100 Greatest Discoveries (2004) s01e08 Episode Script
Physics
Physics is the study of the world around us Asking some of the most profound questions in human history How did the universe work What holds matter together And what's the strange force gentle enough to make an apple fall yet powerful enough to lock the moon in captive orbit Our need to understand has inspired some of humankind's greatest discovery From unleashing the fearsome power of the atom To uncovering the nature of light itself To revealing the forces that hold our entire universe together These are the greatest discoveries in physics This curiosity that drives us to understand the world around us isn't new.
In fact it has been around well as long as we have The ancient Greeks for example were the first to developed the idea that nature obeys a set of laws This is a tremendous breakthrough They gave us the notion about how the universe works, and about the way things move Trouble was, most its notion were dead wrong that's because the laws of physics sometimes seem to defy common sense Like our first great discovery For some two thousand years, it was believed that heavier objects fall faster than lighter objects This conventional bit of wisdom was based on observations made by the Greek philosopher Aristotle And people believed him because it seems like common sense But in the 17 century, Galileo Galilei decided to test Aristotle's law Legend has it that his test involved dropping balls of difference masses from the top of the leaning tower of pizza.
To see Galileo's experiment in action I paved a visit to the NANA's Glenn research center at Cleveland, Ohio And met with Steven Simons, project manager for microgravity research - So this is the chamber, - Yes This is the vacuum chamber.
It goes four feet into the ground We have to pomp air out of this so we can get good microgravity drop And this is goes back a long way to Aristotle Yes, Aristotle, yes it does.
While Aristotle thought that objects with different masses would fall at different rates - Which seems reasonable.
- Seems very reasonable Cause all of the history that people had with objects with different masses fall at different rates For example, if you have a feather and a ping-pang ball Both fairly light objects but they will fall at different rates To illustrate the difference between two objects that are roughly the same size and shape but obviously very different masses Is a golf ball and a ping-pang ball And if we drop those, they do drop at the same rates Through Galileo's experiment, he found that a heavier object seems to fall faster than a lighter one because of air resistance Air resistance slow lighter more than the heavier one The other way we do it is as if we shield the experiment which we can simulate with this leaf from the effects of air then they will drop at the same rate so what we are doing here By pumping all of the air out from this huge vacuum tank We got an experiment set up here today To check our new fire extinguisher for possible use on international space station so we are goanna to see if helium a better fire extinguisher than carbon dioxide Anita please.
- So she's goanna drop the big vehicle down - And there goes And you can fell the full shake when the drop vehicle hits - Let me take you down to the vital vacuum chamber.
We can retrieve the experiment and see what happened.
- Fun Galileo's challenged Aristotle's law was a turning point in science It mark beginning of testing the accepted laws of science through experimentation And Galileo's experiments with falling bodies led to our earliest understanding of acceleration caused by gravity Lift off.
We have lift off.
Right on my left hand have a feather in my right hand and a hammer And I will drop to here and hope it to hit the ground at the same time How about that Galileo was correct We own our next great discovery to Sir Isaac Newton Who is born in England the same year that Galileo died Legend has it that Newton was relaxing in an orchard one day when he saw an apple fall from a tree This simple incident caused him to wonder why is the apple had fallen to earth or the pale August moon continue to sail contently overhead It was eureka moment of insight for the young man.
He realized that the same gravitational force act on the apple and moon alike He think about, you get the feeling that all through the apples are shared there is some force that played the apples down It's always great about was he set the on the apple way out to the moon.
He realized that this force is everywhere.
It's something that nobody had really thought about before Newton's reason that the moon tries to travel straight line in space pass the earth.
The earth gravitational force posed the moon toward them This keeps the moon trapped in orbit around the earth But the moon pose on the earth too with its own gravitational force Newton had discovered what is called the laws of universal gravitation Universal because relationship applies to all bodies in the cosmos, including apples, moons, and planets When the gravitational force of a large body like the moon adds upon the earth, big things can happen Such as the ebb and flow of the earth's oceans The water in the ocean that's near the moon feels a greater pull water than the other side of the earth far from the moon So as the earth pull out the earth's rotate this kind of bulge the water and the earth rotates against its the higher water and lower water Newton's recognition that all objects have their own gravitational force was a landmark discovery in science But is our next great discovery shows he was far from finished To many people Isaac Newton is physics And it's largely because of a series of books he wrote which contained Newton's second discovery, the laws of motion The law explained the motion of all physical objects That's simple enough, you hit hockey pokey and it just keep sliding off across the ice You can see the unfrictional surface is just a little pretty much keep on indefinitely When you kick your stick against the pokey and it accelerates and makes that acceleration that's from in stand still up to speed is explained by the second law.
You can calculate using the second law The third law says when you hit the pokey with a stick and the stick get the force opposite to the pock or to another way When a hockey players punch the other one's face It's likely to break his knuckle as really as strong Newton's law of motion were a bold insight in the mechanic of how the universe works They established the foundation of what is now known as classical physics This is the science of thermodynamic in action The science of hit transformed into mechanical energy The power driven machinery of the industrial revolution depended on it Hit energy can be turn into the energy of motion Such as by turning a crank or piston or turbine to be use to pomp water, to turn a loom, to make fabric To move a boat through the water, to move a train down rails Now, it's desirable to get more oomph for your dollar to get more work down for the amount of fuel you are going to use And so people began to study how heat engines and how steam engines really work Among those who studied it was German scientist named Rudolf Clausius What became known as the second law of thermodynamics The law states that in any energy exchange such as heating the water as steam engine boil, some energy is always wasted Clausius called the word entropy to explain why the efficiency of a steam engine is limited Because some of its energy were always be lost in the process of converting it to mechanical work It was a momentous insight, one that changed our understanding of how energy works There is no heat engine that is one hundred percent efficient While a car is moving along, how much of the energy implicit in the gasoline that put into the car actually get used to move the car in a united Only about twenty percent.
Where is the rest of go It goes to heating up the pavement on the road, heating up the tires, the cylinders in engine block get hotter.
They wire out parts corrode It's sobering to think how wasteful this processes are While the second law of thermodynamic was the driving force behind the industrial revolution Our next great discovery power the world into the modern age 726 feet high, weighs 6.
