How does the sun heat us?

It gives us heat! It warms us with heat!

Hydrogen atoms in the sun undergo a nuclear reaction and helium is produced. 

This nuclear reaction also releases energy.

That energy reaches the earth by convection and warms us.

Yes, we can simplify it like this. 

But in fact it is not that simple.

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So how does all this happen?

There is enormous pressure at the core of the sun. 

Even though the sun normally doesn't have a shell like the earth, the gravitational effects of gaseous hydrogen atoms generate a lot of pressure and heat in its core. 

With heat and pressure, hydrogen atoms start to fuse with each other.

What is the element we call hydrogen? 

The simplest element in nature with a single proton in its nucleus and a single electron in its orbit! 

The first member of the periodic table! 

The first element created by the big bang!

The helium atom has two protons in its nucleus and two electrons in constant motion in the orbits around the nucleus.

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So far everything seems normal.

But there is actually a problem.

In addition to the two protons in the nucleus of the helium atom, there are also two neutrons!

Where do these neutrons come from?

After all, in the beginning there are only hydrogen atoms in the Sun, and because of pressure and heat, two of them come together and become the two protons in the nucleus of helium, but there are also two neutrons in the nucleus of the helium atom!

Where do these neutrons come from?

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James Chadwick (1891-1974), British physicist known for his discovery of the neutron in 1932. 

He received the Nobel Prize in Physics for this discovery in 1935. 

What is a neutron?

Particles with no electric charge, like protons in the nucleus, but with a neutral charge.

They are slightly heavier than protons, they have no charge, but they are affected by magnetic fields because they have magnetic momentum.

Yes, neutrons, like protons, are made of quarks.

Two up quarks and one down quark make a proton. 

One up quark and two down quarks make a neutron.

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A proton is stable in the free state. A neutron is not stable in free state.

What is being stable?

To remain as it is without turning into something else. 

When a single proton has a positive charge and a negatively charged electron, it becomes a hydrogen atom. 

Two hydrogen atoms come together and form a covalent bond to form a hydrogen gas molecule, and they can remain in this state forever. 

Because that single proton in the nucleus of hydrogen atoms is a stable particle.

A free neutron decays into a proton, an electron and an antineutrino in less than 15 minutes.

The neutron is not a stable particle!

By the way, this transformation is called negative beta decay.

Yes, what we call a neutron can actually be thought of as that proton in the nucleus of a hydrogen atom and the electron in its orbit coming together and fusing due to pressure and heat.

This transformation is called plus beta decay. 

In plus beta decay, the transformation of a proton into a neutron by fusing with an electron, a neutrino and a positron, the antiparticle of the positron, are released.

Structurally, an up quark in the proton is transformed into a down quark.

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What are these things called neutrinos and counter neutrinos?

Where do they come from?

Neutrinos are elementary particles that have a speed close to the speed of light, have no electric charge and can pass through matter with almost no interaction. 

They have no electric charge, but they have a mass close to the mass of an electron. 

Therefore, they are affected by spacetime distortions that affect mass, in practical terms, gravity.

The actual force that neutrinos are affected by is one of the four fundamental forces in nature that most of us don't really know what it is. It is a nuclear force called the weak nuclear force, which acts at the level of the nucleus.

Yes, the force that holds the positively charged protons together in the nucleus is called the strong nuclear force. I have written about this before.

If you remember, the basic carriers of this force are gluons, that is, these gluons are the fundamental particles derived from the English word glue, which means sticky in Turkish.

Quarks can stay together thanks to gluons, and since the strong nuclear force is much stronger than the electromagnetic force, it can keep the positive charges of protons together. By the way, neutrons are also needed in the nucleus for the system to work, neutrons keep the nucleus stable.

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The electromagnetic force is the force of interaction between protons and electrons, and its carrier is photons.

Gravity is not normally a force anyway, it's a bending of space-time. I have written about this before.

The Higgs boson, which creates mass, is a separate subject. I won't go into that now.

