Tuesday, May 31, 2011

Words to Lose and Their Replacements

1) Philosophy <=== replace with "Logic"

2) Physicist <=== replace with "Realist" , also Physics with "Reality"

3) Doctor <=== replace with "Expert"

Therefore, instead of a PhD in Physics getting a "Doctor of Philosophy in Physics" they would rather earn the exalted and well-earned title of "Expert in Logic of Reality."  Much more descriptive of what they actually are. Well, the good ones, anyway.

4-7) Smart, Stupid, Idiot, Dumb, Dumbarse, Moron, etc. <==== Replace with "Knowledgeable", "Ignorant", "Intelligent", Unintelligent"

Well as far as 4-7 are concerned, I must confess I slip at times and use those words as well. If I do however, you can be sure it's because I'm really, truly pissed ("upset").

Have a nice ("enjoyable") day. 


Monday, May 30, 2011

Casimir Effect

Casimir forces on parallel plates

In quantum field theory, the Casimir effect and the Casimir-Polder force are physical forces arising from a quantized field. The typical example is of two uncharged metallic plates in a vacuum, placed a few micrometers apart, without any external electromagnetic field. In aclassical description, the lack of an external field also means that there is no field between the plates, and no force would be measured between them.[1] When this field is instead studied using quantum electrodynamics, it is seen that the plates do affect the virtual photonswhich constitute the field, and generate a net force[2]—either an attraction or a repulsion depending on the specific arrangement of the two plates. Although the Casimir effect can be expressed in terms of virtual particles interacting with the objects, it is best described and more easily calculated in terms of the zero-point energy of a quantized field in the intervening space between the objects. This force has been measured, and is a striking example of an effect purely due to second quantization.[3][4] However, the treatment of boundary conditions in these calculations has led to some controversy. In fact "Casimir's original goal was to compute the van der Waals force betweenpolarizable molecules" of the metallic plates. Thus it can be interpreted without any reference to the zero-point energy (vacuum energy) orvirtual particles of quantum fields.[5]
Dutch physicists Hendrik B. G. Casimir and Dirk Polder proposed the existence of the force and formulated an experiment to detect it in 1948 while participating in research at Philips Research Labs. The classic form of the experiment, described above, successfully demonstrated the force to within 15% of the value predicted by the theory.[6]
Because the strength of the force falls off rapidly with distance, it is only measurable when the distance between the objects is extremely small. On a submicrometre scale, this force becomes so strong that it becomes the dominant force between uncharged conductors. In fact, at separations of 10 nm—about 100 times the typical size of an atom—the Casimir effect produces the equivalent of 1 atmosphere of pressure (101.325 kPa), the precise value depending on surface geometry and other factors.[7]
In modern theoretical physics, the Casimir effect plays an important role in the chiral bag model of the nucleon; and in applied physics, it is significant in some aspects of emerging microtechnologies and nanotechnologies.[8]



Sunday, May 29, 2011


Minus the celibacy thing (to each their own) I totally love this guy. The West has damed little knowledge of India, but THIS was one of the greatest men of all time. 

Ramakrishna (Bengali: রামকৃষ্ণ পরমহংস Ramkṛiṣṇo Pôromôhongśo) (February 18, 1836 – August 16, 1886), born Gadadhar Chattopadhyay[2] (Bengaliগদাধর চট্টোপাধ্যায় Gôdadhor Chôţţopaddhae), was a famous mystic of 19th-century India.[3] His religious school of thought led to the formation of the Ramakrishna Mission by his chief disciple Vivekananda[4][5][6][7] – both were influential figures in theBengali Renaissance[8] as well as the Hindu renaissance during the 19th and 20th centuries.[9][10][11] Many of his disciples and devotees believe he was an Avatar or incarnation of God.[12] He is also referred as "Paramahamsa" by his devotees, as such he is popularly known as Ramkrishna Paramhansa.
Ramakrishna was born in a poor Brahmin Vaishnava family in rural Bengal. He became a priest of the Dakshineswar Kali Temple, dedicated to the goddess Kali, which had the influence of the main strands of Bengali bhakti tradition.[2] His first spiritual teacher was an ascetic woman skilled in Tantra and Vaishnava bhakti.[13] Later an Advaita Vedantin ascetic taught him non-dual meditation, and according to Ramakrishna, he experienced nirvikalpa samadhi under his guidance. Ramakrishna also experimented with other religions, notably Islam and Christianity, and said that they all lead to the same God.[2] Though conventionally uneducated, he attracted the attention of the middle class and numerous Bengali intellectuals.[citation needed]



Saturday, May 28, 2011

Entropic Gravity

Eric Verlinde

Verlinde's statistical description of gravity as an entropic force leads to the correct inverse square distance law of attraction between classical bodies.

Entropic gravity is a hypothesis in modern physics that describes gravity as an entropic force; not a fundamental interaction mediated by a particle, but a probabilistic consequence of physical systems' tendency to increase their entropy.


