Vibration

Vibration is a mechanical phenomenon whereby oscillations occur about an equilibrium point. The word comes from Latin vibrationem ("shaking, brandishing") The oscillations may be periodic, such as the motion of a pendulum—or random, such as the movement of a tire on a gravel road.

Vibration can be desirable: for example, the motion of a tuning fork, the reed in a woodwind instrument or harmonica, a mobile phone, or the cone of a loudspeaker.

In many cases, however, vibration is undesirable, wasting energy and creating unwanted sound. For example, the vibrational motions of engines, electric motors, or any mechanical device in operation are typically unwanted. Such vibrations could be caused by imbalances in the rotating parts, uneven friction, or the meshing of gear teeth. Careful designs usually minimize unwanted vibrations.

The studies of sound and vibration are closely related. Sound, or pressure waves, are generated by vibrating structures (e.g. vocal cords); these pressure waves can also induce the vibration of structures (e.g. ear drum). Hence, attempts to reduce noise are often related to issues of vibration.

Home

A home is a dwelling-place used as a permanent or semi-permanent residence for an individual, family, household or several families in a tribe. It is often a house, apartment, or other building, or alternatively a mobile home, houseboat, yurt or any other portable shelter. Homes typically provide areas and facilities for sleeping, preparing food, eating and hygiene. Larger groups may live in a nursing home, children's home, convent or any similar institution. A homestead also includes agricultural land and facilities for domesticated animals. Where more secure dwellings are not available, people may live in the informal and sometimes illegal shacks found in slums and shanty towns. More generally, "home" may be considered to be a geographic area, such as a town, village, suburb, city, or country.

Transitory accommodation in a treatment facility for a few weeks is not normally considered permanent enough to replace a more stable location as 'home'. In 2005, 100 million people worldwide were estimated to be homeless.

Bad

Bad or BAD may refer to:

Acronyms

Films

Music

Good Good

"Good Good" is the fourth and final single from Ashanti's album The Declaration.

Song information

The accompanying video featured a cameo by Nelly. It premiered on July 17, 2008 on Yahoo!. The song contains samples of "Bennie and the Jets" by Elton John and "The Girl is Mine" from Michael Jackson.

On their 2009 collaboration album, We Are Young Money, Lead rapper Lil Wayne and his group says the line of "She got that good good" on the song "BedRock" which features Ashanti's former label mate R&B singer Lloyd.

Critical reception

Many album reviews named 'Good Good' a good single choice pick.

Music video

The music video was premiered in Yahoo Music and BET on July 17, 2008. It was directed by Melina Matsoukas . The video features an appearance by the rapper Nelly playing Ashanti's husband in the video. Ashanti described the video as "reality vs. fantasy vs. pin up. It's basically just saying that to keep your man, you know, you got the good-good, you look sexy, and you're still cleaning the house with your high-heels and your shades and your diamonds! (Laughs)"

Negative energy

Negative energy is a concept used in physics to explain the nature of certain fields, including the gravitational field and a number of quantum field effects.

In more speculative theories, negative energy is involved in wormholes which allow time travel and warp drives for faster-than-light space travel.

Gravitational energy

The strength of the gravitational attraction between two objects represents the amount of gravitational energy in the field which attracts them towards each other. When they are infinitely far apart, the gravitational attraction and hence energy approaches zero. As two such massive objects move towards each other, the motion accelerates under gravity causing an increase in the positive kinetic energy of the system. At the same time the gravitational attraction - and hence energy - also increase in magnitude. But the law of energy conservation requires that the net energy of the system does not change. This can only be resolved if the change in gravitational energy is negative, thus cancelling out the positive change in kinetic energy. Since the gravitational energy is getting stronger, this decrease can only mean that it is negative.