IB Physics 1 -- HL/SL
"All science is either physics or stamp collecting."
|
Assignments -- 2015-2016
3rd Quarter -- Jan 6 to Mar 11
Wed, Jan 6, Floater Fifth
Due:
- None Agenda: - Physics Day Lab Questions - Complete Centripetal Acceleration Lab Data Collection Assignment: - Complete Physics Day Lab - Complete Centripetal Acceleration Lab 6-Word Memoir: School, TV, Baseball, Running, Eat, Sleep |
Thur, Jan 7
Due:
- Reading Activity 3-2 - Physics Day Lab Agenda: - Complete Lsn 3-2 Lecture - PhET Density, Buoyancy and Free Body Diagrams Lab Assignment: - HW Lsn 3-2, #13-32 - Chapter 3 Test Review (Due Date TBD) - Complete PhET Density, Buoyancy and Free Body Diagrams Lab - Complete Centripetal Acceleration Lab 6-Word Memoir: Six words I will never forget |
|
Words of Wisdom: All those who believe in psychokinesis, raise my hand.
Physics in Action - Cleaning with Sound
Sound may not be a normal cleaning product in your house, but it is just the thing for cleaning delicate jewelry, surgical instruments, lenses, and many other small, intricate objects. Soon, it could also make cleaning big objects like houses or machines much more efficient. A technique called ultrasonic cleaning is often used to get rid of the dust, dirt, oils, and other particles clinging to small objects. The term ultrasonic means that the frequency of the sound waves used in this technique are higher than what a human can hear. Ultrasonic cleaners usually involve frequencies between 20,000 Hz and 40,000 Hz, but sometimes they are even higher. Each cleaner has a "bath" area that is filled with water (or a water-detergent mix). At the bottom of the bath there is a device that makes ultrasonic waves by vibrating up and down thousands of times each second. In an ultrasonic cleaner, a wave generator is connected to a diaphragm, the cone-shaped part that vibrates inside of a speaker. The generator causes the diaphragm to vibrate at a specific frequency and amplitude. Instead of causing air molecules to vibrate like a speaker does, the diaphragm causes the water molecules in the bath to vibrate. The vibrations in the water cause tiny cavities (bubbles) to form, about the size of a red blood cell or bacteria. However, the constant vibrating puts pressure on the cavities—they are rapidly stretched and compressed. This causes the cavities to violently implode, and if they are near a hard surface, turn into jets of liquid traveling at high speeds. An object submerged in the bath is hit by these jets millions of times per second. On impact the jets dislodge particles like dust and oil from the object, giving it a nice cleaning. The cavities are very small, so despite the millions of collisions the process is gentle.
So what's new? Currently, this process only works for objects that can fit inside a water bath. Another downside is that after a particle is dislodged from an object's surface, it floats around inside of the bath and could latch back onto a different part of the object's surface. To overcome these challenges, the Southampton scientists packed all of this technology into a nozzle. In addition to spraying water, the nozzle generates ultrasonic waves. The water is constantly running in this system, so dust and other particles are carried away from the object being cleaned. A hose with an ultrasonic nozzle can clean objects with much less force and water than a pressure washer, and do it with less power. That leads to energy savings during the cleaning process and less runoff, which often needs to be purified before it can be used again.
From: http://www.physicscentral.com/explore/action/ultrasonic-cleaning1.cfm
So what's new? Currently, this process only works for objects that can fit inside a water bath. Another downside is that after a particle is dislodged from an object's surface, it floats around inside of the bath and could latch back onto a different part of the object's surface. To overcome these challenges, the Southampton scientists packed all of this technology into a nozzle. In addition to spraying water, the nozzle generates ultrasonic waves. The water is constantly running in this system, so dust and other particles are carried away from the object being cleaned. A hose with an ultrasonic nozzle can clean objects with much less force and water than a pressure washer, and do it with less power. That leads to energy savings during the cleaning process and less runoff, which often needs to be purified before it can be used again.
From: http://www.physicscentral.com/explore/action/ultrasonic-cleaning1.cfm
Tue, Jan 12
Due:
- PhET Density, Buoyancy and Free Body Diagrams Lab - Centripetal Acceleration Lab Agenda: - Specific Heat of a Mystery Metal Lab Assignment: - HW Lsn 3-2, #13-32 - Chapter 3 Test Review - Complete Specific Heat of a Mystery Metal Lab 6-Word Memoir: Too late to back out now |
|
Fri, Jan 15
Due:
- Specific Heat of a Mystery Metal Lab - HW Lsn 3-2, #13-32 - Chapter 3 Test Review Agenda: - Review HW Lsn 3-2, #13-32 - Review Chapter 3 Test Review Assignment: - Study for Chapter 3 Test 6-Word Memoir: Traveling never ceases to amuse me |
|
Words of Wisdom: When I'm not in my right mind, my left mind gets pretty crowded.