6 million tons The electricity created using a magnetic field Scientists had figured out how the created magnetism electricity by running in a electric current through loops of wire The result is a electro magma Turn on the electro current and magnetic field is created.
Turn off the current and the magnetic field disappears In 1831, a book binder with an interest in electricity named Michael Faraday Was the first enable to reverse the process, using a moving magnetic field to create electricity An electric generator in its most basic form is coil of wire between the poles of magnet Michael Faraday discovered when the magnet and the wire move near each other, an electric current passes through the wire Every electrical generator works on this simple principle Faraday kept some equipped notes on his experiments But years later they proved invaluable to a physicist names James Clerk Maxwell Who used them to contribute to our understanding of how electromagnetic works To find out more about this discovery I paved a visit of museum of science in Boston.
Hi I am bill.
It's great So, what is device Well, this is a generator and we use here in museum to talk about lightning and lightning safety And a little bit of what you just mentioning that sort of connection between electricity and magnetic We've got this demonstration sort of giant bird cage.
We can use that to show how electricity and magnetism are sort of interrelated - Would you like to try it - Yes of course - One test is worth than thousands of expert's opinion.
- After you One of the things Maxwell helped us to understand is how electromagnetic field are distributed on a conducting surface Like the metal this cage are made of And now, if you want, When I start to make some of sparks, you put your finger on the inside of that bar You should be ok if you wanna give a try If Maxwell was right And that wouldn't be able to penetrate the inside Right now, I am hoping that James Maxwell was right - Ready - Yeah We'll go ahead and put your finger up there.
We'll give it a try here we go It's So, what's happening The electricity is hitting the cage and that created a magnetic field That lightning bolt is current electricity It strikes the cage and that turned the entire cage in a sort of a giant magnet, the magnet in turn makes another electric field And that electric field around the outside of the cage pushes all the electrical currents to the very outmost surface - It's amazing.
Well thank you very much.
- Thanks for coming I'll never forget that.
that's just spectacular.
I'm fine If you wanna know what the world would be like without the work of Faraday and Maxwell Imagine the world with no electricity To be no radios, no televisions, no cell phones, no satellites, no modern communication of any kind, no computers Think of being in 19 century.
That was you dig Well Faraday and Maxwell couldn't know was their discoveries would inspire a young man would go on to unlock the secrets of light And its connection to a fearsome power of universe In 1905, the scientific world was turned upset down by our next great discovery One of several revolutionary theories put forth by a young unknown scientist working in a patent office in Berne Switzerland His name, Albert Einstein To find out about Einstein and his discovery I paved a visit to Michio Kaku, a physicist at the City University of New York.
Einstein once said that all ideas should be presented to children And if children can't understand it, the theory is worthless When he was a child, he read a children's book.
Electricity was just coming in at the turn of the century And people are fascinated by telegraph wires And there's one book by Bernstein says imagine yourself racing alongside a telegraph signal inside a wire That's what we think the historically speaking Einstein got his earth-shattering idea, from a children's book When Einstein was a teenager, he was inspired by his memory of a children's book To imagine what will happen if you were writing the beam of light And began thinking about light, time and space He realized that Newton's theory that space and time were fixed in absolute, did not applied to approach the beat of light From this insight, he formulated what he called the special theory of relativity In Newton's world, space and time were always separated, If it's ten o'clock on the earth, it's ten o'clock on Venus, it's ten o'clock on Jupiter, it's ten o'clock around the universe Time was like an arrow, once you fire it, it never came back, never deviated Einstein comes along and says not so fast Time is like a river, a river that meanders around the stars and speeds up and slows down Of course the space and time can changed, that changes everything Everything we know about atoms, everything we know about our bodies and universe changes once time and space also change Einstein demonstrated his theory with what he called thought experiments The most famous thought experiment is the twin paradox.
You get two twins on the earth, you put one on the rocket ship, sent that person off and Of course that person accelerated near the speed of light and times slows down So, when the two people come together, the twin in the rocket ship is younger than the twin on the earth Time beats at different rates throughout the universe - Depending on what - Depending on your velocity The faster you move the slower time beats Now we have in a very small way done the experiment with orbiting astronaut right Right, if you have astronaut sent into outer space and time beats slower on the space station time beats slower That affects all satellites.
Look at the GPS satellites You realize that it is so accurate you can locate your position into within about 20 feet on the planet earth - Until you are at the street round - that's right, So the satellite going around the earth is going very fast, eighteen thousand miles per hour Therefore you have to include the relativistic effects Now if the two clocks are out of the synchronization, if the clock in outer space run slower than the clock on the earth The GPS system is totally out of luck a few months after publishing his special theory of relativity, Einstein followed it up with our next great discovery The most famous equation ever written E equal mc square may be the most famous equation known Where did it come from Einstein use relativity to show that as you approach light speed bizarre it distortion displace Time beats slower, space contracts and you get heavier The faster you move the heavier you get Now think about that, the energy of motion has turned into making you heavier.
M came from velocity energy, here is how he did it.
He imagined a flashlight, a flashlight shooting a light beam exactly how much the energy came out of the flashlight, but the flashlight he showed weightless the flashlight weights less by meeting a beam of light therefore the e of light came from the m of the flashlight And the ratio is c square.
That's how it's done The equation also hinted that enormous amount of energy contain even a small quantity of matter Suppose I throw a baseball, you cash the fast As throw more energy, it's got And what about when it's stand still.
When Einstein goes through the equation He find even with a stand still is still there is a lot of energy In fact when you do the equations.
It got enormous amount of energy Einstein's discovery was a gigantic leap for science Our first real glimpse into the power of the atom, while scientists were still trying to digest it Our next great discovery sent science thrilling again.
A quantum leap is the smallest leap possible in the nature But it proved to be an enormous step in thought Subatomic particles like electrons are able to move from one point to another without ever occupying any of the space between And impossible in our every day work but common place in the round of atom In the subatomic world, atoms and their constitute parts are played by a completely different set of rules from larger bodies of matter A German scientist named Max Planck described these new rules in what he called quantum theory And it's our next great discovery The quantum theory emerged around nineteen hundred because there was a crisis in physics of monumental proportions - A crises - A crisis New phenomena would be discovered that violated Newton's laws Marie curie for example refined something called radium.
Radium has magical property of glowing in the dark Energy was coming out of nothing; particles would coming out of nothing That violated the conservation of energy.
