The Wonders of Gravity

&rechno ogy Department: Science and Technology REPUBLIC OF SOUTH AFRICA The Mystery of Falling Objects The Case of the Falling Moon TRY THIS AT HOME UNIVERSAL GRAVITY 1 Take an empty cooldrink can and make a small hole at the bottom". Around 1590, + -- --- Suppose you are standing on the top of a very high mountain with a canon (V). The first shot you fire lands a short distance away at (D). By adding more gunpowder and firing, the cannonball it will go further to (E) or maybe cven to (B). If you get the canonball moving fast enough It will eventually be put Into a low orbit (A) and come right back to (V). Galileo Galilei dropped two objects of different weights from the same height, and found that they reached the ground at the same time. 2 Fl the can with water Notice that if the can is held up, the water flows out the bottom. F. F, = Gmxm. Every object with mass in Newton realized that the moon's curved the universe atoracts every path in the sky could be caused in exactly the same way as the cannonball's orbit! He was also able to calculate that the moon falls toward the earth at other object with mass 3 Now drop the Galileo found that gravity acts exactly the same way on all matter. Scientises call this the universalicy of free-fall. can Does the water still flow out the can while it is falling? WHY? nl665. haa Newton divcomred the -science of optics, the laws of mechanic iented cakulus and aho wrote down the Irws of mity. Newton was sting under an apple tree when he noticed an apple tall and wondered if the same force that :DID YOU KNOW WWould a feather fall at the same speed s a hammer? Not on earth! Whyt Amazingy when atronsuts of the APOLLO I5 mission did this experiment on the moan, they confirmed that Galleo was correct. Why did it work on the moon! The speed hat a rocket mu blast off with in order to leave the Earth's gravitational pul is 1124 kns ? How fest is that in kstr? a rate of 1.37mm every second. Why does it not crash into the Earth? made the pple tall aho kapt the moon * Always k en aduk to help pou orbit around the earth Tody we call this s idea, the universality of gravity. The Darkest Place THE WONDERS The Magic of Gravity in the Universe OF GRAVITY Weighing something on a scale measures the force of the earch's gravity on that object. This force acts as if all the mass of the object were concentrated at one point, called the centre of mass. Ten years before writing down his famous General Theory. Einatein developed a Special Theory of Relativity According to this theory, the speed of light is the ultimste speed amk in the Universe. Nothing, not even light, could travel faster than the speed of light. TRY THIS AT HOME The Geometry of Gravity The escape speed needed by a rocketship to completely lezve the gravitational pull of a panet is inversely proportional to the density (mns/volume) of the planet. The greater the density, the harder it is to leve the planet, A Black Hole is an object that isso dee that the escape speed is greater than the speed of light. kis black because no Ighe According to this theory of gravity. all of space and time become one spacetime continuum. Anything with mass (like the Sun, for example) will bend the spacetime around itself. The bigger the mass, the more the bending, Any ocher body that finds itself moving near such a massive body will be forced to move in this warped spacetime along a geodesic In this way, the Yorce of gravity that attracts the two bodies is the geometry of the spacetime continuum around them. Take a can of cooldrink and drink about 3 of the contents The centre of mass can sometimes can get to us from it. The event horizon is the point of no return for an astronaut falling into a of the black hole Once crossed, not only will the astronaut not be able to return but she will also not be able to communicate with anyone outside the hole! lie outside of the object itself. For example, the centre of mass of a donut is at its centre which is not actually part of the donut! The idea of centre of mass is crucial to the physics of balance. When the centre of mass of an object is no longer above its base of support, the object will topple over. Tip the can tver until it makes an angle of about 45 Newton was the king of gravity. until a young Swiss patent clerk called Albert Einstein changed the way we understand the force of gravity. Einstein realised that there was no way for someone sitting in a closed room to tell if they were in a gravicational field (like on Earth) or accelerating (say out in space). This is the principle of equivalence between gravity and acceleration and forms the