The History of Physics and Its Applications

Summary

This script takes a journey through the history of physics, highlighting key figures and discoveries that shaped our world. From Thales of Miletus' elemental theories to Archimedes' buoyancy principle, it explores ancient contributions. It delves into the scientific revolution with Galileo's challenge to Aristotle's views on falling objects and Newton's laws of motion and gravity. The script also covers the development of optics, electricity, thermodynamics, and quantum mechanics, leading to modern applications in technology and medicine, showcasing how physics has been a catalyst for human progress.

Takeaways

• 📚 Physics has been shaped by thousands of years of research, leading to modern technologies and a deeper understanding of the universe.
• 🔮 Thales of Miletus is considered the father of science for attempting to explain phenomena through theories rather than mythology.
• 🌗 Thales is believed to have predicted the Eclipse of Daly's in 585 BC, which may have ended a war between two kingdoms.
• 🔥 The classical elements of water, earth, air, and fire, and Aristotle's 'aether' were foundational to understanding matter and celestial bodies.
• 🛁 Archimedes is known for discovering the principle of buoyancy while taking a bath, leading to the Archimedes' Principle.
• 🔧 Archimedes also invented various machines, like the claw of Archimedes, which used mechanical advantage to defend Syracuse's city wall.
• 👀 Ibn al-Haytham, known as the father of optics, conducted experiments proving light travels in straight lines and comes from objects to our eyes.
• 🌈 Theodoric of Freiburg's experiments with glass spheres contributed to the understanding of rainbows through refraction and reflection.
• 🧭 The first compass was invented around 2000 years ago, and William Gilbert later proved that the Earth acts as a giant magnet.
• 🚀 Galileo's thought experiments and work on pendulums laid the groundwork for the concept of relativity and the laws of motion.
• ⚛️ Newton's Principia established the laws of motion and universal gravitation, and his reflecting telescope improved upon the Galilean design.

Q & A

Who is considered the father of science and what was his approach to explaining phenomena?

Thales of Miletus is considered the father of science. He is known for his attempts to explain phenomena through theories and hypotheses rather than relying on mythology.

What theory did Thales of Miletus propose about the composition of all matter?

Thales of Miletus proposed that all matter was made up of a single substance, which he believed to be water.

What significant event is associated with Thales of Miletus and how did it impact history?

Thales of Miletus is believed to have predicted a solar eclipse on May 28th, 585 BC, known as the Eclipse of Daly's. This eclipse is said to have interrupted and possibly helped end a war between two local kingdoms at the time.

What was the classical theory of the four elements proposed by 5th century BC philosophers?

The classical theory proposed that matter was not made up of just water but a collection of four elements: water, earth, air, and fire.

How did Aristotle contribute to the classical elements theory?

Aristotle suggested a fifth element known as aether, which he believed made up celestial bodies and stars, differentiating them from the elements found on Earth.

What is the Archimedes' principle and how did he come up with it?

Archimedes' principle states that the upward buoyant force exerted on a body in a fluid is equal to the weight of the fluid displaced by the body. He came up with this principle when he noticed the water level rise in his bath and used this observation to calculate the volume and density of a gold crown to determine if it was made of pure gold.

What invention is attributed to Archimedes that demonstrates the use of mechanical advantage?

Archimedes is credited with the invention of various networks of pulleys and levers, which make use of mechanical advantage to amplify applied forces.

What significant contribution to optics did Ibn al-Haytham make?

Ibn al-Haytham, considered the father of optics, proved that light travels in a straight line and was the first to suggest that light travels from objects and enters our eyes, rather than our eyes emitting rays that bounce off objects.

How did Theodoric of Freiburg contribute to the understanding of rainbows?

Theodoric of Freiburg used spherical flasks and glass globes to simulate water droplets during rainfall. He observed that light refracted onto the droplets, reflected back out, or was refracted again, leading to a better understanding of the formation of rainbows.

What discovery did William Gilbert make about the Earth's magnetic properties?

William Gilbert proved that the Earth was a giant magnet, not just attracted to a large magnetic island on the North Pole, through his experiments with the torella, a sphere made out of naturally magnetized material.

What experiment did Galileo reportedly conduct to challenge Aristotle's theory on the rate of falling objects?

Galileo reportedly dropped spheres of different masses from the Leaning Tower of Pisa to demonstrate that their time to reach the ground was independent of mass, challenging Aristotle's theory that heavier objects fall faster.

