Yesterday I was preparing for my Saturday meeting with my ex supervisor and I found the article about first stars numerical Simulation. So I can simply explain what was going on many many years ago.....(200-400 millions years after Big D... Bang)
When the Universe first began to evolve, almost everything in it was hydrogen and helium. These were the primordial elements, and there was so much of them that, in the end, the first stars would form from them.
But how exactly did stars begin to appear, and why is it so important?
At the very beginning of the Universe, there was just cold and sparse gas. As it gradually compressed under the influence of gravity, its density increased and its temperature began to rise. However, because the gas lacked heavy elements (like carbon or oxygen), it was hard to cool down. Without cooling, it couldn’t compress enough to form stars. (If a star is too hot, molecules just scatter because of the strong kinetic energy.)
For the gas to cool, there needed to be hydrogen molecules in it. They acted as cooling agents, helping to dissipate excess heat, which allowed the gas to keep compressing.
As a result of the gas compressing, the first stars began to form and they were very massive. These stars could be tens, even hundreds, of times bigger than our Sun (our star formed a generation later). Why? Because in the early Universe, the gas was much denser, and therefore the stars that formed were much larger.
And when these first stars ran out of fuel, they exploded as supernovae, spreading heavy elements throughout the Universe.
You might ask, where did these heavy elements come from? They were the result of chemical reactions during the star's life. Heavier elements formed from hydrogen and helium. These elements became the building blocks for subsequent stars and planets. And for us too: we are the children of stars.
Well I divided the post, bc it was toooo big this morning (oh no😮💨, I joked even didn't realize I did it).
Next time I will show it with the Friedman equation.
Dark matter is not directly observable, but its influence can be measured through various astrophysical observations. The main methods confirming that dark matter constitutes about 27% of the total mass-energy of the universe include: 1. Cosmic Microwave Background (CMB) 2. Gravitational Lensing 3. Dynamics of Galaxies and Clusters
Today, I’ll focus on the first point, because otherwise, you’ll die reading all of this. :)
Cosmic Microwave Background (CMB)
The CMB is light that has traveled freely since the early hot phase of the universe(of course, not as hot as i am, kidding). When the universe was only 380,000 years old (VERY hot MILF, forgive me, Christ), its temperature dropped enough for photons to stop scattering off free electrons and start traveling freely through space(like independent women now, like me for example, haha). These photons now form the cosmic microwave background.
They detected small temperature fluctuations. These fluctuations correspond to variations in density in the early universe. In other words, photons interacted differently with regions of varying density, leaving an imprint that can be detected today. Ordinary matter creates shock waves, while dark matter provides additional gravitational pull, influencing the shape of these waves.
To determine how much dark matter exists in the universe, scientists analyze the intensity and frequency of these fluctuations. Usually scientists just compare theoretical models with observational data. If there is only ordinary matter - the structure of these fluctuations would be different.
You've heard of dark matter (no, antimatter is different)? Today I thought about what would happen if you swapped ordinary and dark matter. But to make things simpler, I'll give you some analogies.
Imagine the Universe is a house you're building. There are two important materials in this house: ordinary matter (bricks) and dark matter (the frame). Ordinary matter is what we can see: stars, planets, gas. Dark matter is invisible, but it’s abundant and holds the entire structure of the Universe together.
Currently, there is much more dark matter than ordinary matter in our Universe. This helps stars and galaxies move in predictable ways, and gravity is distributed evenly. Without dark matter, galaxies and stars wouldn’t have formed the way we see them.
Now, imagine we swap them: ordinary matter becomes abundant, and dark matter is almost gone. This would drastically change the situation. With a lot of ordinary matter, galaxies would become bright and dense, but without a strong framework (dark matter), they would be less stable. The structure of the Universe would change: in the centers of galaxies, stars would be bright and powerful, but at the edges, where there is less gravity, stars would move slower, and the galaxies would be less stable.
So now you understand how important it is:) I also attached the pic
Any movement of bodies follows Newton’s laws. During sex, the following principles apply:
Friction - a key factor in the process; without it, nothing happens. It can be considered a dynamic force, which is reduced by natural lubrication or special substances.
Momentum and energy transfer - partners exchange momentum, maintaining a rhythm of movement. Ideally, they reach harmonic oscillations, where the amplitude and frequency of movements are optimal.
