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It’s Alive. Does anyone remember that film? It was about a mutant baby who ate people, though was sadly misunderstood, very poignant and a classic film should you be in need of a horror with depth..

Anyway I would like to introduce the Optineo Office Furniture Range.

A brand new range for Autumn 2006. Designed to compete with Dams International on Price and, manufactured across the Channel in Honfluer France, this product range has style and build quality far in excess of any other office furniture solution remotely close to this price point.

It has just been uploaded to our www.affableaardvark.com website and will shortly wander across to some of the other ecommerce sites.

Literature is still sparse as the sawdust is still in the air though, having seen this range at the factory preview earlier this year I can deliberate on the quality and value for money with much confidence.

Optineo – It’s Alive!

Gravitational potential

The above equation leads to the equation for the work done in moving a mass from a radius R to infinity, which is obtained by integrating the force of gravity over this distance:

U_g = \int_{R}^{\infty} {G m_1 m_2 \over r^2} dr = {G m_1 m_2 \over R}

The work done when moving a mass from infinity to a radius R is therefore

- {G m_1 m_2 \over R} and this is known as the gravitational potential energy.

Using the Earth as an example, the work done in moving a mass from the Earth’s surface to infinity is given by:

W = \int_{r_e}^{\infty} {G m m_e \over r^2} dr = {G m m_e \over r_e}

where G is the universal gravitational constant, m is the object’s mass, re is the Earth’s radius, and me is the Earth’s mass.

General relativity

Newton’s conception and quantification of gravitation held until the beginning of the 20th century, when the German-born physicist Albert Einstein proposed the general theory of relativity. In this theory Einstein proposed that inertial motion occurs when objects are in free-fall instead of when they are at rest with respect to a massive object such as the Earth (as is the case in classical mechanics). The problem is that in flat spacetimes such as those of classical mechanics and special relativity, there is no way that inertial observers can accelerate with respect to each other, as free-falling bodies can do as they each are accelerated towards the center of a massive object.

To deal with this difficulty, Einstein proposed that spacetime is curved by the presence of matter, and that free-falling objects are following the geodesics of the spacetime. More specifically, Einstein discovered the field equations of general relativity, which relate the presence of matter and the curvature of spacetime. The Einstein field equations are a set of 10 simultaneous, non-linear, differential equations whose solutions give the components of the metric tensor of spacetime. This metric tensor allows to calculate not only angles and distances between space-time intervals (segments) measured with the coordinates against which the spacetime manifold is being mapped but also the affine-connection from which the curvature is obtained, thereby describing the spacetime’s geometrical structure. Notable solutions of the Einstein field equations include:

General relativity has enjoyed much success because of how its predictions have been regularly confirmed. For example:

Specifics

Earth’s gravity

Southern Ocean gravity field

Enlarge

Southern Ocean gravity field

Main article: Gravity (Earth)

Every planetary body, including the Earth, is surrounded by its own gravitational field, which exerts an attractive force on any object that comes under its influence. This field is proportional to the body’s mass and varies inversely with the square of distance from the body. The gravitational field is numerically equal to the acceleration of objects under its influence, and its value at the Earth’s surface, denoted g, is approximately 9.81 m/s² or 32.2 ft/s². This means that, ignoring air resistance, an object falling freely near the earth’s surface increases in speed by 9.81 m/s (around 22 mph) for each second of its descent. Thus, an object starting from rest will attain a speed of 9.81 m/s after one second, 19.62 m/s after two seconds, and so on. According to Newton’s 3rd Law, the earth itself experiences an equal and opposite force to that acting on the falling object, meaning that the earth also accelerates towards the object. However, because the mass of the earth is huge, the acceleration produced on the earth by this same force is negligible.

Equations for a falling body

Under normal earth-bound conditions, when objects move owing to a constant gravitational force a set of kinematical and dynamical equations describe the resultant trajectories. For example, Newton’s law of gravitation simplifies to F = mg, where m is the mass of the body. This assumption is reasonable for objects falling to earth over the relatively short vertical distances of our everyday experience, but is very much untrue over larger distances, such as spacecraft trajectories, because the acceleration far from the surface of the Earth will not in general be g. A further example is the expression that we use for the calculation of potential energy of a body = mgh. This expression can be used only over small distances from the earth. Similarly the expression for the maximum height reached by a vertically projected body,”h = u^2/2g ” is useful for small heights and small initial velocities only. In case of large initial velocities we have to use the principle of conservation of energy to find the maximum height reached.