What are Newton's three laws of motion and how did they impact physics?

Newton's three laws of motion are: 1) An object at rest stays at rest, and an object in motion stays in motion with the same speed and in the same direction unless acted upon by an unbalanced force. 2) The acceleration of an object is directly proportional to the net force acting on it and inversely proportional to its mass (F = ma). 3) For every action, there is an equal and opposite reaction. These laws laid the foundation for classical mechanics and are fundamental to our understanding of motion.

What is the significance of James Joule's experiment in the context of thermodynamics?

James Joule's experiment demonstrated the mechanical equivalent of heat, showing that heat and mechanical work are interchangeable forms of energy. This led to the development of the first law of thermodynamics, which states the principle of conservation of energy.

What discovery did Wilhelm Röntgen make while investigating vacuum tubes that led to the development of diagnostic radiography?

Wilhelm Röntgen discovered X-rays while investigating vacuum tubes and external effects of current passing through them. He noticed a fluorescent effect on a screen and deduced the presence of a new type of ray, which he called X-rays.

How did Antoine Henri Becquerel's research contribute to the understanding of radioactivity?

Antoine Henri Becquerel discovered that uranium salts emitted radiation without the need for sunlight, which he initially thought was necessary for the emission of X-rays. This finding led to the understanding of radioactivity as a natural property of certain elements.

What are the three types of radiation discovered by Ernest Rutherford when working with uranium?

Ernest Rutherford discovered three types of radiation from uranium: alpha radiation, which can be blocked by a thin sheet of paper and consists of two protons and two neutrons; beta radiation, which can pass through paper but is blocked by aluminum and is more dangerous; and gamma radiation, which is the most dangerous and requires thick barriers like lead or iron to be stopped.

What are Maxwell's equations and why are they significant in physics?

Maxwell's equations describe the relationship between electricity and magnetism and predict the existence of electromagnetic waves, which propagate through a vacuum at the speed of light. They are significant because they form the foundation of optics, wireless communications, and various other technologies.

Outlines

00:00

🔬 Ancient Theories and Discoveries in Physics

This paragraph discusses the foundational theories and discoveries in physics that shaped our modern world. Starting from the 7th and 6th centuries BC, it highlights Thales of Miletus, considered the father of science, who attempted to explain natural phenomena through theories rather than mythology. His hypothesis that all matter was made of water and his purported prediction of the Eclipse of May 28th, 585 BC, are mentioned. The paragraph then transitions to the 5th century BC, where philosophers proposed that matter was composed of four elements: water, earth, air, and fire, with Aristotle suggesting a fifth element, aether. The narrative continues with the story of Archimedes in the 3rd century BC, who is known for his work on buoyancy and the principle that bears his name, which explains the buoyant force on objects submerged in a fluid. Archimedes' inventions, such as the claw of Archimedes, and his famous quote about moving the earth with a lever, illustrate the practical applications of physics in ancient times.

05:05

🌈 Advancements in Optics and the Understanding of Light

The second paragraph delves into the evolution of our understanding of light, starting with Alhazen in the 11th century, who is considered the father of optics. His experiments, which involved observing light traveling in straight lines through a hole in a wall, refuted the earlier belief that the eye emitted rays for sight. Alhazen's work laid the groundwork for future studies in optics, including Theodoric of Freiburg's investigation of rainbows in 1300, which used spherical flasks to demonstrate the refraction and reflection of light. The paragraph also touches on the invention of the first compass and the eventual realization by William Gilbert that the Earth itself is a giant magnet. Gilbert's work in electricity, including the invention of the electroscope, is also highlighted, setting the stage for later discoveries by Victor Hess.

10:07

📚 The Shifting Paradigms of Physics and the Dawn of Modern Science

This paragraph marks a significant shift in the history of physics, beginning with the challenge to Aristotle's belief that heavier objects fall faster, which was debunked by Galileo's thought experiment at the Leaning Tower of Pisa. Galileo's work on pendulums and his introduction of the concept of relativity are discussed, emphasizing his assertion that the laws of physics remain the same in any system moving at a constant speed in a straight line. The paragraph then moves to Newton's Principia, published in 1687, which established the foundations of classical mechanics, including his laws of motion and the universal law of gravitation. Newton's contributions to optics, such as the invention of the reflecting telescope and the concept of the spectrum, are also mentioned, illustrating the breadth of his impact on physics.

