Does Time ever run backwards: Perhaps.

https://en.wikipedia.org/wiki/Relative_direction

Since definitions of left and right based on the geometry of the natural environment are unwieldy, in practice, the meaning of relative direction words is conveyed throughtradition, acculturation, education, and direct reference. One common definition of up and down uses gravity and the planet Earth as a frame of reference. Since there is a very noticeable force of gravity acting between the Earth and any other nearby object, down is defined as that direction which an object moves in reference to the Earth when the object is allowed to fall freely. Up is then defined as the opposite direction of down.
In most cases, up is a directionally oriented position generally opposite to that of the pull of gravity.

 

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What direction is the center of mass located?

 

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I wouldn't both him too much, he's rather emotional. Our friend has an axe to grind, and he wants to grind it on my head.

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Gullible...The indirect and possibly unintentional (on your part) inference is that scientists are fooling around. I don't think so. Few things things which cannot be questioned are the individual intelligence, integrity and ability of a mainstream scientist. But if many people, extremely intelligent, of very high character value with utmost and unblemished integrity, unwittingly or even circumstantially become part of a group and this group attains Mob psychology, then what? The mob behaviour cannot be attributed to individual, it is not even the reflection of individual character.....I am leaving it here for time being.

Coming back to your question, there is a well defined maths with respect to coordinate time from r = infinity upto EH, just google the Gravitational time dilation and you get a mathematical term inside the square root as (1-rs/r), so slowing down of time is mathematically there, reversal I do not know? This math does not give reversal. Honestly speaking my head hurts and I feel like stripping even reading/hearing the term in a scientific discourse "that time flows backwards". Scientists are very nice fellas, the Event Horizon is pushed around in such a way that whatever is inside, is absolutely out of perview of outside. Any scientific theory or law or lemma must be falifiable (testable) otherwise it is pure gibberish. Is the backward flow of time testable?

 

And more importantly there is no means for an observer to know the direction of flow of time. We see or observe things because light comes to us from that thing (light is omnidirectional in our universe), but theoretically can an observer falling (he cannot remain stationery) inside BH see anything? Just think, he cannot see anything.

 

No, please go on. You are revealing more every time you post.
This is a science forum, and of course any anti mainstream, supernatural, conspiracy, or paranormal claims will certainly need to run the gauntlet.
That they are unable to do this, is the indication that the claims are unscientific.

Although what exactly happens inside a BH is only inferred based on our laws of physics and GR outside, it is not beyond comprehension to see that time could reverse inside, considering that it stops at the speed of light which applies to the EH.
The aspect of assigning certain properties to the BH was raised in another thread and it was agreed by at least three experts, that based on current knowledge and GR, it was a reasonable aspect to do.

Here is an E-Mail from one of those experts......
Barry,

> The question being debated is simply, can we logically and reasonably assign angular momentum to a ring singularity/mass, and the spacetime within the EH proper?

A black hole is a place where space is falling faster than the speed of light.
http://jila.colorado.edu/~ajsh/insidebh/waterfall.html
The horizon is the place where space falls at the speed of light.
Inside the horizon, space falls faster than light. That is why
light cannot escape from a black hole.

Light emitted directly upward from the horizon of a black hole
stays there forever, barrelling outward at the speed of light
through space falling at the speed of light. It takes an infinite
time for light to lift off the horizon and make it to the outside
world. Thus when you watch a star collapse to a black hole,
you see it appear to freeze, and redshift and dim, at the horizon.

Since gravity also propagates at the speed of light, gravity,
like light, cannot escape from a black hole. The gravity you
experience from a black hole is the gravity of the frozen star,
not the gravity of whatever is inside the black hole.

> Or are we only allowed to assign angular momentum [frame dragging] to the ergopshere?

All the gravity, including the frame-dragging, is from the frozen star.

> Is it not logical that if we observe frame dragging, we should be able to assume that we have a rotating mass?

Indeed you have a rotating mass.

> And is not angular momentum conserved by the mass that has collapsed to within its Schwarzchild radius to give us a BH?

