✓ Accepted Answer
The human brain contains roughly 86 billion neurons connected by about 100 trillion synapses — connections between neurons. Information travels as electrical impulses along neurons and chemical signals across synapses.
Different regions specialise in different functions. The prefrontal cortex handles planning, decision-making, and personality. The hippocampus forms and retrieves memories. The amygdala processes emotions, particularly fear. The cerebellum coordinates movement and balance. The brainstem controls basic survival functions like breathing and heart rate.
Memory isn't stored in one location but distributed across networks. Long-term memories form through synaptic strengthening — when neurons repeatedly fire together, their connections strengthen, which is why practice and repetition improve memory. Sleep is critical for consolidating memories from short-term to long-term storage.
The brain is remarkably plastic, especially in youth. It reorganises in response to experience and learning. Neuroplasticity continues in adulthood, though more slowly. This is why learning new skills at any age remains beneficial and why stroke rehabilitation can be effective.
by sebastianahmed
· 58 upvotes
Quantum mechanics describes how matter and energy behave at the subatomic scale, and it's deeply counterintuitive. Several principles will sound strange:
Superposition: quantum particles can exist in multiple states simultaneously until measured. Schrödinger's famous thought experiment — a cat that's both alive and dead — illustrates this absurdity at everyday scales.
Entanglement: two particles can become correlated so that measuring one instantly determines the state of the other, regardless of distance. Einstein called this "spooky action at a distance." It's now experimentally confirmed and forms the basis of quantum cryptography.
Uncertainty principle: Heisenberg showed you cannot precisely know both a particle's position and momentum simultaneously. This isn't a measurement limitation — it's a fundamental feature of reality.
These aren't abstract — they're why transistors (and therefore all computers) work, why MRI machines function, and how lasers operate. Quantum mechanics is the most precisely tested theory in all of science.
by chloeouellet95249
· 6 upvotes