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Douglas Harper's Etymology Dictionary

in physics, in reference to the work of German physicist Max Planck (1858-1947); such as Planck's constant, attested in English from 1901.

Planck (crater)

Planck is a huge lunar crater that is located in the southern hemisphere of the Moon, on the far side as seen from the Earth. It lies to the west of the walled plain Poincaré, another enormous formation only slightly larger than Planck. Both formations are larger than the walled plain Bailly, the largest crater on the near side. Lying across the southeast rim of Planck is the crater Prandtl, and to the northeast is Hildegard.

Like many lunar formations of this size, the outer rim has been damaged and eroded by lesser impacts, leaving a rugged ring of peaks and ridges that is notched and incised by small craters. The western rim of this walled plain is neatly overlain by a long lunar valley designated the Vallis Planck. Despite its name, however, this valley is actually radial to the walled plain Schrödinger to the south. The valley is about 451 kilometers in length.

The most notable feature on the interior floor of Planck is a multi-crater formation in the northern half consisting of Planck W, Planck Y, Planck Z, Planck B, and Planck A. The interior of Planck Y has been almost completely flooded by lava, leaving only a shallow perimeter. Likewise Planck Z has been flooded, although its rim is somewhat more prominent. The interior of Planck B is partly occupied by a concentric crater, and the floor contains several clefts. Parts of the remaining floor of Planck are level and smooth, at least in comparison with the surrounding terrain. This is particularly so in an arc along the northern inner wall. The southern half of the crater is somewhat more irregular, although still forming level plains in places. There are many small craters across the interior of Planck, and a few ghost-crater remnants.

Planck (spacecraft)

Planck was a space observatory operated by the European Space Agency (ESA) from 2009 to 2013, which mapped the anisotropies of the cosmic microwave background (CMB) at microwave and infra-red frequencies, with high sensitivity and small angular resolution. The mission substantially improved upon observations made by the NASA Wilkinson Microwave Anisotropy Probe (WMAP). Planck provided a major source of information relevant to several cosmological and astrophysical issues, such as testing theories of the early Universe and the origin of cosmic structure; as of 2013 it has provided the most accurate measurements of several key cosmological parameters, including the average density of ordinary matter and dark matter in the Universe.

The project was started around 1996 and was initially called COBRAS/SAMBA: the Cosmic Background Radiation Anisotropy Satellite/Satellite for Measurement of Background Anisotropies. It was later renamed in honour of the German physicist Max Planck (1858–1947), who derived the formula for black-body radiation.

Built at the Cannes Mandelieu Space Center by Thales Alenia Space, and created as a medium-sized mission for ESA's Horizon 2000 long-term scientific programme, Planck was launched in May 2009, reaching the Earth/Sun by July, and by February 2010 had successfully started a second all-sky survey. On 21 March 2013, the mission's first all-sky map of the cosmic microwave background was released, with an expanded release including polarization data in February 2015; final data analysis will continue into 2016.

At the end of its mission Planck was put into a heliocentric orbit and passivated to prevent it from endangering any future missions. The final deactivation command was sent to Planck in October 2013.

Planck (disambiguation)

Planck may refer to:

  • Max Planck (1858–1947), a German physicist considered to be the founder of quantum theory

Usage examples of "planck".

There was a Planck constant governing energy, an Avogadro number giving the number of molecules in a standard volume of gas, a Faraday in electricity and a Stefan-Boltzmann constant in radiation.

Core knew that the topography of the Void Which Binds could be modulated to transmit information instantaneously -- via the fatline -- but that this was a clumsy and destructive use of the medium of Planck space, rather like communicating across a continent by means of artificially produced earthquakes.

Core personae from human-based dataspheres to the Void Which Binds megasphere that the Core discovered that Planck space was not an empty universe.

Planck machine had found a counterexample, a number in the region of ten raised to the power eighty.

Garden-hose universe in which the radius of the circular dimension is shorter than the Planck length and is decreasing are absolutely identical to physical processes in which the circular dimension is longer than the Planck length and increasing!

Ord recited everything, including data accurate to a fraction of a femtosecond and to the brink of Planck space, and at every critical junction, he gave the names and failings of those gods most directly in charge.

As the radius of the circular dimension shrinks to the Planck length and, in the mold of general relativity, continues to shrink to yet smaller lengths, string theory insists upon a radical reinterpretation of what actually happens.

And so another possibility, should strings fail to be the final theory, is that they are one more layer in the cosmic onion, a layer that becomes visible at the Planck length, although not the final layer.

As our most powerful particle accelerators can reach energies only on the order of a thousand times the proton mass, less than a millionth of a billionth of the Planck energy, we are very far from being able to search in the laboratory for any of these new particles predicted by string theory.

Planck Center, where they endured yet another check of their new identification cards, this time with a wand that scanned both the barcode and the memory strip across the bottom edge so the security log could compare their contents.

His calculations indicated that the additional circular dimension might be as small as the Planck length, far shorter than experimental accessibility.

Rather than heading through the Planck length on to ever smaller size, the radius, as measured by the lightest string modes, decreases to the Planck length and then immediately starts to increase.

There are those physicists who are willing to note the problem, but happily go about using quantum mechanics and general relativity for problems whose typical lengths far exceed the Planck length, as their research requires.

As we shall now see, there is evidence that string theory once again sets a lower limit to physically accessible distance scales and, in a remarkably novel way, proclaims that the universe cannot be squeezed to a size shorter than the Planck length in any of its spatial dimensions.

Recall from Chapter 6—and the Price is Right example—that the "natural" energy scale of string theory is the Planck energy, and it is only through extremely delicate cancellations that string theory yields vibrational patterns with masses in the vicinity of those of the known matter and force particles.