Black Holes part 2

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Message 1701820 - Posted: 15 Jul 2015, 17:14:17 UTC - in response to Message 1701817.  

I still have problems with the notion of spacetime. I understand Euclidean space with time as the fourth dimension, and I understand that time passes differently on something observed than for the observer. But combining space and time into a single manifold just to simplify theories, just seems wrong to me.

I think of it as a movie. An object/event occurs at a location and time. Even when you move beyond the time frame, the event is still where and when it was, even if it is no longer accessible to the observer. Describing a location/event without the time factor just doesn't give enough information, and since time is relative to to event/observer, it must be included.

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Message 1701821 - Posted: 15 Jul 2015, 17:16:08 UTC - in response to Message 1701819.  

I agree with that. Gravity is the distortion, but then how would its propagation be limited to the speed of light. Gravity is a property of mass.
Steve

The speed of light is the ultimate speed limit.
Nothing can travel faster not even information.

Then here is a question. Quantum entanglement. Supposedly particles are instantaneously connected over vast amounts of space. How would that not be a transfer of information?

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Message 1701824 - Posted: 15 Jul 2015, 17:31:17 UTC - in response to Message 1701817.  
Last modified: 15 Jul 2015, 17:33:17 UTC

I still have problems with the notion of spacetime. I understand Euclidean space with time as the fourth dimension, and I understand that time passes differently on something observed than for the observer. But combining space and time into a single manifold just to simplify theories, just seems wrong to me.

Chris, spacetime is a four dimensional Riemann manifold with a pseudo-euclidean metric. Its symmetry group is the Lorentz group SO(3,1). This is pure Einstein.
To go further, you need to know group theory. The symmetry group of the strong nuclear force is the SU(3) special unitary group, which gives rise to the quark idea of M.Gell-Mann and G.Zweig, today confirmed by the discovery of the pentaquark particle. But how do you connect the two Lie groups? This is an open question even today.
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Message 1701840 - Posted: 15 Jul 2015, 18:05:44 UTC - in response to Message 1701821.  
Last modified: 15 Jul 2015, 18:09:22 UTC

I agree with that. Gravity is the distortion, but then how would its propagation be limited to the speed of light. Gravity is a property of mass.
Steve

The speed of light is the ultimate speed limit.
Nothing can travel faster not even information.

Then here is a question. Quantum entanglement. Supposedly particles are instantaneously connected over vast amounts of space. How would that not be a transfer of information?
Steve

It's not transfer of information.
Once you make a measurement (i.e. interact meaningfully with one of the entangled particles) the entanglement is collapsed.
You can get more info here.
http://physics.stackexchange.com/questions/15282/quantum-entanglement-faster-than-speed-of-light
http://arxiv.org/abs/1401.5387
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Message 1701842 - Posted: 15 Jul 2015, 18:08:17 UTC

Thank you! I am totally enjoying this conversation.

Steve
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Message 1701844 - Posted: 15 Jul 2015, 18:10:08 UTC - in response to Message 1701821.  

I agree with that. Gravity is the distortion, but then how would its propagation be limited to the speed of light. Gravity is a property of mass.
Steve

The speed of light is the ultimate speed limit.
Nothing can travel faster not even information.

Then here is a question. Quantum entanglement. Supposedly particles are instantaneously connected over vast amounts of space. How would that not be a transfer of information?

Steve

One must define information before you can ask that question. Information may be such things as deformations in the electro-weak field and the gravity field. Spin states of a particle might not be included.
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Message 1701851 - Posted: 15 Jul 2015, 18:15:02 UTC - in response to Message 1701843.  

Brilliant explanation but that is at the very limits of my ability to understand things.

Even Einstein had problem. Perhaps not with the theory but with math required so he got help from a mathematian.
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Message 1701852 - Posted: 15 Jul 2015, 18:15:04 UTC - in response to Message 1701843.  

Brilliant explanation but that is at the very limits of my ability to understand things.

I cannot even understand my 1967 thesis whose title was "Simmetrie dinamiche". A Nuovo Cimento article based on it was titled "SU(n,1) representation for the harmonic oscillator". So don't despair.Even I cannot understand many things.
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Message 1701858 - Posted: 15 Jul 2015, 18:22:21 UTC - in response to Message 1701844.  