People In Physics - Lene Hau
In 1999, after years of practice, Lene Hau learned how to bicycle at the speed of light. She's not a racer; she's a physicist at Harvard University. She didn't achieve this amazing feat by cycling faster; instead, she slowed light down - to an incredible 60 kilometers (37 miles) an hour. And just this year, she did something even more amazing - she stopped light dead in its tracks.
Light travels at the “speed of light” - 300 million meters (186,000 miles) per second - only in a vacuum. Whenever light travels through a substance, its speed is slowed. For example, in water, light travels at only 225 million meters (140,000 miles) per second.” When atoms get extremely cold, a few millionths of a degree above absolute zero, they lose their individual identities and blend together. At low enough temperatures, a collection of millions of atoms can behave like a single “superatom.” This collection is known as the “Bose-Einstein Condensate,” after the two physicists whose work predicted its existence in 1924.
In June 1997, Hau and her co-workers finally cooled atoms enough to form a Bose-Einstein Condensate. After making the condensate, Hau and her co-workers began looking for ways to use it. They realized that if they massaged the condensate just right with laser beams, they could make light pass through the previously opaque condensate. And they found that the massaged condensate could slow light more effectively than any material ever discovered.
They used an electromagnet to suspend a cigar-shaped condensate, 0.2 millimeters (0.008 inches) long, inside a vacuum chamber. They first illuminated the cigar from the side with a finely tuned laser beam (the 'coupling' beam), and then shot a pulse of laser light along the long axis of the cigar. The pulse slowed down and compressed as soon as it reached the altered condensate. Hau worked late nights in the lab for a year, trying to perfect her experimental system for slowing light. Finally, in March 1998, she began to see the light slow down. That fall, when she succeeded in getting light to travel at the speed of a bicycle, she decided to publish her results.
This year, her group took its experiments a step further by getting light inside a Bose-Einstein Condensate to stop completely. While the light pulse was totally compressed and contained entirely within the condensate, the team abruptly turned off the coupling laser. This adjustment left the light trapped inside. When they turned the coupling laser back on, the original light pulse came out the other end. “We can park a light pulse in the cloud for a millisecond,” Hau said. “It might sound short to you, but it's really long - long enough for light at its normal speed to travel 300 kilometers - and there's no doubt that we can get the storage times up.”
Slow or stopped light could someday be used in future computers that use light instead of electrons to carry and process information. Or, the light could be used by scientists to create simulated black holes in the lab. “Slow light has a tremendous variety of applications,” Hau said.
Hau recently moved from the Rowland Institute to a full-time job as a professor of physics at Harvard. She loves her work, even the long nights in the lab. But she always enjoyed long nights, especially summer nights in Denmark, when the sun sets at 10:30 PM and rises at 3 AM. When Hau is not in the lab, she enjoys bicycling - at the speed of slow light - around the beaches of nearby Cape Cod.
From: http://www.physicscentral.com/explore/people/hau.cfm
Light travels at the “speed of light” - 300 million meters (186,000 miles) per second - only in a vacuum. Whenever light travels through a substance, its speed is slowed. For example, in water, light travels at only 225 million meters (140,000 miles) per second.” When atoms get extremely cold, a few millionths of a degree above absolute zero, they lose their individual identities and blend together. At low enough temperatures, a collection of millions of atoms can behave like a single “superatom.” This collection is known as the “Bose-Einstein Condensate,” after the two physicists whose work predicted its existence in 1924.
In June 1997, Hau and her co-workers finally cooled atoms enough to form a Bose-Einstein Condensate. After making the condensate, Hau and her co-workers began looking for ways to use it. They realized that if they massaged the condensate just right with laser beams, they could make light pass through the previously opaque condensate. And they found that the massaged condensate could slow light more effectively than any material ever discovered.
They used an electromagnet to suspend a cigar-shaped condensate, 0.2 millimeters (0.008 inches) long, inside a vacuum chamber. They first illuminated the cigar from the side with a finely tuned laser beam (the 'coupling' beam), and then shot a pulse of laser light along the long axis of the cigar. The pulse slowed down and compressed as soon as it reached the altered condensate. Hau worked late nights in the lab for a year, trying to perfect her experimental system for slowing light. Finally, in March 1998, she began to see the light slow down. That fall, when she succeeded in getting light to travel at the speed of a bicycle, she decided to publish her results.
