A team led by students probes the mass-radius relation of white dwarf stars, observing in their data evidence of quantum mechanics and Einstein’s theory of general relativity.
This puzzling relationship between a white dwarf’s mass and size, called the mass-radius relation, was first theorized by Nobel Prize-winning astrophysicist Subrahmanyan Chandrasekhar in the 1930s. Now, a team of Johns Hopkins astrophysicists has developed a method to observe the phenomenon itself using astronomical data collected by the Sloan Digital Sky Survey and a recent dataset released by the Gaia Space Observatory. The combined datasets provided more than 3,000 white dwarfs for the team to study.
A report of their findings, led by Hopkins senior Vedant Chandra, is now published in The Astrophysical Journal.
Dear Ayaz Mohmood Dar
General relativity pronounced for one galaxy universe and based on indivisible atomic size not for quantum mechanics, therefore QM can not interact with GTR.
On the other hand, GR is not strong theory to apply it for over billions of galaxies universe with over trillion solar system while it is not even working with our small solar system.
Mr. Chandrasekhar got his Nobel Prize for some other thing (BH and vanishing suns, and light relation) in addition, The perception of knowing stars still is very unknown.
Our well organized Universe with billions of galaxies can not be result of four dumb forces of the big bang to put everything in a right manner.
Article How the Quantum Universe Works
regards.
Javad Fardaei ,
You may be confusing your Chandrasekhar with the one to which this discussion thread question is referring, as follows:
" Chandrasekhar Limit
The Chandrasekhar limit (/tʃʌndrəˈseɪkər/) is the maximum mass of a stable white dwarf star. The currently accepted value of the Chandrasekhar limit is about 1.4 M☉ (2.765×10³⁰ kg). White dwarfs resist gravitational collapse primarily through electron degeneracy pressure (compare main sequence stars, which resist collapse through thermal pressure). The Chandrasekhar limit is the mass above which electron degeneracy pressure in the star's core is insufficient to balance the star's own gravitational self-attraction. Consequently, a white dwarf with a mass greater than the limit is subject to further gravitational collapse, evolving into a different type of stellar remnant, such as a neutron star or black hole. Those with masses up to the limit remain stable as white dwarfs. "
Best wishes.
Some results of GR related to gravitation , match with results provides from Quantum Physics and this has been experimentally verified. This does not mean that GR and QM can be unified, it will never happen, gravitation and electrodynamics together will not be a merge of GR and QM, to think about in this way blocks every progress in unification.
GR describes spacetime. In this context, gravity is a derived force – particles “feel” nothing, they just stay in their own spacetime bubble which is shaped by other spacetime bubbles. QM describes the other forces. It is open to question if these are derived forces or fundamental ones, i.e. if these “forces” are merely disturbances in other fields or “bubbles”.
The manifest disparity between the observed behaviour of gravity, the elusive nature of “dark matter”, the dark energy problem and quantum entanglement show that we are nowhere near the “theory of everything”.
There is no such spacetime exist. Nothing in the universe is working mechanics.
https://www.academia.edu/43351041/How_the_Quantum_Universe_Works
Dear Sydney Ernest Grimm ,
>
there are experiments which tested succesfully GR but GR is not based experimentally, is not found with a constructivist approach.
The main point is that gravitation is not at all harmonized with electrodynamics, we do not really need to disturb quantum Phyiscs but already EM is sufficient.
the perspective is not very difficult to present. The Lorentz Invariance does not hold it is an approximation valid only in accelerators...
In fact the Lorentz Transformations unfortunately do not reduce to classical physics in general
Preprint THE LORENTZ TRANSFORMATIONS AT LOW SPEEDS DO NOT REDUCE TO T...
unless at small dimensions where the speed of light becomes a quantity which can be considered so huge that delays are negligible. We have to go deeper in what LT actually provide us and for this reason you can have a look at
Preprint THE DOPPLER EFFECT IN ACCELERATED MOTION, RELATION AT HIGHER ORDERS
The relativity of simultaneity, at the base of SR, is an effect which occurs only in particular cases.
What GR and SR have so far presented is a limited word based on particular symmetries occurring in particular cases, all based on the constancy of the speed of light.
Well the speed of light is not constant at all at least in gravitation:
Preprint SHAPIRO TIME-DELAY, Curved 4D space-time or Variable speed of light
Sydney Ernest Grimm
it is a constant locally and this descends from local measurements in IRFs, the Local Lorentz Invariance holds...
this sounds like a generic statement
>
these are evidences from experiments and applications of experimentally verified formulas. It does not really matter if somebody else did the same attempt, what is important is the fact.
Dear Sydney Ernest Grimm ,
main results of GR will be maintained, quite important to understand how gravitation works. Gravitation will eventually be unified with Quantum Phyiscs but it will mostly start from QP, space-time will evaporate. The challenge is to understand the role of the quantum vacuum which has little to do with space-time, a tool of calculation which as well misses the necessary degrees of freedom.
“The mass-radius relation is a spectacular combination of quantum mechanics and gravity, but it’s counterintuitive for us—we think that as an object gains mass, it should get bigger,” says Nadia Zakamska, an associate professor in the Department of Physics and Astronomy who supervised the student researchers. “The theory has existed for a long time, but what’s notable is that the dataset we used is of unprecedented size and unprecedented accuracy. These measurement methods, which in some cases were developed years ago, all of a sudden work so much better and these old theories can finally be probed.” https://scitechdaily.com/quantum-mechanics-and-general-relativity-come-together-astrophysicists-observe-long-theorized-quantum-phenomena/amp/
In general relativity, events are continuous and deterministic, meaning that every cause matches up to a specific, local effect. In quantum mechanics, events produced by the interaction of subatomic particles happen in jumps (yes, quantum leaps), with probabilistic rather than definite outcomes. https://www.theguardian.com/news/2015/nov/04/relativity-quantum-mechanics-universe-physicists
String theory attempts to unify all four forces, and in so doing, unify general relativity and quantum mechanics. ... String theory implies that the particles that comprise all the matter that you see in the universe—and all the forces that allow matter to interact—are made of tiny vibrating strands of energy. https://www.pbs.org/wgbh/nova/teachers/activities/3012_elegant_00.html
if string theory try to unify GR and QP will be useless since it is not possible to unify them. The Lorentz Symmetry is the main obstacle for unification, it gives issues to Gravitational theories and Quantum Mechanics. The postulated symmetry is one of the main issues.
Hi actually I discoveried the use of white dwarf theory to state the first paper on quantum gravity...already published...Article Spacetime Singularity & Poincare’s Balayage: Mathematical Re...
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