pantheory

There are not evidence. The link that you cite is open to several objections. Who wrote the section "Alternative black hole models" seems to believe that a gravastar is another model of black hole, but the link to gravastars correctly emphasize that a gravastar is "an alternative to the black hole".

My point is and was: there have been many mainstream models of black holes other than singularity models, and many alternative models to black holes such as gravistars.

(my quote)

If GR is simply wrong, as some propose

(your quote)

This has nothing to see (do) with what I said.

Congrats on your English, I would wish that my Spanish would have so few errors as your English

(your quote)

When one adds additional corrections to the GR model, one finally finds that black holes never form.

Your quote asserts that GR with changes might disprove black hole theory. My quote was that if GR is wrong (concerning theoretical fundamentals) then changes to it will also probably be wrong, in my opinion.

//

As said above, if one considers only GR, a black hole with its corresponding horizon can form. The problem is that GR is very far from being a final theory... When one considers effects beyond the scope of GR, one obtains that a black hole never forms. ....................

The evidence that black holes exist is now beyond dispute. There is much dispute, however, regarding Einstein's model of them as vacuous points. There are many other theoretical models of them but none are presently considered to be any more valid. Mathematics aside, black hole models concerning something physical inside them, have a pretty big following and numerous proposals made. Here's just a few of the better known alternative models.

http://en.wikipedia....ack_hole_models

Hawking lost the bet about black holes, because he was ignoring several technical details; although some of us warned him that his work was science fiction. When one adds additional corrections to the GR model, one finally finds that black holes never form.

If GR is simply wrong, as some propose, then there could be no such thing as "adds additional corrections to the GR model." Because the mathematics of a model is functional in some venues does not mean that the underlying theory has validity, such as Newton's pulling force, Einstein's warped space, or Milgram's MOND, concerning a logical explanation of their formulations. None seemingly can answer questions like why matter has an associated pulling force, why is the universal gravity constant the value that it is, why should matter warp space, why the force of gravity changes at galactic scales, etc. Any logic so far proposed, if any, by these models seems to be unsatisfactory to those that think there is a simpler underlying logic explaining everything.

I think both dark matter and dark energy have reached the peak of their following and that dark matter is now on a downhill slide concerning the portion of astronomers and theorists that are strong advocates. In time I expect the same thing will happen to the dark energy idea, although I realize evidence for or against it will be even more difficult to come by.

//

juanrga,

....The final result of a collapse (of a stellar mass) is not clear when quantum gravity and other effects are considered.

Quantum gravity is at best an alternative mainstream idea/ hypothesis. There is no presently acceptable working model of it.

Several experts affirm that a black hole never form (and I recall that even Hawking is changing his mind about this).

That black holes could never form, is contrary to mainstream theory. That stellar black holes can form by collapse of remnant stellar masses above the Chandrasekhar limit (~3 solar masses) following novas and supernovas, is presently well accepted theory. What a stellar black hole really is inside its very small diameter (as small as 15 miles) may be debatable since it depends upon the black hole theoretical model(s) that are being discussed.

//

Then would there be a way for inhabitants of a planet with higher gravity to live longer? Maybe give them stronger bone systems?

Human inhabitants could be genetically selected for muscularity and longevity traits. In a few hundred generations a better adapted breed of humans could be created. In the future we probably will also be able to identify which genes are most suitable for a particular environment and build a new human genetically without going through intermediate steps .

//

So if someone was born on a planet three times as big as Earth, they would grow up to develop stronger muscles?

I don't know about a planet three times larger, there would be a limit how big a planet could be for human genetics to continue to function properly. But a larger planet in general, if we were eventually able to function, would seemingly produce bigger muscles. Could we live longer (rhetorical)? We probably would live for a shorter period of time with increased gravity. Could we live longer on a planet with a little less gravity than Earth (rhetorical)? Maybe some people would

//

Here's another group of 8 questions thought to be presently unanswered in astronomy and cosmology. Here's my answers.

1) What is dark energy?