foundation of Einstein's theory of General Relativity Coca-Cola According to General Relativity. even light falls in a gravicational field. This causes light rays to be bene around a massive object a phenomenon known as gravitational lensing. This prediction of Einstein's theory was confirmed by Sir Arthur Eddington during the solar eclipse of 1919. Why do you think that a solar eclipse was necessary to carry out this test? Let go of the can What happens? Can you explain why, using the ideas of c DID YOU KNOW? Soentists use the speed af ight, 299 792 458 kmis, 1a define the netert What do you think this defnibon is? Coca-Cola of mass? Mhowom ACHNOWDGEMENTS Conene Dr Jet Mulgan and Or Amando weman CT. Oeportment ot Manemarios and Applied Motematet UCT Facuty of Scionco Marieoing Commitice Design and iayout Evalusion Marknting atlonal Sclence Week NRF SAASTA Notional Ressarch South Acan Agency for Science Fountetion | and Technology Advancement &rechno ogy Department: Science and Technology REPUBLIC OF SOUTH AFRICA The Mystery of Falling Objects The Case of the Falling Moon TRY THIS AT HOME UNIVERSAL GRAVITY 1 Take an empty cooldrink can and make a small hole at the bottom". Around 1590, + -- --- Suppose you are standing on the top of a very high mountain with a canon (V). The first shot you fire lands a short distance away at (D). By adding more gunpowder and firing, the cannonball it will go further to (E) or maybe cven to (B). If you get the canonball moving fast enough It will eventually be put Into a low orbit (A) and come right back to (V). Galileo Galilei dropped two objects of different weights from the same height, and found that they reached the ground at the same time. 2 Fl the can with water Notice that if the can is held up, the water flows out the bottom. F. F, = Gmxm. Every object with mass in Newton realized that the moon's curved the universe atoracts every path in the sky could be caused in exactly the same way as the cannonball's orbit! He was also able to calculate that the moon falls toward the earth at other object with mass 3 Now drop the Galileo found that gravity acts exactly the same way on all matter. Scientises call this the universalicy of free-fall. can Does the water still flow out the can while it is falling? WHY? nl665. haa Newton divcomred the -science of optics, the laws of mechanic iented cakulus and aho wrote down the Irws of mity. Newton was sting under an apple tree when he noticed an apple tall and wondered if the same force that :DID YOU KNOW WWould a feather fall at the same speed s a hammer? Not on earth! Whyt Amazingy when atronsuts of the APOLLO I5 mission did this experiment on the moan, they confirmed that Galleo was correct. Why did it work on the moon! The speed hat a rocket mu blast off with in order to leave the Earth's gravitational pul is 1124 kns ? How fest is that in kstr? a rate of 1.37mm every second. Why does it not crash into the Earth? made the pple tall aho kapt the moon * Always k en aduk to help pou orbit around the earth Tody we call this s idea, the universality of gravity. The Darkest Place THE WONDERS The Magic of Gravity in the Universe OF GRAVITY Weighing something on a scale measures the force of the earch's gravity on that object. This force acts as if all the mass of the object were concentrated at one point, called the centre of mass. Ten years before writing down his famous General Theory. Einatein developed a Special Theory of Relativity According to this theory, the speed of light is the ultimste speed amk in the Universe. Nothing, not even light, could travel faster than the speed of light. TRY THIS AT HOME The Geometry of Gravity The escape speed needed by a rocketship to completely lezve the gravitational pull of a panet is inversely proportional to the density (mns/volume) of the planet. The greater the density, the harder it is to leve the planet, A Black Hole is an object that isso dee that the escape speed is greater than the speed of light. kis black because no Ighe According to this theory of gravity. all of space and time become one spacetime continuum. Anything with mass (like the Sun, for example) will bend the spacetime around itself. The bigger the mass, the more the bending, Any ocher body that finds itself moving near such a massive body will be forced to move in this warped spacetime along a geodesic In this way, the Yorce of gravity that attracts the two bodies is the geometry of the spacetime continuum around them. Take a can of cooldrink and drink about 3 of the contents The centre of mass can sometimes can get to us from it. The event horizon is the point of no return for an astronaut falling