1. Newton's universal law of gravitation states that every mass attracts every other mass, with an attraction proportional to the product of their masses and inversely proportional to the square of the distance between them.
2. Newton showed that Kepler's laws of planetary motion, including elliptical orbits, could be explained and extended by his laws of motion and universal law of gravitation.
3. Newton's version of Kepler's third law relates the orbital period and average orbital distance of orbiting bodies to determine the total mass of the system.
As the moon waxes (the amount of illuminated surface as seen from Earth is increasing), the lunar phases progress through new moon, crescent moon, first-quarter moon, gibbous moon, and full moon. The moon is then said to wane as it passes through the gibbous moon, third-quarter moon, crescent moon and back to new moon.
As the moon waxes (the amount of illuminated surface as seen from Earth is increasing), the lunar phases progress through new moon, crescent moon, first-quarter moon, gibbous moon, and full moon. The moon is then said to wane as it passes through the gibbous moon, third-quarter moon, crescent moon and back to new moon.
In 1929 Edwin Hubble discovered that the universe is expanding. Ever since, we have been striving to fully comprehend the implications of his discovery. Our understanding of the universe and our place in it has evolved from an anthropocentric, static, earth-centered model to a dynamic, evolving cosmos where galaxies are flung across time and space, where the cosmic horizon is quickly receding and the discoveries that await us are limited only by our imagination.
Based on Edwin Hubble’s discovery that the universe is expanding, a study was begun in 1998 to determine the expansion rate of the universe at great distances. Culminating with the 2011 Nobel Prize in Physics being awarded to 2 Americans and an Australian, it was determined that the expansion rate of the universe is not decreasing but increasing at great distances, a finding that was quite unexpected and had far-reaching implications for our cosmological models and understanding of the expanding universe. In this presentation, I discuss this discovery in detail and how a specific type of exploding star (supernova) was used to make this discovery.
Exploding stars 2011 Nobel Prize in PhysicsThomas Madigan
views
In 1929 Edwin Hubble discovered that the universe is expanding. Ever since, we have been striving to fully comprehend the implications of his discovery. Our understanding of the universe and our place in it has evolved from an anthropocentric, static, earth-centered model to a dynamic, evolving cosmos where galaxies are flung across time and space, where the cosmic horizon is quickly receding and the discoveries that await us are limited only by our imagination.
Based on Edwin Hubble’s discovery that the universe is expanding, a study was begun in 1998 to determine the expansion rate of the universe at great distances. Culminating with the 2011 Nobel Prize in Physics being awarded to 2 Americans and an Australian, it was determined that the expansion rate of the universe is not decreasing but increasing at great distances, a finding that was quite unexpected and had far-reaching implications for our cosmological models and understanding of the expanding universe. In this presentation, I discuss this discovery in detail and how a specific type of exploding star (supernova) was used to make this discovery.
This public event was hosted at the Ross School (East Hampton, NY) by the Montauk Observatory on July 9th, 2014.
The Structure of the Universe - Between Science and QuranHussein Mhanna
If we had the chance to go outside the universe and take a huge zoom-out picture, how would it look like?!
A recent computer simulation from a supercomputer at NASA answers this question.
But did Allah describe the universe in the Quran 14 centuries ago?!
Lattice Energy LLC - Many body collective magnetic mechanism creates ultrahig...Lewis Larsen
“The main reason why the origin of cosmic rays(CRs) is still unknown, one century after their discovery, is that they are charged nuclei isotropized by the turbulent magnetic field in the Galaxy to such a high degree that their observed flux is essentially identical in all directions, with no sources or decisive hot spots identified in any region the sky …” - Etienne Parizot (Univ. of Paris-Diderot), Nuclear Physics B (2014)
In 2008 (arXiv) and 2010 (Pramana), we derived and published approximate, rule-of-thumb formulas for calculating estimated one-shot, mean center-of-mass acceleration energies for charged particles present in plasma-filled magnetic flux tubes (also called “coronal loops”) for two cases: (1) steady-state and (2) explosive destruction of an unstable flux tube (this second case is subset of “magnetic reconnection” processes).
Our simple equations for magnetic flux tubes are robust and scale-independent. They consequently have broad applicability from exploding wires (which in early stages of explosion comprise dense dusty plasmas), lightning, to solar flux tubes and other astrophysical environments that are characterized by vastly higher magnetic fields; these include many other types of stars besides the Sun, neutron stars, magnetars, and regions located near black holes and active galactic nuclei.