Energy was coming from nowhere around nineteen hundred, people thought that energy was continued and that you could cut electricity magnetism, you can cut to final final final pieces without end - And why did he say that - Because if you soon that the light come into this package, then you could explain all the different kinds of phenomena that we were seeing That the fundamental level of the atom, the level of that was a quantum of effect that the energy was occurring in package This also meant by the way that matter has wavelike property - And this is what we call quantum mechanics.
- That's right That's not the way the universe was suppose because constructed The atom was like a bowling ball, how could a bowling ball have wavelike properties While in 1925, Erwin Schrodinger, an Austral physicist finally writes down the wave equation governing the electron This is one of the greatest achievements of the human intellect, all of the son we can now peer into the atom self So atoms are waves.
Atoms are particles but there is uncertain association with them, right That's right, then a few years later, Marx Bohr, college of Albert Einstein made a faithful step The question was if a matter is a wave, then what is waving Marx Bohr said what's waving is the probability of locating it at any given point We sometimes give our graduate students the problem Calculate the probability that you will dissolve and you will rematerialize on the other side of the break wall Now, that's absurd.
How could you wake up in the morning upon Mars.
How could you go to bed once upon Jupiter That's crazy, and yet you can calculate the probability of that happening - It's probably low.
- It's very low.
You have to wait long enough time to ruin the universe But for electron, It happens all the time.
That's what we called electronics All the modern marvels of electronic age and laser beams and microchips ultimately come down to the fact That electrons you don't know where they are.
They can be two places at the same time How can that be two places at the same time Because you don't know where objects really are This cause so much problem that even Einstein finally broke with the quantum theory And he said I can't believe the god plays dice with the universe With all this weirdness and built in uncertainty, quantum theory remains the best model of the subatomic world we have The ancient asked a fundamental question what is the university made of They thought it was earth, air, fire, water But as the world is made up of what is light You can't put it in a box, you cant' shake it, you can't touch it, it's ephemeral yet it's everywhere light is everywhere and nowhere.
Everyone experience it in euphoric life But the question is, what is it And that's dog physic for thousands of years Dog physics.
Is it make you data or other reason you come to this office That's right.
That's why some of the greatest mind is going back to Isaac Newton made the first definitive study on the nature of light.
Newton for example took white light from the sun shot through a prism and showed that all the colors of the rainbow would come out of white light Showing that white light is really a composite, a sum of red, orange, yellow, blue light - Did he also recombine it - That's right; he also showed that red orange yellow, the violet could be recombined to create white light.
So Newton thought that light was in some sense particulate little tiny corpuscle that he called it made up the stream called light So we have the first theory of light, the fact that light is based out of particles But however it was alternative theory, a rival theory to Newton's theory that set that light was a wave And it was Thomas Young who made years ago had showed that white light had wavelike properties I think of surfing for example.
Every surfer know he could ride an ocean wave But if the second ocean wave comes at you from another angel, the two waves interfered, giving you an interference pattern And then of course if you are not careful you wipe out.
Well Young showed this with light.
He was able to get light shining with small pinhole Get another pinhole of light and has these two waves collide with each other, and there was a beautiful interference pattern So, we now have two rival theories of light The Newton's corpuscular particular theory of light and young's and other's wavelike theory of light Now, Einstein took the next step When Einstein said, and this is the genius of Einstein, he said perhaps both are right Perhaps Newton shows that has particle properties and Young showed that light has wavelike properties and two are different manifestations of the same thing Thinking of you are blind and looking at an elephant, you touch the trunk you think the elephant is a snake You touch the legs, you think the elephant is a tree, and yet elephant is a merger of all these qualities So Einstein introduced the concept of duality, particle and wavelike duality What we are looking at Here we are looking at a helium-neon gas laser, it meets a miliwatt of energy And it demonstrate that light has both particulate and wavelike nature Look at this, it does look like light consists of particles It's a collimate beam, very very coherent, meaning all the waves are vibrating in unison.
- If there were waves, - Yes.
If there were waves Now it goes to this double slip and as it goes to the slip it started to interfered with itself Waves start to crisscross, and the wave is created this pattern So as we see here the wave start to disperse Now if waves were nothing but photons, individual particles, this would simple a red dot But it is not red dot, it looks like a waved pattern That demonstrate one experiment both the particle and wavelike nature of light, the duality of light Without them, we may be as well live in the dark ages The atom, so small it is hard to imagine Finding out what an atom was made of led to our next great discovery To get the story, I went to Fermi lab outside Chicago in met with physicist John Womersley Even a hundred years ago, people knew how big the atom was, and they thought electrons and protons would be spread pretty much uniformerly throughout the atom And they called this plum pudding model Because they thought the electrons like raisins of a fruit cake spread throughout the inside of the fruit cake In the early nineteen hundreds, physicist earnest Rutherford conducted an experiment to further explore the structure of the atom He shot radioactive alpha particles at a sheet of gold foil And he wanted to see what happen when the alpha particle hit the gold, he didn't expect very much what happening For most the alpha particles recarried straight on through without being deflected, without being bent through any large angle - Well what happened - He found something completely different And had be altered shell bounce back to you Somebody alpha particle bounce straight back of the gold foil So the only way this could happen is as if the inside the atom is a very small dense concentration of matters Not spread out like slum pudding Rutherford called this small dense concentration the nucleus What we doing here at Fermi lab is extend that experiment We take a beam of protons collide with a beam of antiprotons to see what the proton is made of Thanks to Rutherford's discovery, scientists now knew that the structure of the atom includedprotons, electrons and a nucleus But was up to James Chadwick, a student of Rutherford's to complete the picture with the discovery of the neutron What is that standing now inside the D0 detective Which is one of the particle detective in Fermi lab collider That detect whether proton and antiprotons eventually circulate Come to collision few feet to your right and all the instrumentation around are record we use to detect the result of those collisions This is kind of back to the history of neutron Chadwick was able to carry out the experiment.
They showed the nucleus was made of protons and neutrons Almost Chadwick use was a clever detection technique which is what we stand in the middle of to do that So hit those big piece of apparatus like this, he used paraffin wax - Like form of candle.
