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meshpig
02-12-2016, 01:28 AM
I remember as a kid asking myself why gravity didn't just collapse everything down to nothing... trillions of times weaker than the 3 other fundamental forces.

meshpig
02-12-2016, 02:48 AM
... as in (https://www.theguardian.com/science/2016/feb/11/gravitational-waves-discovery-hailed-as-breakthrough-of-the-century)

inkpen3d
02-12-2016, 04:26 AM
Here's a more detailed report on the Phys.org web site: http://phys.org/news/2016-02-gravitational-years-einstein.html

It's an amazing achievement. Some truly awesome science/technology was used at advanced LIGO - the detection of a change in length of the 4km optical paths of less than the diameter of a proton, that's just mind boggling!

Given that the event detected was two 30 solar mass black holes merging one billion light-years distant, then the odds of them detecting more interesting events closer to home (e.g. in nearby galaxies or our own) are pretty high.

meshpig
02-13-2016, 04:39 AM
... "About three times the mass of the sun was converted into gravitational waves in a fraction of a second"

Thanks for the link :)

Rayek
02-21-2016, 10:11 PM
Here is another perspective:
https://www.youtube.com/watch?v=J3Hoax81rkI

glebe digital
02-22-2016, 03:34 AM
Here is another perspective:
https://www.youtube.com/watch?v=J3Hoax81rkI

Gotta love Wal Thornhill.....when the whole World goes one way, we need people that say 'yeah but'.....

“I have come to believe that the whole world is an enigma, a harmless enigma that is made terrible by our own mad attempt to interpret it as though it had an underlying truth. Perhaps the mission of those who love mankind is to make people laugh at the truth, to make truth laugh, because the only truth lies in learning to free ourselves from insane passion for the truth.”

Umberto Eco RIP

inkpen3d
02-22-2016, 03:51 AM
Here is another perspective:
https://www.youtube.com/watch?v=J3Hoax81rkI

Unfortunately, Wal Thornhill is just another one of those self proclaimed "radical thinkers" who's supposedly heroically battling against all those other pesky self-serving, grant seeking, experts in the scientific community. However, his theories and evidence, when you take the trouble to dig a just little deeper with a critical eye, turn out to be all just smoke and mirrors!

For example, see: http://neutrinodreaming.blogspot.co.uk/2011/09/electric-universe-theory-debunked.html, which is just one of many, many sites pouring scorn on the pseudo-science peddled by advocates of the "Electric Universe" such as Thornhill.

A couple of things I immediately picked up on in his diatribe as being blatantly untrue and/or simply mis-information:

Firstly, Thornhill talks about the speed of propagation of gravity as being too slow and that it must be millions of times faster than the speed of light. However, the speed of propagation of gravity has been independently determined (as between 2.55 and 3.81 x 10^8 metres per second) way back in 2003 by measuring the gravitational bending of light from a distant quasar by the mass of Jupiter, which supports Einstein's predictions. So, indeed, if our sun were to suddenly vanish from the universe, it would take ~8.3 minutes for the effect to reach us. [See http://www.nrao.edu/pr/2003/gravity/ for more information.]

Secondly, he says that you need the speed of gravitational propagation to be many millions of times faster than the speed of light in order to prevent close binary stars spiralling into each other. The fact is that measurements of an orbiting binary pulsar system (PSR B1534+12) have revealed that the two neutron stars are indeed spiralling in towards each other and that the energy of the system is being lost as gravitational waves - this completely contradicts Thornhull's assertions. [For example, see http://arxiv.org/abs/astro-ph/9712296]

I could go on and on poking holes in this chaps time-wasting pseudo-scientific arguments, but alas, life is just too short!

Regards,
Peter

Rayek
02-22-2016, 12:17 PM
I am unsure about all of the EU's assertions. I do think, however, that there is merit in those who base their assumptions, hypotheses, and theories on actual observations (inductive reasoning), rather than mostly merely deductive reasoning based on mental mathematical models. Einstein himself doubted the validity of his own work later in life.