Herein we show how plasma-filled magnetic flux tubes likely occur in many different astrophysical systems from relatively small objects (neutron stars and magnetars) to relatively large objects (accretion disks and jet bases of supermassive black holes). When these ordered magnetic structures explode (reconnection, flares), enormous amounts of magnetic energy are converted into kinetic energy of charged particles present inside exploding flux tubes. Using reasonable parametric assumptions, we calculate one-shot, center-of-mass acceleration energies for protons in collapsing protoneutron stars (5.5 x 1018 eV), two cases for BH accretion disks (2.2 x 1017 eV and 0.9 x 1019 eV), and finally for the jet base of a supermassive black hole (2.2 x 1021eV).
What all these numbers suggest, including those for the Sun, is that W-L-S particle acceleration mechanism for magnetic flux tubes can create cosmic ray particles at energies that span the entire cosmic-ray energy spectrum from top to bottom. This argues that commonplace flux tubes may well play a significant role in generating the observed cosmic ray energy spectrum and would be consistent with apparent overall anisotropy of sources at all but the very highest particle energies. That said, we think a number of different acceleration mechanisms likely contribute to entire spectrum, including shock acceleration and perhaps exotic mechanisms such as evaporation of gaseous winds from neutron stars (Widom et al. arXiv:1410.6498v2 -2015).
In 1929 Edwin Hubble discovered that the universe is expanding. Ever since, we have been striving to fully comprehend the implications of his discovery. Our understanding of the universe and our place in it has evolved from an anthropocentric, static, earth-centered model to a dynamic, evolving cosmos where galaxies are flung across time and space, where the cosmic horizon is quickly receding and the discoveries that await us are limited only by our imagination.
Based on Edwin Hubble’s discovery that the universe is expanding, a study was begun in 1998 to determine the expansion rate of the universe at great distances. Culminating with the 2011 Nobel Prize in Physics being awarded to 2 Americans and an Australian, it was determined that the expansion rate of the universe is not decreasing but increasing at great distances, a finding that was quite unexpected and had far-reaching implications for our cosmological models and understanding of the expanding universe. In this presentation, I discuss this discovery in detail and how a specific type of exploding star (supernova) was used to make this discovery.
Exploding stars 2011 Nobel Prize in PhysicsThomas Madigan
views
In 1929 Edwin Hubble discovered that the universe is expanding. Ever since, we have been striving to fully comprehend the implications of his discovery. Our understanding of the universe and our place in it has evolved from an anthropocentric, static, earth-centered model to a dynamic, evolving cosmos where galaxies are flung across time and space, where the cosmic horizon is quickly receding and the discoveries that await us are limited only by our imagination.
Based on Edwin Hubble’s discovery that the universe is expanding, a study was begun in 1998 to determine the expansion rate of the universe at great distances. Culminating with the 2011 Nobel Prize in Physics being awarded to 2 Americans and an Australian, it was determined that the expansion rate of the universe is not decreasing but increasing at great distances, a finding that was quite unexpected and had far-reaching implications for our cosmological models and understanding of the expanding universe. In this presentation, I discuss this discovery in detail and how a specific type of exploding star (supernova) was used to make this discovery.
This public event was hosted at the Ross School (East Hampton, NY) by the Montauk Observatory on July 9th, 2014.
The Structure of the Universe - Between Science and QuranHussein Mhanna
If we had the chance to go outside the universe and take a huge zoom-out picture, how would it look like?!
A recent computer simulation from a supercomputer at NASA answers this question.
But did Allah describe the universe in the Quran 14 centuries ago?!
Lattice Energy LLC - Many body collective magnetic mechanism creates ultrahig...Lewis Larsen
“The main reason why the origin of cosmic rays(CRs) is still unknown, one century after their discovery, is that they are charged nuclei isotropized by the turbulent magnetic field in the Galaxy to such a high degree that their observed flux is essentially identical in all directions, with no sources or decisive hot spots identified in any region the sky …” - Etienne Parizot (Univ. of Paris-Diderot), Nuclear Physics B (2014)
In 2008 (arXiv) and 2010 (Pramana), we derived and published approximate, rule-of-thumb formulas for calculating estimated one-shot, mean center-of-mass acceleration energies for charged particles present in plasma-filled magnetic flux tubes (also called “coronal loops”) for two cases: (1) steady-state and (2) explosive destruction of an unstable flux tube (this second case is subset of “magnetic reconnection” processes).