Gravity and astronomy

The discovery and application of Newton’s law of gravity accounts for the detailed information we have about the planets in our solar system, the mass of the sun, the distance to stars and even the theory of dark matter. Although we haven’t traveled to all the planets nor to the sun, we know their mass. The mass is 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 in clusters, and clusters orbit in superclusters.

Gravity versus gravitation

It is important to note, in some contexts, that gravitation is not gravity, per se. Gravitation is a phenomenon independent of any particular cause. Some theorize that it is possible for gravitation to exist without a force; according to general relativity, that is indeed the case. In common usage “gravity” and “gravitation” are either used interchangeably, or the distinction is sometimes made that “gravity” is specifically the attractive force of the earth, while “gravitation” is the general property of mutual attraction between bodies of matter. In technical usage, “gravitation” is the tendency of bodies to accelerate towards one another, and “gravity” is the force that some theories use to explain this acceleration.

Gravity was rather poorly understood until Isaac Newton formulated his law of gravitation in the 17th century. Newton’s theory is still widely used for many practical purposes, though for more advanced work it has been supplanted by Einstein‘s general relativity. While a great deal is now known about the properties of gravity, the ultimate cause of gravitation remains an open question and gravity remains an important topic of scientific research.

Applications

A vast number of mechanical contrivances depend in some way on gravity for their operation. For example, a height difference can provide a useful pressure differential in a liquid, as in the case of an intravenous drip or a water tower. The gravitational potential energy of water can be used to generate hydroelectricity as well as to haul a tramcar up an incline, using a system of water tanks and pulleys; the Lynton and Lynmouth Cliff Railway [1] in Devon, England employs just such a system. Also, a weight hanging from a cable over a pulley provides a constant tension in the cable, including the part on the other side of the pulley to the weight.

Examples are numerous: For example molten lead, when poured into the top of a shot tower, will coalesce into a rain of spherical lead shot, first separating into droplets, forming molten spheres, and finally freezing solid, undergoing many of the same effects as meteoritic tektites, which will cool into spherical, or near-spherical shapes in free-fall. Also, a fractionation tower can be used to manufacture some materials by separating out the material components based on their specific gravity. Weight-driven clocks are powered by gravitational potential energy, and pendulum clocks depend on gravity to regulate time. Artificial satellites are an application of gravitation which was mathematically described in Newton’s Principia.

Gravity is used in geophysical exploration to investigate density contrasts in the subsurface of the Earth. Sensitive gravimeters use a complicated spring and mass system (in most cases) to measure the strength of the “downward” component of the gravitational force at a point. Measuring many stations over an area reveals anomalies measured in mGal or microGal (1 gal is 1 cm/s^2. Average gravitational acceleration is about 981 gal, or 981,000 mGal.). After corrections for the obliqueness of the Earth, elevation, terrain, instrument drift, etc., these anomalies reveal areas of higher or lower density in the crust. This method is used extensively in mineral and petroleum exploration, as well as time-lapse groundwater modeling. The newest instruments are sensitive enough to read the gravitational pull of the operator standing over them.

Alternative theories

Historical alternative theories

Recent alternative theories

electrogavitics, magnetogravitics, gravity wave harmonics: electrogravitics: (eg. see books published by integrity research institute [2]) basic principle: electrons push, protons pull – using this principle, Nikola Tesla predicted gravitational repulsion in the 1880s, experimented with it in the 1890s, & designed the cigar shaped aircraft in the early 20th century. The Biefeld-Brown effect (1923) demonstrates this & Thomas Townsend Brown later designed asymetric capacitors suchas the disc shaped aircraft with a negatively electrical charged (repulsion) plate on the bottom & the positively charged (attraction) plate on top. gravity wave harmonics (eg. see book: How to Build a Flying Saucer and Other Proposals in Speculative Engineering, T.B. Pawlicki): gravity is a wave like any other – all the planets rest at harmonic intervals in a standing wave from the source of the wave, the sun.