As far as quasars, black holes, dark matter, dark energy, and the big bang theory goes, I do think enough reasonable doubts and issues have been raised to warrant a second critical look at the fundamental assumptions of the current accepted view of the majority of astronomers and cosmologists.

Just one example being the late astronomer Alton Harp, who was meticulous in his observations, and the observations show many quasars with high red-shifts visibly connected to nearby galaxies which have a low red-shift. This seems to indicate that red-shift can be an intrinsic property to stellar objects. The response of the scientific consensus to his observations has been quite interesting to observe over the years.

In your second reference to the binary pulsar system the authors state "although the precision of this test is limited to about 15% by the otherwise poorly known distance to the pulsar." I think a number of valid arguments against the use of red-shift to measure the distance of objects have been made, to cast doubts over this article's base assumptions. Aside from this, gravitational waves may not exist at all (the jury is still out in my opinion whether this latest detection actually detected gravity waves). There are just too many deductive assumptions underlying it, in my opinion. And even when the observed result is real, other mechanisms may be at work. The problem is that the authors of that article mathematically deduce their findings on the basis of more mathematical deductions with no observational confirmations. That is dangerous, in my mind. A house of cards built upon another house of cards.

Black holes may not exist at all. In the end, they were after all a mentally conceived mathematical construct necessary to explain the insanely high energetic deep-space objects we observe in the skies, since gravity is a very weak force. But what if these objects are much closer than we thought, and there is a viable alternative to explain these high energies also seen in galaxies' centers)? Black holes have not been observed yet. Only the effects of presumed black holes. The alternative of plasma and electricity makes more sense to me in this case, and the structures and patterns seen in observations seem to fit the ones we observe in plasma quite well.

I know I am veering into a side path here, but if red-shift is intrinsic to objects, it undermines the big bang model, which undermines many other assumptions made by the standard universe model.

Anyway, we live in interesting times.

Oh, I just found out about another debunking article:
http://motherboard.vice.com/read/electric-universe-theory-thunderbolts-project-wallace-thornhill

inkpen3d
02-22-2016, 03:17 PM
I am unsure about all of the EU's assertions. I do think, however, that there is merit in those who base their assumptions, hypotheses, and theories on actual observations (inductive reasoning), rather than mostly merely deductive reasoning based on mental mathematical models. Einstein himself doubted the validity of his own work later in life.

As far as quasars, black holes, dark matter, dark energy, and the big bang theory goes, I do think enough reasonable doubts and issues have been raised to warrant a second critical look at the fundamental assumptions of the current accepted view of the majority of astronomers and cosmologists.

Just one example being the late astronomer Alton Harp, who was meticulous in his observations, and the observations show many quasars with high red-shifts visibly connected to nearby galaxies which have a low red-shift. This seems to indicate that red-shift can be an intrinsic property to stellar objects. The response of the scientific consensus to his observations has been quite interesting to observe over the years.

In your second reference to the binary pulsar system the authors state "although the precision of this test is limited to about 15% by the otherwise poorly known distance to the pulsar." I think a number of valid arguments against the use of red-shift to measure the distance of objects have been made, to cast doubts over this article's base assumptions. Aside from this, gravitational waves may not exist at all (the jury is still out in my opinion whether this latest detection actually detected gravity waves). There are just too many deductive assumptions underlying it, in my opinion. And even when the observed result is real, other mechanisms may be at work. The problem is that the authors of that article mathematically deduce their findings on the basis of more mathematical deductions with no observational confirmations. That is dangerous, in my mind. A house of cards built upon another house of cards.