Our simple equations for magnetic flux tubes are robust and scale-independent. They consequently have broad applicability from exploding wires (which in early stages of explosion comprise dense dusty plasmas), lightning, to solar flux tubes and other astrophysical environments that are characterized by vastly higher magnetic fields; these include many other types of stars besides the Sun, neutron stars, magnetars, and regions located near black holes and active galactic nuclei.
Herein we show how plasma-filled magnetic flux tubes likely occur in many different astrophysical systems from relatively small objects (neutron stars and magnetars) to relatively large objects (accretion disks and jet bases of supermassive black holes). When these ordered magnetic structures explode (reconnection, flares), enormous amounts of magnetic energy are converted into kinetic energy of charged particles present inside exploding flux tubes. Using reasonable parametric assumptions, we calculate one-shot, center-of-mass acceleration energies for protons in collapsing protoneutron stars (5.5 x 1018 eV), two cases for BH accretion disks (2.2 x 1017 eV and 0.9 x 1019 eV), and finally for the jet base of a supermassive black hole (2.2 x 1021eV).
What all these numbers suggest, including those for the Sun, is that W-L-S particle acceleration mechanism for magnetic flux tubes can create cosmic ray particles at energies that span the entire cosmic-ray energy spectrum from top to bottom. This argues that commonplace flux tubes may well play a significant role in generating the observed cosmic ray energy spectrum and would be consistent with apparent overall anisotropy of sources at all but the very highest particle energies. That said, we think a number of different acceleration mechanisms likely contribute to entire spectrum, including shock acceleration and perhaps exotic mechanisms such as evaporation of gaseous winds from neutron stars (Widom et al. arXiv:1410.6498v2 -2015).
Force and Mass;
Types of Forces;
Contact forces;
Field forces;
Newtons laws of motion;
Explanation;
It’s not Newton’s Laws;
Its Rishi Kanad laws;
Proof of stolen three laws of motion; how newton theft the laws ?
newton a modern thief?
laws of motion by Rishi Kanad
Vaisheshika - laws of motion
Comparision - Kanad rishi vs Newton
References for theft
Astronomers are gravity experts. All of the heavenly motions described in the preceding chapters are dominated by gravitation. Isaac Newton gets the credit for discovering gravity, but even Newton couldn’t explain what gravity was. Einstein proposed that gravity is a curvature of space, but that only pushes the mystery further away. “What is curvature?” we might ask.
This chapter shows how scientists build theories to explain and unify observations. Theories can give us entirely new ways to understand nature, but no theory is an end in itself. Astronomers continue to study Einstein’s theory, and they wonder if there is an even better way to understand the motions of the heavens.
The principles we discuss in this chapter will be companions through the remaining chapters. Gravity is universal.
Saeed Jafari
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
(May 29th, 2024) Advancements in Intravital Microscopy- Insights for Preclini...Scintica Instrumentation
Intravital microscopy (IVM) is a powerful tool utilized to study cellular behavior over time and space in vivo. Much of our understanding of cell biology has been accomplished using various in vitro and ex vivo methods; however, these studies do not necessarily reflect the natural dynamics of biological processes. Unlike traditional cell culture or fixed tissue imaging, IVM allows for the ultra-fast high-resolution imaging of cellular processes over time and space and were studied in its natural environment. Real-time visualization of biological processes in the context of an intact organism helps maintain physiological relevance and provide insights into the progression of disease, response to treatments or developmental processes.
In this webinar we give an overview of advanced applications of the IVM system in preclinical research. IVIM technology is a provider of all-in-one intravital microscopy systems and solutions optimized for in vivo imaging of live animal models at sub-micron resolution. The system’s unique features and user-friendly software enables researchers to probe fast dynamic biological processes such as immune cell tracking, cell-cell interaction as well as vascularization and tumor metastasis with exceptional detail. This webinar will also give an overview of IVM being utilized in drug development, offering a view into the intricate interaction between drugs/nanoparticles and tissues in vivo and allows for the evaluation of therapeutic intervention in a variety of tissues and organs. This interdisciplinary collaboration continues to drive the advancements of novel therapeutic strategies.