In the 1920s, astronomer Edwin Hubble discovered that the universe is not static, but rather is expanding. In 1998, the Hubble Space Telescope, named for the astronomer, studied distant supernovas and found that the universe was expanding more slowly a long time ago compared with the pace of its expansion today. This groundbreaking discovery puzzled scientists, who long thought that the gravity of matter would gradually slow the universe's expansion, or even cause it to contract. Explanations of the universe's accelerated expansion led to the bizarre and hotly debated concept of dark energy, which is thought to be the enigmatic force that is pulling the cosmos apart at ever-increasing speeds.

 

While dark energy is thought to make up approximately 73 percent of the universe, the force remains elusive and has yet to be directly detected.

Answer: dark energy does not exist. Instead the idea is based upon miscalculations of distances to galaxies/ supernova which could be corrected by modifications of the Hubble formula.

2) How hot is dark matter?

In the 1960s and 1970s, astronomers hypothesized that there might be more mass in the universe than what is visible. Vera Rubin, an astronomer at the Carnegie Institution of Washington, studied the speeds of stars at various locations in galaxies.

Rubin, a now famous astronomer, observed that there was virtually no difference in the velocities of stars at the center of a galaxy compared to those farther out which contradicted present models of gravity and resulted in the dark matter hypothesis. There is a present debate as to the possible temperature of dark matter.

Answer: dark matter does not exist whether hot or cold.

The problem instead is our model of gravity. Upon changing both the formulation of gravity and explanations of its mechanics, then gravity could be correctly understood -- no pulling force and no warping of space.

3) Where are the missing baryons?

If dark energy and dark matter combine to make up roughly 95 percent of the universe, regular matter makes up about 5 percent of the cosmos. Yet, more than half of this regular matter is missing.

Answer: Since both dark matter and dark energy do not exist, there is no missing matter/ baryons.

4) How do stars explode?

When a massive star runs out of fuel and dies, it triggers a spectacular explosion called a supernova that can briefly shine more brightly than an entire galaxy.

 

Over the years, scientists have studied supernovas and re-created them using sophisticated computer models, but how these gigantic explosions occur is an enduring astronomical puzzle.

Answer: The missing peace of the puzzle is that substantial heat is created by the compression of stars so that only about 1/3 the nuclear fusion is required. Adding this additional heat into the equations points toward a chain reaction explosion once critical temperatures and pressures are reached.

5) What re-ionized the universe?

The broadly accepted theory for the origin and evolution of the universe is the Big Bang model, which states that the cosmos began as an incredibly hot, dense point roughly 13.7 billion years ago. A dynamic phase in the history of the early universe, about 13 billion years ago, is known as the age of re-ionization. During this period, the fog of hydrogen gas in the early universe was clearing and becoming transparent to ultraviolet light for the first time.

Answer: The Big Bang model is the wrong model of the universe so there was no re-ionization process or era to explain since the universe is far older than what the BB model proposes.

6) What's the source of the most energetic cosmic rays?

The source of cosmic rays has long perplexed astronomers, who have spent a century investigating the origins of these energetic particles. Cosmic rays are charged subatomic particles — predominantly protons, electrons and charged nuclei of basic elements — that flow into our solar system from deep in outer space. As cosmic rays flow into the solar system from elsewhere in the galaxy, their paths are bent by the magnetic fields of the sun and Earth

Answer: Although type II supernova are not the cause of cosmic rays, the accelerations of galactic black holes are, which is a type of cyclotron radiation. This is also the second choice of the mainstream model.

7) Why is the solar system so bizarre?

As astronomers and space observatories discover alien planets around other stars, researchers have been keen to understand the unique characteristics of our solar system. For instance, while extremely varied, the four innermost planets have rocky outer shells and metallic cores. The four outermost planets are vastly different and each possess their own identifiable features. Scientists have studied the process of planetary formation in hopes of grasping how our solar system came to be, but the answers have not been simple.

Answer: Since we cannot know what the insides of all the planets are comprised of, I expect the larger planets also have a large rocky and metallic interior but atmospheres of hydrogen and helium readily are blown off the inner planets, or never condensed in the first place because of higher temperatures and a stronger solar wind. The numbers, positions and sizes of the resulting planets is simply the result of random encounters in the proto-stellar system.

8) Why is the sun's corona so hot?