- Right What Chadwick did is to use this wax set into particles that came out into radioactive process And suddenly all the pieces fit into place The discovery of the neutron changed the history In 1939, a group of scientist led by physicists in Enrico Fermi used neutron as a bullet to split the atom, giving to the birth of the nuclei age Fermi lab is home to one of the largest particle accelerators in the world To accomplish this feat requires the help of our next great discovery The superconductor Who discovered superconductive Why is this such a big deal Way back the time before the first world war, 1909 something like that A Dutch physicist called Heike Kamerlingh Onnes was the first to figure out turn helium from a gas into a liquid And once he figured out how to do that, he could use liquid helium as refrigerator fluid to make other materials very cold He wanted to study the properties of material that very low temperature One of the things that people are interested in at that time is how did this electrical resistance of a metal for example depend on temperature Does it rise Maybe it gets very resistive in a very low temperatures that was one idea So took some sample of mercury which he could make very pure and he put it in an apparatus kind of This one, he just dig it into liquid helium and refrigerator vessel measured it electrical resistance as he lower the temperature and what he found was that as you lower the temperature, the resistance went down very smoothly and then suddenly when he got to four point two degrees of absolute zero the resistance dropped to nothing, absolutely to zero this mercury could conducted electricity with no resistance without losing any energy without dissipating the current at all and that was what he called superconductivity so to see the superconductor that works well this is the Fermi accelerated tunnel in this tunnel we have a large ring of superconducting magnet which we use to accelerate and contain protons and antiprotons that we using to study the properties of matter - it's lovely.
Beautiful isn't - it is so we are using superconductors here superconductor allows current to flow without any energy we can use them to generate strong magnetic field that's what we are doing here this is magnet.
So we use magnets to keep the protons and antiprotons circulate into the taptron going round round this big ring they travel at close the speed of light, one hundred eighty sixty miles a second fast than we are going accelerated the speed at this car.
I feel massive the particle accelerate at Fermi lab require enormous power it caused more than a million dollar worth electricity every month to refrigerate the superconductor to minus 445 degrees Fahrenheit the point where electricity flows with zero resistance the technical challenge now is to find super conductors that work at much higher temperatures at a much lower cost studying back in the 1980, a researcher in IBM Switzerland found a class of material Of course the holy goal is to find the material suit to superconductor in room temperature Cause that kind of thing if could be make of into useful electrical conductor will really revolutionize the world All of the things in your house that use electrical current that use electrical motors would be changed to make more efficient by that Our next discovery takes on the quest to find the smallest piece of matter in the universe First the electron was discovered Then the proton And finally the neutron Science now have a new model of the atom the tiny building blocks that make up all matter And once accelerators were developed that could slam subatomic particles together at nearly the speed of light Dozens of new particles broke the way of process that were discovered So many affect, physicist began to refer the mass "the particle zoo" In the late forties and early fifties when the discovery of the so-called strange particles began I got very interest in that That would be in an offbeat field, one wasn't encourage to work out that American physicist Murray Gell-Mann began to see patterns in obliterated ray of all the new members of the particle zoo He used common characteristics to divide particles into different families In the process, he isolated the smallest components of the atom nucleus the very pieces that protons and neutrons are built from As a theoretician, I couldn't really, I suppose to discover new things But I could proposed and if that could be right, you could call it a discovery in sense What I did was to propose that the neutron and proton were not elementary as everybody thought But were a composed instead of smaller particles called quarks with some very bizarre properties Gall-Mann's quarks did for subatomic particles what the periodical table did for the chemical elements His classification of the tinniest beat of matter brought order to the chaos of the particle zoo I thought that the sound quarks was a good sound for these fundamental constitute It sounds like a good name for the fundamental constitutes for neutrons, protons, mesons, quarks But I didn't spell it.
I thought may be k-w-o-r-k But then perusing James Joyce's Finnegans Wake as I do once throughout I noticed that the line three quarks for master mark And maybe I should spell q-u-a-r-k Well Gall-Mann believe quarks to be real.
He never expected anyone to find one Some of the earliest evidence that quarks was correct came from an experiments by a friend of mine the Stanford linear accelerator In which electrons were scattered off protons and essentially what they were doing was taking an electron microscopic picture of the proton And sure enough, There are three quarks Our search for answers questions about the universe around this Have taken us from the submicroscopic scale of atoms and quarks to the farthest reaches of the galaxy and beyond Our last great discovery is Actually the result of centuries of effort by countless men and women of science Since the discovery of Isaac Newton and Michael Faraday, scientist believed that there were two basic forces of nature But in the twenty century Scientists discovered that there were two more at work, what known as nuclear forces Each one act over different range We have gravity with keeps this on the earth.
Without gravity by the way, we will float at thousand miles per hour into outer space - That's what keeps us on the floor.
- That's surprising - And that would really ruin your life.
- Playing baseball would be hard - Yes and you will suffocate in outer space.
- Yes couple of issues.
Ok Then we have an extra magnetic force.
Light which illuminating the world, radio, television and all of that electromagnetic force We have the strong nuclear force that holds the nucleus together and the weak nuclear force gives us radioactive decay And that's actually heats up the center of the earth That's why the center of the earth is still hot after some billion years That's the energy of volcanoes; the energy of earthquake, the energy of plain tectonics is the weak force as manifest through heat How do you go about detecting, the weak force How do you know it's there We know it's there because we have a Geiger counter These particles that they can raising out of the atom raped apart other atom And causes the slight electrical charge.
You can measure that charge and it cause a click inside a Geiger counter How did you detect the strong nuclear force Well the strong nuclear force is more difficult because it's what holds the atoms together For that we need atoms' smashers For that we have this smash particles that blow down the reeds Some of ones compared this to try to figure out how a piano works by throwing it down a stairwell And listening for all the tinkling sound as the piano disintegrates going down the stairs As how we do it, we smash atoms apart You got gravity, you got magnetic force, you got weak and strong force.
What's next Now we now know that the quantum forces can be summarized as something can be called standard model It's perhaps the ugly theory known to science but very successful at the subatomic level I like to think of it as getting scorch tape and cause tapping aardvark to a shark to a giraffe And calling this horrible animal nature's finest product evolution This is supposed to be the ultimate theory that the standard model.
It's so ugly Then we have gravity, beautiful, gorgeous, supreme Based on curve surfaces, you cry.
Physicist literary cry when they see Einstein's equation Well, obviously, the two have to come together.
