Science

Simulation suggests 68 percent of the universe may not actually exist

Simulation suggests 68 percent...
New computer simulations have questioned the existence of dark energy, a so-far theoretical force that is said to be driving the expansion of the universe
New computer simulations have questioned the existence of dark energy, a so-far theoretical force that is said to be driving the expansion of the universe
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A comparison of three models of universal expansion: top left, in red, is the Lambda-CDM model, including dark energy; middle, in blue, is the new Avera model, which accounts for the structure and doesn't require dark energy; and right, in green, is the original Einstein-de Sitter model, which also doesn't include dark energy
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A comparison of three models of universal expansion: top left, in red, is the Lambda-CDM model, including dark energy; middle, in blue, is the new Avera model, which accounts for the structure and doesn't require dark energy; and right, in green, is the original Einstein-de Sitter model, which also doesn't include dark energy
New computer simulations have questioned the existence of dark energy, a so-far theoretical force that is said to be driving the expansion of the universe
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New computer simulations have questioned the existence of dark energy, a so-far theoretical force that is said to be driving the expansion of the universe

According to the Lambda Cold Dark Matter (Lambda-CDM) model, which is the current accepted standard for how the universe began and evolved, the ordinary matter we encounter every day only makes up around five percent of the universe's density, with dark matter comprising 27 percent, and the remaining 68 percent made up of dark energy, a so-far theoretical force driving the expansion of the universe. But a new study has questioned whether dark energy exists at all, citing computer simulations that found that by accounting for the changing structure of the cosmos, the gap in the theory, which dark energy was proposed to fill, vanishes.

Published in 1915, Einstein's general theory of relativity forms the basis for the accepted origin story of the universe, which says that the Big Bang kicked off the expansion of the universe about 13.8 billion years ago. The problem is, the equations at work are incredibly complicated, so physicists tend to simplify parts of them so they're a bit more practical to work with. When models are then built up from these simplified versions, small holes can snowball into huge discrepancies.

"Einstein's equations of general relativity that describe the expansion of the universe are so complex mathematically, that for a hundred years no solutions accounting for the effect of cosmic structures have been found," says Dr László Dobos, co-author of the new paper. "We know from very precise supernova observations that the universe is accelerating, but at the same time we rely on coarse approximations to Einstein's equations which may introduce serious side effects, such as the need for dark energy, in the models designed to fit the observational data."

Dark energy has never been directly observed, and can only be studied through its effects on other objects. Its properties and existence are still purely theoretical, making it a placeholder plug for holes in current models.

The mysterious force was first put forward as a driver of the universe's accelerated expansion in the 1990s, based on the observation of Type Ia supernovae. Sometimes called "standard candles," these bright spots are known to shine at a consistent peak brightness, and by measuring the brightness of that light by the time it reaches Earth, astronomers are able to figure out just how far away the object is.

This research was instrumental in spreading acceptance of the idea that dark energy is accelerating the expansion of the universe, and it earned the scientists involved the Nobel Prize in Physics in 2011. But other studies have questioned the validity of that conclusion, and some researchers are trying to develop a more accurate picture of the cosmos with software that can better handle all the wrinkles of the general theory of relativity.

A comparison of three models of universal expansion: top left, in red, is the Lambda-CDM model, including dark energy; middle, in blue, is the new Avera model, which accounts for the structure and doesn't require dark energy; and right, in green, is the original Einstein-de Sitter model, which also doesn't include dark energy
A comparison of three models of universal expansion: top left, in red, is the Lambda-CDM model, including dark energy; middle, in blue, is the new Avera model, which accounts for the structure and doesn't require dark energy; and right, in green, is the original Einstein-de Sitter model, which also doesn't include dark energy

According to the new study from Eötvös Loránd University in Hungary and the University of Hawaii, the discrepancy that dark energy was "invented" to fill might have arisen from the parts of the theory that were glossed over for the sake of simplicity. The researchers set up a computer simulation of how the universe formed, based on its large-scale structure. That structure apparently takes the form of "foam," where galaxies are found on the thin walls of each bubble, but large pockets in the middle are mostly devoid of both normal and dark matter.

The team simulated how gravity would affect matter in this structure and found that, rather than the universe expanding in a smooth, uniform manner, different parts of it would expand at different rates. Importantly, though, the overall average rate of expansion is still consistent with observations, and points to accelerated expansion. The end result is what the team calls the Avera model.

"The theory of general relativity is fundamental in understanding the way the universe evolves," says Dobos. "We do not question its validity; we question the validity of the approximate solutions. Our findings rely on a mathematical conjecture which permits the differential expansion of space, consistent with general relativity, and they show how the formation of complex structures of matter affects the expansion. These issues were previously swept under the rug but taking them into account can explain the acceleration without the need for dark energy."

