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Einstein's Theory Improved?
skaet writes to tell us that A Chinese astronomer from the University of St Andrews claims to have fine-tuned Einstein's theory of gravity. Dr Hong Sheng Zhao has created a 'simple' theory which could "solve a dark mystery that has baffled astrophysicists for three-quarters of a century." This new law seeks to discover whether Einstein's theory was correct and if dark matter actually exists.
Even if that is the worst graphic accompanying a well-written, intelligent article I've seen in my lifetime.
Ex nihilo nihil fit.
Would people please stop using the word "Law" when referring to scientific theories. It confuses the creationists.
I'm sure that there are lots of people that are far more clued up on this than I am that can find holes in what I am about to say but I always felt like dark matter was a bit of a fudge because we don't understand what is happening.
My problem with dark matter is that it's almost as difficult to believe in as God. The only real proof we have is that the universe doesn't appear to move correctly without it. If that's as good as we can do then we might as well say God (or the FSM) is holding the universe together. To my mind it is a big leap from "the universe isn't moving as we expect" to "90% of the universe is made of something we can't see". Surely if the universe was full of this stuff we would be able to detect it because it would block radiation from distant galaxies - or is dark matter conveniently transparent?
I used to have a better sig but it broke.
How exactly would the law itself discover anything? Wouldn't that have to be a hypothesis first that would have to be tested experimentally before it becomes a law?
It's not dark matter. It's light.
If you check the equations, you'll find that light from a star causes its gravitational field to fall off as 1/r, whereas its mass causes it to fall off as 1/r^2. This is an old equation, originally derived for the gravitational field of a candle.
Needless to say, this effect is only present within the "sphere" of radius (speed of light)x(age of star), but of course for most stars, this is enormous. Galaxy spanning in fact.
This is all relatively offtopic by the way, but given the controversy surrounding dark matter, and the dubious qualities of "landscape theories" lately, I thought I'd throw this one into the mix as well.
I wonder if this is what the guys have come up with actually.
May the Maths Be with you!
Won't it be ready until April? Stranger things have happened.
http://michaelsmith.id.au
I would like to know a formula for [roughly] calculating the terminal velocity an object will run into with the force of gravity. Because this has a lot to do with the aerodynamics of the object and not just its exposed surface area and mass I bet it'd be pretty tricky, but what about a simplified version. Anyone?
What a clear and well-written article. And what a pleasant, unassuming statement from Dr Zhao:
"A non-Newtonian gravity theory is now fully specified on all scales by a smooth continuous function. It is ready for fellow scientists to falsify. It is time to keep an open mind for new fields predicted in our formula while we continue our search for Dark Matter particles."
Even if the theory turns out not to stand up, words like this take us back to what makes science interesting and important. That "falsify" is worlds away from the publicity hounds and egomaniacs who so often represent science to the lay reader.
Las qué passoun
tournoun pas maï
Name something that doesn't!
My problem with dark matter is that it's almost as difficult to believe in as God. The only real proof we have is that the universe doesn't appear to move correctly without it..... or is dark matter conveniently transparent
I have to disagree with that, I have no problem believing in the existance of dark matter. In fact I don't have to 'believe' in the existence of dark matter at all, I found some between my toes this morning and it was most certainly not transparent.
Only to idiots, are orders laws.
-- Henning von Tresckow
Although it is not the theory that has been improved, it is the model. It takes a simple function to interpolate between the dark matter area (which is non Newtonian - Modified Newtonian Dynamics or MOND) and the Newtonian area, where baryonic matter seems to reign. Despite a simple continuation function for the two areas, the authors find a nice agreement with rotation curves of galaxies including our own, and some external ones. The theory which has been used is the TeVeS (Tensor Vector Scalar) theory by Bekenstein. The scalar part of the theory could explain the dark matter behaviour.
E=mc^2
Unfortunately, like Cambridge, St. Andrews has suffered from negative publicity as a result of its taking occasional pupils from failing schools and admitting them with A level scores which would not normally allow a student to be admitted. But at least it meant that some of the Windsors got access to higher education, so perhaps the policy is defensible.
Anyway, I'm very pleased that the astrophysics tradition is continuing. But I'm still left with a question: Why are the nicest British Universities (Cambridge, Durham, St Andrews) in such bloody cold places?