That's called the theory of everything The theory that we unite all four forces into a single super force that existed at the beginning of time We don't know forever to write physics theory of everything But this much in certain Each discovery lead to more exploration And we human's are curious species with the drive to understand, explore and discover
In fact it has been around well as long as we have The ancient Greeks for example were the first to developed the idea that nature obeys a set of laws This is a tremendous breakthrough They gave us the notion about how the universe works, and about the way things move Trouble was, most its notion were dead wrong that's because the laws of physics sometimes seem to defy common sense Like our first great discovery For some two thousand years, it was believed that heavier objects fall faster than lighter objects This conventional bit of wisdom was based on observations made by the Greek philosopher Aristotle And people believed him because it seems like common sense But in the 17 century, Galileo Galilei decided to test Aristotle's law Legend has it that his test involved dropping balls of difference masses from the top of the leaning tower of pizza.
To see Galileo's experiment in action I paved a visit to the NANA's Glenn research center at Cleveland, Ohio And met with Steven Simons, project manager for microgravity research - So this is the chamber, - Yes This is the vacuum chamber.
It goes four feet into the ground We have to pomp air out of this so we can get good microgravity drop And this is goes back a long way to Aristotle Yes, Aristotle, yes it does.
While Aristotle thought that objects with different masses would fall at different rates - Which seems reasonable.
- Seems very reasonable Cause all of the history that people had with objects with different masses fall at different rates For example, if you have a feather and a ping-pang ball Both fairly light objects but they will fall at different rates To illustrate the difference between two objects that are roughly the same size and shape but obviously very different masses Is a golf ball and a ping-pang ball And if we drop those, they do drop at the same rates Through Galileo's experiment, he found that a heavier object seems to fall faster than a lighter one because of air resistance Air resistance slow lighter more than the heavier one The other way we do it is as if we shield the experiment which we can simulate with this leaf from the effects of air then they will drop at the same rate so what we are doing here By pumping all of the air out from this huge vacuum tank We got an experiment set up here today To check our new fire extinguisher for possible use on international space station so we are goanna to see if helium a better fire extinguisher than carbon dioxide Anita please.
- So she's goanna drop the big vehicle down - And there goes And you can fell the full shake when the drop vehicle hits - Let me take you down to the vital vacuum chamber.
We can retrieve the experiment and see what happened.
- Fun Galileo's challenged Aristotle's law was a turning point in science It mark beginning of testing the accepted laws of science through experimentation And Galileo's experiments with falling bodies led to our earliest understanding of acceleration caused by gravity Lift off.
We have lift off.
Right on my left hand have a feather in my right hand and a hammer And I will drop to here and hope it to hit the ground at the same time How about that Galileo was correct We own our next great discovery to Sir Isaac Newton Who is born in England the same year that Galileo died Legend has it that Newton was relaxing in an orchard one day when he saw an apple fall from a tree This simple incident caused him to wonder why is the apple had fallen to earth or the pale August moon continue to sail contently overhead It was eureka moment of insight for the young man.
He realized that the same gravitational force act on the apple and moon alike He think about, you get the feeling that all through the apples are shared there is some force that played the apples down It's always great about was he set the on the apple way out to the moon.
He realized that this force is everywhere.
It's something that nobody had really thought about before Newton's reason that the moon tries to travel straight line in space pass the earth.
The earth gravitational force posed the moon toward them This keeps the moon trapped in orbit around the earth But the moon pose on the earth too with its own gravitational force Newton had discovered what is called the laws of universal gravitation Universal because relationship applies to all bodies in the cosmos, including apples, moons, and planets When the gravitational force of a large body like the moon adds upon the earth, big things can happen Such as the ebb and flow of the earth's oceans The water in the ocean that's near the moon feels a greater pull water than the other side of the earth far from the moon So as the earth pull out the earth's rotate this kind of bulge the water and the earth rotates against its the higher water and lower water Newton's recognition that all objects have their own gravitational force was a landmark discovery in science But is our next great discovery shows he was far from finished To many people Isaac Newton is physics And it's largely because of a series of books he wrote which contained Newton's second discovery, the laws of motion The law explained the motion of all physical objects That's simple enough, you hit hockey pokey and it just keep sliding off across the ice You can see the unfrictional surface is just a little pretty much keep on indefinitely When you kick your stick against the pokey and it accelerates and makes that acceleration that's from in stand still up to speed is explained by the second law.
You can calculate using the second law The third law says when you hit the pokey with a stick and the stick get the force opposite to the pock or to another way When a hockey players punch the other one's face It's likely to break his knuckle as really as strong Newton's law of motion were a bold insight in the mechanic of how the universe works They established the foundation of what is now known as classical physics This is the science of thermodynamic in action The science of hit transformed into mechanical energy The power driven machinery of the industrial revolution depended on it Hit energy can be turn into the energy of motion Such as by turning a crank or piston or turbine to be use to pomp water, to turn a loom, to make fabric To move a boat through the water, to move a train down rails Now, it's desirable to get more oomph for your dollar to get more work down for the amount of fuel you are going to use And so people began to study how heat engines and how steam engines really work Among those who studied it was German scientist named Rudolf Clausius What became known as the second law of thermodynamics The law states that in any energy exchange such as heating the water as steam engine boil, some energy is always wasted Clausius called the word entropy to explain why the efficiency of a steam engine is limited Because some of its energy were always be lost in the process of converting it to mechanical work It was a momentous insight, one that changed our understanding of how energy works There is no heat engine that is one hundred percent efficient While a car is moving along, how much of the energy implicit in the gasoline that put into the car actually get used to move the car in a united Only about twenty percent.
Where is the rest of go It goes to heating up the pavement on the road, heating up the tires, the cylinders in engine block get hotter.
They wire out parts corrode It's sobering to think how wasteful this processes are While the second law of thermodynamic was the driving force behind the industrial revolution Our next great discovery power the world into the modern age 726 feet high, weighs 6.
6 million tons The electricity created using a magnetic field Scientists had figured out how the created magnetism electricity by running in a electric current through loops of wire The result is a electro magma Turn on the electro current and magnetic field is created.