into a of the black hole Once crossed, not only will the astronaut not be able to return but she will also not be able to communicate with anyone outside the hole! lie outside of the object itself. For example, the centre of mass of a donut is at its centre which is not actually part of the donut! The idea of centre of mass is crucial to the physics of balance. When the centre of mass of an object is no longer above its base of support, the object will topple over. Tip the can tver until it makes an angle of about 45 Newton was the king of gravity. until a young Swiss patent clerk called Albert Einstein changed the way we understand the force of gravity. Einstein realised that there was no way for someone sitting in a closed room to tell if they were in a gravicational field (like on Earth) or accelerating (say out in space). This is the principle of equivalence between gravity and acceleration and forms the foundation of Einstein's theory of General Relativity Coca-Cola According to General Relativity. even light falls in a gravicational field. This causes light rays to be bene around a massive object a phenomenon known as gravitational lensing. This prediction of Einstein's theory was confirmed by Sir Arthur Eddington during the solar eclipse of 1919. Why do you think that a solar eclipse was necessary to carry out this test? Let go of the can What happens? Can you explain why, using the ideas of c DID YOU KNOW? Soentists use the speed af ight, 299 792 458 kmis, 1a define the netert What do you think this defnibon is? Coca-Cola of mass? Mhowom ACHNOWDGEMENTS Conene Dr Jet Mulgan and Or Amando weman CT. Oeportment ot Manemarios and Applied Motematet UCT Facuty of Scionco Marieoing Commitice Design and iayout Evalusion Marknting atlonal Sclence Week NRF SAASTA Notional Ressarch South Acan Agency for Science Fountetion | and Technology Advancement &rechno ogy Department: Science and Technology REPUBLIC OF SOUTH AFRICA The Mystery of Falling Objects The Case of the Falling Moon TRY THIS AT HOME UNIVERSAL GRAVITY 1 Take an empty cooldrink can and make a small hole at the bottom". Around 1590, + -- --- Suppose you are standing on the top of a very high mountain with a canon (V). The first shot you fire lands a short distance away at (D). By adding more gunpowder and firing, the cannonball it will go further to (E) or maybe cven to (B). If you get the canonball moving fast enough It will eventually be put Into a low orbit (A) and come right back to (V). Galileo Galilei dropped two objects of different weights from the same height, and found that they reached the ground at the same time. 2 Fl the can with water Notice that if the can is held up, the water flows out the bottom. F. F, = Gmxm. Every object with mass in Newton realized that the moon's curved the universe atoracts every path in the sky could be caused in exactly the same way as the cannonball's orbit! He was also able to calculate that the moon falls toward the earth at other object with mass 3 Now drop the Galileo found that gravity acts exactly the same way on all matter. Scientises call this the universalicy of free-fall. can Does the water still flow out the can while it is falling? WHY? nl665. haa Newton divcomred the -science of optics, the laws of mechanic iented cakulus and aho wrote down the Irws of mity. Newton was sting under an apple tree when he noticed an apple tall and wondered if the same force that :DID YOU KNOW WWould a feather fall at the same speed s a hammer? Not on earth! Whyt Amazingy when atronsuts of the APOLLO I5 mission did this experiment on the moan, they confirmed that Galleo was correct. Why did it work on the moon! The speed hat a rocket mu blast off with in order to leave the Earth's gravitational pul is 1124 kns ? How fest is that in kstr? a rate of 1.37mm every second. Why does it not crash into the Earth? made the pple tall aho kapt the moon * Always k en aduk to help pou orbit around the earth Tody we call this s idea, the universality of gravity. The Darkest Place THE WONDERS The Magic of Gravity in the Universe OF GRAVITY Weighing something on a scale measures the force of the earch's gravity on that object. This force acts as if all the mass of the object were concentrated at one point, called the centre of mass. Ten years before writing down his famous General Theory. Einatein developed a Special Theory of Relativity According to this theory, the speed of light is the ultimste speed amk in the Universe. Nothing, not even light, could travel faster than the speed of light. TRY THIS AT HOME The Geometry of Gravity The escape speed needed by a rocketship to completely lezve the