Chinese scientists find evidence for speed of gravity

[KRAIT]

@fast Thanks for this post.

As for 4th point, I think, correct me if I am wrong, the cooling of earth's inner core and change in convective currents of molten material is the reason for earth slowing down. I think due to change in solidified and molten part of the earth is the reason. I may be wrong.

Also, can you tell me what is the effect of heavenly bodies because of the gravitational pull of them on time and space as they supposed to effect space time grid. I remember a documentary where they told about movement of huge planets and stars affecting space time.

Hope I asked the question clearly.

 

[Srinivas]

How can anything in the universe travel FASTER than the speed of light? This is a bunch of unmitigated nonsense!

Secondly, the gravitational equation says that the force of gravity is proportional to the product of the two masses (m1 and m2), and inversely proportional to the square of the distance (r) between their centers of mass. Mathematically speaking,

F=Gm1m2 / r2,

where G is called the Gravitational Constant. It has a value of 6.6726 x 10-11 m3 kg-1 s-2.

Gravity is present everywhere in space thanks to Dark Matter which is responsible for mass in the universe. More the mass of an object, more the gravity. Where does speed come in?

The 'speed' of gravity doesn't figure in this at all. If the Chinese are correct, then we need to revisit this formula too.

A significant fact, usually overlooked, is that Newton’s law of gravity does not involve time.

Gravity must act instantly for the planets to orbit the Sun in a stable fashion. If the Earth were attracted to where the Sun appears in the sky, it would be orbiting a largely empty space because the Sun moves on in the 8.3 minutes it takes for sunlight to reach the Earth. If gravity operated at the speed of light all planets would experience a torque that would sling them out of the solar system in a few thousand years.

So much for the so called 'speed' of gravity!

What you have mentioned in the formula F = G *(m1*m2)/ r2 is the quantity of the force of attaction experienced by earth or any other mass, to experience that, The mass should be in the gravitational field and so the, The rate at which the Gravitational field travels is called "Gravity waves".

To measure the speed of light we need at a large distance source which blinks so that the speed can be measured. Similarly to measure the speed of Gravity we need a pulsar which switches the gravitational field on and off (This is the scenario which the scientists are trying to Emulate on Earth).


Since Earth is already in Sun's gravitational field and cannot emulate the switching of on/off gravitational fields of Sun.

The research is how to do it??

 

[fast]

@<u><a href="http://www.defence.pk/forums/member.php?u=38354" target="_blank">fast</a></u> Thanks for this post.

As for 4th point, I think, correct me if I am wrong, the cooling of earth's inner core and change in convective currents of molten material is the reason for earth slowing down. I think due to change in solidified and molten part of the earth is the reason. I may be wrong.

Also, can you tell me what is the effect of heavenly bodies because of the gravitational pull of them on time and space as they supposed to effect space time grid. I remember a documentary where they told about movement of huge planets and stars affecting space time.

Hope I asked the question clearly.

You might be right about the reason on the Earth slowing down. There might be a number of reasons, and the molten core cooling could be one of them. Not sure there's conclusive evidence or experiments to show the real cause of the slow down. It's one of the open questions.

One of the ideas of general relativity is that an object's mass bends the space-time near it to cause a curvature depressed toward it. Since a star has huge mass, it severely bends the nearby space-time to curve toward it, causing passing by objects to "fall" toward it.

The beauty of Einstein's theory is that it can be explained in pure geometry. Geometry is simple to understand and visualize; it's just plane or volume. You can forget about gravity as a force, only considering the geometry of space-time and seeing gravity as the result of the alteration of the spacetime to curve toward the object.

Let's consider it on a 2-D plane since it's simpler. Let's say the universe is just a 2-D plane. Without any stars, it's just a flat plane. When an object rolls across the plane, it just goes straight. When a star appears, its mass "bends" the plane by creating a depression on the plane where the depression curved toward the star. See the video below.