Pining for the fjords
Worst article ever.
Dark Matter particles come naturally from physics,
Dark Matter is an ad hoc theory. Dark Matter is made up crap and came directly from the ass of a physicist that drank too much snake oil. How does this guy's work differ? We'll never know from this article.
A non-Newtonian gravity theory is now fully specified on all scales by a smooth continuous function. It is ready for fellow scientists to falsify.
Describing a function with words is lacking at best. When I first read this I thought "they're poised to falsify data?"
The author uses words like: Legend, mystery, golden laws. I expect the headline below this article to say "Mr. Fuzzy Wuzzy weds Batman".
Dark Matter at odds with General Relativity
Autonomous Retard -- Is your camp safe? UnsafeCamp.com
I am not an astronomer. I just tend to apply logic to everything I collide with.
And when I can't collide or interact with it, it kinda ruffles me the wrong way. What kinda magical stuff is this supposed to be. Doesn't interact, doesn't shine, doesn't emit, doesn't absorb, all it does is offer some convenient gravity to explain a few things that don't make sense otherwise.
It kinda reminds me how about 500 years ago astronomers came up with double and triple rotations of planets around an imaginary point to explain why the planets move the way they move since they believed the Earth and not the sun is the center of our system. And if they rotated around earth, they had to jump through a few hoops to explain that odd orbits they showed. Instead of abandoning the system that didn't work and accept one that does, they religiously clinged to it and tried to explain what could not be explained.
Maybe we're at that point again?
Maybe, just maybe, it's not dark matter but some of our "laws" are simply wrong. Or, if not wrong, they maybe don't extrapolate well into the larger scale, what works and makes sense in the (comparably) small scale of our solar system doesn't make sense and doesn't work on a galactic scale.
I do hope this is a step into the right direction. Science is all about not setting stuff in stone. Everything has to be questioned, everything has to be tested, even the most holy scriptures from the most revered astronomers of all times should be ripped if they showed an error.
If not, science is no better than religion.
We used to have a Bill of Rights. Now, with the rights gone, all we have left is the bill.
I've heared once that the original hebrew text reads "Thou shalt not murder." If that's true, the contradiction is easy to resolve: Just define that killing ordered by god is no murder.
My understanding was similar but different. I had heard that the original ancient language of the bible did not have a rich engouh vocabulary to distingiuish between kill (e.g. an enemy) and murder (e.g. one in your own society), but the next most recent translation of the bible used the word "murder", not "kill".
The point is, when Moses was taking his tribe around the desert with their new commandments, they were to preserve their own society (which is what the 10 commandments promote), but if they had to kill competing tribes to survive, they could do so because it would be *killing*, not *murder*. Any society that condones unbridled murder within itself will quickly commit suicide.
The link at the bottom of the page labelled "About PPARC" obviously goes too close to a singularity and ends up in a parallel universe with a quantum difference of this address is a 404 page. They've got me convinced.
It was Kepler who realised that ellipses could be the correct model for orbits, and even there, to try and keep the Church happy, he tried to fit the major and minor axes into the shapes of the "Platonic solids".
History suggests that the example you are quoting is the opposite of what you want to show. It is better to let scientists come up with initially ad hoc explanations because they lead to the truth. Making initial unscientific assumptions and treating them as dogma suppresses and delays progress. Scientists are ambitious and a good way to become important is to replace someone else's theory - so scientists can be relied on to do that. For every established Dark Matter theorist there are probably several PhD students who would love to annihilate Dark Matter.
The line of argument in the parent annoys me because it tries to suggest that scientists left to themselves will produce ridiculous non-explanatory theories and then cling to them forever. It's the anti-scientific agenda of the Creationists who want to discredit science. Creationists and their like want to confuse the public as to the explanatory status of different scientific theories so they can claim their snake oil is on an explanatory par with plate tectonics, quantum electrodynamics or evolutionary biology.
Pining for the fjords
His identical twin brother won't have returned from a journey around the universe at 0.99c until April
init 11 - for when you need that edge.
Tell me about it ...
:p
Every year I've been in Cambridge (since 1996) the winters have been bitterly cold, whilst not having the benefit of much snow. It's the nasty artic winds sweeping down off the North Sea, over the flat land straight into Cambridge. Grr!
