Classical Physics vs Modern Physics

 

Traditional Physics Comes to an End

We're about to enter the modern physics era. Scientists began investigating the fundamentals of matter, space, and time in the early 1800s. The fundamental premise is that Newton's physics describes around 90% of how things work in the universe, which can be very puzzling at times (mechanics). When you talk about things like objects moving at the speed of light, the insides of atoms, high temperatures, and when the items are large, his thoughts start to fall apart (like galaxies interacting with each other).

Into the Atomic World

Niels Bohr's first concept of atoms suggested a structure made up of different shells and a nucleus at the center. The protons and neutrons were discovered in the nucleus, whereas the electrons were discovered in those shells. There are various methods to look at atom structure (you may have heard of "spdf"), but for many of our topics, we'll stick with the standard perspective. One of the bases of contemporary physics was this concept of the structure of an atom.

Into the Universe

Albert Einstein had a significant impact on modern physics. He developed formulas to describe the relationship between matter and energy. E=mc2 is a formula that almost everyone has heard of. This formula describes how energy and mass are connected. The concept was applied to the study of fission reactions, and it was shown that even one atom of a substance may store huge quantities of energy.

Einstein’s Cosmic Speed Limit (NASA/GSFC Video)

Recent Research

Scientists are still pushing the limits of physics and testing the principles of physics. A new state of matter was created only a few years ago. Although the Bose-Einstein condensate has been postulated for decades, scientists have just lately been able to replicate it in the lab. Astronomers study space daily, discovering how black holes and galaxies interact. One of the most well-known scientists working on this topic is Stephen Hawking. Our point is that there is still a lot to learn.

Examining the Nucleus

Nuclear physics is concerned with the nucleus of the atom, while atomic physics is concerned with the atom as a whole. Physicists still need to know about the area surrounding the nucleus, but they're more interested in the forces that hold it together. They frequently try to develop new forms of fusion and fission processes once they have a better understanding of those forces.

Nuclear Energy

The energy generated when the nuclei of atoms split or fuse is known as nuclear energy. Protons and neutrons make form the nucleus. All of the parts are held together by nuclear forces. When two nuclei come together, this is called fusion. When one nucleus splits into two or more fragments, this is called fission. When either of these processes takes place, massive amounts of energy are released. Much of the energy emitted by the Sun comes from fusion processes. The protons and neutrons that physicists analyze every day are made up of even smaller particles.

Antimatter: the opposite of matter

We wanted to tell you about antimatter because we're talking about atomic and nuclear physics. It isn't limited to television shows. Scientists have discovered proof of its existence. Antimatter is the polar opposite of matter, which has positive and neutral pieces (protons/neutrons) in the nucleus and negative components in orbiting clouds (electrons). The nucleus of antimatter contains a negative charge, and the orbiting include few positive components. Positrons are positively charged particles.

Exploring Atoms

Quantum physics is a field of physics that studies the internal activity of atoms. They're talking about the interactions of subatomic particles. Here, we're beginning to discuss Albert Einstein and Max Planck's views. In the early 1900s, scientists began to investigate the inner workings of atoms. They were curious as to what was going on inside those objects that had previously been regarded to be solid. One of the major conclusions they reached was that the energy of an electron is proportional to the frequency, or wavelength, of electromagnetic radiation. Another intriguing concept they uncovered was that energy was unaffected by the intensity or quantity of radiation.

When you apply this concept to the structure of an atom, you'll notice that the earlier Bohr model has a nucleus and energy rings (levels) surrounding it. Each orbit's length corresponded to a wavelength. There can't be two electrons with exactly the same wave properties. Scientists now believe that electrons act like waves, filling sections of the atom in the same way as sound waves fill a room. The electrons are then found in what scientists refer to as "electron clouds." The size of the shells now corresponds to the cloud's size. This is where the spdf stuff comes in handy, as they specify the cloud shape.

What is a Proton? (Brookhaven Nat’l Labs Video)

Energy Packets

EM radiation, scientists found in the early 1900s, not only flows like a wave but also has packs of energy (quanta). It's as though you're seeing a stream of individual packets.