If the research stands up to scrutiny, it could change the direction of the study of physics away from chasing the ghost of dark energy.

The research was published in the Monthly Notices of the Royal Astronomical Society, and an animation below compares the different models.

Source: Royal Astronomical Society

The AvERA simulation of the expansion of the universe.

64 comments
Bob
Dark matter probably doesn't exist either. These dark theories were invented to prop up the "Big Bang" which didn't happen 13.8 billion years ago. More like 50-100 billion years ago if that theory has any validity at all. 13.8 billion years is not enough time for all the required expansion and generations of stars to form, reform, and burn out. Those cold burnt out stars which didn't reform after each generation most likely make up the un-observable dark matter. Theoretical physics is more philosophy than science. When an experiment can not be recreated to prove a theory, it just becomes a popular opinion and not a fact. Computer models are simply tools and never proof of anything. When I worked with x-ray spectra we used about five models for various tests. Which model gave the correct answer? The one that came closest to our preconceived assumptions.
XinhangShen
Please be aware that Einstein’s relativity theory has already been disproved both logically and experimentally (see “Challenge to the special theory of relativity” March 1, 2016 Physics Essays). The most obvious and indisputable evidence disproving special relativity is the existence of the absolute time shown by the universally synchronized clocks on the GPS satellites which are moving with huge velocities relative to each other (see Wikipedia on GPS: The GPS concept is based on time and the known position of specialized satellites. The satellites carry very stable atomic clocks that are synchronized with one another and to ground clocks.) while special relativity claims that time is relative (i.e. different on different reference frame) and can never be synchronized on clocks with relative velocities. That is, our current Big Bang Theory, Standard Model of Particle Physics and other relativistic spacetime based theories are wrong. We should completely abandon all these theories. Our visible universe is at least filled up with a fluid medium called aether, the waves of which is light or other electromagnetic waves. It is possible that more media coexist in the space too. Now we can measure the speed of aether through a modified Fizeau experiment shown on the paper mentioned above, which can be a starting point for the development of new physics theories for electromagnetic phenomena, particles, gravitation, cosmos, etc. Regarding kinematic time dilation on the clocks on the GPS satellites, some people claim that the clocks are synchronized only in the earth centered inertial reference frame, but not on the frame of each satellite. If this were true, then there were kinematic time dilation between the clocks of different satellites observed on a satellite frame and this time dilation would accumulate. After a period of running, the time dilation should be significant. Now comes the contradiction: the clock of which satellite should be adjusted as all these clocks are still perfectly synchronized in the earth centered inertial reference frame? Any correction on one clock would break the synchronization. Therefore, the answer is obvious: all the clocks are still synchronized and don't need to be corrected except for those random drifts. There is no kinematic time dilation at all. This conclusion has also been shown on Wikipedia: The GPS concept is based on time and the known position of specialized satellites. The satellites carry very stable atomic clocks that are synchronized with one another and to ground clocks. That is, all the clocks are not only synchronized relative to the ground clocks, but also relative to one another. Therefore, all clocks show the same absolute time and special relativity is wrong.
Douglas Bennett Rogers
Applying general relativity to the GPS problem results in a ten-fold increase in accuracy, from 10 meters to 1 meter.
f8lee
Huh - and I thought GPS did in fact take into account relativistic time changes - but if @XinhangShen read about it on Wikipedia, well then it must be true! So now I'm thinking that Earth really does sit on the back of a big turtle and everything else is bunk.
RaymondC.Porter
Could it be possible that there are pockets of empty space we can not detect or see? Like air bubbles in water are just pockets that take up space.
Grainpaw
Dark matter exists and is controlled by cats. How else could an eight-pound cat feel like it weighs fifty pounds when it is standing on your chest? This phenomenon has been completely ignored by modern physics.
JonathanWagner
Is an "Electric or Plasma universe" possible?
Tanstar
XinhangShen, mnay experiments have been done PROVING that time is affected by speed and gravity. Since we are using WikiPedia as our source today . . . https://en.wikipedia.org/wiki/Time_dilation
JimmyDavis
As much as science disdains the philosophical , all of their theories are purely philosophical . This article is no different . 68% ? LOL....pluck another number out of the air . All science is sure of is what can be tested on a very local level . There are too many holes in the standard model to plug up , and dark matter is but another philosophical plug .The true nature of the Universe will remain inscrutable ,and since it can not be rolled back for study, the mystery will remain . Quantum Entanglement may be observed but never understood .
TerryVasquez
Too many people getting paid too much money making up theories that won't change the price of rice in China ...