Still, it cools our heads, allowing our brains to operate faster
(if only)
(1) Jobs where if you goof up, some money goes down the drain, or you're embarrassed or, somebody gets hurt or dies. You know, like being a doctor or lawyer or engineer.
(2) Jobs where it doesnt matter one whit if you're wrong. Jobs like theoretical physicist in a field where there isnt the slightest possibility of carrying out an experiment. Such as dabbling in the theory of gravity.
Like an idiot, I'm in category #1. What a dope.
E = mc^2 and sometimes Y.
You see? You see? Your stupid minds! Stupid! Stupid!
... just last week or so, we were told there was *no question* that it exits; we're just studying it's properties now. No question *at all*: commence ridicule of any who disagree.
Just who are we supposed to ridicule now? Would someone please give me my nerd marching orders?
What great timing the bbc has, only last week Horizon aired a documentary on the search to find, or disprove the need for dark matter. A synopsis is here : - http://www.bbc.co.uk/sn/tvradio/programmes/horizon /missing.shtml.
What was good about this one in particular was that the scientists actually seemed to be open minded and not clinging to their theories with an immature pride. Even the 'defenders' of dark matter were open and interested by the idea of modifying the laws of gravity.
What made me laugh is that one Professor has been in the bottom of the deepest mine in Europe for 16 years searching for neutrinos, and has found nothing.
If this were really happening, what would you think?
Or am I the only one who is almost completely jaded to "Yet another theory this year that challenges our understanding of the universe".
Our we all jehovahs Whitnesses or what?
Oh wait, I guess every project needs funding. More importantly every scientist needs funding and since global warming is taboo via near Presidential verdict, lets go after dark matter and the E-man himself.
Almost easier if you go after Darwin, oh except thats not physics and that is also taboo due to political unrest given this semi-new intelligent design crap. Hmm. Better to go after physics itself, chruch goind fundamentalist creationsts dont care about that, Presidents dont care, its a clean cut case of fundage.
Excuse me whilst I be jaded to myself for a moment..... Oh, by the way, fuck everyone who challenges Einstien and the usefull parts of Darwin. Give it up for like a few years.
Damnit, bring on the new!
Its currently like an alternate reality game show.
At least Jehovahs Whitnesess have the forsight to delay all scientific information by at least a year (or a decade).
Sorry, I know I dont have to troll on this and I did not have the option to not RTFA. I am not complaining about the coverage. I think I am bitching about everything except the coverage.
Do we really have nothing new but Mars and the newest explanation of Dark Matter? If so then let us admit it.
Yes I am a bitchy mood.
I think you underestimate just how much I just dont care.
PPARC still posts the scientists e-mail addresses in tfa? I can think of many spam e-mails that contain 'dark matter' but not of the kind they're looking for!
Time is an illusion. Lunchtime doubly so. - Douglas Adams
The statement that "science is/isn't better than religion" is not scientific, it's rather religious.
Yesterday was the time to do it right. Are we having a REVOLUTION yet?
http://arxiv.org/abs/astro-ph/0512425 The phenomena customly called Dark Matter or Modified Newtonian Dynamics (MOND) have been argued by Bekenstein (2004) to be the consequences of a covariant scalar field, controlled by a free function (related to the MOND interpolating function) in its Lagrangian density. In the context of this relativistic MOND theory (TeVeS), we examine critically the interpolating function in the transition zone between weak and strong gravity. Bekenstein's toy model produces too gradually varying functions and fits rotation curves less well than the standard MOND interpolating function. However, the latter varies too sharply and implies an implausible external field effect (EFE). These constraints on opposite sides have not yet excluded TeVeS, but made the zone of acceptable interpolating functions narrower. An acceptable "toy" Lagrangian density function with simple analytical properties is singled out for future studies of TeVeS in galaxies. We also suggest how to extend the model to solar system dynamics and cosmology, and compare with strong lensing data (see also astro-ph/0509590).
They have created a formula that allows gravity to change continuously over various distance scales and, most importantly, fits the data for observations of galaxies...It is time to keep an open mind...
There is not much in this article that gives us a clue as to what they are referring to. But I guess we have to wait for their Edinburgh presentation in April.
He who knows best knows how little he knows. - Thomas Jefferson
Non-believers will be sacrificed to the Flying Spaghetti Monster. Observe His noodly greatness!