gravitational pull of a panet is inversely proportional to the density (mns/volume) of the planet. The greater the density, the harder it is to leve the planet, A Black Hole is an object that isso dee that the escape speed is greater than the speed of light. kis black because no Ighe According to this theory of gravity. all of space and time become one spacetime continuum. Anything with mass (like the Sun, for example) will bend the spacetime around itself. The bigger the mass, the more the bending, Any ocher body that finds itself moving near such a massive body will be forced to move in this warped spacetime along a geodesic In this way, the Yorce of gravity that attracts the two bodies is the geometry of the spacetime continuum around them. Take a can of cooldrink and drink about 3 of the contents The centre of mass can sometimes can get to us from it. The event horizon is the point of no return for an astronaut falling into a of the black hole Once crossed, not only will the astronaut not be able to return but she will also not be able to communicate with anyone outside the hole! lie outside of the object itself. For example, the centre of mass of a donut is at its centre which is not actually part of the donut! The idea of centre of mass is crucial to the physics of balance. When the centre of mass of an object is no longer above its base of support, the object will topple over. Tip the can tver until it makes an angle of about 45 Newton was the king of gravity. until a young Swiss patent clerk called Albert Einstein changed the way we understand the force of gravity. Einstein realised that there was no way for someone sitting in a closed room to tell if they were in a gravicational field (like on Earth) or accelerating (say out in space). This is the principle of equivalence between gravity and acceleration and forms the foundation of Einstein's theory of General Relativity Coca-Cola According to General Relativity. even light falls in a gravicational field. This causes light rays to be bene around a massive object a phenomenon known as gravitational lensing. This prediction of Einstein's theory was confirmed by Sir Arthur Eddington during the solar eclipse of 1919. Why do you think that a solar eclipse was necessary to carry out this test? Let go of the can What happens? Can you explain why, using the ideas of c DID YOU KNOW? Soentists use the speed af ight, 299 792 458 kmis, 1a define the netert What do you think this defnibon is? Coca-Cola of mass? Mhowom ACHNOWDGEMENTS Conene Dr Jet Mulgan and Or Amando weman CT. Oeportment ot Manemarios and Applied Motematet UCT Facuty of Scionco Marieoing Commitice Design and iayout Evalusion Marknting atlonal Sclence Week NRF SAASTA Notional Ressarch South Acan Agency for Science Fountetion | and Technology Advancement &rechno ogy Department: Science and Technology REPUBLIC OF SOUTH AFRICA The Mystery of Falling Objects The Case of the Falling Moon TRY THIS AT HOME UNIVERSAL GRAVITY 1 Take an empty cooldrink can and make a small hole at the bottom". Around 1590, + -- --- Suppose you are standing on the top of a very high mountain with a canon (V). The first shot you fire lands a short distance away at (D). By adding more gunpowder and firing, the cannonball it will go further to (E) or maybe cven to (B). If you get the canonball moving fast enough It will eventually be put Into a low orbit (A) and come right back to (V). Galileo Galilei dropped two objects of different weights from the same height, and found that they reached the ground at the same time. 2 Fl the can with water Notice that if the can is held up, the water flows out the bottom. F. F, = Gmxm. Every object with mass in Newton realized that the moon's curved the universe atoracts every path in the sky could be caused in exactly the same way as the cannonball's orbit! He was also able to calculate that the moon falls toward the earth at other object with mass 3 Now drop the Galileo found that gravity acts exactly the same way on all matter. Scientises call this the universalicy of free-fall. can Does the water still flow out the can while it is falling? WHY? nl665. haa Newton divcomred the -science of optics, the laws of mechanic iented cakulus and aho wrote down the Irws of mity. Newton was sting under an apple tree when he noticed an apple tall and wondered if the same force that :DID YOU KNOW WWould a feather fall at the same speed s a hammer? Not on earth! Whyt Amazingy when atronsuts of the APOLLO I5 mission did this experiment on the moan, they confirmed that Galleo was correct. Why did it work on the moon! The speed hat a rocket mu blast off with in order to leave the