See also

Notes

  • Note 1: Proposition 75, Theorem 35: p.956 – I.Bernard Cohen and Anne Whitman, translators: Isaac Newton, The Principia: Mathematical Principles of Natural Philosophy. Preceded by A Guide to Newton’s Principia, by I. Bernard Cohen. University of California Press 1999 ISBN 0-520-08816-6 ISBN 0-520-08817-4
  • Note 3: Max Born (1924), Einstein’s Theory of Relativity (The 1962 Dover edition, page 348 lists a table documenting the observed and calculated values for the precession of the perihelion of Mercury, Venus, and Earth.)

References

  1. ^ Clark, John, O.E. (2004). The Essential Dictionary of Science. Barnes & Noble Books. ISBN 0-7607-4616-8.
  1. Halliday, David, Robert Resnick; Kenneth S. Krane (2001). Physics v. 1. New York: John Wiley & Sons. ISBN 0-471-32057-9.
  2. Serway, Raymond A., Jewett, John W. (2004). Physics for Scientists and Engineers, 6th ed., Brooks/Cole. ISBN 0-534-40842-7.
  3. Tipler, Paul (2004). Physics for Scientists and Engineers: Mechanics, Oscillations and Waves, Thermodynamics, 5th ed., W. H. Freeman. ISBN 0-7167-0809-4.
  4. Jefimenko, Oleg D., “Causality, electromagnetic induction, and gravitation : a different approach to the theory of electromagnetic and gravitational fields“. Star City [West Virginia] : Electret Scientific Co., c1992. ISBN 0-917406-09-5
  5. Heaviside, Oliver, “A gravitational and electromagnetic analogy“. The Electrician, 1893.

Gravity without it I would weigh less!

One of our suppliers used to be a Dexion agent for all the shelving and racking systems and they are trying to bring to the publics awareness of how their pension scheme was stolen and how we all need to be vigilant.

We all need to be aware how safe our pensions. I have included links and text below from the famous Saga organisation;

Please sign the petition and advise your friends and relatives.

The data below has been copied from http://www.saga.co.uk/magazine/

Pension theft campaign

Did you lose some or all of your company pension? Dr Ros Altmann explains how you can join the fight

How you can help

Sign our petition
When Parliament reconvenes in the Autumn, we expect a debate on the Government’s refusal to compensate. We need you to help make sure that MPs vote for a proper compensation scheme – and urgently.
So if you want to help, please write to your MP now, whatever party he or she represents.

Tell them that when issue is debated in Parliament in the autumn, you expect them to stand up for our democracy and social justice and vote for a proper compensation scheme.

MPs have the power to hold Ministers to account and stop the Government from ignoring these good people They can defeat the Government in a vote and call for urgent measures to be introduced.

You can tell your MP to ensure our Parliamentary safeguards are respected and that this shameful injustice is remedied properly.

How to write to your MP

Your MP is your representative in Parliament, If you don’t know who your MP is, or how to contact them, visit the ‘Write to them ‘ website. That link has email addresses.

If you prefer to write a letter the address for any MP is (name of MP) House of Commons, London, SW1A 0AA

What to say

It is best that you write in your own words, rather than sending a standardised letter.

Here are some points you may want to include:

State clearly that you want your MP to put pressure on the Government, the Chancellor and the Secretary of State for Work and Pensions and the Pensions Minister to organise proper compensation quickly for those who have lost their pensions.
If the Parliamentary Ombudsman – the final arbiter in these matters – says the Government is guilty of maladministration, then the Government must accept that.

This is because if the Government can simply reject findings it does not like, it puts our entire democratic process at risk. If allowed to stand, ordinary citizens have no protection against politicians behaving wrongly.

Your MP must stand up now for basic democracy and not just toe a party line.

Ministers have their own high pensions paid for by the taxpayer, yet they are denying pensions to people who, – by trusting the system – are facing a retirement in penury.

Trust in pensions is being severely damaged by the sight of people who have saved all their lives, in schemes which Government said were safe and protected by law, but then lost their money.

This is not just a political issue, it is a matter of social justice. No other country has allowed this to happen, everywhere else had proper protections.

Justice delayed is justice denied. People are dying right now, without their pensions, and leaving widows or widowers with nothing. Your MP must ask for action quickly.

We will bring you the latest news and further campaigning options. For further information, or if you have been directly affected, see also the following sites.

Useful websites

Pensions Theft

Ros Altmann

Pensions Resource Group

Write to them

Pensions Ombudsman

Pension Pinched?