The sun's ultrahot outer atmosphere is called the corona, and it is typically heated to temperatures ranging from 900,000 degrees Fahrenheit (500,000 degrees Celsius) to 10.8 million degrees F (6 million degrees C). For the better part of a century, solar physicists have been mystified by the sun's ability to reheat its corona,

Answer: Very large magnetically induces plasma currents are driven in flares at the sun's surface. The great speeds and energy of this magnetically induced plasma acceleration produces great energy in the form of heat and light. Such subsurface currents are limited to the resistance of motions within the stellar plasma, but can blow free at the sun's surface. These magnetically induced flairs cannot conduct back to the star since they are insulated by space so the corona becomes progressively hotter when moving away from the sun's surface.

http://www.msnbc.msn...e/#.T8fflVIpOnA

//

Earthlings would be stronger and faster than people that were born and lived on Mars, without their extra exercise and aerobics such as running with weights fastened to them.

Muscle deterioration happens even faster in space. Some astronauts and cosmonauts have found it difficult to walk and function when first coming back after spending some time in space.

Geriatric daily living, for instance, would be much easier on the moon and broken hips from falling would be uncommon. After maybe a year on the moon without substantial regular exercise, a person in a moon nursing home might not be able to ever walk again on Earth if they ever came back here.

//

Come on dude, I know when something is above my pay grade, that's why i asked, you suggested that Mars would form a magnetic field if it had an denser atmosphere then you gave links but the links didn't support your opinion at all, in fact never mentioned it. Why would you expect mars to generate a magnetic field if it had a substantial atmosphere?

 

I could see how spinning the moon, if it still has a molten core might generate a magnetic field, but why would mars?

The first link discussed their findings that the Earth's core appears to be non-conductive. If true the dynamo effect would not be the cause of the Earth's magnetic field or influence the extent of its strength.

The second link explains that the moon reacts differently to the solar wind than what theory had predicted.

The bottom line to me is that our Theories of planetary magnetism are simply wrong. My expectation is that planetary magnetism has two causes and influences; neither are accordingly related to the core of the planet or moon. The primary cause, I expect, is the relative motion of a relatively dense atmosphere with a liquid and/or solid surface. This causes ionization of the atmosphere and electrical currents through its fluids in the opposite direction of its rotation. The magnetic field would accordingly be created perpendicular to the atmospheric wind for most planets. The second cause of planetary magnetism would be the charged particles from the solar wind that could strengthen a pre-existing magnetic field.

The Earth has these condition but Venus' rotation is too slow. Mars' atmosphere is too thin and when it flows in strength and volume (the wind) it is seasonally moving south-north, north-south (primarily water and CO2). The result is a very small east-west magnetic field.

The outer planets have a thick atmosphere and thought to have liquid interiors/ surfaces. Being farther from the sun there would be less strengthening of a pre-existing magnetic field by the solar wind. Mercury has a weak magnetic field accordingly due to a miniscule atmosphere and relatively little spin rate. The solar wind there, however, is very strong and may be the only cause of its weak magnetic field. Titan, on the other hand, has a substantial atmosphere, liquid on its surface, but a slow spin rate, about 16 Earth days. It also experiences mush less solar wind per volume of its atmosphere. The result is that it also has only a very weak magnetic field.

Magnetic fields could accordingly reverse upon a great solar storm which would overload the atmosphere with an influx of positive ions. The 'Earth's magnetic field is half way between its spin access and its incline to the solar system plane.

Of course this is only theory, and not the present mainstream dynamo model of planetary magnetism, which I believe has been contradicted by observations of most planets.

//

TransformerRobot,

Yes, perhaps the moon would be easier than Mars or Venus.

Also, are you saying that even if people were planning to live on a terraformed Mars, they would have to be genetically altered to better suit it's atmosphere and climate?

No, only the plants and animals I think would need modification. I would expect some day there would be a difference in the physical characteristics between native born Martians and Earthlings. Earthlings, for one thing, would probably be stronger because of its gravity, resulting in native born Martians not doing as well physically on Earth.

//

Moontanman,

I see nothing in either of those links to support this assertion.

I would also expect Mars to immediately develop a magnetic field once it has a substantial atmosphere . (This would also apply to the moon concerning both an atmosphere and an adequate rotation period)

Tis true my friend. That's why I said "I would expect (not I assert)," since it is my opinion and expectation based upon contradictions of present theory, whereby all could come to their own conclusions, which is what it seems that you have done

I realize that I am getting close to your field of expertise concerning moon tans so I tread lightly

Another idea I was thinking of for my alien character was that she is part of a new species created in a special laboratory, through the splicing of humans and another animal, so that whatever happens to us our genes will be carried on through them.

