I Can’t Sleep - Gravity | Calm Bedtime Reading for Sleep

Episode Date: August 20, 2019

Relax with calm bedtime reading about gravity to ease insomnia and restless nights. This soothing episode explores the natural force that shapes the universe, from keeping our feet on the ground to guiding the motion of planets and stars. Benjamin’s gentle cadence makes complex science peaceful, turning the story of Newton, Einstein, and the nature of gravity into a calming journey. With no whispering or hypnosis—just calm, fact-filled storytelling—you’ll find stress melting away and your mind quieting. Press play, let gravity hold you, and drift into restful sleep. Want More? Request a Topic: https://www.icantsleeppodcast.com/request-a-topic Ad-Free Episodes: https://icantsleep.supportingcast.fm/ Shop Sleep-Friendly Products: https://www.icantsleeppodcast.com/sponsors Join the Discussion on Discord: https://discord.gg/myhGhVUhn7 This content is derived from the Wikipedia article on Gravity, available under the Creative Commons Attribution-ShareAlike (CC BY-SA) license. Read the full article: Wikipedia – Gravity. Happy sleeping! Learn more about your ad choices. Visit megaphone.fm/adchoices

You're listening to a Glassbox media podcast. What if I told you that most of the modern day self-help advice you've been hearing could actually make you worse? The key to a better life isn't about feel-good gimmicks that sound catchy. The Mentally Stronger Podcast gives you access to a licensed therapist who shares science-backed tools that will actually change your life. Hi, I'm Amy Morin, psychotherapist, mental strength trainer, and international best-selling author. In each episode, we cover research-back strategies, like how to stop relying on willpower and start creating habits for lasting change. And the five mental strength-building exercises you can do from your couch. I also speak to world-class experts like Dr. Nicole Kane, who shares how to permanently heal anxiety by addressing the root cause.

With over 200 episodes in our catalog, this podcast is for you if you're ready to crush self-doubt, conquer challenges, become stronger than ever with therapist-approved strategies that can change your life. Listen to Mentally Stronger with Therapist Amy Morin, wherever you get your podcasts. Welcome to the I Can't Sleep Podcast, where I read random articles to bore you to sleep with my soothing voice. I'm your host, Benjamin Boster. Today's episode is from a Wikipedia article titled Gravity. Gravity from Latin gravitus, meaning weight, or gravitation, is a natural phenomenon by which all things with mass or energy, including planets, stars, galaxies, and even light, are brought toward or gravitate toward one another.

On Earth, gravity gives weight to physical objects, and the moon's gravity causes the ocean-time. The gravitational attraction of the original gas-gous matter present in the universe caused it to begin coalescing, forming stars, and for the stars to group together into galaxies. So gravity is responsible for many of the large-scale structures in the universe. Gravity has an infinite range, although its effects become increasingly weaker on farther objects. Gravity is most accurately described by the general theory of relativity proposed by Albert Einstein in 1915,

which describes gravity not as a force, but as a consequence of the curvature of space-time caused by the uneven distribution of mass. The most extreme example of this curvature of space-time is a black hole, from which nothing not even light can escape once past the black hole's event horizon. However, for most applications, gravity is well approximated by Newton's law of universal gravitation, which describes gravity as a force which causes any two bodies to be attracted to each other, with the force proportional to the product of their masses, and inversely proportional to the square of the distance between them. Gravity is the weakest of the four fundamental interactions of physics,

approximately 10 to the 38th times weaker than the strong interaction, 10 to the 36th times weaker than the electromagnetic force, and 10 to the 29th times weaker than the weak interaction. As a consequence, it has no significant influence at the level of subatomic particles. In contrast, it is the dominant interaction at a macroscopic scale and is the cause of the formation, shape, and trajectory orbit of astronomical bodies. For example, gravity causes the Earth and the other planets to orbit the Sun. It also causes the moon to orbit the Earth, and causes the formation of tides, the formation and evolution of the

solar system, stars, and galaxies. The earliest instance of gravity in the universe, possibly in the form of quantum gravity, supergravity, or a gravitational singularity, along with ordinary space and time, developed during the Plank epic, up to 10 to the negative 43rd seconds after the birth of the universe, possibly from a primeval state, such as a false vacuum, quantum vacuum or virtual particle in a currently unknown manner. Attempts to develop a theory of gravity consistent with quantum mechanics, a quantum gravity theory, which would allow gravity to be united in a common mathematical framework,

a theory of everything, with the other three fundamental interactions of physics, are a current area of research. Archimedes discovered the center of gravity of a triangle. He also postulated that if the centers of gravity of two equal weights wasn't the same, it would be located in the middle of the line that joins them. The Roman architect and engineer Vitruvius in the Arcatura postulated that gravity of an object didn't depend on weight, but its nature. Ariabata first identified the force to explain why objects are not.

thrown out when the earth rotates. Bromagupta described gravity as an attractive force and used the term grutvacarchen for gravity. Modern work on gravitational theory began with the work of Galileo-Galai in the late 16th and 17th centuries. It is famous, though possibly apocryphal, experiment dropping balls from the Tower of Pisa, and later with careful measurements of balls ruling. down inclines. Galileo showed the gravitational acceleration is the same for all objects.