Earliest Galaxies in the JADES Origins Field: Luminosity Function and Cosmic ...Sérgio Sacani
We characterize the earliest galaxy population in the JADES Origins Field (JOF), the deepest
imaging field observed with JWST. We make use of the ancillary Hubble optical images (5 filters
spanning 0.4−0.9µm) and novel JWST images with 14 filters spanning 0.8−5µm, including 7 mediumband filters, and reaching total exposure times of up to 46 hours per filter. We combine all our data
at > 2.3µm to construct an ultradeep image, reaching as deep as ≈ 31.4 AB mag in the stack and
30.3-31.0 AB mag (5σ, r = 0.1” circular aperture) in individual filters. We measure photometric
redshifts and use robust selection criteria to identify a sample of eight galaxy candidates at redshifts
z = 11.5 − 15. These objects show compact half-light radii of R1/2 ∼ 50 − 200pc, stellar masses of
M⋆ ∼ 107−108M⊙, and star-formation rates of SFR ∼ 0.1−1 M⊙ yr−1
. Our search finds no candidates
at 15 < z < 20, placing upper limits at these redshifts. We develop a forward modeling approach to
infer the properties of the evolving luminosity function without binning in redshift or luminosity that
marginalizes over the photometric redshift uncertainty of our candidate galaxies and incorporates the
impact of non-detections. We find a z = 12 luminosity function in good agreement with prior results,
and that the luminosity function normalization and UV luminosity density decline by a factor of ∼ 2.5
from z = 12 to z = 14. We discuss the possible implications of our results in the context of theoretical
models for evolution of the dark matter halo mass function.
Slide 1: Title Slide
Extrachromosomal Inheritance
Slide 2: Introduction to Extrachromosomal Inheritance
Definition: Extrachromosomal inheritance refers to the transmission of genetic material that is not found within the nucleus.
Key Components: Involves genes located in mitochondria, chloroplasts, and plasmids.
Slide 3: Mitochondrial Inheritance
Mitochondria: Organelles responsible for energy production.
Mitochondrial DNA (mtDNA): Circular DNA molecule found in mitochondria.
Inheritance Pattern: Maternally inherited, meaning it is passed from mothers to all their offspring.
Diseases: Examples include Leber’s hereditary optic neuropathy (LHON) and mitochondrial myopathy.
Slide 4: Chloroplast Inheritance
Chloroplasts: Organelles responsible for photosynthesis in plants.
Chloroplast DNA (cpDNA): Circular DNA molecule found in chloroplasts.
Inheritance Pattern: Often maternally inherited in most plants, but can vary in some species.
Examples: Variegation in plants, where leaf color patterns are determined by chloroplast DNA.
Slide 5: Plasmid Inheritance
Plasmids: Small, circular DNA molecules found in bacteria and some eukaryotes.
Features: Can carry antibiotic resistance genes and can be transferred between cells through processes like conjugation.
Significance: Important in biotechnology for gene cloning and genetic engineering.
Slide 6: Mechanisms of Extrachromosomal Inheritance
Non-Mendelian Patterns: Do not follow Mendel’s laws of inheritance.
Cytoplasmic Segregation: During cell division, organelles like mitochondria and chloroplasts are randomly distributed to daughter cells.
Heteroplasmy: Presence of more than one type of organellar genome within a cell, leading to variation in expression.
Slide 7: Examples of Extrachromosomal Inheritance
Four O’clock Plant (Mirabilis jalapa): Shows variegated leaves due to different cpDNA in leaf cells.
Petite Mutants in Yeast: Result from mutations in mitochondrial DNA affecting respiration.
Slide 8: Importance of Extrachromosomal Inheritance
Evolution: Provides insight into the evolution of eukaryotic cells.
Medicine: Understanding mitochondrial inheritance helps in diagnosing and treating mitochondrial diseases.
Agriculture: Chloroplast inheritance can be used in plant breeding and genetic modification.
Slide 9: Recent Research and Advances
Gene Editing: Techniques like CRISPR-Cas9 are being used to edit mitochondrial and chloroplast DNA.
Therapies: Development of mitochondrial replacement therapy (MRT) for preventing mitochondrial diseases.