 

They would need a planet to live on near Earth, so I was thinking Mars, because Mars would be easier to work with than Venus.

 

How would we be able to terraform Mars, and when would we be able to do so?

 

I was thinking that we could use a device to heat up the surface of Mars, melting the CO2 below the surface, freeing it back into the atmosphere, causing a greenhouse effect to get more heat from the sun, melting the Martian ice, thus creating oceans. The only problem I've encountered now is restoring Mars' magnetic field.

Mars is one of the primary transforming possibilities within maybe a thousand years minimum. But I think the moon would be easier. The moon is the right distance from the sun and could be "spun up" as part of the terraforming process. Even though it probably has underground water, we probably would need to import much more from the outer moons or the asteroid belt. We probably could import an atmosphere of nitrogen, oxygen, and Co2 in the form of ices with sun shades needed as such ices are imported, also probably from the asteroid belt. My expectation would be that once there is an atmosphere, and a moon-spin fast enough, a magnetic field would almost immediately develop to shield from UV and other deleterious solar radiation. Without direct solar wind, I believe this atmosphere might last maybe thousands of years before needing to be replenished. Manufacturing processing could also produce a regular replenishment of these same molecular gasses.

As far as genetic alterations, I would expect that we would engineer both plant and animal life primarily for food purposes to start with, to be better adapted to live in a foreign environment. I would also expect Mars to immediately develop a magnetic field also once it has a substantial atmosphere.

Here's a couple of links that might give a clue concerning the possibility that our present model of Earth and Planetary magnetism may be wrong.

http://www.nature.co...ll/485319a.html

http://www.sciencedaily.com/releases/2012/05/120531102443.htm

Venus, I believe, will also eventually be terraformed but I think not in the foreseeable future. I think vast asteroid, space (solar system) colonies, and other planetary moon colonies will come first because they would be easier, cheaper, and more profitable in the foreseeable future.

//

Swansot, Pantheory, Airbrush, thanks for your replies!

 

I read about hypothetical particles - weakly interacting massive particles (WIMPs) as possible solution to the dark matter. I wonder if these hypothetical particles obey the Pauli exclusion principle, or can they form a Bose-Einstein condensate?

Since dark matter is only hypothetical, the answer to your question would depend upon the reality of its existence. If you would assume that it exists then it would depend upon what particular model of dark matter particles that you are interested in. If dark matter was particulate and matter-like it would seemingly follow Pauli's exclusion principle like all other matter in general. Since dark matter, if it exists, would not be atomic matter it seemingly could not form a Bose-Einstein condensate.

//

JustinW,

...So what is the exact cause of vacuum in that space (bag), if not the space itself?

There are models of space whereby space has physical characteristics to it. Via these supposed characteristics space can accordingly bend, warp, expand at different rates, etc. No physical characteristics of space have ever been observed in the lab, however, excepting for its energy potential called the Zero Point Field. If dark matter is real it would also be in the bag. If Higg's particles are real they also would be in the bag. Neutrinos would be in the bag.

It depends upon what theories you prefer, as to what's in the bag

//

dmg,

....explain to me in more detail why gravitational energy has to be dissipated? Does it have anything to do with conservation of energy? It just cannot be locked up inside an event horizon and has to be dissipated?

There are several ways energy can be converted concerning a pre-stellar nebula. One of the beginning ways that the energy of gravitational contraction is converted begins with the energy conversion into a gravitational vortex. Following that energy is absorbed by the friction of the vortex that turns into heat. Following that matter agglomerates at the center of the vortex and the energy of relative motion is converted into the energy of stellar compression. As the heat builds up it is radiated away from the vortex center.

In black hole theory the energy of influx accordingly turns into a torus and then into heat and accelerating momentum. If there is a great deal of matter in the torus then accordingly jets can form and much of the energy converted into these jets. Inside the event horizon energy could then be turned into the rotational momentum of the black hole. The in-falling mass will also be converted into the increased mass equivalence of the black hole. There is also theoretical Hawking radiation and outward moving theoretical waves called gravitational waves accordingly produced from the in-falling energy of matter.