This was a major departure from Aristotle's belief that heavier objects have a higher gravitational acceleration. Galileo postulated air resistance as the reason that objects with less mass fall more slowly in an atmosphere. Galileo's work set the stage for the formulation of Newton's theory of gravity. In 1687, English mathematician Sir Isaac Newton published Principia, which hypothesizes the inverse square law of universal gravitation. In his own words, I deduced that the forces which keep the planets in their orbs must be reciprocally as the squares of their distances from the centers about which they revolve, and thereby compared the force requisite to keep the moon in her orb with the force of gravity of the surface of the earth,

and found them answer pretty nearly. Newton's theory enjoyed its greatest success when it was used to predict the existence of Neptune based on motions of Uranus that could not be accounted for by the actions of the other planets. calculations by both John Couch Adams and Urbane Laverier predicted the general position of the planet, and Laverier's calculations are what led John Gottfried Gaul to the discovery of Neptune. A discrepancy in Mercury's orbit pointed out flaws in Newton's theory. By the end of the 19th century, it was known that its orbit shows slight perturbations that could not be accounted for entirely under Newton's theory,

but all searches for another pertubing body, such as a planet orbiting the sun even closer than Mercury, had been fruitless. The issue was resolved in 1915 by Albert Einstein's new theory of general relativity, which accounted for the small discrepancy in Mercury's orbit. This discrepancy was the advance in the perihelion of Mercury of 42.98 arc seconds per century. Although Newton's theory has been superseded by Einstein's general relativity,

most modern non-relativistic gravitational calculations are still made using Newton's theory because it is simpler to work with, and it gives sufficiently accurate results for most applications involving sufficiently small masses, speeds, and energies. The equivalence principle explored by a succession of researchers including Galileo, Laurent, Eotvos, and Einstein, expresses the idea that all objects fall in the same way, and that the effects of gravity are indistinguishable from certain aspects of acceleration and deceleration. The simplest way to test the weak equivalence principle is to drop two objects of different masses or compositions in a vacuum and see whether they hit the ground at the same time.

Such experiments demonstrated that all objects fall at the same rate when other forces, such as air resistance and electromagnetic effects, are negligible. For sophisticated tests, use a torsion balance of a type invented by Eotvos. Satellite experiments, for example, STEP, are planned for more accurate experiments in space. Formulations of the equivalence principle include the weak equivalence, principle, the trajectory of a point mass and a gravitational field depends only on its initial position and velocity and is independent of its composition. The Einstein equivalence principle, the outcome of any local non-gravitational experiment in a freely falling laboratory, is independent of the velocity

of the laboratory and its location in space-time. The strong equivalence principle requiring both of the above. In general relativity, the effects of gravitation are ascribed to spacetime curvature instead of a force. The starting point for general relativity is the equivalence principle, which equates free fall with inertial motion and describes free-falling inertial objects as being accelerated relative to non-inertial observers on the ground. In Newtonian physics, however, No such acceleration can occur unless at least one of the objects is being operated on by a force. Einstein proposed that spacetime is curved by matter, and that free-falling objects are moving along locally straight paths in curved spacetime.

These straight paths are called geodesics. Like Newton's first law of motion, Einstein's theory states that if a force is applied in an object, it would deviate from a geodesic. For instance, we are no longer following geodesics while standing because the mechanical resistance of the Earth exerts an upward force on us, and we are non-inertial on the ground as a result. This explains why moving along the geodesics in space-time is considered inertial. Einstein discovered the field equations of general relativity, which relate the presence of matter and the curvature of space time and are named after him.

The Einstein field equations are a set of ten simultaneous nonlinear differential equations. The solutions of the field equations are the components of the metric tensor of space time. A metric tensor describes the geometry of space time. The geodesic paths for a space time are calculated from the metric tensor. Notable solutions of the Einstein field equations, include the Schwartzschild solution which describes space-time surrounding a spherically symmetric non-rotating uncharged massive object. For compact enough objects, this solution generated a black hole with a central singularity. For radial distances from

the center which are much greater than the Schwartzschild radius, the accelerations predicted by the Schwartzschild solution are practically identical to those predicted by Newton's theory of gravity. The Reisner Nordstrom solution in which the central object has an electrical charge. For charges with the geometrised length, which are less than the geometrised length of the mass of the object, the solution produces black holes with double event horizons. The Kerr-Newman solution for charged rotating massive objects. This solution also produces black holes with multiple event horizons. The cosmological Friedman-Lamator Robertson-Walker solution, which predicts the expansion of the universe. The tests of general relativity include the following. General relativity accounts for the

anomalous perihilion procession of mercury. The prediction that time runs lower at lower potentials, gravitational time dilation, has been confirmed by Pound-Rebka Experiment, 1959. the Half-Hale-Kedian experiment and the GPS. The prediction of the deflection of light was first confirmed by Arthur Stanley Eddington from his observations during the solar eclipse of 29 May 1919. Eddington measured starlight deflections twice those predicted by Newtonian capuscular theory in accordance with the predictions of general relativity. However, his interpretation of the results was later disputed,

