Looks Like Dark Matter Does Not Exist After All, Says New Study That Tries To Redefine Gravity
Any physicist, upon being asked about their take on the elusive Dark Matter, would probably call it a giant pain in the b*tt. Perhaps, rightly so -- after all, despite years of painstaking research on this mysterious matter that is believed to comprise approximately 27 percent of the universe's total mass and energy, dark matter still remains one of the biggest conundrums in the history of modern physics.
Such perplexing is the study of dark matter that some scientists have long wondered if it exists at all. And now, a new study by theoretical physicist Erik Verlinde of the University of Amsterdam is likely to embolden that school of thought (regarding a universe without dark matter) even more.
For the uninitiated, unlike normal matter, dark matter does not interact at all with the electromagnetic force, meaning it does not emit, absorb or reflect light, as noted by CERN. That, in turn, makes it incredibly hard to be detected. The only way scientists came to know about its alleged existence was because of its gravitational interactions with ordinary matter (which, by the way, happens to comprise only 6 percent of the known universe).
However, according to Verlinde's theory, our understanding of gravity could be fundamentally flawed in certain aspects which may have eventually misled the astrophysicist community worldwide to root for theories 'prophesying' the existence of dark matter.
Unlike the traditional view of gravity as one of the fundamental forces of nature, Verlinde thinks it is more of an emergent property of space. Emergence is basically the process by which nature builds something large and complicated using small and simple pieces. Any such substance built by the process of emergence generally tends to exhibit properties that its original constituents don't.
According to HyperPhysics, Verlinde's theory suggests that gravity is essentially a property of the universe that emerges from entropy -- the messy kid in the cosmos that has traditionally played a huge role in making the universe as it is today. Simply put, entropy is the measure of the degree of randomness or disorder in a system.
Verlinde calls his new theory concerning gravity, the entropic gravity theory. It predicts exactly the same amount of deviation in the rotation rates of stars in galaxies that is currently thought to be caused by dark matter. In other words, the theory of entropic gravity predicts that it is possible for our universe to behave the same way as it does without requiring any intervention from dark matter.
According to him, gravity comes into existence because of changes in the fundamental bits of information preserved in the very structure of space-time, meaning gravity is actually a consequence of entropy rather than being a fundamental force.
Worth noting, Verlinde has been working on this theory for quite some time now. In a 2010 article posted on Cornell University Library, the physicist showed how everyone's favorite Newton's law of gravity that explains pretty much everything from apple falling on the head of future geniuses to stars like our Sun orbiting the center of the Milky Way can be seen as a direct consequence of the underlying microscopic blocks.
In his new paper, Emergent Gravity and the Dark Universe [PDF], Verlinde tries to address the conundrum of dark energy using the concept of entropic gravity.
"We find that the elastic response of this 'dark energy' medium takes the form of an extra 'dark' gravitational force that appears to be due to 'dark matter'," writes Verlinde.
"So the observed dark matter phenomena is a remnant, a memory effect, of the emergence of spacetime together with the ordinary matter in it."