15:09

🔋 The Unraveling of Electricity's Mysteries and the Birth of Electromagnetism

The fourth paragraph explores the early investigations into electricity, beginning with the accidental discovery of the Leyden jar by Ewald Georg von Kleist in 1745, which could store electric charge and is considered the first capacitor. The paragraph then discusses the work of James Joule, who demonstrated the mechanical equivalent of heat and contributed to the first law of thermodynamics. The narrative continues with the contributions of Julius Robert von Mayer, whose ideas on energy conservation were initially overlooked. The paragraph concludes with the groundbreaking work of James Clerk Maxwell, who formulated Maxwell's equations, predicting the existence of electromagnetic waves that travel at the speed of light, and Wilhelm Conrad Röntgen's discovery of X-rays, which revolutionized medical imaging and earned him the first Nobel Prize in Physics.

Keywords

💡Physics

Physics is the natural science that studies matter, its motion, and behavior through space and time, and the related entities of energy and force. In the video, it is the central theme, highlighting the historical development and impact of physics on technology, scientific understanding, and the world we live in.

💡Thales of Miletus

Thales of Miletus is considered one of the founders of philosophy and is known as the 'father of science.' He attempted to explain natural phenomena through theories rather than mythology, such as hypothesizing that all matter was made of water. His approach is foundational to the scientific method, which the video discusses as a key development in the history of physics.

💡Archimedes

Archimedes was an ancient Greek mathematician, physicist, and engineer known for his contributions to the understanding of density, buoyancy, and the principle of levers. The video refers to his famous 'Eureka' moment in the bath and his principle, which explains the buoyant force on objects submerged in a fluid.

💡Classical Elements

The classical elements of water, earth, air, and fire, with the addition of 'aether' by Aristotle, were early theories on the basic substances that composed the universe. The video mentions these as precursors to our modern understanding of elements and their role in the states of matter.

💡Alhazen (Ibn al-Haytham)

Alhazen, or Ibn al-Haytham, is known as the 'father of optics.' His work significantly advanced the understanding of light and vision, proving that light travels in straight lines and originates from external sources, not the eyes. The video discusses his experiments and their impact on the field of optics.

💡Theodoric of Freiburg

Theodoric of Freiburg contributed to the understanding of rainbows by using spherical flasks to simulate water droplets and observing the refraction and reflection of light. His work is mentioned in the video as an example of scientific discovery building upon the foundations laid by earlier scholars like Alhazen.

💡Galileo Galilei

Galileo Galilei was a pivotal figure in the scientific revolution, known for his experiments and theories on motion, pendulums, and the principle of relativity. The video references his challenge to Aristotelian physics and his support for the Copernican heliocentric model.

💡Isaac Newton

Isaac Newton is renowned for his laws of motion and universal law of gravitation, which the video describes as foundational to classical mechanics. His work in optics, including the discovery of the spectrum and the invention of the reflecting telescope, is also highlighted.

💡James Joule

James Joule is known for his experiments that established the mechanical equivalent of heat, demonstrating that energy could be converted between different forms. The video mentions Joule's work as a precursor to the first law of thermodynamics.

💡Maxwell's Equations

Maxwell's Equations describe the relationship between electricity and magnetism and predict the existence of electromagnetic waves. The video emphasizes their significance in various technologies, including wireless communications and optics.

💡Marie Curie

Marie Curie was a physicist and chemist known for her research on radioactivity, leading to the discovery of polonium and radium. The video discusses her contributions to science and her recognition as the first person to win two Nobel Prizes.

💡Ernest Rutherford

Ernest Rutherford's work on radioactivity led to the identification of alpha and beta radiation. His experiments are mentioned in the video as foundational to the understanding of atomic structure and the nature of radiation.

Highlights

Thales of Miletus is considered the father of science for explaining phenomena through theories and hypotheses rather than mythology.

Thales predicted a solar eclipse on May 28th, 585 BC, known as the Eclipse of Thales.

In the 5th century BC, philosophers theorized that matter is composed of elements: earth, air, fire, and water.

Aristotle suggested a fifth element, aether, which made up celestial bodies and stars.

Archimedes, in the 3rd century BC, calculated the density of a gold crown using water displacement, leading to Archimedes' principle of buoyancy.

Archimedes invented the claw of Archimedes, a weapon that used mechanical advantage to defend Syracuse during the Second Punic War.

In the 11th century, Alhazen, the father of optics, proved that light travels in a straight line.