Slide 10: Conclusion
Summary: Extrachromosomal inheritance involves the transmission of genetic material outside the nucleus and plays a crucial role in genetics, medicine, and biotechnology.
Future Directions: Continued research and technological advancements hold promise for new treatments and applications.
Slide 11: Questions and Discussion
Invite Audience: Open the floor for any questions or further discussion on the topic.
Salas, V. (2024) "John of St. Thomas (Poinsot) on the Science of Sacred Theol...Studia Poinsotiana
I Introduction
II Subalternation and Theology
III Theology and Dogmatic Declarations
IV The Mixed Principles of Theology
V Virtual Revelation: The Unity of Theology
VI Theology as a Natural Science
VII Theology’s Certitude
VIII Conclusion
Notes
Bibliography
All the contents are fully attributable to the author, Doctor Victor Salas. Should you wish to get this text republished, get in touch with the author or the editorial committee of the Studia Poinsotiana. Insofar as possible, we will be happy to broker your contact.
Toxic effects of heavy metals : Lead and Arsenicsanjana502982
Heavy metals are naturally occuring metallic chemical elements that have relatively high density, and are toxic at even low concentrations. All toxic metals are termed as heavy metals irrespective of their atomic mass and density, eg. arsenic, lead, mercury, cadmium, thallium, chromium, etc.
Nutraceutical market, scope and growth: Herbal drug technologyLokesh Patil
As consumer awareness of health and wellness rises, the nutraceutical market—which includes goods like functional meals, drinks, and dietary supplements that provide health advantages beyond basic nutrition—is growing significantly. As healthcare expenses rise, the population ages, and people want natural and preventative health solutions more and more, this industry is increasing quickly. Further driving market expansion are product formulation innovations and the use of cutting-edge technology for customized nutrition. With its worldwide reach, the nutraceutical industry is expected to keep growing and provide significant chances for research and investment in a number of categories, including vitamins, minerals, probiotics, and herbal supplements.
Observation of Io’s Resurfacing via Plume Deposition Using Ground-based Adapt...Sérgio Sacani
Since volcanic activity was first discovered on Io from Voyager images in 1979, changes
on Io’s surface have been monitored from both spacecraft and ground-based telescopes.
Here, we present the highest spatial resolution images of Io ever obtained from a groundbased telescope. These images, acquired by the SHARK-VIS instrument on the Large
Binocular Telescope, show evidence of a major resurfacing event on Io’s trailing hemisphere. When compared to the most recent spacecraft images, the SHARK-VIS images
show that a plume deposit from a powerful eruption at Pillan Patera has covered part
of the long-lived Pele plume deposit. Although this type of resurfacing event may be common on Io, few have been detected due to the rarity of spacecraft visits and the previously low spatial resolution available from Earth-based telescopes. The SHARK-VIS instrument ushers in a new era of high resolution imaging of Io’s surface using adaptive
optics at visible wavelengths.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
Professional air quality monitoring systems provide immediate, on-site data for analysis, compliance, and decision-making.
Monitor common gases, weather parameters, particulates.
Comparing Evolved Extractive Text Summary Scores of Bidirectional Encoder Rep...University of Maribor
Slides from:
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Track: Artificial Intelligence
https://www.etran.rs/2024/en/home-english/
2. Making Sense of the Universe:
Understanding Motion, Energy, and Gravity
3. 4.1 Describing Motion: Examples from Daily
Life
• Our goals for learning:
– How do we describe motion?
– How is mass different from weight?
4. • Precise definitions to describe motion:
• Speed: Rate at which object moves
Example: 10 m/s
• Velocity: Speed and direction
Example: 10 m/s, due east
• Acceleration: Any change in velocity
units of speed/time (m/s2
)
How do we describe motion?
speed =
distance
time
units of
m
s
5. The Acceleration of Gravity
• All falling objects
accelerate at the
same rate (not
counting friction of
air resistance).
• On Earth, g ≈ 10
m/s2
: speed
increases 10 m/s
with each second
of falling.
6. Apollo 15 demonstration
The Acceleration of Gravity (g)
• Galileo showed that g is the same for all falling
objects, regardless of their mass.
7. Momentum and Force
• Momentum = mass x velocity
• A net force changes momentum, which
generally means an acceleration (change in
velocity).