The probabilistic description of gravity has a history that goes back at least to Richard Feynman in the early 1960's,[1] and to research on black hole thermodynamics by Bekenstein and Hawking in the mid-1970s. These studies suggest a deep connection between gravity and thermodynamics, which describes the behavior of heat and gases. In 1995, Jacobson demonstrated that the Einstein equations describing relativistic gravitation can be derived by combining general thermodynamic considerations with the equivalence principle.[2] Subsequently, other physicists began to explore links between gravity and entropy.[3][4]

Erik Verlinde's theory

In 2009, Erik Verlinde disclosed a conceptual theory that describes gravity as an entropic force.[5] On January 6, 2010 he published a preprint of a 29 page paper titled On the Origin of Gravity and the Laws of Newton.[6] (It was published in April 2011).[7] Reversing the logic of over 300 years, it argued that gravity is a consequence of the laws of thermodynamics. This theory combines the thermodynamic approach to gravity with Gerardus 't Hooft's holographic principle. If proven correct, this implies gravity is not a fundamental interaction, but anemergent phenomenon which arises from the statistical behavior of microscopic degrees of freedom encoded on a holographic screen. The paper drew a variety of responses from the scientific community. Andrew Strominger, a string theorist at Harvard said “Some people have said it can’t be right, others that it’s right and we already knew it — that it’s right and profound, right and trivial."[8]
Verlinde's article also attracted a large amount of media exposure,[9][10] and led to immediate follow-up work in cosmology,[11][12] the dark energy hypothesis,[13] cosmological acceleration,[14][15] cosmological inflation,[16] and loop quantum gravity.[17] Also, a specific microscopic model has been proposed that indeed leads to entropic gravity emerging at large scales.[18]


Verlinde’s theory is criticized [19] on the basis that it fails to reproduce gravitational bound states of neutron observed in the experiments with ultracold neutrons[20]

See also


  1. ^ R.P. Feynman, The Character of Physical Law (Messenger Lectures, 1964): Lecture 2 on The Relation of Mathematics to Physics; Feynman's attempt at a statistical description of gravity starts 7 minutes into this video clip
  2. ^ Jacobson, Theodore (4 April 1995). "Thermodynamics of Spacetime: The Einstein Equation of State". Phys.Rev.Lett.75:1260-1263,1995 75 (7): 1260–1263. arXiv:gr-qc/9504004.Bibcode 1995PhRvL..75.1260Jdoi:10.1103/PhysRevLett.75.1260.
  3. ^ Padmanabhan, Thanu (26 November 2009). "Thermodynamical Aspects of Gravity: New insights". Rep. Prog. Phys. 73 (2010)01 73 (4): 6901. arXiv:0911.5004Bibcode2010RPPh...73d6901Pdoi:10.1088/0034-4885/73/4/046901.
  4. ^ Mok, H.M. (13 August 2004). "Further Explanation to the Cosmological Constant Problem by Discrete Space-time Through Modified Holographic Principle".arXiv:physics/0408060 [physics.gen-ph].
  5. ^ van Calmthout, Martijn (12 December 2009). "Is Einstein een beetje achterhaald?" (in Dutch). de Volkskrant. Retrieved 6 September 2010.
  6. ^ Verlinde, Eric (6 January 2010). "Title: On the Origin of Gravity and the Laws of Newton". arXiv:1001.0785 [hep-th].
  7. ^ E.P. Verlinde. "On the Origin of Gravity and the Laws of Newton". JHEP 04, 29 (2011)doi:10.1007/JHEP04(2011)029.
  8. ^ Overbye, Dennis (July 12, 2010). "A Scientist Takes On Gravity"The New York Times. Retrieved 6 September 2010.
  9. ^ The entropy force: a new direction for gravityNew Scientist, 20 January 2010, issue 2744
  10. ^ Gravity is an entropic form of holographic informationWired Magazine, 20 January 2010
  11. ^ Fu-Wen Shu; Yungui Gong (2010). "Equipartition of energy and the first law of thermodynamics at the apparent horizon". arXiv:1001.3237 [gr-qc].
  12. ^ Rong-Gen Cai; Li-Ming Cao; Nobuyoshi Ohta (2010). "Friedmann Equations from Entropic Force". Phys. Rev. D 8101(R) (2010) 81 (6). arXiv:1001.3470Bibcode2010PhRvD..81f1501Cdoi:10.1103/PhysRevD.81.061501.
  13. ^ It from Bit: How to get rid of dark energy, Johannes Koelman, 2010
  14. ^ Easson; Frampton; Smoot (2010). "Entropic Accelerating Universe". Phys.Lett.B696:273-277,2011 696 (3): 273–277. arXiv:1002.4278Bibcode 2011PhLB..696..273E.doi:10.1016/j.physletb.2010.12.025.
  15. ^ Yi-Fu Cai; Jie Liu; Hong Li (2010). "Entropic cosmology: a unified model of inflation and late-time acceleration". Phys.Lett.B 690:213-219,2010 690 (3): 213–219. arXiv:1003.4526.Bibcode 2010PhLB..690..213Cdoi:10.1016/j.physletb.2010.05.033.
  16. ^ Yi Wang (2010). "Towards a Holographic Description of Inflation and Generation of Fluctuations from Thermodynamics". arXiv:1001.4786 [hep-th].
  17. ^ Lee Smolin (2010). "Newtonian gravity in loop quantum gravity". arXiv:1001.3668 [gr-qc].
  18. ^ Jarmo Mäkelä (2010). "Notes Concerning "On the Origin of Gravity and the Laws of Newton" by E. Verlinde (arXiv:1001.0785)". arXiv:1001.3808 [gr-qc].
  19. ^ Kobakhidze, Archil (15 January 2011). "Gravity is not an entropic force". Phys. Rev. D83: 021502,2011 83 (2): 021502(3 pages). arXiv:[hep-th arXiv:1009.5414 [hep-th]]. Bibcode2011PhRvD..83b1502Kdoi:10.1103/PhysRevD.83.021502.
  20. ^ Nesvizhevsky, V.V., et al. (17 January 2002). "Quantum states of neutrons in the Earth's gravitational field". Nature 415: 297-299. Bibcode 2002Natur.415..297N.doi:10.1038/415297a.

]Further reading