William Gilbert, in the 17th century, proved that the Earth is a giant magnet and coined the term 'electricity.'

Galileo demonstrated that the time for objects to reach the ground is independent of mass and introduced the idea of relativity.

Isaac Newton, in 1687, published 'Principia,' laying the foundations of classical mechanics and introducing the laws of motion and universal gravitation.

In 1745, Ewald von Kleist invented the Leyden jar, the first capacitor, which could store electric charge.

Thomas Young's double slit experiment in 1804 proved that light behaves as a wave, supporting Huygens' theory.

James Joule's experiments in 1843 showed the interchangeability of mechanical work and heat, leading to the first law of thermodynamics.

Maxwell's equations in the mid-1800s described the relationship between electricity and magnetism, predicting electromagnetic waves.

Wilhelm Röntgen discovered X-rays in the 1880s, leading to their use in medical imaging.

Marie Curie coined the term 'radioactivity' and, along with her husband Pierre Curie, discovered the elements polonium and radium.

Ernest Rutherford discovered alpha and beta radiation and identified gamma radiation with Paul Villard.

Transcripts

Thousands of years of physics research and discoveries has shaped the world. We live in today from technologies

we use all the time to machines and inventions that change the world all the way to our knowledge of the universe from the very

Baked to the very small without the advancement of physics. These would not exist

Although we have discovered quite a lot these discoveries happened over a long period of time some of them even by accident

So let's take a look at the thousands of years of work that went into creating the world

We live in today and some of the people who got us here

Let's start this in the seventh and sixth century BC with a man named Thales of Miletus

Whom some consider to be the father of science?

He's known for his attempts to explain phenomena through theories and hypotheses rather than mythology

For example, although this may seem like nonsense to us now one theater

He had was that all matter was made up of a single substance, and that was water

He may have missed the mark on that one

But is believed by some that he was able to predict as solar eclipse on May 28th

585 BC

Now known as the Eclipse of Daly's this eclipse actually interrupted and may have helped end a war between two local kingdoms at the time

now fast-forward to the 5th century BC when philosophers came up with a new theory that

Matters not made up of just water but a collection of elements

Water was one the others were earth air and fire

several years later

Aristotle also

Suggested a fifth element known as aether that made up celestial bodies and stars probably would not be made of the same elements down on

Earth, he definitely would have been shocked to learn that they are in fact made up of the elements found here on earth

But even though we know these classical elements to be wrong, they do align quite well with these four states of matter

We all know us

Now those are some ancient theories but where I really want to start this video is with a story

I'm sure many of you know of which begins with a gold crown and a bathtub in

The 3rd century BC live scientist engineer and mathematician Archimedes who contributed more to the world than any other scientist of ancient times

Probably his most famous contribution was made while he was taking a bath

Archimedes need to calculate the density of supposedly gold crown to determine whether some silver had been substituted by dishonest Goldsmith

He was not allowed to melt the crown to a normal shape in order to perform calculations, though

one day taking a bath

He knows the level of the water rise as he got in and he used this principle to determine the volume of the crown

Since the crown would displace his own volume in water

He was able to then calculate the density of the crown using mass over volume and concluded it was less than that of gold

Proving that silver had in fact been mixed in

later Archimedes went on to write on floating bodies where he continued his research into submerged objects and this he describes what is known as

Archimedes principle which states how the upward buoyant force exerted on a body in a fluid is equal to the weight of the fluid displaced

by the body

This principle is why you feel lighter when in water or white is very difficult to push an inflated beach ball under water

now the story of the gold crown has actually been called into question due to the accuracy needed to measure the water displacement and how

Difficult, that would be given the instruments available to Archimedes

instead a more practical technique that actually makes use of Archimedes principle would be to suspend the crown on one end of a scale and

Balance it with an equal mass of gold on the other

Then when put into water the crown would have displaced more water than the gold due to its larger volume and thus experience a higher

Buoyant force making it more apparent it was mixed with silver

Now physics is not just a foundational science

But it's also the basis of technology new physics discoveries today lead to new technologies tomorrow

And this goes way back during ancient times many Greeks were interested in the development of machines

For example Archimedes is recognized for the invention of various networks of pulleys and levers

His famous quote is give me a place to stand and I will move the earth

This of course has to do with mechanical advantage in the amplification of applied forces

Machines that make use of mechanical advantage allow us to let's say lift a car using only our own strength