Earth's gravitational pul is 1124 kns ? How fest is that in kstr? a rate of 1.37mm every second. Why does it not crash into the Earth? made the pple tall aho kapt the moon * Always k en aduk to help pou orbit around the earth Tody we call this s idea, the universality of gravity. The Darkest Place THE WONDERS The Magic of Gravity in the Universe OF GRAVITY Weighing something on a scale measures the force of the earch's gravity on that object. This force acts as if all the mass of the object were concentrated at one point, called the centre of mass. Ten years before writing down his famous General Theory. Einatein developed a Special Theory of Relativity According to this theory, the speed of light is the ultimste speed amk in the Universe. Nothing, not even light, could travel faster than the speed of light. TRY THIS AT HOME The Geometry of Gravity The escape speed needed by a rocketship to completely lezve the gravitational pull of a panet is inversely proportional to the density (mns/volume) of the planet. The greater the density, the harder it is to leve the planet, A Black Hole is an object that isso dee that the escape speed is greater than the speed of light. kis black because no Ighe According to this theory of gravity. all of space and time become one spacetime continuum. Anything with mass (like the Sun, for example) will bend the spacetime around itself. The bigger the mass, the more the bending, Any ocher body that finds itself moving near such a massive body will be forced to move in this warped spacetime along a geodesic In this way, the Yorce of gravity that attracts the two bodies is the geometry of the spacetime continuum around them. Take a can of cooldrink and drink about 3 of the contents The centre of mass can sometimes can get to us from it. The event horizon is the point of no return for an astronaut falling into a of the black hole Once crossed, not only will the astronaut not be able to return but she will also not be able to communicate with anyone outside the hole! lie outside of the object itself. For example, the centre of mass of a donut is at its centre which is not actually part of the donut! The idea of centre of mass is crucial to the physics of balance. When the centre of mass of an object is no longer above its base of support, the object will topple over. Tip the can tver until it makes an angle of about 45 Newton was the king of gravity. until a young Swiss patent clerk called Albert Einstein changed the way we understand the force of gravity. Einstein realised that there was no way for someone sitting in a closed room to tell if they were in a gravicational field (like on Earth) or accelerating (say out in space). This is the principle of equivalence between gravity and acceleration and forms the foundation of Einstein's theory of General Relativity Coca-Cola According to General Relativity. even light falls in a gravicational field. This causes light rays to be bene around a massive object a phenomenon known as gravitational lensing. This prediction of Einstein's theory was confirmed by Sir Arthur Eddington during the solar eclipse of 1919. Why do you think that a solar eclipse was necessary to carry out this test? Let go of the can What happens? Can you explain why, using the ideas of c DID YOU KNOW? Soentists use the speed af ight, 299 792 458 kmis, 1a define the netert What do you think this defnibon is? Coca-Cola of mass? Mhowom ACHNOWDGEMENTS Conene Dr Jet Mulgan and Or Amando weman CT. Oeportment ot Manemarios and Applied Motematet UCT Facuty of Scionco Marieoing Commitice Design and iayout Evalusion Marknting atlonal Sclence Week NRF SAASTA Notional Ressarch South Acan Agency for Science Fountetion | and Technology Advancement &rechno ogy Department: Science and Technology REPUBLIC OF SOUTH AFRICA The Mystery of Falling Objects The Case of the Falling Moon TRY THIS AT HOME UNIVERSAL GRAVITY 1 Take an empty cooldrink can and make a small hole at the bottom". Around 1590, + -- --- Suppose you are standing on the top of a very high mountain with a canon (V). The first shot you fire lands a short distance away at (D). By adding more gunpowder and firing, the cannonball it will go further to (E) or maybe cven to (B). If you get the canonball moving fast enough It will eventually be put Into a low orbit (A) and come right back to (V). Galileo Galilei dropped two objects of different weights from the same height, and found that they reached the ground at the same time. 2 Fl the can with water Notice that if the can is held up, the water flows out the bottom. F. F, = Gmxm. Every object with mass in Newton realized that the moon's curved the