This year, her group took its experiments a step further by getting light inside a Bose-Einstein Condensate to stop completely. While the light pulse was totally compressed and contained entirely within the condensate, the team abruptly turned off the coupling laser. This adjustment left the light trapped inside. When they turned the coupling laser back on, the original light pulse came out the other end. “We can park a light pulse in the cloud for a millisecond,” Hau said. “It might sound short to you, but it's really long - long enough for light at its normal speed to travel 300 kilometers - and there's no doubt that we can get the storage times up.”
Slow or stopped light could someday be used in future computers that use light instead of electrons to carry and process information. Or, the light could be used by scientists to create simulated black holes in the lab. “Slow light has a tremendous variety of applications,” Hau said.
Hau recently moved from the Rowland Institute to a full-time job as a professor of physics at Harvard. She loves her work, even the long nights in the lab. But she always enjoyed long nights, especially summer nights in Denmark, when the sun sets at 10:30 PM and rises at 3 AM. When Hau is not in the lab, she enjoys bicycling - at the speed of slow light - around the beaches of nearby Cape Cod.
From: http://www.physicscentral.com/explore/people/hau.cfm
Wed, Jan 20
|
|
Thu, Jan 21
Due:
- PhET States of Matter Lab Agenda: - Thermodynamics Demos - PhET Gas Properties Lab Assignment: - Complete PhET Gas Properties Lab - Study for Chapter 3 Test 6-Word Memoir: An awfully long and twisted roller-coaster |
|
Words of Wisdom: I used to have an open mind but my brains kept falling out.
Famous Dead Guys in Physics - Blaise Pascal
(born June 19, 1623, Clermont-Ferrand, France—died August 19, 1662, Paris)
French mathematician, physicist, religious philosopher, and master of prose. He laid the foundation for the modern theory of probabilities, formulated what came to be known as Pascal's law of pressure, and propagated a religious doctrine that taught the experience of God through the heart rather than through reason. The establishment of his principle of intuitionism had an impact on such later philosophers as Jean-Jacques Rousseau and Henri Bergson and also on the Existentialists.
In 1640 he wrote an essay on conic sections, Essai pour les coniques, based on his study of the now classical work of Girard Desargues on synthetic projective geometry. The young man's work, which was highly successful in the world of mathematics, aroused the envy of no less a personage than the great French Rationalist and mathematician René Descartes. Between 1642 and 1644, Pascal conceived and constructed a calculating device to help his father—who in 1639 had been appointed intendant (local administrator) at Rouen—in his tax computations. The machine was regarded by Pascal's contemporaries as his main claim to fame, and with reason, for in a sense it was the first digital calculator since it operated by counting integers. Absorbed in his scientific interests, he tested the theories of Galileo and Evangelista Torricelli (an Italian physicist who discovered the principle of the barometer). To do so, he reproduced and amplified experiments on atmospheric pressure by constructing mercury barometers and measuring air pressure, both in Paris and on the top of a mountain overlooking Clermont-Ferrand. These tests paved the way for further studies in hydrodynamics and hydrostatics. While experimenting, Pascal invented the syringe and created the hydraulic press, an instrument based upon the principle that became known as Pascal's law: pressure applied to a confined liquid is transmitted undiminished through the liquid in all directions regardless of the area to which the pressure is applied. His publications on the problem of the vacuum (1647–48) added to his reputation. When he fell ill from overwork, his doctors advised him to seek distractions; but what has been described as Pascal's “worldly period” (1651–54) was, in fact, primarily a period of intense scientific work, during which he composed treatises on the equilibrium of liquid solutions, on the weight and density of air, and on the arithmetic triangle: Traité de l'équilibre des liqueurs et de la pesanteur de la masse de l'air (Eng. trans., The Physical Treatises of Pascal, 1937) and also his Traité du triangle arithmétique. In the last treatise, a fragment of the De Alea Geometriae, he laid the foundations for the calculus of probabilities. Pascal died in 1662 after suffering terrible pain, probably from carcinomatous meningitis following a malignant ulcer of the stomach.
Copyright © 1994-2011 Encyclopædia Britannica, Inc. For more information visit Britannica.com
From: http://www.biography.com/people/blaise-pascal-9434176
French mathematician, physicist, religious philosopher, and master of prose. He laid the foundation for the modern theory of probabilities, formulated what came to be known as Pascal's law of pressure, and propagated a religious doctrine that taught the experience of God through the heart rather than through reason. The establishment of his principle of intuitionism had an impact on such later philosophers as Jean-Jacques Rousseau and Henri Bergson and also on the Existentialists.