The weak nuclear force is the force that creates neutrons from protons and electrons, or vice versa, the force that decays a neutron into electrons and protons with neutrinos and anti-neutrinos.

Like the strong nuclear force, it is only effective at the nuclear level at very short distances and has a very short time interval. Its strength is also quite low compared to the strong nuclear force.

However, since it is effective in these neutron decays, we can call the weak nuclear force a force of nature that is essential for the stability of the nuclei of atoms.

If there were no neutrons, atomic nuclei would not be able to hold together in a stable way.

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If we put the fundamental forces in order of their strength and say that the strong nuclear force is 1 unit for comparison, we can say that the electromagnetic force is one hundredth (1/100) of a percent of that.

The weak nuclear force is one hundred thousandth (1/10^5) of the strong nuclear force. So it is a very low force in proportion.

Gravity, on the other hand, is ten to forty times (1/10^40) less than the strong nuclear force.

In this sense, it seems as if gravity is a pathetic effect that has no effect on the universe, but on the contrary, we spend our lives observing gravitational effects.

So how is it that we observe mostly gravitational effects in the universe?

Let's say we observe the electromagnetic force, after all, light is an electromagnetic effect, but we don't feel the effect of the strong nuclear force, for example, whereas the strong nuclear force is the strongest? 

E=mc2

Einstein's famous formula is not one of the formulas we use in everyday life.

Yes, this is the formula for the strong nuclear force!

In daily life we use Newton's formula F=m.a.

Or we use the formulas related to electromagnetics.

The weak nuclear force, as I said, only works in neutron-proton decays. 

I don't know what the formula for the weak nuclear force is, probably the experts have found a formula for it. But I think its formula should be related to the spring formulas, because I have read somewhere that there is a force from the horse as you move away up to a distance.

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So all we have is mass and visible matter! And the formulas related to them.

We don't feel the other forces at all?

Actually, we feel them, but we don't know that we feel them. 

After all, the formation of all the matter we see around us is the result of the strong nuclear force and the weak nuclear force, which is effective in the formation of neutrons.

The stars that twinkle in the sky also shine thanks to the strong and weak nuclear forces, so they are able to emit light all the way to us.

Normally, without nuclear reactions, there would be no light reaching us!

But as I said, strong and weak nuclear forces are forces that can act at very short distances, so they are not forces that we are aware of in everyday life. 

The electromagnetic and gravitational forces, on the other hand, are inversely proportional to the square of the distance.

Therefore, gravitational effects are the most visible in this vast universe of distances.

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Let's go back to neutrons.

As you may have guessed by now, yes, during the transformation of hydrogen atoms into helium atoms in the sun, some hydrogen atoms also decay into neutrons, and in the pressure-heat clamp, these also combine with two other hydrogen protons to form helium atoms with two protons and two neutrons in their nuclei.

The energy of the resulting nuclear reaction travels from the sun all the way to the earth, warming us.

In the meantime, neutrinos, which are produced during the transformation from protons to neutrons, also travel from the sun to our planet.

Every second, 65 billion neutrinos from the sun reach every cm2 of the Earth's surface at right angles to the sun. They also pass through you and go deep into the earth.

In fact, neutrinos are divided into three types, and each type has its own anti-neutrino. But I think that's enough nuclear physics for today. 

Special sensors have been built to catch these neutrinos hundreds of meters deep underground, scientists have placed such sensors especially in old coal mines. These details are quite long and boring.

The important thing is that we only need to know that neutrons are actually made of protons and electrons squeezed together and fused.

Neutrons are uncharged particles, but they can be manipulated in a magnetic field, and a slightly unstable uranium atom bombarded with neutrons can split and become an atomic bomb. 

When the uranium is shattered by this bombardment, it releases neutrons. And then the chain reaction starts.

So humanity, which once controlled neutrons, almost lost control and almost destroyed the world with atomic bombs!

Fortunately, nobody uses atomic bombs anymore.

Otherwise, could anyone still intend to use them?

Don't be afraid, I don't think such a madman will come out.

Let me end this article by saying stay with science.

Love and respect to everyone from Moscow