Turn off the current and the magnetic field disappears In 1831, a book binder with an interest in electricity named Michael Faraday Was the first enable to reverse the process, using a moving magnetic field to create electricity An electric generator in its most basic form is coil of wire between the poles of magnet Michael Faraday discovered when the magnet and the wire move near each other, an electric current passes through the wire Every electrical generator works on this simple principle Faraday kept some equipped notes on his experiments But years later they proved invaluable to a physicist names James Clerk Maxwell Who used them to contribute to our understanding of how electromagnetic works To find out more about this discovery I paved a visit of museum of science in Boston.
Hi I am bill.
It's great So, what is device Well, this is a generator and we use here in museum to talk about lightning and lightning safety And a little bit of what you just mentioning that sort of connection between electricity and magnetic We've got this demonstration sort of giant bird cage.
We can use that to show how electricity and magnetism are sort of interrelated - Would you like to try it - Yes of course - One test is worth than thousands of expert's opinion.
- After you One of the things Maxwell helped us to understand is how electromagnetic field are distributed on a conducting surface Like the metal this cage are made of And now, if you want, When I start to make some of sparks, you put your finger on the inside of that bar You should be ok if you wanna give a try If Maxwell was right And that wouldn't be able to penetrate the inside Right now, I am hoping that James Maxwell was right - Ready - Yeah We'll go ahead and put your finger up there.
We'll give it a try here we go It's So, what's happening The electricity is hitting the cage and that created a magnetic field That lightning bolt is current electricity It strikes the cage and that turned the entire cage in a sort of a giant magnet, the magnet in turn makes another electric field And that electric field around the outside of the cage pushes all the electrical currents to the very outmost surface - It's amazing.
Well thank you very much.
- Thanks for coming I'll never forget that.
that's just spectacular.
I'm fine If you wanna know what the world would be like without the work of Faraday and Maxwell Imagine the world with no electricity To be no radios, no televisions, no cell phones, no satellites, no modern communication of any kind, no computers Think of being in 19 century.
That was you dig Well Faraday and Maxwell couldn't know was their discoveries would inspire a young man would go on to unlock the secrets of light And its connection to a fearsome power of universe In 1905, the scientific world was turned upset down by our next great discovery One of several revolutionary theories put forth by a young unknown scientist working in a patent office in Berne Switzerland His name, Albert Einstein To find out about Einstein and his discovery I paved a visit to Michio Kaku, a physicist at the City University of New York.
Einstein once said that all ideas should be presented to children And if children can't understand it, the theory is worthless When he was a child, he read a children's book.
Electricity was just coming in at the turn of the century And people are fascinated by telegraph wires And there's one book by Bernstein says imagine yourself racing alongside a telegraph signal inside a wire That's what we think the historically speaking Einstein got his earth-shattering idea, from a children's book When Einstein was a teenager, he was inspired by his memory of a children's book To imagine what will happen if you were writing the beam of light And began thinking about light, time and space He realized that Newton's theory that space and time were fixed in absolute, did not applied to approach the beat of light From this insight, he formulated what he called the special theory of relativity In Newton's world, space and time were always separated, If it's ten o'clock on the earth, it's ten o'clock on Venus, it's ten o'clock on Jupiter, it's ten o'clock around the universe Time was like an arrow, once you fire it, it never came back, never deviated Einstein comes along and says not so fast Time is like a river, a river that meanders around the stars and speeds up and slows down Of course the space and time can changed, that changes everything Everything we know about atoms, everything we know about our bodies and universe changes once time and space also change Einstein demonstrated his theory with what he called thought experiments The most famous thought experiment is the twin paradox.
You get two twins on the earth, you put one on the rocket ship, sent that person off and Of course that person accelerated near the speed of light and times slows down So, when the two people come together, the twin in the rocket ship is younger than the twin on the earth Time beats at different rates throughout the universe - Depending on what - Depending on your velocity The faster you move the slower time beats Now we have in a very small way done the experiment with orbiting astronaut right Right, if you have astronaut sent into outer space and time beats slower on the space station time beats slower That affects all satellites.
Look at the GPS satellites You realize that it is so accurate you can locate your position into within about 20 feet on the planet earth - Until you are at the street round - that's right, So the satellite going around the earth is going very fast, eighteen thousand miles per hour Therefore you have to include the relativistic effects Now if the two clocks are out of the synchronization, if the clock in outer space run slower than the clock on the earth The GPS system is totally out of luck a few months after publishing his special theory of relativity, Einstein followed it up with our next great discovery The most famous equation ever written E equal mc square may be the most famous equation known Where did it come from Einstein use relativity to show that as you approach light speed bizarre it distortion displace Time beats slower, space contracts and you get heavier The faster you move the heavier you get Now think about that, the energy of motion has turned into making you heavier.
M came from velocity energy, here is how he did it.
He imagined a flashlight, a flashlight shooting a light beam exactly how much the energy came out of the flashlight, but the flashlight he showed weightless the flashlight weights less by meeting a beam of light therefore the e of light came from the m of the flashlight And the ratio is c square.
That's how it's done The equation also hinted that enormous amount of energy contain even a small quantity of matter Suppose I throw a baseball, you cash the fast As throw more energy, it's got And what about when it's stand still.
When Einstein goes through the equation He find even with a stand still is still there is a lot of energy In fact when you do the equations.
It got enormous amount of energy Einstein's discovery was a gigantic leap for science Our first real glimpse into the power of the atom, while scientists were still trying to digest it Our next great discovery sent science thrilling again.
A quantum leap is the smallest leap possible in the nature But it proved to be an enormous step in thought Subatomic particles like electrons are able to move from one point to another without ever occupying any of the space between And impossible in our every day work but common place in the round of atom In the subatomic world, atoms and their constitute parts are played by a completely different set of rules from larger bodies of matter A German scientist named Max Planck described these new rules in what he called quantum theory And it's our next great discovery The quantum theory emerged around nineteen hundred because there was a crisis in physics of monumental proportions - A crises - A crisis New phenomena would be discovered that violated Newton's laws Marie curie for example refined something called radium.
Radium has magical property of glowing in the dark Energy was coming out of nothing; particles would coming out of nothing That violated the conservation of energy.
Energy was coming from nowhere around nineteen hundred, people thought that energy was continued and that you could cut electricity magnetism, you can cut to final final final pieces without end - And why did he say that - Because if you soon that the light come into this package, then you could explain all the different kinds of phenomena that we were seeing That the fundamental level of the atom, the level of that was a quantum of effect that the energy was occurring in package This also meant by the way that matter has wavelike property - And this is what we call quantum mechanics.