In 1640 he wrote an essay on conic sections, Essai pour les coniques, based on his study of the now classical work of Girard Desargues on synthetic projective geometry. The young man's work, which was highly successful in the world of mathematics, aroused the envy of no less a personage than the great French Rationalist and mathematician René Descartes. Between 1642 and 1644, Pascal conceived and constructed a calculating device to help his father—who in 1639 had been appointed intendant (local administrator) at Rouen—in his tax computations. The machine was regarded by Pascal's contemporaries as his main claim to fame, and with reason, for in a sense it was the first digital calculator since it operated by counting integers. Absorbed in his scientific interests, he tested the theories of Galileo and Evangelista Torricelli (an Italian physicist who discovered the principle of the barometer). To do so, he reproduced and amplified experiments on atmospheric pressure by constructing mercury barometers and measuring air pressure, both in Paris and on the top of a mountain overlooking Clermont-Ferrand. These tests paved the way for further studies in hydrodynamics and hydrostatics. While experimenting, Pascal invented the syringe and created the hydraulic press, an instrument based upon the principle that became known as Pascal's law: pressure applied to a confined liquid is transmitted undiminished through the liquid in all directions regardless of the area to which the pressure is applied. His publications on the problem of the vacuum (1647–48) added to his reputation. When he fell ill from overwork, his doctors advised him to seek distractions; but what has been described as Pascal's “worldly period” (1651–54) was, in fact, primarily a period of intense scientific work, during which he composed treatises on the equilibrium of liquid solutions, on the weight and density of air, and on the arithmetic triangle: Traité de l'équilibre des liqueurs et de la pesanteur de la masse de l'air (Eng. trans., The Physical Treatises of Pascal, 1937) and also his Traité du triangle arithmétique. In the last treatise, a fragment of the De Alea Geometriae, he laid the foundations for the calculus of probabilities. Pascal died in 1662 after suffering terrible pain, probably from carcinomatous meningitis following a malignant ulcer of the stomach.
Copyright © 1994-2011 Encyclopædia Britannica, Inc. For more information visit Britannica.com
From: http://www.biography.com/people/blaise-pascal-9434176
Tues, Jan 26
Due:
- Chapter 3 Test Review - - PhET Lab: Gas PropertiesPhET Gas Properties Lab Agenda: - Chapter 3 Test Assignment: - Reading Activity 4-1 6-Word Memoir: Be unique. Be creative. Be innovative. |
|
Fri, Jan 29
Due:
- Reading Activity 4-1 Agenda: - Lsn 4-1 Lecture - PhET Pendulum Lab Assignment: - HW Lsn 4-1, Pg. 152, #1-5 - Reading Activity 4-2 - Complete PhET Pendulum Lab 6-Word Memoir: Born, lived, journey to be continued |
|
Words of Wisdom: If at first you don't succeed, destroy all evidence that you tried. -- Hillary Clinton
Tues, Feb 2
|
|
Wed, Feb 3
Due:
- HW Lsn 4-1, #1-5 - PhET Pendulum Lab Agenda: - Review HW Lsn 4-1, #1-5 - Finish Lsn 4-2 Lecture - Ballistic Pendulum Lab Assignment: - HW Lsn 4-2, #6-14 - Reading Activity 4-3 6-Word Memoir: I am always the optimistic guy |
Words of Wisdom: For every action, there is an equal and opposite criticism.
People In Physics - Laura Smoliar
Laura Smoliar became interested in physics at a young age – her mother was a physicist. “Sometimes I’d get to go to her lab,” Smoliar said. “It was a fun place. There were lots of toys.” She went to college at Columbia University, and went on for a PhD in physical chemistry from the University of California at Berkeley. For the last year of her PhD, she studied in Taiwan, then stayed there for one year after finishing her degree.
Smoliar had always thought she would become a professor, but watching her colleagues work showed her the range of careers she could have as a physicist. She was attracted to high-tech business when she saw her colleagues’ love of technology, fast pace of life, and diverse work force. In 1996, she moved to Menlo Park, California, in the heart of Silicon Valley, and began to work for a technology firm. In 2001, the management at Lightwave Electronics invited her to start her current job.
