Or under some peoples' capability of understanding. ;-)

Cheers.

The problem with discovering the graviton is said to be that this would require much higher energies than any of the current particle accelerators can provide. That seems to be a good incentive, all by itself, to continue to expand our capabilities in this area. Discovery of the graviton might eventually make it possible to control and use the force of gravity, much as we currently do with electromagnetism.

The study of particle physics can be quite rewarding.
The electron was discovered by J. J. Thomson in 1897.
That discovery gave way to a multi-trillion dollar industry.
Finding the graviton will perhaps do the same.
Just think space exploration.

I claim that Gravity is not a force. It is an acceleration caused by the warped geometry of spacetime. Objects accelerate since Nature wants them to be in the lowest energy state as they fall into a gravity well.

Yes, that's what Relativity Theory says. What is it, though, that allows matter to warp space-time? Since Quantum Mechanics describes the other three fundamental forces, it seems that it should be able to cover gravity, as well. Relativity Theory and Quantum Mechanics are each incomplete descriptions of nature. The hope is to unify them somehow, someday, giving one complete theory that covers all four fundamental forces.

The biggest question is: what is dark matter?
Tullio

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They are both postulated by astronomers according to their observations. No physics experiment has found any trace of them, including the LHC results. Build a bigger accelerator? A doubtful choice.
Tullio

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It's the postulated Dark Matter that is the "glue" that keeps the stars in the galaxies together.
Dark Energy is very different and is a theory to explain the accelerating expansion of our Universe.

Katherine Freese said I think three years ago that Dark Matter would be found in a couple of years...
https://twitter.com/ktfreese
https://www.quantamagazine.org/why-the-best-place-to-find-dark-matter-may-be-in-a-rock-20190107/
No accelerator needed:)

I think Dark Matter will be found when the first fusion reactor reaches break even.
Tullio

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I think Dark Matter will be found when the first fusion reactor reaches break even.
Tullio

Oh! That soon:)

If you look at the solar system, you will find that the planets orbit the sun at a rate based on their distance from the sun, slower as the distance increases.
Therefore you might expect that the stars orbit the black hole at the center of the galaxy in a similar manner, but they don't they all travel at the same speed.
Can you explain why this happens, under our present day knowledge, without bringing in some other force or 'gravitational body'?

There may be no "Dark Matter" the spinning stars don't fly off because they are falling into a gravity well formed primarily by the massive black hole at the center of our galaxy. Also the center of mass would likely be very near the Galaxy center as well. Space would warp and the stars and gas would spiral in to the bottom of this well. How much matter is missing--is it likely to be the sum of all the masses of some, as yet, unfound "Particle" ?

Like I have punned before--if there is dark matter, lets send a probe and bring some of it back.

On another thought --how much energy would we have to ascribe to neutrinos to account for the apparent missing matter and energy.

Like I have punned before--if there is dark matter, lets send a probe and bring some of it back.

Sorry. Won't work. Dark Matter doesn't interact with light and any matter for that matter.

How much matter is missing--is it likely to be the sum of all the masses of some, as yet, unfound "Particle" ?

Dark matter makes up approximately 85 percent of the total mass in our known universe, but the mysterious substance does not interact with light, leaving scientists in the dark about the its precise nature. So, instead of viewing it, astronomers must rely on dark matter's gravitational pull on the normal matter, called baryonic matter, that makes up the stars, nebulas and planets we see in the night sky, as well as all the trees, rocks and people on Earth.

Black holes ruled out as universe's missing dark matter
https://www.sciencedaily.com/releases/2018/10/181002102723.htm

Neutrinos are ruled out as well. Perhaps neutrinos make up between 3% and 5% of the total dark matter mass.

Wm. your understanding of gravity and mine seem to coincide, Those posters who disagree need to go visit a LIGO, they work and do confirm what you have posted.

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Wm. your understanding of gravity and mine seem to coincide, Those posters who disagree need to go visit a LIGO, they work and do confirm what you have posted.

Hang on.
LIGO confirmed that gravitational waves exist that Einstein once predicted in his theory of General Relativity.
Nothing more.
Kip Thorne got a Nobel Prize for that discovery quite recently.
But the understanding of gravity is still a mystery!

LIGO is a huge machine that also costed a lot of money.
For what purpose? Yes, to verify scientific theories.

Gravity waves, now confirmed to exist, seem to indicate that gravitons probably exist, too. Photons convey electromagnetic energy. It seems reasonable that a particle, the graviton, conveys the force that allows matter to bend space-time.

This thread is starting getting off topic right know.
But what have the fact that the Earth has an iron core and the Moon has some have to do with understanding gravity?

Perhaps you should do a trip to the Alps like Schrödinger did with his girlfriend.
It only took a weekend to him to realise that a cat can be both alive and dead at the same time.
Then perhaps spend some time on a sailing boat to prove Dr. Avi Loeb wrong.

And also take some lessons in math as well.

Black holes ruled out as universe's missing dark matter

Not the mass of the black hole but rather the hyperbolic geometrical shape of the Gravity well that causes the swirling motion of the stars and gasses as they slowly spiral down to the bottom where the black hole resides.

Of course we can't see it if it is not there. If it is there and does not interact with light that does not preclude us from capturing a sample and bringing it back to not look at. Maybe we could weigh it ?[/url]https://www.youtube.com/watch?v=XTipCQxJ6Ak

Yes Ligo ostensibly detected gravity waves propagating a ripple in space time fabric. Whether or not there is the notion of a graviton--I am not so sure.

I always thought that gravity waves were too faint to be detected here on Earth due to vibrations and the sensitivity required of the interferometer.--I thought that they would be found when the Mirrors were moved to space. Apparently the collision of two black holes created enough of a disturbance to be detected.

We are a long way from CERN at LIGO, but ...
There has to be a force carrier for gravity. We have named it the graviton. Unlike the photon it will be a tensor. Until we have some naked gravitons in the right detectors we will not know what their decay products are, or if they even do decay. There are bound to be some very interesting things going on, perhaps an entire additional standard model built around them. Undoubtedly one or several of those things will be what we call dark matter today, and some others may well be dark energy.

We must look or we are dead as a species.