More recent tests using radio interferometric measurements of quasars passing behind the sun have more accurately and consistently confirmed the deflection of light to the degree predicted by general relativity. See also gravitational lens. The time delay of light passing close to a massive object was first identified by Erwin I. Shapiro in 1964 in interplanetary spacecraft signals. Gravitational radiation has been indirectly confirmed through studies of binary pulsars. On 11th February 2016, the LIGO and Virgo collaborations announced the first observation of a gravitational wave. Alexander Friedman in 1920 found that Einstein equations have non-stationary solutions, even in the presence of the cosmological constant. In 1927, Georges Le Maitreuf showed that static solutions,

of the Einstein equations, which are possible in the presence of the cosmological constant, are unstable, and therefore the static universe envisioned by Einstein could not exist. Later in 1931, Einstein himself agreed with the results of Friedman and Lemaitre. Thus general relativity predicted that the universe had to be non-static. It had to either expand or contract. The expansion of the universe discovered by Edwin Hubble in 1929 confirmed this prediction. The theory's prediction of frame-dragging was consistent with the recent gravity probe B results. General relativity predicts that light should lose its energy when traveling away from massive bodies through gravitational redshift.

This was verified on Earth and in the solar system around 1960. In the decades after the publication of the theory of general relativity, it was realized that general relativity is incompatible with quantum mechanics. It is possible to describe gravity in the framework of quantum field theory, like the other fundamental interactions, such that the attractive force of gravity arises due to exchange of virtual gravitations. In the same way as the electromagnetic force arises from exchange of virtual protons. This reproduces general relativity in the classical limit. However, this approach

fails at short distances of the order of the plank length, where a more complete theory of quantum gravity or a new approach to quantum mechanics is required. Every planetary body, including the earth, is surrounded by its own gravitational field, which can be conceptualized with Newtonian physics as exerting an attractive force on all objects. Assuming a spherically symmetrical planet, the strength of this field at any given point above the surface is proportional to the planetary body's mass and inversely proportional to the square of the distance from the center of the body. The strength of the gravitational field is numerically equal to the acceleration of objects under its influence. The rate of acceleration of

falling objects near the Earth's surface varies very slightly depending on latitude, surface features such as mountains and ridges, and perhaps unusually high or low subsurface densities. For purposes of weights and measures, a standard gravity value is defined by the International Bureau of Wights and Measures under the International System of Units. according to Newton's third law, the Earth itself experiences a force equal in magnitude and opposite interaction to that which it exerts on a falling object. This means that the Earth also accelerates towards the object until they collide. Because the mass of the Earth is huge, however, the acceleration imparted to the Earth

by this opposite force is negligible in comparison to the object. If the object does not bounce after it has collided with the earth, each of them then exerts a repulsive contact force on the other, which effectively balances the attractive force of gravity and prevents further acceleration. The force of gravity on Earth is the resultant vector sum of two forces. A, the gravitational attraction in accordance with Newton's universal law of gravitation, and B, the same. centrifugal force, which results from the choice of an earthbound rotating frame of reference. The force of gravity is the weakest at the equator because of the centrifugal force caused by the Earth's rotation, and because points on the equator are furthest from the center of the Earth. The application of Newton's law of gravity has enabled the acquisition of much of the detailed information we have about the planets and the solar system, the mass of the sun, and details of

Quasars. Even the existence of dark matter is inferred using Newton's law of gravity. Although we have not traveled to all the planets nor to the sun, we know their masses. These masses are obtained by applying the laws of gravity to the measured characteristics of the orbit. In space, an object maintains its orbit because of the force of gravity acting upon it. Planets orbit stars, stars orbit galactic centers, galaxies orbit a center of mass and clusters, and clusters orbit in superclusters. The force of gravity exerted on one object by another is directly proportional to the product of those objects' masses, and inversely proportional to the square of the distance between them.

the earliest gravity, possibly in the form of quantum gravity, supergravity, or a gravitational singularity, along the ordinary space and time developed during the Planck epic, up to 10 to the negative 43rd seconds after the birth of the universe, possibly from a primal state, such as a false vacuum, quantum vacuum, or virtual particle, in a currently unknown manner.