As a Program Manager at Lightwave, a small technology company in California’s Silicon Valley, Smoliar spends most of her time working with people to solve a variety of problems. She manages a team of about fifteen physicists and engineers; she flies regularly from her office to Europe and Japan to work with other physicists and engineers; she discusses specifications with her customers; she reports on her progress to Lightwave’s management. She says that working with other people is her favorite part of the job – especially working with her fellow physicists and engineers on the technical specifics of the lasers. “I have an awesome team,” she says. “They are very, very bright people.”
Smoliar and her team are building a new type of “fiber laser”, whose beam travels through a glass fiber, similar to those used for fiber-optic telephone lines.. The fiber allows the laser to be miniaturized, which makes fiber lasers useful in applications where small size is important.
Today, Smoliar’s workday often starts at 6 or 7 AM, when she calls her team members in Europe. She discusses how the lasers are developing, and identifies problems with the system. “The discussions are quite technical,” she says – the team reviews scientific and engineering details about how the lasers work. Later in the day, Smoliar might meet with the customer to update them on the schedule, with suppliers to purchase equipment needed to build the lasers, with company managers to talk about progress, or with job applicants looking to join her team. About once a month, she travels to Japan to meet with team members there. She needs information from all these meetings because, as Program Manager, she is responsible for deciding on what direction to take with the project. “The biggest part of my job is making decisions, judgment calls,” she says. “It’s not a purely technical job, but you need a technical background to make decisions.” By taking a job with Lightwave, Smoliar certainly feels that she made the right decision.
From: http://www.physicscentral.com/explore/people/smoliar.cfm
Smoliar had always thought she would become a professor, but watching her colleagues work showed her the range of careers she could have as a physicist. She was attracted to high-tech business when she saw her colleagues’ love of technology, fast pace of life, and diverse work force. In 1996, she moved to Menlo Park, California, in the heart of Silicon Valley, and began to work for a technology firm. In 2001, the management at Lightwave Electronics invited her to start her current job.
As a Program Manager at Lightwave, a small technology company in California’s Silicon Valley, Smoliar spends most of her time working with people to solve a variety of problems. She manages a team of about fifteen physicists and engineers; she flies regularly from her office to Europe and Japan to work with other physicists and engineers; she discusses specifications with her customers; she reports on her progress to Lightwave’s management. She says that working with other people is her favorite part of the job – especially working with her fellow physicists and engineers on the technical specifics of the lasers. “I have an awesome team,” she says. “They are very, very bright people.”
Smoliar and her team are building a new type of “fiber laser”, whose beam travels through a glass fiber, similar to those used for fiber-optic telephone lines.. The fiber allows the laser to be miniaturized, which makes fiber lasers useful in applications where small size is important.
Today, Smoliar’s workday often starts at 6 or 7 AM, when she calls her team members in Europe. She discusses how the lasers are developing, and identifies problems with the system. “The discussions are quite technical,” she says – the team reviews scientific and engineering details about how the lasers work. Later in the day, Smoliar might meet with the customer to update them on the schedule, with suppliers to purchase equipment needed to build the lasers, with company managers to talk about progress, or with job applicants looking to join her team. About once a month, she travels to Japan to meet with team members there. She needs information from all these meetings because, as Program Manager, she is responsible for deciding on what direction to take with the project. “The biggest part of my job is making decisions, judgment calls,” she says. “It’s not a purely technical job, but you need a technical background to make decisions.” By taking a job with Lightwave, Smoliar certainly feels that she made the right decision.
From: http://www.physicscentral.com/explore/people/smoliar.cfm
Mon, Feb 8
Due:
- HW Lsn 4-2, #6-14 - Reading Activity 4-3 - Ballistic Pendulum Lab Agenda: - Review HW Lsn 4-2, #6-14 - Lsn 4-4 Lecture Assignment: - HW Lsn 4-4, #25-31 - Reading Activity 4-3 6-Word Memoir: I am still figuring everything out
|
Note: I will not be at school on Monday. Go through the lecture slides and videos on your own, discuss among your table group, and start on the homework.
|
Thu, Feb 11
Due:
- HW Lsn 4-4, #25-31 - Reading Activity 4-4 Agenda: - Review HW Lsn 4-4, #25-31 - Lsn 4-3 Lecture - Ballistic Pendulum Lab Questions Assignment: - HW Lsn 4-3, #15-24 - Reading Activity 4-5 6-Word Memoir: I am nice and sometimes funny
|
|
Words of Wisdom: The colder the X-ray table, the more of your body is required to be on it.