Center of mass - its position is crucial for the stability of different positions. In certain cases, angles and levers play a decisive role.
2. Thermodynamics
Sex involves the conversion of chemical energy (glucose) into mechanical and thermal energy:
Heat generation: active muscle movement increases body temperature, as in any high-metabolism process.
Heart activity increases oxygen supply, leading to higher energy consumption.
Evaporation (sweat) - a natural cooling mechanism that follows the laws of heat exchange.
3. Wave Nature of Arousal
Electromagnetic waves also play a role:
Nerve impulses are transmitted as electrical signals along neurons at speeds up to 120 m/s, creating instant reactions.
4. Acoustics
Sex is also about sound. Moans and breathing are linked to acoustic waves:
Resonant frequencies - vocal cords function as an oscillatory system, generating harmonics.
Sex, from a physics standpoint, is a fascinating interplay of forces, energy, and resonance is a perfect example of applied science in real life.
Last time I told you about eV, now you a smart enough to understand this post😌😌
1. Low-energy particles
Energy: less than 10⁹ eV (this is roughly the energy of a single gamma particle: stronger than a visible light photon, but still no superhero).
Example: these particles have about the same energy as electrons in an old CRT television or a microwave. They kind of work, but honestly, they're not that impressive.
Danger: No threat at all. These guys are so weak that Earth’s magnetic field "sends them go fuck themselves🫢
2. Medium-energy particles
Energy: from 10⁹ to 10¹² eV
Example: this is like the energy of a baseball thrown by an angry pitcher or a minor car crash (hopefully without you involved).
Danger: Safe on the ground, but if you’re flying in a plane, you’ll get a tiny dose of radiation. Don’t worry, it’s not enough to turn you into the Hulk.
3. High-energy particles
Energy: from 10¹² to 10¹⁵ eV.
Example: these particles carry energy equivalent to a 1 kg rock falling from a height of 1 meter. Imagine this "cosmic rock" zooming through the universe, completely indifferent to what’s happening on your little planet.
Danger: No issues on Earth, but in space, these particles can cause a "blue screen of death" for your equipment, I hope you stay at home today!
4. Ultra-high-energy particles
Energy: from 10¹⁶ to 10¹⁹ eV
Example: a particle with this energy is like a tennis ball launched with enough force to make your neighbor storm out and yell at you.
Danger: These particles can cause a "cosmic shower" of secondary particles that reach nearly to the surface. For astronauts, they’re a nightmare. For Earth, just a rare curiosity.
5. Extremely high-energy particles
Energy: above 10¹⁹ eV
Example: imagine a basketball flying at ridiculous speeds. These are the rare "champions" of cosmic rays, but you’d catch one only once a year over an area the size of a square kilometer.
Danger: These particles are so rare they’re more likely to break scientists’ brains than anything on Earth. They don’t cause any harm but make physicists scratch their heads, asking, "Where the hell did you come from?"
An electron-volt is a unit of energy. But don’t think it’s some kind of super-powerful thing. It’s actually the smallest and most humble unit of energy physicists use because in the microscopic world, big numbers just make your brain hurt.
How does an electron-volt work?
Imagine you have a 1-volt battery. If an electron (a tiny and speedy guy) zips through the electric field of this battery, it gains an energy of 1 electron-volt. It’s like giving the electron a tiny kick and watching it speed off, thinking it’s the fastest thing in the universe.
How powerful is it, really?
Well… let’s just say: That’s like asking an ant to pull a truck. The ant might try, but let’s face it: it’s not making a dent.
To lift a glass of water 1 meter high, you’d need about 10²⁰ eV. That’s like recruiting 100 billion billion electrons to team up and lift that glass. Teamwork makes the dream work😁
Why do physicists love electron-volts so much?🤤
In the atomic world, everything is tiny: electrons, nuclei, energies - everything except the physicists’ ambitions💅. If they used joules(I hope you know it, sometimes they write it on your chips pack) they’d be stuck writing numbers with a hundred zeros. But with electron-volts, it’s simple:
The energy of an electron in an atom? A few eV.
X-rays? Thousands of eV (kiloelectron-volts, keV).
Particles in an accelerator? Millions or billions of eV (MeV, GeV).
Rigidity of a particle is its ability to "punch through" magnetic fields(Yes, in space we have sooo fucking big magnetic field. Galactic one) Rigidity is the ratio of the particle’s momentum(kinda speed*mass, except photon ofc) to its charge. The greater the particle’s energy (momentum) and the smaller its charge, the harder it is to deflect its trajectory.
