enow.com Web Search

Search results

  1. Results from the WOW.Com Content Network
  2. Unity of opposites - Wikipedia

    en.wikipedia.org/wiki/Unity_of_opposites

    Anaximander posited that every element had an opposite, or was connected to an opposite (water is cold, fire is hot). Thus, the material world was said to be composed of an infinite, boundless apeiron from which arose the elements (earth, air, fire, water) and pairs of opposites (hot/cold, wet/dry). There was, according to Anaximander, a ...

  3. Second law of thermodynamics - Wikipedia

    en.wikipedia.org/wiki/Second_law_of_thermodynamics

    The second law of thermodynamics is a physical law based on universal empirical observation concerning heat and energy interconversions.A simple statement of the law is that heat always flows spontaneously from hotter to colder regions of matter (or 'downhill' in terms of the temperature gradient).

  4. List of materials properties - Wikipedia

    en.wikipedia.org/wiki/List_of_materials_properties

    A material property is an intensive property of a material, i.e., a physical property or chemical property that does not depend on the amount of the material. These quantitative properties may be used as a metric by which the benefits of one material versus another can be compared, thereby aiding in materials selection .

  5. Resonant ultrasound spectroscopy - Wikipedia

    en.wikipedia.org/wiki/Resonant_ultrasound...

    The natural frequency depends on the elasticity, size, and shape of the object—RUS exploits this property of solids to determine the elastic tensor of the material. The great advantage of this technique is that the entire elastic tensor is obtained from a single crystal sample in a single rapid measurement. [ 1 ]

  6. List of paradoxes - Wikipedia

    en.wikipedia.org/wiki/List_of_paradoxes

    Yablo's paradox: An ordered infinite sequence of sentences, each of which says that all following sentences are false. While constructed to avoid self-reference, there is no consensus whether it relies on self-reference or not. Opposite Day: "It is opposite day today." Therefore, it is not opposite day, but if you say it is a normal day it ...

  7. Negative thermal expansion - Wikipedia

    en.wikipedia.org/wiki/Negative_thermal_expansion

    Other materials that exhibit NTE behaviour include other members of the AM 2 O 8 family of materials (where A = Zr or Hf, M = Mo or W) and HfV 2 O 7 and ZrV 2 O 7, though HfV 2 O 7 and ZrV 2 O 7 only in their high temperature phase starting at 350 to 400 K. [7] A 2 (MO 4) 3 also is an example of controllable negative thermal expansion. Cubic ...

  8. Entropy (order and disorder) - Wikipedia

    en.wikipedia.org/wiki/Entropy_(order_and_disorder)

    Similarly, in a gas, the order is perfect and the measure of entropy of the system has its lowest value when all the molecules are in one place, whereas when more points are occupied the gas is all the more disorderly and the measure of the entropy of the system has its largest value. [10]

  9. Natural frequency - Wikipedia

    en.wikipedia.org/wiki/Natural_frequency

    Natural frequency, measured in terms of eigenfrequency, is the rate at which an oscillatory system tends to oscillate in the absence of disturbance. A foundational example pertains to simple harmonic oscillators, such as an idealized spring with no energy loss wherein the system exhibits constant-amplitude oscillations with a constant frequency.