Physics In Pictures
From: http://www.physicscentral.com/explore/pictures/index.cfm
Chladni Plate in the Physics Lab in the Oregon Museum of Science and Industry (OMSI). When a Chladni plate vibrates patterns emerge in the sand. It's not magic, or the hand of an invisible artist, but the vibrations themselves that cause the lines and patterns to emerge.
When the plate vibrates at frequencies, the plate bends in waves starting from where the vibration originated, moving across the plate and then reflecting back. When the frequency of the wave moving across the plate is the same as the frequency being reflected, this is called the natural resonance or natural frequency of the plate. When this happens, the waves moving across the plate interfere, cross paths, with the waves reflecting back across the plate. The interference of these waves is what causes the patterns to emerge.
A wave consists of a crest and a trough. When two interfere, the resulting wave gets bigger. When two troughs interfere the resulting wave is a larger trough, meaning that the wave is deeper. When a crest and a trough interfere, they cancel the wave out. When there is a natural frequency and the original wave and the reflecting wave have the same magnitude, or height (one going up and one going down), they create what is known as a node, a place of stillness, where no vibration is happening. In these nodes is where the sand settles, creating the patterns on the Chladni plate.
To learn more: http://www.physics.ucla.edu/demoweb/demomanual/acoustics/effects_of_sound/chladni_plate.html
Picture Courtesy of Kerry Montgomery
When the plate vibrates at frequencies, the plate bends in waves starting from where the vibration originated, moving across the plate and then reflecting back. When the frequency of the wave moving across the plate is the same as the frequency being reflected, this is called the natural resonance or natural frequency of the plate. When this happens, the waves moving across the plate interfere, cross paths, with the waves reflecting back across the plate. The interference of these waves is what causes the patterns to emerge.
A wave consists of a crest and a trough. When two interfere, the resulting wave gets bigger. When two troughs interfere the resulting wave is a larger trough, meaning that the wave is deeper. When a crest and a trough interfere, they cancel the wave out. When there is a natural frequency and the original wave and the reflecting wave have the same magnitude, or height (one going up and one going down), they create what is known as a node, a place of stillness, where no vibration is happening. In these nodes is where the sand settles, creating the patterns on the Chladni plate.
To learn more: http://www.physics.ucla.edu/demoweb/demomanual/acoustics/effects_of_sound/chladni_plate.html
Picture Courtesy of Kerry Montgomery
Tue, Feb 16,
|
Wed, Feb 17
Due:
- HW Lsn 4-3, #15-24 - HW Lsn 4-4, #25-31 - Reading Activity 4-5 Agenda: - Review HW As Needed - Lsn 4-5 Lecture - A Word About Gravity Waves Assignment: - HW Lsn 4-5, #32-46 - Chapter 4 Test Review 6-Word Memoir: I Love Pho King Food |
|
Words of Wisdom: The problem with the gene pool is that there is no lifeguard.
Gravitational Waves Detected
|
A century after Albert Einstein rewrote our understanding of space and time, physicists have confirmed one of the most elusive predictions of his general theory of relativity. In another galaxy, a billion or so light-years away, two black holes collided, shaking the fabric of spacetime. Here on Earth, two giant detectors on opposite sides of the United States quivered as gravitational waves washed over them. After decades trying to directly detect the waves, the recently upgraded Laser Interferometer Gravitational-Wave Observatory, now known as Advanced LIGO, appears to have succeeded, ushering in a new era of astronomy.
What are gravitational waves?
Colossal cosmic collisions and stellar explosions can rattle spacetime itself. General relativity predicts that ripples in the fabric of spacetime radiate energy away from such catastrophes. The ripples are subtle; by the time they reach Earth, some compress spacetime by as little as one ten-thousandth the width of a proton.
How are they detected?
To spot a signal, LIGO uses a special mirror to split a beam of laser light and sends the beams down two 4-kilometer-long arms, at a 90 degree angle to each other. After ricocheting back and forth 400 times, turning each beam’s journey into a 1,600 kilometer round-trip, the light recombines near its source. The experiment is designed so that, in normal conditions, the light waves cancel one another out when they recombine, sending no light signal to the nearby detector. But a gravitational wave stretches one tube while squeezing the other, altering the distance the two beams travel relative to each other. Because of this difference in distance, the recombining waves are no longer perfectly aligned and therefore don’t cancel out. The detector picks up a faint glow, signaling a passing wave. LIGO has one detector in Louisiana and another in Washington to ensure the wave is not a local phenomenon and to help locate its source.