universe atoracts every path in the sky could be caused in exactly the same way as the cannonball's orbit! He was also able to calculate that the moon falls toward the earth at other object with mass 3 Now drop the Galileo found that gravity acts exactly the same way on all matter. Scientises call this the universalicy of free-fall. can Does the water still flow out the can while it is falling? WHY? nl665. haa Newton divcomred the -science of optics, the laws of mechanic iented cakulus and aho wrote down the Irws of mity. Newton was sting under an apple tree when he noticed an apple tall and wondered if the same force that :DID YOU KNOW WWould a feather fall at the same speed s a hammer? Not on earth! Whyt Amazingy when atronsuts of the APOLLO I5 mission did this experiment on the moan, they confirmed that Galleo was correct. Why did it work on the moon! The speed hat a rocket mu blast off with in order to leave the Earth's gravitational pul is 1124 kns ? How fest is that in kstr? a rate of 1.37mm every second. Why does it not crash into the Earth? made the pple tall aho kapt the moon * Always k en aduk to help pou orbit around the earth Tody we call this s idea, the universality of gravity. The Darkest Place THE WONDERS The Magic of Gravity in the Universe OF GRAVITY Weighing something on a scale measures the force of the earch's gravity on that object. This force acts as if all the mass of the object were concentrated at one point, called the centre of mass. Ten years before writing down his famous General Theory. Einatein developed a Special Theory of Relativity According to this theory, the speed of light is the ultimste speed amk in the Universe. Nothing, not even light, could travel faster than the speed of light. TRY THIS AT HOME The Geometry of Gravity The escape speed needed by a rocketship to completely lezve the gravitational pull of a panet is inversely proportional to the density (mns/volume) of the planet. The greater the density, the harder it is to leve the planet, A Black Hole is an object that isso dee that the escape speed is greater than the speed of light. kis black because no Ighe According to this theory of gravity. all of space and time become one spacetime continuum. Anything with mass (like the Sun, for example) will bend the spacetime around itself. The bigger the mass, the more the bending, Any ocher body that finds itself moving near such a massive body will be forced to move in this warped spacetime along a geodesic In this way, the Yorce of gravity that attracts the two bodies is the geometry of the spacetime continuum around them. Take a can of cooldrink and drink about 3 of the contents The centre of mass can sometimes can get to us from it. The event horizon is the point of no return for an astronaut falling into a of the black hole Once crossed, not only will the astronaut not be able to return but she will also not be able to communicate with anyone outside the hole! lie outside of the object itself. For example, the centre of mass of a donut is at its centre which is not actually part of the donut! The idea of centre of mass is crucial to the physics of balance. When the centre of mass of an object is no longer above its base of support, the object will topple over. Tip the can tver until it makes an angle of about 45 Newton was the king of gravity. until a young Swiss patent clerk called Albert Einstein changed the way we understand the force of gravity. Einstein realised that there was no way for someone sitting in a closed room to tell if they were in a gravicational field (like on Earth) or accelerating (say out in space). This is the principle of equivalence between gravity and acceleration and forms the foundation of Einstein's theory of General Relativity Coca-Cola According to General Relativity. even light falls in a gravicational field. This causes light rays to be bene around a massive object a phenomenon known as gravitational lensing. This prediction of Einstein's theory was confirmed by Sir Arthur Eddington during the solar eclipse of 1919. Why do you think that a solar eclipse was necessary to carry out this test? Let go of the can What happens? Can you explain why, using the ideas of c DID YOU KNOW? Soentists use the speed af ight, 299 792 458 kmis, 1a define the netert What do you think this defnibon is? Coca-Cola of mass? Mhowom ACHNOWDGEMENTS Conene Dr Jet Mulgan and Or Amando weman CT. Oeportment ot Manemarios and Applied Motematet UCT Facuty of Scionco Marieoing Commitice Design and iayout Evalusion Marknting atlonal Sclence Week NRF SAASTA Notional Ressarch South Acan Agency for Science Fountetion | and Technology Advancement