gravity is not a force in the traditional sense, but a curvature of spacetime caused by mass and energy."

"The speed of light is the ultimate speed limit of the universe, a fundamental constant that cannot be exceeded."

"If we could build a perfect map of all particles and forces, would we truly understand the universe?"

"The uncertainty principle reveals that nature has built-in limits to how precisely we can know reality."

"Parallel universes might exist, each with different physical laws, though we may never directly observe them."

"The universe expands, and the expansion is accelerating due to dark energy, suggesting an eternal future."

"Wormholes are mathematical solutions to Einstein's equations, though we don't know if they actually exist."

"Time travel to the past may violate causality unless parallel timelines branch with each change."

"The universe is fundamentally quantum at small scales, yet macroscopic objects behave classically—the bridge between them remains mysterious."

"Our brains evolved to navigate a world of medium-sized objects at moderate speeds, making extreme physics counterintuitive."

"The multiverse concept suggests that our Big Bang was just one event among countless others."

"Consciousness remains one of the great unsolved mysteries, yet physics and philosophy continue to grapple with it."

"The more we learn about the universe, the more we realize how much we don't know."

"Science is not about absolute truth but about better approximations and more accurate models of reality."

"The beauty of physics lies in its economy—simple principles generate immense complexity."

"Every prediction of Einstein's relativity has been confirmed, yet it remains fundamentally incomplete."

"The universe may be deterministic at the quantum level, yet randomness appears fundamental to reality."

"We are not separate from the universe; we are expressions of it, conscious observers of our own creation."

"The quest to understand the universe is a reflection of humanity's deepest curiosity about existence."

"Symmetry principles underlie the deepest laws of physics, suggesting that nature prefers elegant solutions."

"If the Big Bang was the birth of time itself, the question 'what came before?' is meaningless."

"The universe may be infinite in space and finite in age, creating a cosmic horizon beyond which we cannot see."

"Reality is far stranger than our everyday experiences suggest, requiring imagination to grasp."

"The study of physics is not about finding the ultimate answer but about deepening the questions we ask."

"Energy cannot be created or destroyed, only transformed—a principle as fundamental as existence itself."

"The universe operates on principles of probability and quantum mechanics, not certainty and classical determinism."

"To understand the universe, we must embrace both the mathematical elegance of equations and the empirical evidence from experiments."

"Time dilation means that an astronaut traveling at near light-speed ages more slowly than someone on Earth."

"The cosmological principle suggests that the universe is homogeneous and isotropic on large scales, but we are still testing this assumption."