The Uncertainty Principle

The uncertainty principle was proposed by a German scientist named Werner Heisenberg. He reasoned that an atomic particle's position and momentum could not be reliably measured at the same time. Because these particles are so minute, whatever technology you employ to measure them will have an impact on them. Consider that for a moment. Willn't you knock a piece of light about if you use light to study it? Now you've completely lost track of where you're supposed to be. What if you put it in a freezer and keep it there? That's fine, but you still have no idea where it's heading or how much momentum it has. When one measurement's precision is improved, the other measurement suffers.

The observer effect can be used to look at the Heisenberg uncertainty principle in a broader approach. While Heisenberg is interested in measurements, there are analogies to be found in larger observations. It is impossible to view something in its natural state without influencing it in some way. The photons and light used to see an electron would cause the electron to travel. When you go through a field in Africa and the animals notice you, they will behave differently. When a psychiatrist asks a patient a series of questions, he is influenced, and the replies may be influenced by the way the questions are phrased. Field scientists work really hard to observe while causing as little interference as possible.

Releasing Particles

When an atomic nucleus breaks down into smaller particles, radioactivity occurs. Nuclear radiation is divided into three types: alpha, beta, and gamma. Positively charged alpha particles negatively charged beta particles and neutral gamma particles. 

The energy levels of the radiations also increase, starting with Alpha, then Beta, and eventually Gamma, which is the most energetic of them. Gamma is a wave, while Alpha and Beta are particles.

Half of a Life

The remaining nucleus (and atom) is not the same when a radioactive nucleus changes. It alters its appearance. Half-life refers to the amount of time it takes for half of the atoms in a sample to change and the other half to remain unchanged.

Assume you have 100 grams of uranium (don't attempt this at home; it's dangerous). The half-life is the amount of time that has transpired after 50g have remained (and 50g have changed). Every element has a different half-life. Uranium-235 has a half-life of 713,000,000 years. Uranium-238 has a half-life of 4,500,000,000 years. That's a long time to wait for radioactive atoms to shift, especially when many of the new atoms are also radioactive and deadly!

Carbon-14, a radioactive isotope of carbon, exists. Carbon-12 is the most common kind of carbon. C-14 has two additional neutrons and a 5730-year half-life. Carbon dating is a method used by scientists to determine the age of objects. This isn't the same as two carbon atoms going to the mall one night. When scientists strive to determine the age of very old substances, they use carbon dating. C-14 is found in trace levels in the atmosphere. C-14 is found in all living things. Scientists determine the age of objects by measuring the number of C-14 in them. To date the object, they use a half-life of 5730 years.

NASA Harnesses Half-Life (NASA-eClips Video)

A Danger to DNA

In general, radioactivity is harmful to living creatures. Radiation can flow right through organisms without having any effect, but it can also hit DNA or have an influence on replicating cells. When DNA is exposed to radiation, bad things can happen. Cancer is one of the side effects of modest quantities of radioactive particles. Cells replicate in unconventional ways. High levels of radiation can kill a person in as little as 24 hours. Medicine, on the other hand, has figured out how to employ radiation to treat cancer. Doctors target areas of cancer with radioactivity to stop cancer cells from dividing, knowing that high doses of radioactivity can kill cells.

Splitting Up

The splitting of an atom is known as fission. Fission does not occur in all atoms; in fact, it occurs in just a small percentage of them under typical conditions. The atomic mass of 235 amu (atomic mass unit) is found in a small percentage of Uranium atoms (atomic mass units). Because fission occurs only in U-235, these atoms must be isolated from the vastly more common U-238 atoms. Most countries have avoided nuclear weapons because of the complexity and cost of accomplishing this separation.

Scientists fire a large number of neutrons at uranium-235 atoms in a nuclear reaction. Uranium becomes U-236 when one neutron hits the nucleus. The uranium atom wants to split apart when it reaches 236 degrees Celsius. It divides into three neutrons and a lot of energy after splitting. These neutrons collided with three more U atoms in the region, turning them into U-236. The reaction increases three times bigger with each cycle. A chain reaction is a reaction that, once started, continues on its own. An uncontrolled chain reaction is a chain reaction that continues to grow in size. If left alone, and with enough U-235 (which you don't have in a reactor), the energy would build up to the point where an explosion would occur — a big one! When a nuclear reactor loses control, the worst that can happen is a meltdown, which is awful enough but not as severe as an explosion.

Fuse vs. Fizz

We used to get fusion and fission mixed up when we were young. 

It wasn't that the methods were identical; it was just that the terms were comparable. 