When an object rolls pass the star, the depressed plane causes its path to curve toward the star. Remember there is no force to pull the object toward the star. The spacetime has been altered by the star's mass to structure a curvature that when the object moves, it just "rolls" along the curvature toward the star.

In 3-D space, we don't see the bended curvature of the spacetime. We only see the effect of it, i.e. an object being pulled toward another object. And we call that gravity.

The bigger the mass, the more depressed of the curvature on the plane, the more "eager" the object falls into the curvature. This translates into the stronger the gravitational pull.

Einstein basically explained what gravity is, as a curvature of spacetime near an object. Gravity is not a force. It's the mere effect of the bended curvature of spacetime. It can be called a pseudo-force. Just like centrifugal force is not a real force. It's a pseudo-force as a result of spinning object wanting to maintain its inertia going forward.

 

[KRAIT]

@fast Thanks a lot. I was talking of this same grid. Great explanation and video. You cleared many doubts and explained in language which finally made me understand this. The straight line motion and pseudo-force argument was great.

BTW Happy New Year.

 

[fast]

Following up on the previous post and in the context of the current experiment, the "speed of gravity" in term of general relativity is the speed at which the spacetime is being altered. When a star suddenly appears on the plane, it bends the structure of the spacetime near it. The changing of the structure takes time propagating out to far away place. That speed of propagation is the speed of gravity.

So the question is the change of the spacetime structure propagation instantaneous or is it at the speed of light? These experiments will find out.

 

[KRAIT]

Following up on the previous post and in the context of the current experiment, the "speed of gravity" in term of general relativity is the speed at which the spacetime is being altered. When a star suddenly appears on the plane, it bends the structure of the spacetime near it. The changing of the structure takes time propagating out to far away place. That speed of propagation is the speed of gravity.
So the question is the change of the spacetime structure propagation instantaneous or is it at the speed of light? These experiments will find out.

Gotcha. So the rate of change of space time structure is the issue. Huh....now I understood speed of gravity.

Can you me tell what has graviton to do with this phenomenon along with some insight on Quantum Gravity.

 

[fast]

Gotcha. So the rate of change of space time structure is the issue. Huh....now I understood speed of gravity.

Can you me tell what has graviton to do with this phenomenon along with some insight on Quantum Gravity.

Yes, the genius of Einstein is to use geometry to explain complicate stuff and make them easy to visualize. Even abstract stuff like gravity or speed of gravity can be understood easily in the context of geometry.

In case of graviton I don't know much about it. It's some hypothesis trying to fit gravity into quantum field theory, and it's not proven yet. General Relativity (GR) deals with huge objects like stars. Quantum Mechanics (QM) deals with subatomic particles. The remaining work is to unify the two so that we have one theory to explain things from subatomic to cosmological scales.

QM is somewhat incompatible with GR where QM defines the 4 fundamental forces including gravity as forces, whereas GR treats gravity only as a pseudo force. The 3 QM forces (electromagnetism, strong nuclear force, weak nuclear force) apply their forces via messenger particles. The force between two particles can be seen the exchange of these force carrier messenger particles. And particle experiments actually have proven the existence of them. So people think there must be a force messenger particle for gravity and they call it graviton. However, gravity is very weak that its effect can only be seen in large object and in subatomic level, it's extreme difficult to measure.

Graviton is something the QM people make up to make gravity consistent with the other 3 forces, and it's not proven yet.

 

[KRAIT]

@fast You cleared one of the major doubt I had. I read QM in engineering as it was necessary for semi-conductor physics.

BTW I worked on transfer of "thoughts" from one person to other and I thought is there a sub-atomic particle or wave related to it, as brain waves do exists. So may be these waves have dual characteristics and their exists a particle which is sent by sender to the receiver and it affects his mental state just like incident photons changes energy level of electrons and cause photo-electric effect. May be these particles on incidence creates electric current which is the carrier of neurological functions.

There has been some research especially secret research, one was done in Russia where a person has to focus on sending particular thoughts towards a person in sleep through concentrating so that he can alter his dreams.