• Rotational momentum of a spinning or orbiting
object is known as angular momentum.
8. Thought Question
For each of the following is there a net force? Y/N
1. A car coming to a stop
2. A bus speeding up
3. An elevator moving up at constant speed
4. A bicycle going around a curve
5. A moon orbiting Jupiter
9. Thought Question
For each of the following is there a net force? Y/N
1. A car coming to a stop: Y
2. A bus speeding up: Y
3. An elevator moving at constant speed: N
4. A bicycle going around a curve: Y
5. A moon orbiting Jupiter: Y
10. You are weightless in free-fall!
How is mass different from weight?
• Mass – the amount of matter in an object
• Weight – the force that acts upon an object
11. Thought Question
On the Moon:
A. My weight is the same, my mass is less.
B. My weight is less, my mass is the same.
C. My weight is more, my mass is the same.
D. My weight is more, my mass is less.
12. Thought Question
On the Moon:
A. My weight is the same, my mass is less.
B. My weight is less, my mass is the same.
C. My weight is more, my mass is the same.
D. My weight is more, my mass is less.
13. Why are astronauts weightless in space?
• There is gravity in
space.
• Weightlessness is due
to a constant state of
free-fall.
14. What have we learned?
• How do we describe motion?
– Speed = distance/time
– Speed and direction => velocity
– Change in velocity => acceleration
– Momentum = mass x velocity
– Force causes change in momentum,
producing acceleration.
15. What have we learned?
• How is mass different from weight?
– Mass = quantity of matter
– Weight = force acting on mass
– Objects are weightless in free-fall.
16. 4.2 Newton's Laws of Motion
• Our goals for learning:
– How did Newton change our view of the
universe?
– What are Newton's three laws of motion?
17. Sir Isaac Newton
(1642–1727)
How did Newton change our view of the
universe?
• Realized the same
physical laws that operate
on Earth also operate in
the heavens
– one universe
• Discovered laws of motion
and gravity
• Much more: experiments
with light, first reflecting
telescope, calculus…
18. What are Newton's three laws of motion?
• Newton's first law of
motion: An object
moves at constant
velocity unless a net
force acts to change its
speed or direction.
19. Newton's Second Law of Motion
• There are two equivalent ways to express
Newton's Second Law of Motion
– Force = mass x acceleration
– Force = rate of change in momentum
20. Newton's third law of motion:
• For every force, there is always an equal and
opposite reaction force.
21. Thought Question
How does the force the Earth exerts on you
compare with the force you exert on it?
A. Earth exerts a larger force on you.
B. You exert a larger force on Earth.
C. Earth and you exert equal and opposite forces
on each other.
22. Thought Question
How does the force the Earth exerts on you
compare with the force you exert on it?
A. Earth exerts a larger force on you.
B. You exert a larger force on Earth.
C. Earth and you exert equal and opposite
forces on each other.
23. Thought Question
A compact car and a Mack truck have a head-on
collision. Are the following true or false?
1. The force of the car on the truck is equal and
opposite to the force of the truck on the car.
2. The momentum transferred from the truck to
the car is equal and opposite to the momentum
transferred from the car to the truck.
3. The change of velocity of the car is the same as
the change of velocity of the truck.
24. Thought Question
A compact car and a Mack truck have a head-on
collision. Are the following true or false?
• The force of the car on the truck is equal and
opposite to the force of the truck on the car. T
• The momentum transferred from the truck to
the car is equal and opposite to the momentum
transferred from the car to the truck. T
• The change of velocity of the car is the same as
the change of velocity of the truck. F
25. What have we learned?
• How did Newton change our view of the
universe?
– He discovered laws of motion and gravitation.
– He realized these same laws of physics were
identical in the universe and on Earth.
• What are Newton's three laws of motion?
1. Object moves at constant velocity if no net
force is acting.
2. Force = mass x acceleration
3. For every force there is an equal and
opposite reaction force.
26. 4.3 Conservation Laws in Astronomy
• Our goals for learning:
– Why do objects move at constant velocity
if no force acts on them?
– What keeps a planet rotating and orbiting
the Sun?
– Where do objects get their energy?
27. Objects continue at constant velocity
because of conservation if momentum.
Why do objects move at constant velocity if
no force acts on them?