Black holes may not exist at all. In the end, they were after all a mentally conceived mathematical construct necessary to explain the insanely high energetic deep-space objects we observe in the skies, since gravity is a very weak force. But what if these objects are much closer than we thought, and there is a viable alternative to explain these high energies also seen in galaxies' centers)? Black holes have not been observed yet. Only the effects of presumed black holes. The alternative of plasma and electricity makes more sense to me in this case, and the structures and patterns seen in observations seem to fit the ones we observe in plasma quite well.

I know I am veering into a side path here, but if red-shift is intrinsic to objects, it undermines the big bang model, which undermines many other assumptions made by the standard universe model.

Anyway, we live in interesting times.

Oh, I just found out about another debunking article:
http://motherboard.vice.com/read/electric-universe-theory-thunderbolts-project-wallace-thornhill

Indeed, we do live in interesting times, but you have to always be on your guard and utilise a bit of critical thinking in order to separate the wheat from the chaff. You really should treat the EU assertions with a huge amount of the proverbial salt - the physics just doesn't hold water when put under the magnifying glass.

I am all for people throwing radical ideas into the mixing pot and stimulating a re-examination of existing dogma - that's what make scientific investigation such a powerful and rewarding method. An excellent example is that of Alfred Wegener and his hypothesis of continental drift, which he proposed in 1912 and was steadfastly rejected by the stuffy scientific community until the theory of plate tectonics was revived by Carey in 1953 and later confirmed with seismological evidence in 1968. So it does happen occasionally!

Sadly, however, some scientists (and non-scientists) become obsessively hooked on an idea and, despite all the overwhelming evidence to the contrary, refuse to let go of their pet theory. It's probably a form of the classic "sunk cost" fallacy whereby an individual has devoted so much time/effort/resources into pursuing a given activity or idea that they feel compelled to continue despite it being obvious to any other sane observer that, given the evidence, they really should have given up ages ago. Sadly, Alton Harp falls into this category - at the time, his observations and hypothesis did stimulate a lot of re-examination of the relationship between quasars and galaxies. However, in later years he doggedly refused to give up on his ideas despite the overwhelming evidence to the contrary that poured in from observational data obtained using more advance telescopes and techniques.

Regarding using red-shift as a measure of cosmological distances: As far I am aware there are no peer reviewed papers that caste doubt on this being a valid technique. The physics is sound and produces consistent results. So I don't think there is any logical reason to reject the findings I quoted.

Quasars, black holes, dark matter, dark energy, and the big bang theory are all really exciting active areas of research in astronomy and cosmology...

Granted, black holes were originally just a theoretical concept. However, the overwhelming evidence that is now available has confirmed that black holes do exist. This comprises observations of binary star/BH systems (e.g. Cygnus X-1) and of the orbital motions of stars around the Sagitarius A* region at the centre of our galaxy and other nearby galaxies (the orbital mechanics of which conclusively show that the mass of the central object cannot be explained by anything other than a super-massive black hole). It is now accepted that quasars are in fact super-massive black holes embedded at the heart of remote galaxies that were, at the time the light was emitted, actively accreting material and whose unimaginably powerful jets just happen, in some instances, to be aligned towards us. Yes, gravity is the weakest of the forces, but pack enough matter together at high enough densities and the physics gets really interesting and you do end up dealing with the most efficient means of converting matter into energy at incredible rates!

Regarding dark matter and dark energy - well there be dragons! Who knows if these entities really exist or are misinterpretation of observations or some form of systematic observational error? Can dark matter be explained by sterile neutrinos or some as yet undiscovered exotic fundamental particle(s)? Is the dimming of type 1A supernova luminosities with distance really an indication of dark energy causing an accelerated cosmic expansion? [However, if I recall correctly, independent observational techniques have recently backed up the findings of the supernova dimming data.] Who knows?!

Yes, we are all very fortunate to be alive during such interesting and exciting times!

Regards,
Peter

P.S. I highly recommend reading the book by Amanda Gefter: Trespassing on Einstein's lawn, I think you would find it very interesting and slightly mind blowing - in a strictly scientific sense of course!