Still very little research I have found on net and Mind control was also tried by CIA, along with development of drugs like LSD etc. which was part of this program.

But it was just a hypothesis and never got anywhere. Tried to apply QM but didn't have enough background in it.

 

[fast]

@fast You cleared one of the major doubt I had. I read QM in engineering as it was necessary for semi-conductor physics.

BTW I worked on transfer of "thoughts" from one person to other and I thought is there a sub-atomic particle or wave related to it, as brain waves do exists. So may be these waves have dual characteristics and their exists a particle which is sent by sender to the receiver and it affects his mental state just like incident photons changes energy level of electrons and cause photo-electric effect. May be these particles on incidence creates electric current which is the carrier of neurological functions.

There has been some research especially secret research, one was done in Russia where a person has to focus on sending particular thoughts towards a person in sleep through concentrating so that he can alter his dreams.

Still very little research I have found on net and Mind control was also tried by CIA, along with development of drugs like LSD etc. which was part of this program.

But it was just a hypothesis and never got anywhere. Tried to apply QM but didn't have enough background in it.

Interesting. Brain wave is usually just electromagnetic wave as a result of heat, as one concentrating on some thought, one part of his brain heats up and may give some particular shapes of electromagnetic wave. But it's probably very coarse to carry significant information among all the noises. And the distance of the wave is very short as heat dissipated into the surrounding environment quickly. If it's a viable communication mechanism, human would have long evolved to take advantage of it, but we instead have sight and sound for communication, so I don't know how far these mind reading research would go.

One area of "thought transfer" you can look into is the quantum entanglement of a particle since the entangled pair can affect each other at great distance.

 

[KRAIT]

One area of "thought transfer" you can look into is the quantum entanglement of a particle since the entangled pair can affect each other at great distance.

I think brain wave is due to electric current following through neuro transmitters. Of course it will dissipate energy to as chemicals are involved (brain chemistry), not sure how much. Frequency of brain waves is quite low. And you are spot on noise. Its said that earth's magnetic field is enough noise for brain waves. I am still confused over effect of earth's magnetic field on human brain, as brain waves are electromagnetic in nature.

I thought about Quantum entanglement but as I said, I don't have enough background in it and I couldn't dedicate more than six months in this as it was my Final year project.

My work was to propose a mathematical model but couldn't work using QM.

But there is interesting research being done on Consciousness by Dr. Roger Penrose, I think he is in Imperial College, London and he is also working on experimental verification of his theory.

Well that's a completely different topic.

I want to ask your opinion about one thing, our body contains of huge percentage of water.

As babies we are approximately 75 to 80% water and as we grow older this percentage decreases until the percentage is reduced to approximately 60 to 65% for men and 50 to 60% for women. The human brain is about 85% water and our bones are between 10 to 15% water.

Water in the Body

Like tides are caused due to gravitational pull of sea water by the Moon, does Sun, Moon and other planets affect the water in our body. Especially when a child is born, the water percentage is high and it starts decreasing, so the time and place of birth is important. It is widely discussed as a reason to make Astrology as a field of science.

What's your take on it ?

 

[fast]

Water in the Body

Like tides are caused due to gravitational pull of sea water by the Moon, does Sun, Moon and other planets affect the water in our body. Especially when a child is born, the water percentage is high and it starts decreasing, so the time and place of birth is important. It is widely discussed as a reason to make Astrology as a field of science.

What's your take on it ?[/B]

I'm not sure about the answer. I know where you are leading to. The Moon and Sun's gravitational pull might alter the baby's brain a bit, and might change his personality. But there are so many other factors than can affect the development of a baby. The temperature of the season, the water chemical of a locality, the food supplies, the parents, the money, social status, etc. Astrology as a field of science is a non-starter. Science requires repeatable and falsifiable experiments. Astrology tries to propose that birthday/time predicts one's future. There are simply too many factors affect one's future; all these noises simply drown out the birthday/time factors.