- That's right That's not the way the universe was suppose because constructed The atom was like a bowling ball, how could a bowling ball have wavelike properties While in 1925, Erwin Schrodinger, an Austral physicist finally writes down the wave equation governing the electron This is one of the greatest achievements of the human intellect, all of the son we can now peer into the atom self So atoms are waves.
Atoms are particles but there is uncertain association with them, right That's right, then a few years later, Marx Bohr, college of Albert Einstein made a faithful step The question was if a matter is a wave, then what is waving Marx Bohr said what's waving is the probability of locating it at any given point We sometimes give our graduate students the problem Calculate the probability that you will dissolve and you will rematerialize on the other side of the break wall Now, that's absurd.
How could you wake up in the morning upon Mars.
How could you go to bed once upon Jupiter That's crazy, and yet you can calculate the probability of that happening - It's probably low.
- It's very low.
You have to wait long enough time to ruin the universe But for electron, It happens all the time.
That's what we called electronics All the modern marvels of electronic age and laser beams and microchips ultimately come down to the fact That electrons you don't know where they are.
They can be two places at the same time How can that be two places at the same time Because you don't know where objects really are This cause so much problem that even Einstein finally broke with the quantum theory And he said I can't believe the god plays dice with the universe With all this weirdness and built in uncertainty, quantum theory remains the best model of the subatomic world we have The ancient asked a fundamental question what is the university made of They thought it was earth, air, fire, water But as the world is made up of what is light You can't put it in a box, you cant' shake it, you can't touch it, it's ephemeral yet it's everywhere light is everywhere and nowhere.
Everyone experience it in euphoric life But the question is, what is it And that's dog physic for thousands of years Dog physics.
Is it make you data or other reason you come to this office That's right.
That's why some of the greatest mind is going back to Isaac Newton made the first definitive study on the nature of light.
Newton for example took white light from the sun shot through a prism and showed that all the colors of the rainbow would come out of white light Showing that white light is really a composite, a sum of red, orange, yellow, blue light - Did he also recombine it - That's right; he also showed that red orange yellow, the violet could be recombined to create white light.
So Newton thought that light was in some sense particulate little tiny corpuscle that he called it made up the stream called light So we have the first theory of light, the fact that light is based out of particles But however it was alternative theory, a rival theory to Newton's theory that set that light was a wave And it was Thomas Young who made years ago had showed that white light had wavelike properties I think of surfing for example.
Every surfer know he could ride an ocean wave But if the second ocean wave comes at you from another angel, the two waves interfered, giving you an interference pattern And then of course if you are not careful you wipe out.
Well Young showed this with light.
He was able to get light shining with small pinhole Get another pinhole of light and has these two waves collide with each other, and there was a beautiful interference pattern So, we now have two rival theories of light The Newton's corpuscular particular theory of light and young's and other's wavelike theory of light Now, Einstein took the next step When Einstein said, and this is the genius of Einstein, he said perhaps both are right Perhaps Newton shows that has particle properties and Young showed that light has wavelike properties and two are different manifestations of the same thing Thinking of you are blind and looking at an elephant, you touch the trunk you think the elephant is a snake You touch the legs, you think the elephant is a tree, and yet elephant is a merger of all these qualities So Einstein introduced the concept of duality, particle and wavelike duality What we are looking at Here we are looking at a helium-neon gas laser, it meets a miliwatt of energy And it demonstrate that light has both particulate and wavelike nature Look at this, it does look like light consists of particles It's a collimate beam, very very coherent, meaning all the waves are vibrating in unison.
- If there were waves, - Yes.
If there were waves Now it goes to this double slip and as it goes to the slip it started to interfered with itself Waves start to crisscross, and the wave is created this pattern So as we see here the wave start to disperse Now if waves were nothing but photons, individual particles, this would simple a red dot But it is not red dot, it looks like a waved pattern That demonstrate one experiment both the particle and wavelike nature of light, the duality of light Without them, we may be as well live in the dark ages The atom, so small it is hard to imagine Finding out what an atom was made of led to our next great discovery To get the story, I went to Fermi lab outside Chicago in met with physicist John Womersley Even a hundred years ago, people knew how big the atom was, and they thought electrons and protons would be spread pretty much uniformerly throughout the atom And they called this plum pudding model Because they thought the electrons like raisins of a fruit cake spread throughout the inside of the fruit cake In the early nineteen hundreds, physicist earnest Rutherford conducted an experiment to further explore the structure of the atom He shot radioactive alpha particles at a sheet of gold foil And he wanted to see what happen when the alpha particle hit the gold, he didn't expect very much what happening For most the alpha particles recarried straight on through without being deflected, without being bent through any large angle - Well what happened - He found something completely different And had be altered shell bounce back to you Somebody alpha particle bounce straight back of the gold foil So the only way this could happen is as if the inside the atom is a very small dense concentration of matters Not spread out like slum pudding Rutherford called this small dense concentration the nucleus What we doing here at Fermi lab is extend that experiment We take a beam of protons collide with a beam of antiprotons to see what the proton is made of Thanks to Rutherford's discovery, scientists now knew that the structure of the atom includedprotons, electrons and a nucleus But was up to James Chadwick, a student of Rutherford's to complete the picture with the discovery of the neutron What is that standing now inside the D0 detective Which is one of the particle detective in Fermi lab collider That detect whether proton and antiprotons eventually circulate Come to collision few feet to your right and all the instrumentation around are record we use to detect the result of those collisions This is kind of back to the history of neutron Chadwick was able to carry out the experiment.
They showed the nucleus was made of protons and neutrons Almost Chadwick use was a clever detection technique which is what we stand in the middle of to do that So hit those big piece of apparatus like this, he used paraffin wax - Like form of candle.