Gravity waves from black holes verify Einstein’s prediction
https://www.sciencenews.org/article/gravity-waves-black-holes-verify-einsteins-prediction
The long road to detecting gravity waves
https://www.sciencenews.org/article/long-road-detecting-gravity-waves
Gravitational waves explained
https://www.sciencenews.org/article/gravitational-waves-explained
Video: What are gravitational waves?
https://www.youtube.com/watch?v=HwC5IYw5uAE&utm_source=Society+for+Science+Newsletters&utm_campaign=1308960052-gravitational_wave_special_2_11_2016&utm_medium=email&utm_term=0_a4c415a67f-1308960052-104535497
What are gravitational waves?
Colossal cosmic collisions and stellar explosions can rattle spacetime itself. General relativity predicts that ripples in the fabric of spacetime radiate energy away from such catastrophes. The ripples are subtle; by the time they reach Earth, some compress spacetime by as little as one ten-thousandth the width of a proton.
How are they detected?
To spot a signal, LIGO uses a special mirror to split a beam of laser light and sends the beams down two 4-kilometer-long arms, at a 90 degree angle to each other. After ricocheting back and forth 400 times, turning each beam’s journey into a 1,600 kilometer round-trip, the light recombines near its source. The experiment is designed so that, in normal conditions, the light waves cancel one another out when they recombine, sending no light signal to the nearby detector. But a gravitational wave stretches one tube while squeezing the other, altering the distance the two beams travel relative to each other. Because of this difference in distance, the recombining waves are no longer perfectly aligned and therefore don’t cancel out. The detector picks up a faint glow, signaling a passing wave. LIGO has one detector in Louisiana and another in Washington to ensure the wave is not a local phenomenon and to help locate its source.
Gravity waves from black holes verify Einstein’s prediction
https://www.sciencenews.org/article/gravity-waves-black-holes-verify-einsteins-prediction
The long road to detecting gravity waves
https://www.sciencenews.org/article/long-road-detecting-gravity-waves
Gravitational waves explained
https://www.sciencenews.org/article/gravitational-waves-explained
Video: What are gravitational waves?
https://www.youtube.com/watch?v=HwC5IYw5uAE&utm_source=Society+for+Science+Newsletters&utm_campaign=1308960052-gravitational_wave_special_2_11_2016&utm_medium=email&utm_term=0_a4c415a67f-1308960052-104535497
Mon, Feb 22
Due:
- HW Lsn 4-5, #32-46 Agenda: - Review HW Lsn 4-5, #32-46 - PhET Reflection, Diffraction and Interference Lab Assignment: - Complete PhET Reflection, Diffraction and Interference Lab - Chapter 4 Test Review 6-Word Memoir: I love you Mr. Kyle Smith |
|
Thu, Feb 25
Due:
- Chapter 4 Test Review Agenda: - Review Chapter 4 Test Review - PhET Reflection, Diffraction & Interference Lab Questions - PhET Standing Waves Lab Assignment: - Complete PhET Reflection, Diffraction and Interference Lab - Complete PhET Standing Waves Lab - Study for Chapter 4 Test - Reading Activity 9-1 6-Word Memoir: I procrastinate but, it gets done |
|
Words of Wisdom: Monday is an awful way to spend 1/7th of your life.
In Search of the Bacon Boson
Mon, Feb 29, Floater Fifth
Due:
- Reading Activity 9-1 - PhET Reflection, Diffraction & Interference Lab Agenda: - PhET Standing Waves Lab Questions - Lsn 9-1 Lecture Assignment: - HW Lsn 9-1, #1-13 - Reading Activity 9-2 - Complete PhET Standing Waves Lab - Study for Chapter 4 Test 6-Word Memoir: It's simpler than they tell you
|
Tue, Mar 1
Due:
- Chapter 4 Test Review Agenda: - Chapter 4 Test Assignment: - HW Lsn 9-1, #1-13 - Reading Activity 9-2 - Complete PhET Standing Waves Lab 6-Word Memoir: Live forever or die trying
|
Fri, Mar 4
Note: I will be proctoring the FSA this period. Accomplish this lesson independently.
Due: - HW Lsn 9-1, #1-13 - Reading Activity 9-2 - PhET Standing Waves Lab Agenda: - Review HW Lsn 9-1, #1-13 - Lsn 9-2 Lecture Assignment: - HW Lsn 9-2, #14-16 - Reading Activity 9-3 6-Word Memoir: Music, reading, singing, writing, IB, family
|
|
|
|
Words of Wisdom: A clear conscience is usually the sign of a bad memory.
