For most of the history of genetics, the story was simple: you inherit DNA from your parents, that DNA determines your traits, and what happens during your lifetime doesn't change what you pass on. But a field called epigenetics has been quietly rewriting that story.

What Is Epigenetics?

Epigenetics is the study of changes in gene expression that don't involve changes to the DNA sequence itself. Think of your DNA as a book. Epigenetics is about which pages get read — and which ones get skipped.

Where Your Ancestors Come In

Some epigenetic tags can be inherited. One of the most studied examples is the Dutch Hunger Winter of 1944–45. Children born to mothers who were starved during this period had higher rates of obesity, heart disease, and mental illness decades later — not because their DNA changed, but because their epigenome was set by an environment of severe starvation before birth.

What Can Change Your Epigenome?

Diet, stress, exercise, sleep, smoking, and even early-life experiences all leave traces in the epigenome. This is simultaneously hopeful and sobering — your choices genuinely matter, but so do the conditions previous generations lived in.

The Sun contains 99.86% of all the mass in the solar system. About 1.3 million Earths could fit inside it. The core reaches 15 million°C. The surface is a comparatively cool 5,500°C. Weirdly, the outer atmosphere — the corona — is hotter than the surface at over 1 million°C. Scientists are still not fully sure why. This is called the coronal heating problem and it remains unsolved.

Every second, the Sun converts 600 million tonnes of hydrogen into helium through nuclear fusion. The energy produced in the core takes between 10,000 and 170,000 years to reach the surface — but only 8 minutes to reach Earth. The Sun is about 4.6 billion years old and roughly halfway through its life. When it runs out of hydrogen, it will expand into a red giant, then collapse into a white dwarf.

Gsolix wasn't planned. It started as a frustration. We were students trying to understand biology concepts the night before an exam, dealing with platforms that hid their best content behind paywalls. So we started building.

Gsolix now has interactive quizzes for Biology, Physics, Mathematics, CS, and Chemistry. Flashcards, live study chat, XP leaderboards, study clubs, and a community blog. All completely free. No ads, no subscriptions, no gatekeeping. That's not changing.

We believe access to quality education should not depend on how much money you have. Gsolix is and will always be completely free. What started as a collection of notes became a platform with quizzes, flashcards, live chat, and a community of people who care about learning for its own sake.

The biggest lesson was not technical. Explaining something well to someone else forces you to understand it properly yourself. Building Gsolix made us better students, not just better developers.

Slow-twitch fibers (Type I) are dense with mitochondria, resist fatigue, and power endurance. Fast-twitch fibers (Type II) contract explosively but tire fast. Most people have a roughly even split, but genetics play a significant role.

Your gut contains over 100 million neurons and communicates with the brain via the vagus nerve. Your microbiome produces about 90% of the body's serotonin. A high-fibre, plant-rich diet feeds a diverse bacterial community. Antibiotics are the most dramatic disruptor — a single course can alter the microbiome for months.

When you touch yourself, your brain already knows exactly what's coming — it cancels the sensation before it registers. This mechanism is called efference copy. Tickling requires unpredictability. A robot with a slight time delay can tickle you — the lag disrupts the brain's prediction and the sensation gets through.

Salamanders form a blastema — a mass of cells that rebuilds the limb from scratch. Humans form scar tissue instead. Many genes responsible for regeneration exist in humans but are inactive. Full limb regeneration isn't possible today, but it's a serious area of research.

In the 1980s, neuroscientist Benjamin Libet found that brain activity associated with movement began ~550ms before the action — but people reported deciding only ~200ms before. The brain was preparing before the conscious decision. Most philosophers today take a compatibilist view: free will and determinism can both be true. What we call "free will" is the ability to act according to our own values without external coercion.

The dominant scientific view is that consciousness arises from neural activity. But philosopher David Chalmers' "hard problem" points out that knowing brain activity accompanies experience doesn't explain why experience exists at all. Science shows the brain is deeply involved. Philosophy shows this may not be the whole story.

Mathematical truths feel inevitable — two plus two equals four everywhere. Complex numbers were once called "imaginary," then became essential to quantum mechanics. If math were invented, this alignment with reality would be extraordinary. Perhaps we invent the tools to explore mathematical space — but the truths we find were always there.

Einstein's General Relativity: gravity is not a force — it is the curvature of spacetime caused by mass. Objects follow the straightest possible path through curved spacetime. GPS satellites must account for relativistic effects or their clocks drift and navigation fails within hours.

Entropy always increases in a closed system. Entropy is the reason time has a direction — the laws of physics are time-symmetric, but entropy is not. The universe will eventually reach maximum entropy: the heat death — no more gradients, no stars, no life. Just a cold, featureless equilibrium. This takes unimaginably long, but the second law demands it.

Young's double-slit experiment showed light is a wave. Einstein's photoelectric effect showed it's a particle (photon). The resolution: light is a quantum object that behaves like a wave when not measured and a particle when measured. This is wave-particle duality, and it's a fundamental feature of reality — not a limitation of instruments.

Traditional software is written as explicit rules — if this, then that. Machine learning inverts this: give the system data and let it figure out the rules. Modern AI makes predictions, compares them to correct answers, adjusts to reduce errors, and repeats millions of times. Large language models learn to predict what comes next in text. Through this simple objective at enormous scale, they develop something that looks like understanding.

O(1) = constant. O(n) = linear. O(n²) = quadratic — gets painful fast. O(log n) = logarithmic — a billion items takes only ~30 steps with binary search. A fast computer running O(n²) will eventually lose to a slow computer running O(n log n) as input grows. Big O describes the fundamental shape of an algorithm at scale.

1) DNS translates "gsolix.com" to an IP address. 2) TCP handshake establishes a connection. 3) HTTPS request asks the server for the page over an encrypted TLS connection. 4) The server responds with HTML, CSS, JS. 5) Your browser builds the DOM, applies styles, runs JavaScript, and renders what you see — all in a few hundred milliseconds.