One notable invention of his was the claw of Archimedes

They use mechanical advantage as a weapon to defend a portion of Syracuse's city wall during the Second Punic War

its exact design is unclear

But it worked kind of like a crane using pulleys and levers to lift enemy ships slightly out of the water

Causing them to eventually flood and sink

Nowadays simple things like bottle openers nail clippers hammers bike gears wheelbarrows and more make use of these principles

Now let's fast forward all the way to the 11th century when a physicists known as M

Nel Haytham changed the way we think about light

Although a lot of research has been done since I'll hate them is considered the father of optics

For reasons I won't go into I'll hate them was kept under house arrest for several years and during that time

He published a seven-volume collection of books known as the book of optics where he proved that light travels in a straight line

He did this through one of the first scientific experiments ever as a lot of previous theories were simply speculation

Like at this point in time that was still thought that heavier objects followed a faster rate as theorized by Aristotle

This would be proved wrong in a few hundred years though

Anyways, one experiment al-haytham performed was he cut a small hole in a wall and hung two lanterns at different locations in an adjacent room

He observed that the light

Illuminated unique spots in the opposite room and each formed a straight line with the hole and one of the lanterns

also for hundreds of years that was believed that her eyes actually emitted rays of light that would bounce off objects allowing us to see

He was the first to say that in fact light travels from objects and enters our eyes, which is now known to be correct

Now one thing he was wrong about even though he did research on them was rainbows

He assumed rainbows were an image of the Sun formed from a curved mirror due to water within clouds

It wasn't until the year 1300 that Theodoric of Freiburg use spherical

Flasks and glass globes to simulate water droplets that occurred during rainfall

He observed that light refracted onto the droplets reflected back out or they were refracted again

Although I'll Haytham did not contribute to our understanding of rainbows directly Theodoric of Freiburg relied on al-haytham spoke of optics to further

understanding of them

Today optics is applications in medicine

telescopes astronomy laser technology fiber optic cables and much more

Next up just about 2,000 years ago. The first compass was invented and although people did eventually use these for navigation

No, one truly knew how they worked for over a thousand years that was until the turn of the 17th century

It was assumed for a long time that comes as were attracted to a large magnetic island on the North Pole

That was until william gilbert came in and wrote his book where he proved. The earth was actually one giant magnet in

This book he discusses

Experiments in which he miles the earth using something called the torella or a sphere made out of a naturally magnetized material

When he passed the compass over the Torah

He saw it would always point towards the magnetic pole and behave just as it would on earth itself

The Tyrell was improved upon 300 years later by Kristian Birkeland

In order to further investigate the polar aurora and why it appeared near the magnetic poles of earth

Now William Gilbert also did work in electricity

In fact, he is credited with inventing the word electricity and many consider him the father of Electrical Engineering

One of Gilbert's inventions with the electroscope the first instrument to measure the presence of electric charge

Over 300 years later physicist Victor Hess would use the electroscope to discover something that would win him the Nobel Prize

But I'll get to that soon

Now like I said for over a thousand years it was believed that heavier objects would fall at a faster rate

This was introduced by Aristotle and it seems intuitive. But of course, we know now that this is wrong

The story that's been told is around

1590 the scientist Galileo dropped spheres of different masses from the Leaning Tower of Pisa to show that their time to reach the ground was

Independent of mass which we now know to be true

He also showed that the relationship between distance and time could be represented by this equation

Although the basic physics here proved to be accurate many historians believe that the story isn't but rather it was a thought experiment

Then Galileo did work on pendulums, but also introduced the idea of relativity

That would be greatly expanded upon by Einstein

Galileo stated that the laws of physics are the same in any system that is moving at a constant speed in a straight line

Meaning there's no such thing as absolute motion. It's all relative

If you were in a rocketship moving through space at a constant velocity

There'd be no way to determine if you were moving or actually stationary

Your brain probably is telling you that these asteroids are passing by a still observer right now

But look at it some more and you can probably convince yourself that the asteroids are still and you're moving past them

Galileo's work not only set the foundations for Einstein but also provided the framework for what Isaac Newton would go on to discover in

1687 Newton published a book called Principia

They laid out the foundations of classical mechanics and is regarded as one of the most influential scientific

publications of all time and bring Capilla Newton stated that gravity pulls masses together

The earth exerts a force on you just as you actually exert a force on the earth

He explains what this force obeys an inverse-square law

So if you get twice as far from something the gravitational force becomes four times weaker