In other words, the particle doesn’t care about the magnetic field: it keeps flying as if nothing can stop it. Rigidity is the parameter that determines whether a cosmic ray particle can penetrate magnetic fields and, for example, reach Earth.
Earth's magnetic field acts like a huge protective screen, deflecting charged particles. Its strength is most noticeable at the equator, where the field lines are nearly horizontal, and weakest near the poles. This means that particles with low rigidity are deflected and don’t reach Earth, especially in equatorial regions. High-energy particles with greater rigidity, however, overcome the magnetic field and reach the planet’s surface. This is why polar regions are more frequently exposed to cosmic rays, leading to phenomena like auroras(I wrote about here already, just scroll below...long scroll...).
For astronauts and satellites, the picture is much less pleasant🥲 High-energy cosmic rays pose a serious threat: they can penetrate spacecraft walls, damage equipment through radiation, and expose crews to harmful radiation.
Earth’s magnetic field protects us, but in open space, this "shield" is absent, and cosmic radiation becomes a significant challenge for future missions to the Moon and Mars.
You might ask: "But doesn’t the magnetic field fail to protect us from super high-energy particles?"
And I will say "there’s no real need for protection in those cases, because such particles are incredibly rare: about one particle per km² per year. It’s the low-energy(even auroras particles are low energetic) are abundant and far more problematic, but we are protected(unlike astronauts).
Surely you've wondered (well, maybe not always, who knows, but I find it fascinating) why no two snowflakes are alike?
The secret lies in their unique journey of turning water into ice. It’s impossible to create completely identical conditions, only similar ones. Even temperature, which might seem stable, actually fluctuates every millisecond. What you see on weather forecasts or sensors is always an approximation.
The slightest change in these conditions results in a completely different snowflake.
But let’s start from the beginning:
A snowflake forms when a tiny droplet of water in the air freezes onto a speck of dust. Water molecules in ice bond at specific angles due to hydrogen bonds, creating a hexagonal shape - the foundation of a snowflake’s symmetry.
From there, the snowflake grows by attracting more water molecules from the moist air around it.
And here’s where it gets interesting: its growth is heavily influenced by temperature (and humidity too), both of which constantly shift as the snowflake falls through the atmosphere.
For example, in colder conditions, the edges grow faster, forming intricate patterns. Higher humidity, on the other hand, can lead to more complex branching.
On top of that, a snowflake doesn’t just fall, it spins and moves through different layers of air. Each branch grows independently, and even the smallest changes in conditions alter its structure.
Even if two snowflakes started out identical(just theoretically), their journeys through the atmosphere would never be the same, and the final result would always be unique.
Since regular dumbbells don’t work in space (no gravity), ARED uses vacuum cylinders. These cylinders create resistance, just like lifting something heavy on Earth. Instead of weights, it uses air pressure — the higher the pressure, the "heavier" the exercise feels.
On this machine, astronauts can do familiar exercises like squats, bench presses, or leg presses. It also has a computer that shows how much effort you're putting in and helps adjust the load.
The closest place to Earth where snow falls is Mars. The average temperature on the Red Planet is a balmy -60 °C perfect for snow formation if you like your winters Siberian and your frostbite instant. But Martian snowfalls are nothing like the cozy, fluffy ones we know, thanks to its thin atmosphere and otherworldly climate.
In 2008, NASA’s Phoenix lander observed water snow falling from clouds near Mars' north pole. This snow consists of tiny ice crystals, but because the atmospheric pressure is just 6 mbar (0.6% Earth's), and the temperature is brutally low, the snow sublimates before reaching the surface.
In 2012, snow made of carbon dioxide (dry ice) was detected near Mars' south pole during its winter. This type of snow forms at temperatures below -125 °C. Unlike water snow, these particles can actually hit the ground, but they evaporate almost instantly when the sun rises.
Martian snow falls from high-altitude clouds and drifts down slowly, thanks to the planet’s thin atmosphere and weak gravity. Picture it as snowflakes in slow motion, taking their sweet time, only to ghost the surface before making contact. Even in a rare storm, snow never sticks around.
In short, Martian snowfalls are rare, fleeting, and scientifically fascinating—but not much use if you're hoping to build a snowman or snowwoman😏