I agree with that. Gravity is the distortion, but then how would its propagation be limited to the speed of light. Gravity is a property of mass.
Steve

The speed of light is the ultimate speed limit.
Nothing can travel faster not even information.

Then here is a question. Quantum entanglement. Supposedly particles are instantaneously connected over vast amounts of space. How would that not be a transfer of information?

Steve

One must define information before you can ask that question. Information may be such things as deformations in the electro-weak field and the gravity field. Spin states of a particle might not be included.

I found this analogy.
The shadow can move faster than light speed; but the shadow is in no way controlled by the objects that it falls upon, but by the fly which is far away. The shadow carries information about the fly, which is propagating at light speed from the fly, not about the objects it falls upon. So the shadow can sweep across distances faster than light, but the shadow is not an information-bearing signal across those distances
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Message 1702131 - Posted: 16 Jul 2015, 12:22:36 UTC - in response to Message 1701670.  

Rome was not built in a day. It took 50 years and 12 billion dollars to build LHC to detect the Higgs boson. Advanced LIGO is about to start getting data in fall and we at Einstein@home shall crunch that data. Please be patient.
Tullio

yes, but 1 example might also be a deviance of the nature - not something applied through out Universe... ;)


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Message 1702342 - Posted: 16 Jul 2015, 23:13:35 UTC
Last modified: 16 Jul 2015, 23:13:59 UTC

Here's what would happen to you if you encountered a small black hole
Correct: You'd die. But aside from that, what would happen if a black hole the size of a nickel suddenly appeared on Earth? A new video explains.

A new video from the folks at Kurz Gesagt posted July 16 tries to answer those questions with some helpful animations. The video explores a few different assumptions, as the impact of the black hole would depend on whether its size was based on the mass or width of a nickel. Either way, if a black hole developed anywhere near you, you would certainly die, but the impact on the Earth would be drastically different.

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Message 1702955 - Posted: 19 Jul 2015, 3:09:27 UTC

Roberto Battiston, Head of Italian Space Agency, informs me that the launch of eLISA Pathfinder mission in search of gravitational waves by a Vega Launcher built in Italy will be around November 25, and that it will be a great way for Italy to celebrate the 100 years of Einstein's General Relativity.
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Message 1703273 - Posted: 20 Jul 2015, 10:21:33 UTC - in response to Message 1702955.  

LPF launch slot opens in autumn 2015 Oct 01, 2015 - Nov 30, 2015
LISA Pathfinder reaches Lagrange Point L1: around 25/11/2015
After a last injection manouevre, LISA Pathfinder reaches its operational orbit around the first Lagrange point (L1). This will be a large eclipse-free Lissajous orbit. LISA Pathfinder will have an 8 hour-per-day communication window with a 15m ground station.

https://www.elisascience.org/
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Message 1703276 - Posted: 20 Jul 2015, 10:52:30 UTC
Last modified: 20 Jul 2015, 10:54:06 UTC

Should become the fourth "hit" this year, after Rosetta/Philae, Dawn/Ceres and New Horizons/Pluto. AMS-02 on the ISS is still collecting data searching for dark matter and prof. Battiston was one of its designers. together with Samuel Ting. In the June issue of CERN Courier, still online, there is an interview with Roberto, explaining why he went from particle physics to astrophysics.
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Message 1703289 - Posted: 20 Jul 2015, 12:41:22 UTC

Just watched a documentary about the failed attempts by researchers at the south pole to detect gravitational waves theoretically produced shortly after the big bang. The BICEP2 telescope was originally thought to have detected the sought after wave patterns but after further review sharing data from the Planck telescope it was determined to be interstellar dust instead.

What a bummer for those scientists who have spent the last 15 years or so on this project. They are hoping their next telescope BICEP3 will have the capability to detect the elusive gravity waves.
Bob DeWoody

My motto: Never do today what you can put off until tomorrow as it may not be required. This no longer applies in light of current events.
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Message 1703347 - Posted: 20 Jul 2015, 15:04:48 UTC - in response to Message 1703337.  

General relativity produces a tensor equation which foresees a wave solution, just as Maxwell equations have a wave solution and a Schroedinger equation has a wave solution. Waves are simply solutions of differential equations. The fact that gravitational waves have not been detected directly is because they are very weak,as Einstein himself has recognized.
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Message 1703352 - Posted: 20 Jul 2015, 15:09:08 UTC - in response to Message 1703337.  