And of course as three laws of motion were discussed here

Which one of the first things we all learn when we take a first level physics course

Newton was also heavily interested in orbiting bodies and celestial mechanics

It was believed for a long time that celestial bodies orbit in perfect circles

But Newton proved that actually an elliptical path would form as a result of the inverse square law that governed gravity

Newton also contributed to the field of optics

in fact

He coined the term spectrum in order to explain the colors that appear when white light enters a prism during his studies

He invented the first known functioning reflecting telescope or the Newtonian telescope

He did not come up with this idea

But seems to be the first to make a working one

reflecting telescopes are very simple in design and did not use a lens which offered certain advantages a

Few decades earlier Galileo design was known as a Galilean telescope. They used refraction instead of reflection

It contained two lenses and can magnify images about 30 times in size but flaws in the design caused images to be blurry or distorted

However, these flaws did not stop Galileo from being able to observe craters on the moon or various moons of Jupiter

Reflecting telescopes while not perfect did not contain some of these flaws such as unwanted refractions. Otherwise known as chromatic aberrations

Then by the 1700s more and more research was being done with electricity, but note at this time

No one knew that electricity came from charged particles

We now call electrons that was still over a hundred years away, but that would not prevent research from being done

in fact, one of the key pieces of electrical equipment in your computer phone and other electronics was first formed in

1745 when a well von Kleist was connecting metal foil to the inside surfaces of a glass jar

That was then filled with water. The goal is to charge the water by connecting it to a generator that could produce an electric charge

When kleiss then touched the foil with his hand, he experienced a very strong electric shock when that was arguably life-threatening

but what was going on was that the jar was storing electricity this became known as a Leyden jar that

Name may not be familiar to some of you but the Leyden jars also considered the first ever capacitor

Capacitors exist in all sorts of electronics nowadays and what they do is store charge

most people who be taking a basic physics class can expect to learn some basic circuit analysis with these

The applications of capacitors have a wide range store charts can be used to represent binary within a digital system

It can be used to supply large amounts of current to things like lasers and particle accelerators

They can be used as sensors. They can adjust the power and high voltage systems as needed and so on

Moving on when Isaac Newton was alive

He became a very powerful figure in the scientific community very few were willing to challenge his ideas and this continued even after his death

but he was not right about everything and the late 1700s and early 1800s Thomas Young would challenge Isaac Newton's view of optics in

1678 the scientist Christiaan Huygens actually proposed that light was a wave but Isaac Newton disregarded this and put forward his own theories

Isaac Newton viewed light as a stream of particles since he could use his laws of motion to describe them better in

The late 1700s Thomas Young defended Huygens theory and in 1804 all doubt had disappeared

We reported the results of his double slit experiment one of the most famous experiments in all of physics

He actually first observed how water waves would behave in a ripple tank

He saw that the waves were either combine or cancel each other out making some kind of interference pattern

When he performed this experiment with light and shine it through two small slits

He saw the same patterns emerge proving. That light was in fact aways

Now shifting gears in 1843 James Joule devised an experiment to measure the mechanical equivalent of heat

Back, then it seemed as though these were two very different things heat being transferred versus the physical motion of something

But he eventually showed that these were interchangeable what he did was meet a device such that you could turn a handle

Causing two weights to rise and fall

This would then turn a paddle that would stir the water within a container

When the weights fell joule noticed a rise in temperature as measured by a thermometer

After raising and lowering the weight several times

He calculated a value of about four point one four joules being equivalent to one calorie

This is the amount of energy need to raise one gram of water one degree, Kelvin

This was a little off as we now know is about 4.18 joules per calorie

Drool also showed that energy did not disappear

It was just transferred in different forms this then led to the development of the first law of thermodynamics. Just a few years later

Now something you may not know is that years earlier in?

1842 a man named Julius Robert mayor wrote a paper that discussed the concept of energy not being created nor destroyed as well as the

interchangeability of mechanical work and heat

Unfortunately for mayor he was not an actual physicist, but rather a physician so his papers were widely ignored by experts in the field

He read up on others experiments and use his own observations to come up with ideas

But not of the Train to present his findings in the proper way

This led to some disappointment when he found out years later that Joule got the credit for many of the topics

He had been an advocate for years earlier

Joule did set up his own experiments and all that

So it's not like he stole mayor's ideas

But we now give credit to Joule for these findings and he even has a unit of energy named after him and now of course

Thermodynamics has gone on to have applications in engine design refrigerators power plans and more

Then if you look up the most influential equations of all time, just about any article or video you find will include Maxwell's equations

These are the equations that tell us the relationship between electricity and magnetism these also predicted the existence of electromagnetic waves

Which propagate through a vacuum at the speed of light?