Famous Dead Guy -- Johannes Kepler
The German astronomer Johannes Kepler's discovery of three basic laws governing the motion of planets made him one of the chief founders of modern astronomy. Kepler sought the job of assistant to Tycho Brahe (1546–1601), astrologer (one who interprets the positions of stars and planets and their effect on human affairs) and mathematician to Rudolph II (1552–1612), in Prague, Czechoslovakia. When Brahe died the following year, Kepler was appointed to replace him. His first job was to prepare Brahe's collection of studies in astronomy for publication, which came out between 1601 and 1602.
Kepler was also left in charge of Brahe's records, which forced him to make an assumption that led to a new theory about the orbits of all the planets. A difference between his theory and Brahe's data could be explained only if the orbit of Mars was not circular but elliptical (oval-shaped). This meant that the orbits of all planets were elliptical (Kepler's first law). This helped prove another of his statements. It is known as Kepler's second law, according to which the line joining a planet to the sun sweeps over equal areas in equal times in its elliptical orbit.
Kepler also published two important works while in Linz. In the Harmonice mundi (1618) his third law was announced. It stated that the average distance of a planet from the sun, raised to the third power, divided by the square of the time it takes for the planet to complete one orbit, is the same for all planets. Kepler's second work, the Epitome astronomiae Copernicanae (published 1618–21), proposed a physical explanation of the motions of planets, namely, "magnetic arms" extending from the sun.
Kepler wandered over Europe in the last three years of his life. He was in Ulm, Germany, when his Tabulae Rudolphinae (1628) was published. It not only added the positions of over two hundred stars to those contained in Brahe's published works, but it also provided planetary tables that became the standard for the next century. Kepler died on November 15, 1630. He was a unique symbol of the change over from the old to the new spirit of science.
From: http://www.notablebiographies.com/Jo-Ki/Kepler-Johannes.html
Kepler was also left in charge of Brahe's records, which forced him to make an assumption that led to a new theory about the orbits of all the planets. A difference between his theory and Brahe's data could be explained only if the orbit of Mars was not circular but elliptical (oval-shaped). This meant that the orbits of all planets were elliptical (Kepler's first law). This helped prove another of his statements. It is known as Kepler's second law, according to which the line joining a planet to the sun sweeps over equal areas in equal times in its elliptical orbit.
Kepler also published two important works while in Linz. In the Harmonice mundi (1618) his third law was announced. It stated that the average distance of a planet from the sun, raised to the third power, divided by the square of the time it takes for the planet to complete one orbit, is the same for all planets. Kepler's second work, the Epitome astronomiae Copernicanae (published 1618–21), proposed a physical explanation of the motions of planets, namely, "magnetic arms" extending from the sun.
Kepler wandered over Europe in the last three years of his life. He was in Ulm, Germany, when his Tabulae Rudolphinae (1628) was published. It not only added the positions of over two hundred stars to those contained in Brahe's published works, but it also provided planetary tables that became the standard for the next century. Kepler died on November 15, 1630. He was a unique symbol of the change over from the old to the new spirit of science.
From: http://www.notablebiographies.com/Jo-Ki/Kepler-Johannes.html
Wed, Mar 9
Due:
- HW Lsn 9-2, #14-16 - Reading Activity 9-3 Agenda: - Review HW Lsn 9-2, #14-16 - Lsn 9-3 Lecture Assignment: - HW Lsn 9-3, #17-26 - Reading Activity 9-4 6-Word Memoir: Traveling never ceases to amuse me |
|
Fri, Mar 11
|
Friday the 13th
|
Lsn 9-4 Lecture | |
File Size: | 437 kb |
File Type: | pptx |
Lsn 9-4 Lecture | |
File Size: | 666 kb |
File Type: |
Reading Activity Lsn 9-5 | |
File Size: | 76 kb |
File Type: | docx |
Reading Activity Lsn 9-5 | |
File Size: | 220 kb |
File Type: |
Thought for the Day: I was sad because I had no shoes, until I met a man who had no feet. So I said, "Got any shoes you're not using?"
|
(Reuters) - Britain's Peter Higgs and Francois Englert of Belgium won the Nobel Prize for physics on Tuesday [Oct 8, 2013] for predicting the existence of the Higgs boson particle that explains how elementary matter attained the mass to form stars and planets. Half a century after their original work, the new building block of nature was finally detected in 2012 at the European Organization for Nuclear Research (CERN) centre's giant, underground particle-smasher near Geneva. The discovery was hailed as one of the most important in physics. http://www.reuters.com/article/2013/10/08/us-nobel-physics-idUSBRE9970B620131008
|