It's important to understand that one phase is a breaking down process, while the other is a building up process. When things fuse (fuse), smaller objects (tritium, deuterium) are used to build larger objects (helium). You start with a larger object (uranium) and work your way down to smaller objects when things "fiss" or break down (strontium, calcium, barium, etc).

Fission vs Fusion (NASA/Spitzer Video)

Action of Isotopes

Why do we use the term "radioactive" to describe atoms? The number 238 refers to a different isotope of uranium. When one of those free neutrons collides with a 238 it raises the number to 239 (that just makes sense). However, that 239 is radioactive, and when it decays, it emits a beta particle. It isn't over yet. Neptunium-239 is formed when U-239 is broken down. Neptunium is also a radioactive element. When it degrades into plutonium-239, it releases another beta particle. Eventually, the plutonium will emit an alpha particle (not as strong as beta and less dangerous). There are a lot of particles being emitted.

The Legacy of Albert Einstein

Fission is the main reaction that occurs in many nuclear devices, regardless of how radioactive it is. 

Einstein's equation E=mc2 was the starting point. The military began developing weapons with vast destructive abilities as soon as scientists believed there were massive amounts of energy available in each atom of the universe. The bomb usually contains uranium or plutonium, and the fission reaction is triggered by a smaller explosion of material surrounding the uranium or plutonium. They've even created fusion bombs that are triggered by fission reactions.

Bringing Together

Fusion is the process of two tiny atomic nuclei combining to form a bigger, stable nucleus. Deuterium and tritium are the most basic nuclei to employ (isotopes of hydrogen). Deuterium is found in the oceans by scientists, so it's rather easy to find if you know where to search.

Look up to the sky

Many stars' fusion reactions aren't the same as the ones we're aiming to produce on Earth. The proton-proton chain reaction is the name given to the fusion process on a star by scientists. A deuteron is formed when two protons collide with one another. After then, a third proton collides with the deuteron, forming the helium isotope. The isotopes of helium then fuse to form beryllium, which then decomposes. Two protons are released when beryllium breaks down, allowing the reaction to restart.

Fuse vs. Fizz

We used to get fusion and fission mixed up when we were young. It wasn't that the methods were identical; it was just that the terms were comparable. It's important to understand that one phase is a breaking down process, while the other is a building up process. When things fuse (fuse), smaller objects (tritium, deuterium) are used to build larger objects (helium). You start with a larger object (uranium) and work your way down to smaller objects when things "fiss" or break down (strontium, calcium, barium, etc).

Bringing Fusion to Reality

Fusion reactions can only take place in extremely hot conditions. Temperatures reached millions of degrees, similar to those of the Sun. Plasma is formed when a gas is heated. The issue is that we have yet to develop a container capable of heating plasma to the temperature required for fusion to occur. Scientists employ magnetic fields to hold the plasma in place so that it doesn't really touch the container. It's as though the plasma is floating in space, unaffected by anything. The ideal container right now is in the shape of a torus. That reminds me of a doughnut shape. When a fusion reaction is complete, there is extremely less radioactivity released compared to a fission process.

A Star on Earth (US Dept. of Energy Video)

Creating Energy That Can Be Used

In many nuclear reactors, uranium 235, an isotope of uranium, is used (In some cases, they use plutonium instead). Small pellets of uranium are delivered to the reactor. These pellets are then placed in fuel rods. Because the fission reaction generates heat and the entire reactor must be cooled by water, nuclear power stations are built near rivers, lakes, and other bodies of water. Because the reaction continues to grow, and no one wants a reactor to melt, they must do more than simply cool things down. The size of the reaction is controlled by the number of neutrons, so you may regulate the reaction by manipulating the neutrons. Control rods absorb neutrons and are inserted into reactors to keep the reactor under control. The reaction is slower/smaller the further the rods are inserted. The rods are removed and maintained in a large pool of water for a year after the majority of the fuel pellets have converted from U-235 to other atoms. Then, in their place, fresh fuel rods are installed. Officials must bury the nuclear waste deep below after enough time has passed and the radioactive materials have cooled. They bury them so that the radioactivity does not pollute the water or land around them.

When biological substances are exposed to extremely high levels of radiation, they are rendered incapable of surviving. Radiation poisoning is the outcome, and nuclear plant workers must exercise extreme caution.

Advanced Test Reactor Tour (Idaho Nat’l Labs Video)

Was this article helpful? Give it a share!