Electromagnetic waves are what encompass the signals that travel through the air when we talk in a cell phone they income as visible light

Microwaves x-rays gamma rays and so on. So basically anything dealing with optics wireless communications lasers, etc

Has its foundations rooted in Maxwell's equations

Now Maxwell's equations did predict the existence of all these types of waves you see here?

But at this time most of them really hadn't been discovered yet

We never sent a radio signal or observed x-rays, for example

But within just a few decades these would all be discovered in the late 1880s

The physicist Wilhelm Rankin was investigating vacuum tubes and external effects as current passed through them

One day while running experiment with these he noticed a florescent effect on a screen with in his lab

He deduced that a new Ray was having this effect because these were still unknown at the time

He just called these Ray's X like we do in math for unknowns

Well, he continued his investigation

He finally saw a radiographic image

which was a flickering image of his skeleton on a platinocyanide screen as

You can guess we had finally discovered was what we now call x-rays

Just a few weeks later. He used these x-rays to take a picture of his wife's hand to which she exclaimed

I have seen my own death

Only a year after this x-rays were being used in medical imaging and of course are still used today for medical and security purposes

For this discovery rongkhun won the first ever Nobel Prize in Physics in 1901. He became known as the father of diagnostic radiography and

2004 a radioactive element on the periodic table was named after him

Rankin's findings

then inspired more research into the existence of these x-rays from other sources and

Antoine Henri Becquerel was one physicist who set out to make his own discovery. He thought certain phosphorescent materials

He was working on such as uranium salts may have been emitting x-rays when exposed to sunlight. He soon discovered that this was completely wrong

What was happening was that the radiation was coming from the uranium itself without the need for sunlight?

By the way, at this point in time uranium was thought of as a harmless metal, but that would soon change

Now this phenomena observed with the uranium salts became known as becker l rays

That was until a few years later when Becker ELLs research student one of the most well-known physicists of all time

Marie Curie began investigating these rays and eventually coined the term radioactivity

although Becker L

Did not get the Rays named after him the unit for how many atomic nuclei decay no substance per second is now called a Becker

L

Marie Curie and her husband Pierre Curie are

Probably the most well known couple in all of science and along with Becker L. The three of them found that thorium was also radioactive

The Curry's additionally went on to discover two new radioactive elements polonium named after Poland where Marie Curie grew up and also radium

Then in 1903 the Curry's as well as Becker L were awarded the Nobel Prize for their work in radioactivity

Pierre Curie died just a few years later in

1906 and is best known for the discovery of the Curie point a temperature in which a magnet loses its magnetism

Marie Curie went on to be the first person to win two Nobel prizes one in physics and another in chemistry in 1911

now when the Kiryas were working on radiation research a physicist named Ernest Rutherford began working with uranium as well and

Discovered two types of radiation one that can be blocked by a thin sheet of paper, which was going alpha radiation

That consists of two protons and two neutrons

Oh, this was not known at the time and another that could pass right through the paper

But would be blocked by something like aluminum. This was named beta radiation and much more dangerous to be exposed to

The most dangerous of these three I'll discuss is known as gamma radiation and was discovered in 1900 by Paul Villard

This gamma radiation was coming off radium, which the Curry's had recently discovered

Gamma rays are not composed of subatomic particles, but instead are very high-energy electromagnetic waves

Gamma rays can only be stopped by thicker barriers made up of things like lead and iron

These are dangerous because they're extremely small wavelength and high-energy makes us that they can interact with human cells causing illness and even cancer

These are released by nuclear weapons. For example

Although this does not make this research and irradiation seem positive

radioactivity eager to apply to nuclear reactors which currently account for 14 percent of the world's power and

Radiation is used in medicine to diagnose and treat illnesses

For example radiation therapy is where we use radiation to specifically kill or slowed the growth of cancer cells

now we are about to enter the 1900s in which physics on an

Unbelievable amount of growth when making this video is honestly surprised just how much I would have to include in that century alone

You'll note our understanding of various extremes like the very large the very small the very cold and the very fast would all be

significantly improved upon in the years to come

Discoveries would lead to new inventions that changed the world and others that were more controversial

You