//

dear friends, just a puzzle was disturbing my mind so i thought i should ask you guys.

 

science (physics) says that time,space ,and matter including we are weaved together ,and time is always running ,and gone time never comes back then here is my question

time (the micro second which was with us at one point) was gone than, how come we remain in present and the universe also remains . where does the passed time elopes, at which dimension of the world ,or the time itself is speculation?

 

if my question is foolish pls ignore

Time is a measurement of change. You need a standard measuring instrument to quantitatively measure it. Time is a construct of an intelligent mind but does not exist as a separate entity. It is like X,Y, and Z, the Cartesian dimensions length, width, and height. It's not reality itself, only a tool to explain changes in reality. Time past is the same thing as yesterday. Both yesterday and any interval of time-past were intervals of change. Strictly speaking 4:00 PM yesterday was not a time itself but just a point in an interval of change which we call time.

This is maybe the simplest understanding of time, but this simplicity can be easily complicated within complicated theory such as Quantum Physics

//

I have two questions, first i want to know if there is anything else other than atoms that can fill up empty space, for example if i have an empty bag, with nothing in it, can it be filled with photons, electrons, or something else?

 

second, if you have an empty bag, but there is a mechanical apparatus that expands the bag, what will the empty space be filled with?

It could have photons within it. It would have maybe trillions of neutrinos within it, maybe electrons, a proton or more depending upon the volume.

"Empty space" here on Earth and within galactic and intergalactic space, is filled with the Zero Point Field. This is a known energy field called Zero Point Energy. There is also thought to be theoretical particulates within this field such as dark matter, gravitons, Higg's particles, quantum foam, etc. It could be called the aether.

Aether: The upper air breathed by the gods; Son of Erebus sired in chaos and darkness.

imatfaal,

Kroupa et al will only have been published for a month or so (on pre-print service) and I don't know if it has seen the light of day in actual journal yet. Definitely a good back and forth

Thanks for that

Hi Pan

 

Have you seen this article which challenges the one mentioned in the OP

 

Guardian - simple treatment

 

Resonaances - hard core blog

 

Pre-print on Arxiv of the paper that challenges the paper which challenges DM

 

Thanks to SwansonT blog for pointing in right direction

No, I haven't seen this commentary yet but did see the Arxiv paper posted by Spyman. The Arxiv paper refers to two researchers that critically analyzed the first paper coming to a different conclusion.

So far I've seen no retort to the report by the British Astronomical Society, maybe because it's more difficult to question their findings.

I read that dark matter accounts for 23% of the mass-energy content of the observable universe, while the ordinary matter accounts for only 4.6%. My question is which category do black holes fall into? Do you count them as ordinary matter?

 

If a massive star collapses, we get a black hole. What if a huge collection of dark matter collapses? Will we get a black hole again? I guess yes. Can we distinguish such two black holes? Can we count the latter black hole as part of dark matter?

I wouldn't be too enamored with percentages of dark matter or dark energy in the universe. Both are still considered by many to be only hypothetical. Black holes are presently not considered either matter or dark matter. So when they are proposing to sum up matter and dark matter in proportions, black holes are not considered in the equation.

There have been some black hole models that have proposed that their insides are a very dense form of matter such as a quark star, etc. There have been one or more other models that have proposed that black holes are a compressed form of dark matter, and still other(s) that propose that there is just one most fundamental particle that makes up everything.

If one looks at the prevailing dark matter models, most do not believe that if it exists that it could collapse becoming a black hole. The proportion of mass equivalence in black holes in the universe can be roughly calculated from the mass of the Milky Way without hypothetical dark matter, roughly 200 billion solar masses, and the mass of its central black hole of about 4 million solar masses. This is a ratio of about one fifty millionth of our galaxy which might be an extrapolated estimate of the universe as a whole.

So if this is a valid estimate black holes don't represent a very big portion of the universe in mass, very roughly one fifty millionth.

//

imatfaal,

Pan - just to be clear, that statement is a personal comment of Prof Kroupa not something for and on behalf of the RAS. It is a very interesting paper though. We are missing some vital spark from our theories - there are too many contradictory findings. I tend to be very boring in my views, and my default recourse is to accept mainstream views; but something nags about dark matter - there is a huge amount that is right, but too many snags and problems.

