Cosmology: no need for strings to explain gravity (Introduction)

by David Turell , Friday, November 06, 2020, 20:24 (1479 days ago) @ David Turell

A whole new approach using particles, not strings:

https://phys.org/news/2020-11-gravity-theory.html

"For decades, most physicists have agreed that string theory is the missing link between Einstein's theory of general relativity, describing the laws of nature at the largest scale, and quantum mechanics, describing them at the smallest scale. However, an international collaboration headed by Radboud physicists has now provided compelling evidence that string theory is not the only theory that could form the link. They demonstrated that it is possible to construct a theory of quantum gravity that obeys all fundamental laws of physics, without strings. They described their findings in Physical Review Letters last week.

"When we observe gravity at work in our universe, such as the motion of planets or light passing close to a black hole, everything seems to follow the laws written down by Einstein in his theory of general relativity. On the other hand, quantum mechanics is a theory that describes the physical properties of nature at the smallest scale of atoms and subatomic particles. Though these two theories have allowed us to explain every fundamental physical phenomenon observed, they also contradict each other. As of today, physicists have severe difficulties to reconcile the two theories to explain gravity on both the largest and smallest scale.

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"...a new demonstration by theoretical physicists at Radboud University now shows that string theory is not the only way to do this. "We show that it is still possible to explain gravity using quantum mechanics without using the laws of string theory at all," says theoretical physicist Frank Saueressig. "We demonstrate that the idea that everything consists of point particles could still fit with quantum gravity, without including strings. This particle physics framework is also verified experimentally, for example, at the Large Hadron Collider (LHC) at CERN."

"'For scientists, this alternate theory is attractive to use because it has been extremely difficult to connect string theory to experiments. Our idea uses the physical principles that are already tested experimentally. In other words: nobody ever observed strings in experiments, but particles are things that people definitely see at LHC experiments. This lets us bridge the gap between theoretical predictions and experiments more easily.'"

Comment: Hurray!!! At last someone is doing critical thinking outside 40-50 year-old dead- end strings.