People turn to Astrology to predict their future. There are simple much better indicators than birthday/time to see if one will succeed in life. Genetic is a big indicator of health. Money is a big indicator for good upbringing, avoiding crimes, avoiding accidental death. Where you live, what parents you have, single or both parents, education, food, social status, etc are much better indicators for predicting future than astrology.

Edit: Fortune tellers are very good in reading people and give vague answers to what people want to hear. And predication is long time down the road that they really don't suffer the consequence of predicting something wrong. Unless they become full of themselves and start predicting the end of the Earth. We see how well that has gone.

 

[KRAIT]

@fast That I agree. OK, if we keep this fortune telling out, does this gravitational pull affect the brain. From physiology, brain chemistry and gravitational aspect of water fluids in brain and other heavenly objects including. Especially when Earth's constant changing position with respect to Sun and other planets and change in gravitational pull by each due to this.

No fortune mumbo jumbo. Is there any research from strictly scientific point of view ?

 

[fast]

@fast That I agree. OK, if we keep this fortune telling out, does this gravitational pull affect the brain. From physiology, brain chemistry and gravitational aspect of water fluids in brain and other heavenly objects including. Especially when Earth's constant changing position with respect to Sun and other planets and change in gravitational pull by each due to this.

No fortune mumbo jumbo. Is there any research from strictly scientific point of view ?

Like I said, it might have a little effect, but the other factors have much greater impact that it simply becomes background noise. E.g. food has much greater impact on one's health, personality, chemicals to the body and brain than gravitational pull.

I mean it's easy to do an experiment. Just have a set of rats born on each day of the month or the year. Feed them the same thing, maintain the same temperature, same lighting, etc, then see how long they live. Repeat it 100 times. Then you will see if birthday/time has impact on one aspect of one's life. Run experiments on different aspects.

One can do a phd thesis on this. At worst you can conclusively prove it has no relationship. At best you can become the prophet who brings astrology into modern science.

 

[KRAIT]

@fast That's why I didn't pick it up for my thesis. I didn't want to spend my precious years thinking and observing rats. I took other field.

 

[OrionHunter]

You need to brush up on your understanding of Astrophysics. The speed of light restriction only applies in the vacuum of space time. Space itself can certainly expand so fast that it causes two objects inside the space to move apart faster than the speed of light. Otherwise how do you think the universe can inflate into being in a fraction of a second right after the Big Bang? Guess what - the universe's space is now expanding in an ever faster speed and the outer galaxies will fly away in a faster than speed of light from us that we will not see them eventually.

Secondly, Newtonian understanding of gravity is so yester-century that I'm surprised you even brought it up in this discussion.

This so called 'speed' of gravity is a fact of life. Better learn about it before you spout ignorant nonsense next time.

The baloney you just wrote is breathtakingly idiotic!! Where did you get this nonsensical clap-trap that 'space itself can certainly expand so fast that it causes two objects inside the space to move apart faster than the speed of light'??? Have you even made the effort to read Einsteins Special Theory of Relativity? You're confusing the issue with 'relative' speed - points which moved faster than the speed of light but with respect to each other. But even here, they don't. Read on....

The speed of light is a constant relative to its source. No object can exceed the speed of light relative to its launch point.

Special Relativity also contends that velocities cannot be added together in the same way as they are in classical mechanics. For example if two objects move in opposite directions both at speed 0.8c from a common starting point, classical mechanics tells us that their velocity relative to each other should be 1.6c &#8211; 60% faster than light.

Special Relativity however uses a different formula namely:

Where v is the observed velocity and v1 and v2 are the velocities of particles 1 and 2 and are in opposite directions. Suffice to say that it comes from the time dilation and length contraction formulas, both of which come from the Lorentz Transform (LT). v1 and v2 are both 0.8c, so the observed velocity will be 0.976c, which is less than the speed of light.

The formula guarantees that v< c. Period. Any amount of your mumbo-jumbo cannot obfuscate this fact.