Thanks for that. Upon a brief reading, I thought it was an explanation of the original paper rather than commentary on the original paper. I think I have already read at least a couple of explanations of that paper. I never have been a fan of the dark side but am a little surprised how fast "evidence" seems to be mounting against dark matter. I would have preferred to see dark energy seriously questioned/ challenged first since I consider the evidence for it to be even less substantial -- but probably more untestable.

We'll see what happens next

pantheory, I am not trying to defend nor attack the concept of matter in dark matter.

 

When I came across the above paper I realized that it was fairly recent, close enough to be of interest in this thread in the Science News.

 

Tremaine is widely regarded as one of the world's leading astrophysicists for his contributions to the theory of solar system and galactic dynamics and the paper is not only criticisms of the study by Moni Bidin, they manage to turn it around and use the data to measure the density of dark matter within the limits of standard estimates and concludes: "This is the most robust direct measurement of the local dark-matter density to date".

 

Kroupa is an astrophysicist who leads a research group on stellar populations and stellar dynamics, his work focuses on a possible connection between satellite galaxies with the bulge of the Milky Way and that they could have formed in an early encounter with another galaxy. His papers points out that a missing dark matter substructure of the Milky Way is a failure of current standard cosmological models with Einsteinian/Newtonian gravity.

 

I have no doubt that a new and better understanding of dark matter will eventually be made and only the future can tell if 'matter' is to remain in the new name when the shadows of the 'dark' are lifted, but right now I think "a paradigm shift" is a too strong statement to make this early.

The article and commentary is certainly news worthy since it generally has a conclusion contrary to the ESO paper.

...but right now I think "a paradigm shift" is a too strong statement to make this early.

I agree but believe what we are seeing concerning these failures to find dark matter may be a harbinger of a paradigm shift that I expect to see within 15 years or less, after the James Webb goes up and some of its observations realized. Maybe the Royal Astronomical Society sees the writing on the wall and is trying to be one of the first to recognize it

//

Spyman,

This was a criticism of the study done by a team of ESO astronomers claiming no dark matter was detectable in the vicinity of the sun, or our solar system. Naturally when there is a study contradicting mainstream beliefs, there will always be criticisms. This is the way good science works. The original study, however, was not the most damaging concerning the dark matter hypothesis. I believe the study below was the most damaging.

http://www.ras.org.u...for-dark-matter

Their conclusion:

"Our model appears to rule out the presence of dark matter in galaxies, threatening a central pillar of current cosmological theory. We see this as the beginning of a paradigm shift, one that will ultimately lead us to a new understanding of the universe we inhabit."

The key words here, I think, were "a new understanding" implying better theories. This is a strong statement coming from a normally conservative organization.

Of course this study and conclusion too should be criticized as well as similar studies conducted, and eventually final conclusions made.

The Big Bang is presently the only considered model in cosmology. When seriously contradicted by observations, the BB model must be able to evolve. When or if it no longer could, it would be replaced.

 

hay im not a astronomer or cosmologist (as you may be?) but i found this guys videos the other day on you tube and found them quite intriguing

This has some interest to me for discussion but is unrelated to dark matter. To discuss this material elsewhere PM me and we might do so in another venue. The rules prohibit such discussions here unless they are news related

that entire model (einsteins general relativity) or whatever sucks as evidenced by the number of "fillers" if you will that has to be put into it to "prop" it up (dark energy dark matter blah blah blah) never ever been observed....the scientific oligarchy owns us all arrrgghhhh! lol... just bored...

Dark matter is needed to support General Relativity, which is the mathematical foundation of the Big Bang model. It is conceivable that another mathematical model of gravity could replace GR in the Big Bang model.

Dark Energy, on the other hand, is not needed by the BB model, but its inclusion into the model was thought to be the only explanation consistent with observations of type 1a supernova. Any other cosmological model would also need to explain this same data by a different explanation, or otherwise it would also need to incorporate the dark energy idea.

...the scientific oligarchy owns us all arrrgghhhh! lol... just bored..

The Big Bang is presently the only considered model in cosmology. When seriously contradicted by observations, the BB model must be able to evolve. When or if it no longer could, it would be replaced.