• The total
momentum of
interacting objects
cannot change
unless an external
force is acting on
them.
• Interacting objects
exchange
momentum through
equal and opposite
28. What keeps a planet rotating and orbiting
the Sun?
29. Conservation of Angular Momentum
Angular momentum = mass x velocity x radius
• The angular momentum of an object cannot
change unless an external twisting force (torque)
is acting on it.
• Earth experiences no twisting force as it orbits
the Sun, so its rotation and orbit will continue
indefinitely.
31. Where do objects get their energy?
• Energy makes matter move.
• Energy is conserved, but it can:
– transfer from one object to another
– change in form
32. Basic Types of Energy
• Kinetic (motion)
• Radiative (light)
• Potential (stored)
• Energy can change type,
but cannot be created or
destroyed.
33. Thermal Energy:
• The collective kinetic energy of many particles
(for example, in a rock, in air, in water)
– Thermal energy is related to temperature but
it is NOT the same.
– Temperature is the average kinetic energy of
the many particles in a substance.
35. Temperature Scales
• Thermal energy is a measure of the total kinetic
energy of all the particles in a substance. It
therefore depends on both temperature AND
density.
Example:
36. Gravitational Potential Energy
• On Earth, depends on:
– object's mass (m)
– strength of gravity (g)
– distance object could
potentially fall
37. Gravitational Potential Energy
• In space, an object or
gas cloud has more
gravitational energy
when it is spread out
than when it
contracts.
– A contracting cloud
converts
gravitational
potential energy to
thermal energy.
38. • Mass itself is a form of potential
energy:
• A small amount of mass can
release a great deal of energy (for
example, an H-bomb).
• Concentrated energy can
spontaneously turn into particles
(for example, in particle
accelerators).
EE == mcmc22
Mass-Energy
39. Conservation of Energy
• Energy can be neither created nor destroyed.
• It can change form or be exchanged between
objects.
• The total energy content of the universe was
determined in the Big Bang and remains the
same today.
40. What have we learned?
• Why do objects move at constant velocity if no force
acts on them?
– Conservation of momentum
• What keeps a planet rotating and orbiting the Sun?
– Conservation of angular momentum
• Where do objects get their energy?
– Conservation of energy: energy cannot be created or
destroyed but only transformed from one type to
another.
– Energy comes in three basic types: kinetic, potential,
radiative.
41. 4.4 The Universal Law of Gravitation
• Our goals for learning:
– What determines the strength of gravity?
– How does Newton's law of gravity extend
Kepler's laws?
42. What determines the strength of gravity?
The universal law of gravitation:
1. Every mass attracts every other mass.
2. Attraction is directly proportional to the product of their
masses.
3. Attraction is inversely proportional to the square of the
distance between their centers.
43. How does Newton's law of gravity extend
Kepler's laws?
• Kepler's laws apply to all
orbiting objects, not just
planets.
• Ellipses are not the only
orbital paths. Orbits can
be:
– bound (ellipses)
– unbound
• parabola
• hyperbola
44. Center of Mass
• Because of
momentum
conservation,
orbiting objects orbit
around their center
of mass.
45. Newton and Kepler's Third Law
• Newton's laws of gravity and motion showed that the
relationship between the orbital period and average
orbital distance of a system tells us the total mass of the
system.
• Examples:
– Earth's orbital period (1 year) and average distance
(1 AU) tell us the Sun's mass.
– Orbital period and distance of a satellite from Earth
tell us Earth's mass.
– Orbital period and distance of a moon of Jupiter tell us
Jupiter's mass.
46. • p = orbital period
∀ α = average orbital distance (between centers)
• (M1 + M2) = sum of object masses
Newton's Version of Kepler's Third Law
47. What have we learned?
• What determines the strength of gravity?
– Directly proportional to the product of the
masses (M × m)
– Inversely proportional to the square of the
separation
• How does Newton's law of gravity allow us to
extend Kepler's laws?
– Applies to other objects, not just planets
– Includes unbound orbit shapes: parabola,
hyperbola
– Can be used to measure mass of orbiting
systems
48. 4.5 Orbits, Tides, and the Acceleration of
Gravity
• Our goals for learning:
– How do gravity and energy together allow
us to understand orbits?
– How does gravity cause tides?
– Why do all objects fall at the same rate?