- Right What Chadwick did is to use this wax set into particles that came out into radioactive process And suddenly all the pieces fit into place The discovery of the neutron changed the history In 1939, a group of scientist led by physicists in Enrico Fermi used neutron as a bullet to split the atom, giving to the birth of the nuclei age Fermi lab is home to one of the largest particle accelerators in the world To accomplish this feat requires the help of our next great discovery The superconductor Who discovered superconductive Why is this such a big deal Way back the time before the first world war, 1909 something like that A Dutch physicist called Heike Kamerlingh Onnes was the first to figure out turn helium from a gas into a liquid And once he figured out how to do that, he could use liquid helium as refrigerator fluid to make other materials very cold He wanted to study the properties of material that very low temperature One of the things that people are interested in at that time is how did this electrical resistance of a metal for example depend on temperature Does it rise Maybe it gets very resistive in a very low temperatures that was one idea So took some sample of mercury which he could make very pure and he put it in an apparatus kind of This one, he just dig it into liquid helium and refrigerator vessel measured it electrical resistance as he lower the temperature and what he found was that as you lower the temperature, the resistance went down very smoothly and then suddenly when he got to four point two degrees of absolute zero the resistance dropped to nothing, absolutely to zero this mercury could conducted electricity with no resistance without losing any energy without dissipating the current at all and that was what he called superconductivity so to see the superconductor that works well this is the Fermi accelerated tunnel in this tunnel we have a large ring of superconducting magnet which we use to accelerate and contain protons and antiprotons that we using to study the properties of matter - it's lovely.
Beautiful isn't - it is so we are using superconductors here superconductor allows current to flow without any energy we can use them to generate strong magnetic field that's what we are doing here this is magnet.
So we use magnets to keep the protons and antiprotons circulate into the taptron going round round this big ring they travel at close the speed of light, one hundred eighty sixty miles a second fast than we are going accelerated the speed at this car.
I feel massive the particle accelerate at Fermi lab require enormous power it caused more than a million dollar worth electricity every month to refrigerate the superconductor to minus 445 degrees Fahrenheit the point where electricity flows with zero resistance the technical challenge now is to find super conductors that work at much higher temperatures at a much lower cost studying back in the 1980, a researcher in IBM Switzerland found a class of material Of course the holy goal is to find the material suit to superconductor in room temperature Cause that kind of thing if could be make of into useful electrical conductor will really revolutionize the world All of the things in your house that use electrical current that use electrical motors would be changed to make more efficient by that Our next discovery takes on the quest to find the smallest piece of matter in the universe First the electron was discovered Then the proton And finally the neutron Science now have a new model of the atom the tiny building blocks that make up all matter And once accelerators were developed that could slam subatomic particles together at nearly the speed of light Dozens of new particles broke the way of process that were discovered So many affect, physicist began to refer the mass "the particle zoo" In the late forties and early fifties when the discovery of the so-called strange particles began I got very interest in that That would be in an offbeat field, one wasn't encourage to work out that American physicist Murray Gell-Mann began to see patterns in obliterated ray of all the new members of the particle zoo He used common characteristics to divide particles into different families In the process, he isolated the smallest components of the atom nucleus the very pieces that protons and neutrons are built from As a theoretician, I couldn't really, I suppose to discover new things But I could proposed and if that could be right, you could call it a discovery in sense What I did was to propose that the neutron and proton were not elementary as everybody thought But were a composed instead of smaller particles called quarks with some very bizarre properties Gall-Mann's quarks did for subatomic particles what the periodical table did for the chemical elements His classification of the tinniest beat of matter brought order to the chaos of the particle zoo I thought that the sound quarks was a good sound for these fundamental constitute It sounds like a good name for the fundamental constitutes for neutrons, protons, mesons, quarks But I didn't spell it.
I thought may be k-w-o-r-k But then perusing James Joyce's Finnegans Wake as I do once throughout I noticed that the line three quarks for master mark And maybe I should spell q-u-a-r-k Well Gall-Mann believe quarks to be real.
He never expected anyone to find one Some of the earliest evidence that quarks was correct came from an experiments by a friend of mine the Stanford linear accelerator In which electrons were scattered off protons and essentially what they were doing was taking an electron microscopic picture of the proton And sure enough, There are three quarks Our search for answers questions about the universe around this Have taken us from the submicroscopic scale of atoms and quarks to the farthest reaches of the galaxy and beyond Our last great discovery is Actually the result of centuries of effort by countless men and women of science Since the discovery of Isaac Newton and Michael Faraday, scientist believed that there were two basic forces of nature But in the twenty century Scientists discovered that there were two more at work, what known as nuclear forces Each one act over different range We have gravity with keeps this on the earth.
Without gravity by the way, we will float at thousand miles per hour into outer space - That's what keeps us on the floor.
- That's surprising - And that would really ruin your life.
- Playing baseball would be hard - Yes and you will suffocate in outer space.
- Yes couple of issues.
Ok Then we have an extra magnetic force.
Light which illuminating the world, radio, television and all of that electromagnetic force We have the strong nuclear force that holds the nucleus together and the weak nuclear force gives us radioactive decay And that's actually heats up the center of the earth That's why the center of the earth is still hot after some billion years That's the energy of volcanoes; the energy of earthquake, the energy of plain tectonics is the weak force as manifest through heat How do you go about detecting, the weak force How do you know it's there We know it's there because we have a Geiger counter These particles that they can raising out of the atom raped apart other atom And causes the slight electrical charge.
You can measure that charge and it cause a click inside a Geiger counter How did you detect the strong nuclear force Well the strong nuclear force is more difficult because it's what holds the atoms together For that we need atoms' smashers For that we have this smash particles that blow down the reeds Some of ones compared this to try to figure out how a piano works by throwing it down a stairwell And listening for all the tinkling sound as the piano disintegrates going down the stairs As how we do it, we smash atoms apart You got gravity, you got magnetic force, you got weak and strong force.
What's next Now we now know that the quantum forces can be summarized as something can be called standard model It's perhaps the ugly theory known to science but very successful at the subatomic level I like to think of it as getting scorch tape and cause tapping aardvark to a shark to a giraffe And calling this horrible animal nature's finest product evolution This is supposed to be the ultimate theory that the standard model.
It's so ugly Then we have gravity, beautiful, gorgeous, supreme Based on curve surfaces, you cry.
Physicist literary cry when they see Einstein's equation Well, obviously, the two have to come together.
That's called the theory of everything The theory that we unite all four forces into a single super force that existed at the beginning of time We don't know forever to write physics theory of everything But this much in certain Each discovery lead to more exploration And we human's are curious species with the drive to understand, explore and discover