//

The problem with sharks is overly exacerbated by the fact that of the entire body, only the vertebrae, jawbones and teeth remain, so they don't even have the entire animal to look at. It's no wonder they had trouble with them. Even normal variances with a species can look like whole new members of the family when you possess so little data. Lining the teeth up in the jaw wrong, or in the wrong jaw (which was, apparently common with early attempts to reconstruct megalodon), would add even more confusion to the mix.

 

As for the assertion that there must be tall and short wolves - I'm sure there are/were - within the norms of variation for the species.

 

Keep in mind that your comparison to dogs is not the way we would expect a natural system to behave. Dogs were selectively bred for certain characteristics (size, speed, sense of smell), and breeding of undesirable traits was actively selected against by ensuring the animal in question not only did not breed, but had no opportunity to breed (either by neutering or euthanasia).

 

In the wild, this second limiting factor isn't present. "Less than perfect" members of the species still get the opportunity to mate, so while there will be some variation, unless that particular mutation provides some overwhelming advantage or detriment, it's probably not going to selected for or against with Nature running the show. It may hang around in the gene pool for millenia until something changes that makes it either a benefit or a detriment, in which case natural selection will take over.

All in the field know there is much speculation involved when there is little skeletal evidence. All one can do is listen to what they claim as evidence to support their conclusions and whether it seems like a logical or likely possibility. Evolution over millions of years developed the wolf. Man's domestication of dogs is thought to have been at least 10,000 years ago and many believe much longer. We learned to breed dogs for work and protection qualities so the best dogs became very valuable. In maybe just 10,000 years since we were able to change dogs by selective breeding. Our ability to do this is because dogs sexually mature in 6-12 months instead of 13-15 years old for humans.

For the last couple of thousand years there have been few recorded attempts lasting only at most 10 generations concerning the breeding of human slaves for strength and stamina for the fields, and for looks as house servants. Hitler attempted "eugenics" for looks, health, and intelligence, but was stopped after just one generation.

So I expect if long-lived aliens wanted to breed humans for some reason, they probably could produce the variety that we see in dogs in the same number of generations which it took us for dogs, which was about 10 to 15 thousand generations of selective breeding. If we get down to understanding genetics better we could breed into animals favorable characteristics in a much shorter time period, with fewer trial and errors, and fewer unfavorable inbreeding traits. Today screening takes place to some extent concerning human amniotic analysis for genetic disease traits which can be selected out by abortion in early pregnancy.

//

eh no... there is evidence.. for super massive... super dense things.. which are dark.

 

THAT.. DOES NOT PROVE THEY ARE HOLES IN SPACE... it does not... not prove black holes exist as proposed.

 

For you to say it does, is nothing but an assumption YOU HAVE BEEN TAUGHT.

IF YOU BELIEVE THINGS... just because others tell you its true... YOU GET MISLED.

 

Sorry.

There is more that one model for black holes. The most accepted definition of a black hole is a small volume where gravity is so strong that matter or light cannot escape from it or pass through it, and therefore it would appear as a black hole in space.

The most common definition: A region of space having a gravitational field so intense that no matter or radiation can escape.

A mathematical model of a singularity is only one of the hypothetical models concerning a black hole. Dense conventional matter is another model concerning galactic black holes. A third model is a very dense volume of matter like a theoretical neutron star or another more dense form of matter. Some have proposed quark stars, graviton black holes, Higg's black holes, dark matter black holes, and the list goes on.

The point is that there is almost a mountain of observational evidence to support the concept of a black hole of stellar size and central galactic black holes of some kind

//

Iggy,

Got your note on that, and thanks for the link. As you may know I am not a fan of present theories/ hypothesis in cosmology (nor have I ever been). I wrote a paper on type 1a supernovas back in '08' that came up with a different conclusion than the dark energy hypothesis, but I used my own formulations for distances based upon my own cosmological model, which is like comparing apples with oranges. My own analysis comes very close to a change in the data occurring at a redshift of about .6, but my conclusion instead was that they were using a somewhat incorrect formulation (the Hubble formula), to come to their dark energy conclusion. Whether right or wrong, they got the Nobel Prize for it And what did I get for all my hard work? Zilch! (a little tongue in cheek humor). It is rare that a mainstream journal would ever publish a non-mainstream paper I was just hoping

//