49. How do gravity and energy together allow
us to understand orbits?
• Total orbital energy
(gravitational +
kinetic) stays
constant if there is
no external force.
• Orbits cannot
change
spontaneously.
Total orbital energy stays constant.
50. Changing an Orbit
• So what can make an
object gain or lose orbital
energy?
• Friction or atmospheric
drag
• A gravitational encounter
51. Escape Velocity
• If an object gains
enough orbital energy,
it may escape (change
from a bound to
unbound orbit).
• Escape velocity from
Earth ≈ 11 km/s from
sea level (about
40,000 km/hr)
53. How does gravity cause tides?
• Moon's gravity pulls harder on near side of Earth
than on far side.
• Difference in Moon's gravitational pull stretches
Earth.
55. • Tidal friction gradually slows Earth's rotation (and
makes the Moon get farther from Earth).
• The Moon once orbited faster (or slower); tidal
friction caused it to ''lock'' in synchronous rotation.
Tidal Friction
56. Why do all objects fall at the same rate?
• The gravitational acceleration of an object like a rock
does not depend on its mass because Mrock in the
equation for acceleration cancels Mrock in the equation for
gravitational force.
• This ''coincidence'' was not understood until Einstein's
general theory of relativity.
57. What have we learned?
• How do gravity and energy together allow us
to understand orbits?
– Change in total energy is needed to change
orbit
– Add enough energy (escape velocity) and
object leaves.
• How does gravity cause tides?
– The Moon's gravity stretches Earth and its
oceans.
• Why do all objects fall at the same rate?
– Mass of object in Newton's second law exactly
cancels mass in law of gravitation.
Editor's Notes
Basic vocabulary of motion. Emphasize that turning, slowing, and speeding up are all examples of acceleration.
When you show this video clip, be sure to point out what is going on since it is not easy to see…
Use to check if students can figure out where a net force is acting. For bonus questions, ask if they can identify the forces.
Compare this weightlessness to that of being in truly empty space. Einstein&apos;s equivalence principle might even be foreshadowed here!
You may wish to discuss the examples in the book on p. 115-116.
You may wish to discuss the examples given in the text on p. 118
You may wish to go over this figure in some detail to be sure the idea is clear.
You may wish to discuss the examples given in the text on pgs. 118-119
Discuss astronomical analogs: disks of galaxies, disks in which planets form, accretion disks…
Begin by defining energy…
Students sometimes get confused when we&apos;ve said there are 3 basic types of energy (kinetic, potential, radiative) and then start talking about subtypes, so be sure they understand that we are now dealing with subcategories.
Use this figure to review temperature scales.
We&apos;ve found this example of the oven and boiling water to be effective in explaining the difference between temperature and thermal energy. You may then wish to discuss other examples. You might also want to note that the temperature in low-Earth orbit is actually quite high, but astronauts get cold because of the low density.
We next discuss 2 subcategories of potential energy that are important in astronomy: gravitational potential energy (this and next slide) and mass-energy.
We next discuss 2 subcategories of potential energy that are important in astronomy: gravitational potential energy (this and next slide) and mass-energy.
We next discuss 2 subcategories of potential energy that are important in astronomy: gravitational potential energy (this and next slide) and mass-energy.
Emphasize that this law allows us to measure the masses of distant objects — an incredibly powerful tool.
Optional: use this slide if you wish to introduce the equation for Newton&apos;s version of Kepler&apos;s third law.
The concept of orbital energy is important to understanding orbits.
Examples worth mentioning:
satellites in low-Earth orbit crashing to Earth due to energy loss to friction with atmosphere
captured moons like Phobos/Deimos or many moons of Jupiter: not easy to capture, and must have happened when an extended atmosphere or gas cloud allowed enough friction for the asteroid to lose significant energy.
Gravitational encounters have affected comets like Halley&apos;s; also used by spacecraft to boost orbits…
Can use this to discuss how adding velocity can make a spacecraft move to a higher orbit or ultimately to escape on an unbound orbit.
Use this figure to explain the origin of the tidal bulges.
Gravitational pull decreases with (distance)2, the Moon&apos;s pull on Earth is strongest on the side facing the Moon, weakest on the opposite side.
The Earth gets stretched along the Earth-Moon line.
The oceans rise relative to land at these points.