Well then you support Fred Hoyle's Steady State theory instead of the Standard Model.
In cosmology, the Steady State theory is a now-obsolete[1] expanding universe model alternative to the Big Bang theory of the universe and its origin.
https://en.wikipedia.org/wiki/Standard_Model
In particle physics, force carriers are particles that give rise to forces between other particles.
https://en.wikipedia.org/wiki/Force_carrier
Wave–particle duality is the fact that every elementary particle or quantic entity exhibits the properties of not only particles, but also waves.
https://en.wikipedia.org/wiki/Wave%E2%80%93particle_duality
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Message 1704032 - Posted: 22 Jul 2015, 16:27:29 UTC - in response to Message 1703352.  
Last modified: 22 Jul 2015, 16:45:53 UTC

Well then you support Fred Hoyle's Steady State theory instead of the Standard Model.
In cosmology, the Steady State theory is a now-obsolete[1] expanding universe model alternative to the Big Bang theory of the universe and its origin.
https://en.wikipedia.org/wiki/Standard_Model
In particle physics, force carriers are particles that give rise to forces between other particles.
https://en.wikipedia.org/wiki/Force_carrier
Wave–particle duality is the fact that every elementary particle or quantic entity exhibits the properties of not only particles, but also waves.
https://en.wikipedia.org/wiki/Wave%E2%80%93particle_duality


Aren't waves based on energy?

This is an interesting article, actually belonging in the Dark Matter/Energy thread:

http://www.space.com/7145-big-wave-theory-offers-alternative-dark-energy.html

This is a scientific paper on the Big Wave theory:

https://www.math.ucdavis.edu/~temple/!!!PubsForWeb/cv83.pdf

The printer at work will have it's work again in a while. :D

Despite earlier reports of a possible detection, a joint analysis of data from ESA's Planck satellite and the ground-based BICEP2 and Keck Array experiments has found no conclusive evidence of primordial gravitational waves.


http://timesofindia.indiatimes.com/home/science/Scientists-recant-Big-Bang-gravitational-wave-theory/articleshow/46076622.cms

So eager to know the truth behind dark energy, if we will ever find out that is..
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Message 1704057 - Posted: 22 Jul 2015, 17:43:39 UTC - in response to Message 1704032.  
Last modified: 22 Jul 2015, 17:44:18 UTC

Aren't waves based on energy?

Some energy types (there are are lot of energy types) are propagated as waves.
But kinetic energy of a moving object and the potential energy of a not moving object are not.

So eager to know the truth behind dark energy, if we will ever find out that is..

No one can explain what energy really is. Then how to explain what dark energy is...
From your link.
In summary: Our view is that the Einstein equations make more physical sense without Dark Energy or the cosmological constant, and Dark Energy is most likely an unphysical fudge factor, if you will, introduced into the theory to meet the data. But ultimately, whether Dark Energy or an expanding wave correctly explains the anomalous acceleration of the galaxies can only be decided by experiments, not the Copernican Principle or Occam’s razor.
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Message 1704063 - Posted: 22 Jul 2015, 17:53:50 UTC - in response to Message 1704057.  
Last modified: 22 Jul 2015, 17:56:20 UTC

Aren't waves based on energy?

Some energy types (there are are lot of energy types) are propagated as waves.
But kinetic energy of a moving object and the potential energy of a not moving object are not.

So eager to know the truth behind dark energy, if we will ever find out that is..

No one can explain what energy really is. Then how to explain what dark energy is...
From your link.
In summary: Our view is that the Einstein equations make more physical sense without Dark Energy or the cosmological constant, and Dark Energy is most likely an unphysical fudge factor, if you will, introduced into the theory to meet the data. But ultimately, whether Dark Energy or an expanding wave correctly explains the anomalous acceleration of the galaxies can only be decided by experiments, not the Copernican Principle or Occam’s razor.


My thoughts are that the energies we cannot perceive might come from the Man Himself. (God) Of course, this is just an assumption and not useful at all for the atheists among us. Cosmic essence (quintessence) is leaping to mind again..
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Message boards : Science (non-SETI) : Black Holes part 2


 
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