• WordNet 3.6
    • n impaction a sharp collision produced by striking or dashing against something
    • n impaction a disorder in which a tooth is so crowded in its socket that it cannot erupt normally
    • n impaction a disorder in which feces are impacted in the lower colon
    • n impaction the condition of being pressed closely together and firmly fixed
    • ***
Webster's Revised Unabridged Dictionary
  • Interesting fact: When the Galileo Probe entered Jupiter's atmosphere, it was traveling at a speed of 106,000 miles per hour. This is the fastest impact speed ever achieved by a man-made object.
    • Impaction An immovable packing; Med, a lodgment of something in a strait or passage of the body; as, impaction of the fetal head in the strait of the pelvis; impaction of food or feces in the intestines of man or beast.
    • Impaction (Surg) The driving of one fragment of bone into another so that the fragments are not movable upon each other; as, impaction of the skull or of the hip.
    • ***
Century Dictionary and Cyclopedia
  • Interesting fact: A squash ball moving at 150 kilometers per hour has the same impact of a .22 bullet
    • n impaction The act of impacting, or the state of being impacted; close fixation.
    • ***


  • John H. Holcomb
    John H. Holcomb
    “You must get involved to have an impact. No one is impressed with the won-lost record of the referee.”
  • Mal Pancoast
    “You get paid to impact the world, not be impacted by it.”
  • Walter Bagehot
    “Conquest is the missionary of valor, and the hard impact of military virtues beats meanness out of the world.”
  • P. W. Bridgman
    P. W. Bridgman
    “There is no adequate defense, except stupidity, against the impact of a new idea.”
  • Jim Rohn
    “Get around people who have something of value to share with you. Their impact will continue to have a significant effect on your life long they have departed.”
  • Dan Quayle
    “People that are really weird can get into sensitive positions and have a tremendous impact on history.”


Webster's Revised Unabridged Dictionary
L. impactio, a striking : cf. F. impaction,


In literature:

Consequently their wavering groups speedily gave way before the impact of the new, solid, central power.
"The Life of Napoleon I (Volumes, 1 and 2)" by John Holland Rose
Sandy grunted at the impact and sat bolt upright in bed before he was fairly awake.
"The Uphill Climb" by B. M. Bower
A chair, stamped into kindling, was hurled aside by the force of their impact.
"Mavericks" by William MacLeod Raine
One projectile smashed against the side of Oke Tor, and sent back the ringing sound of its tremendous impact.
"Children of the Mist" by Eden Phillpotts
Cope attempts to explain by the effects of impact and use among animals which frequented hard or swampy ground respectively.
"Darwinism (1889)" by Alfred Russel Wallace
The German vessel staggered under the force of the impact and seemed to reel backward.
"The Boy Allies with the Victorious Fleets" by Robert L. Drake
Twist, slewed by the impact half across the road, then perceived on which side he had been driving.
"Christopher and Columbus" by Countess Elizabeth Von Arnim
As I dash across the platform I hear the impact of the shack's feet against the steps as he boards.
"The Road" by Jack London
That dread of the future, with which the impact of death had filled him, was allayed.
"The Altar Steps" by Compton MacKenzie
Stronger impacts cause it to contract.
"The Whence and the Whither of Man" by John Mason Tyler
The recollection came at length, with the impact of a blow.
"The Taming of Red Butte Western" by Francis Lynde
The impact of the bullet against the stone could not fail to explode some of the caps.
"The Wings of the Morning" by Louis Tracy
The impact of heat on his hands and his face was different.
"The Time Traders" by Andre Norton
The bag and the head of the miner came into swift impact.
"The Yukon Trail" by William MacLeod Raine
The impact stresses depend so much on local conditions that it is difficult to fix what allowance should be made.
"Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3" by Various
He fell under the impact of so great a weight and the rifle which he could not use at close quarters was torn from his hands.
"The Border Watch" by Joseph A. Altsheler
Stover felt the impact on his own forehead and dropped his eyes uneasily.
"The Varmint" by Owen Johnson
But could the charming simplicity of their lives survive the impact of civilization?
"Impact" by Irving E. Cox
He winced sharply at the impact.
"The Judas Valley" by Gerald Vance
There was no impact, and there was no curtness; there was simply empty space.
"The Dark Tower" by Phyllis Bottome

In poetry:

Still sway the mad crowds to and fro!
I hear their groans and panting breath,
The hideous impacts, blow on blow,
The moans of those who are crushed to death!
"Out Of the Ranks" by John Lawson Stoddard
Why have they come to us from far off Albion?
What do they want? A distant booming sound -
And suddenly, the sea below the bastion
Rose boiling with the impact of the round.
"The Lieutenant" by Konstantin Simonov

In news:

The second exhibition focuses on the impact of Islam and the four routes converging on Mecca from the Arab world — from Egypt, the Yemen, Iraq, and Syria.
Nearly a year after dying of cancer, 11-year-old Fletcher Vines continues to make an impact.
What comes out of that meeting could also impact the future of the Big Ten/Pac-12 scheduling agreement.
STUART — Impact fees totaling as much as $1 million for three luxury auto dealerships planned on US 1 could kill the $20 million-plus project, the developer's representative said.
An innovative, blunt-impact device that instantly converts an officer's duty weapon into a less-lethal weapon system.
Bankhead Tunnel closure is sure to impact travel time.
Banking Industry Trends and IT Impacts.
Looking for a big-impact, low-care perennial for your landscape.
Barnyardgrass is a summer annual grass weed with a global impact on corn production.
Is rising/falling pressure impacting your body.
He noted that he has already raised $50,000 and the project will have a regional impact.
Chris Cherry, a University of Tennessee assistant professor in civil and environmental engineering, is shown in China, where he's researched the impact of lead emissions from green industries.
Prophet Fred, who can be seen daily on Impact Network, will minister for one service only.
NEWPORT BEACH, Calif (AP) — Notre Dame linebacker Manti Te'o has won the Lott IMPACT Trophy as the collegiate defensive player having the biggest impact on his team.
NEWPORT BEACH, Calif. Notre Dame linebacker Manti Te'o has won the Lott IMPACT Trophy as the collegiate defensive player having the biggest impact on his team.

In science:

The matching of super-clusters reconstructed in the calorimeter to hits in the pixel detector takes advantage of the fact that the energy-weighted average impact point of an electron and the bremsstrahlung photons it has radiated, is precisely where a non-radiating electron would have impacted.
The CMS High Level Trigger
The track impact parameter can be calculated either in the transverse view (2D impact parameter) or in three dimensions (3D impact parameter).
The CMS High Level Trigger
The tracks from a B decay should have a positive impact parameter, while those coming from the primary vertex have an impact parameter comparable to the experimental resolution.
The CMS High Level Trigger
The tag makes use of the track impact parameter signiflcance, which is deflned as the ratio of the value of the impact parameter with its uncertainty. A jet is tagged as a b-jet if there exist a minimum number of tracks with impact parameter signiflcance above a given threshold.
The CMS High Level Trigger
The DETF found the impact to be modest, and noted that the best data models actually determine the parameters so well themselves that the impact of additional priors was small.
Evaluating Dark Energy Probes using Multi-Dimensional Dark Energy Parameters
Electron impact ionisation was described by Seaton’s (1962) formula, while the electron impact excitation for the allowed bound-bound transitions was estimated with van Regemorter’s (1962) formula.
NLTE determination of the aluminium abundance in a homogeneous sample of extremely metal-poor stars
Sect. 6, investigates the impact of model errors on the tomographic phase reconstruction and Sect. 7 the impact of statistical errors.
Tomographic reconstruction for Wide Field Adaptive Optics systems: Fourier domain analysis and fundamental limitations
We conclude that this error term is impacting the tomographic reconstruction for large FoV configurations, and that either a good knowledge of the turbulence profile or the use of more GS to reduce the unseen frequencies area is required to limit the impact of this model error.
Tomographic reconstruction for Wide Field Adaptive Optics systems: Fourier domain analysis and fundamental limitations
The top plot in Fig. 12 shows the impact of an overestimation of the noise variance by a factor of 10 (Cb = 10Cb,t), and the bottom plot the impact of an underestimation of the noise variance by a factor of 10 (Cb = Cb,t/10).
Tomographic reconstruction for Wide Field Adaptive Optics systems: Fourier domain analysis and fundamental limitations
Statistical Impact The statistical impact on the data is measured through a number of statistical measures.
Evaluating the Impact of Missing Data Imputation through the use of the Random Forest Algorithm
However, the effects of time-variable renewable generation are beginning to impact this model, and the anticipated growth of wind and photo-voltaic (PV) generation at the utility and residential scale could severely impact the reliability of electrical power systems .
Message Passing for Integrating and Assessing Renewable Generation in a Redundant Power Grid
The dip in the average at larger horizontal impact values (for both data and Monte Carlo) is due to leakage for incomplete shower containment because the beam enters at a 5-degree impact angle.
A Tungsten / Scintillating Fiber Electromagnetic Calorimeter Prototype for a High-Rate Muon g-2 Experiment
In the standard definition of e and theoretical studies of an oblique impact , n is taken at the collision instant, that is, its reorientation during the impact is ignored.
Negative normal restitution coefficient for nanocluster collisions
The Poincar´e map, describing evolution from an impact to the next impact, is a natural tool to study vibro-impacting systems.
Simple models of bouncing ball dynamics and their comparison
The main difficulty with investigating impacting systems is in finding instant of the next impact what typically involves solving a nonlinear equation.
Simple models of bouncing ball dynamics and their comparison