Yes.

> Other questions that have arisen are...
> Can we have massless Black holes held together by the non linearity of spacetime/gravity?

A black hole has mass, whatever it might have been formed from.

It is possible to form a black hole from gravitational waves
focussed towards each other. Gravitational waves propagate
in empty space, and locally cannot be distingished from empty space.
Nevertheless they do curve space, and do carry energy.

Hope this helps,
Andrew

 

Center of mass is a point, direction depends on the position of observer. Up/Dn L-R are general day today usage for ease of understanding, kind of lay man language. In science there is no up or no dn or no left or no right. Brief understanding of frames and coordinates will help.

 

No, that is totally wrong. See my previous link.
Gravity denotes the direction down.

 

He certainly cannot see anything in front of him [towards the Singularity] but he just as certainly can see back out towards and beyond the EH.

 

Paddoboy,

Pleae give the argument for : Is the Backward flow of time testable?

Pl engage yourself in a meaningful dialogue, I am sure you can.

 

This is nice. You are making a claim.

Please explain, how an observer falling towards singularity sees things towards EH and beyond.

 

Ok in what direction does the force of gravity travel in?

 

This is the most important question ever if you haven't realised.

 

Gravity and electromagnetism is traveling in opposite directions...but this is a mathematical illusion like space and time reversal. Hence a possible unification.

 

The EH denotes the escape velocity of the BH which is "c" and at which time stops from the PoV of an outside FoR.
It is scientifically reasonable to suggest that beyond the EH, time may reverse.
Not testable, but again a reasonable speculative hypothesis unlike the BNS hypothetical which totally violated GR.

Anyone falling towards the singularity [there only choice once inside] can of course see other matter/energy that has entered the BH from the EH....In fact he/she could see outside the EH, and see a Universe focused in a sphere directly above their head, due to lensing effects.
Of course like all my claims now and in the past, that I have had verified, I can also verify this one if you like?

 

This also why matter clumps and exerts a force on other mass bodies big or small even separated.

 

One youngboy was arguing with a seasoned Traveller, he was saying that Los Angeles to Narita (Tokyo) is via New York, Green Land, London etc. The seasoned traveller scratched his head and tried to tell him that it is not so. But over enthusiastic youngboy brought a reputable link showing the flat map of the Earth, on which right side was Los Angeles and Left side was Tokyo with all other in between places also on the map.....

So Paddoboy, thank you for providing those reputable links, I and many people read them and try to understand what is written over there, but I am afraid you are taking that "Direction of Gravity is Down' literally too close for comfort. Lack of foundation issues ??

 

'Scientifically Reasonable' is not an exact term, it is kind of oxymoron. Reaonableness seeks accommodation, but science has no place for accommodation as such.

Still an hypothesis or theory can be termed as reasonable if 1. It is testable directly or indirectly, 2. Not in contradiction with general experience or perception 3. Not in contradiction with established axioms.

You say that this time reversal is not testable....so you fail on the first count itself, I need not consider other counts.

 

Paddoboy,

Does Time ever run backwards: Perhaps

It gives me a feeling that you have sensationalised with this heading.

The paper talks of 'Thermodynamic Time', you ignored this Thermodynamic aspect, why?

You should read about Noble Laurate Prigogine and his work wherein he suggests that maximization of Entropy can be stopped or reversed in certain chemical set ups....Many scientists associate arrow of time with the increase in Entropy, thus leading to a concept called Thermodynamic Time.

All this terms as scientifically reasonable, past etc seems to be over exaggeration by you on this thread, without even understanding the implication of the paper and its title.

 

Paddoboy

Claim that a falling observer can see towards EH, is not correct. Imagine a photon falling towards r = 0 on a radial line, so if at all it can see anything towards EH, it can see only one more photon on its radial line...quite a view indeed. Secondly spacetime inside EH falls at a speed at c or higher towards singularity. Now if your ref frame which is falling is at halfway through, then please tell how a photon which is at EH will be observed by this falling reference, because then only your ref can see.