Newton and Einstein's theories of gravity don't always work, so cosmologists decided to make up some new and coincidentally undetectable stuff -- Dark Matter and Dark Energy -- to help them out. The more I read about these ideas, the more they look like fantasy as opposed to science. It's almost as bad as String theory! Why don't the theorists stick to explaining what can actually be observed and measured, instead of making up stuff in order to prop up theories that have more likely found their limits. I can just feel which way Occam's Razor is eventually going to cut on this one. Besides, all my life I've been hearing that gravity is the least understood of the four fundamental forces of nature, so perhaps it's about time it got a tune-up.
"The new formula will be presented to an international workshop at Edinburgh's Royal Observatory in April, which will be given the opportunity to test and debate the reworked theory. Dr Zhao and Dr Famaey will demonstrate their new formula to an audience of Dark Matter and gravity experts from ten different countries."
No preassure. *phew*
SIG: TAKE OFF EVERY 'CAPTAIN'!!
They have created a formula that allows gravity to change continuously over various distance scales and, most importantly, fits the data for observations of galaxies. To fit galaxy data equally well in the rival Dark Matter paradigm would be as challenging as balancing a ball on a needle, which motivated the two astronomers to look at an alternative gravity idea.
:)
Difficult? Sounds like they needed to find the slope between two points to me
My intuition says this is not going to hold up. Firstly, this seems to be an ad hoc theory to explain the fact that galaxies rotate too quickly. There's nothing wrong in ad hoc theories as such, but when it comes to theories like Newton's and Einstein's theories for gravity, they are so well tested that I would expect any amendment to be based on something more substantial.
;-)
Secondly, Newton's formula for gravity around a point mass (on which Einstein's theory is based) seems to fit very well with one's intuition: think of gravity as a sort of 'substance' that 'emanates' out from the point mass; the amount of 'substance' stays constant as it propagates outward, but the area of the resulting sphere of the substance grow as the square of the distance, so the density of the substance falls off as the inverse square of the radius. It makes sense to, at least; it seems natural. Now, in this intuition, if the force of gravity didn't fall as fast as 1/r^2, some 'substance' must have been added along the way - where does it come from?
This is of course only intuition, but that can be said of both general relativity and quantum mechanics too (in their own circumscribed way). Take Heisenberg's uncertainty principle, the intuition here is that all particles are waves, and to measure the properties of one wave/particle, you have to hit it with another. Someone has calculated how good a resuolution you can get from measuring something with waves interactions like that, and from that came Heisenberg's principle; very intuitive, I think.
This amendment to gravitation doesn't seem to have that element of intuition, simply, but perhaps it wasn't explained very well in the article.
Apart from that - dark matter as an explanation isn't very satisfying. It seems to be too much of a big, black box; I can't think that that will be all there is to be said or discovered about 90% of the whole universe, I fully expect that there will be at least 10 times as much detail to discover in physics as we already know. And I'm going to be right there when it happens
I also don't like dark matter/energy theories very much (although I do like the idea that there is more out there that we don't know about). Nor do I like string theories. I think the whole of physics is somehow run amok. A few things do appeal to me however, probably because of my feeling that ultimately it all boils down to a computational algorithm. I think that some aspects of quantum theory fit like the "Bekenstein bound", and that this relates to gravity over the large scale.
For example, when it comes to gravity, we might think of space itself as a substance, not a material substance, but a substance of which all "material" things are made. A volume of this "space" substance then has various "densities" within it, giving cause to gravity, and causing light to bend, in much the same way as light bending through glass of varying density.
Now, when it comes to the galaxy problem mentioned in the article, we might see a galaxy as a "condensation" of hydrogen at the boundary of the region of high and low pressure of the space substance "density". In this model we are viewing a galaxy much like a hurricane forms. A hurricane is a self sustaining structure within a volume of air giving rise to the formation of clouds, and rain. A galaxy is a formation of condensing hydrogen at the boundary of a high and low density of space (seem to be repeating myself). Due to this model, gravity does not vary directly from the center of the volume of the galaxy, but follows the general structure of the galaxy itself.
So what is this space substance of which all things are made? Does it matter (pun intended)? If we see this space substance as a mathematically "continuous" substrate that can manifest all objects, then what is it that gives rise to "size"? If quantum mechanics and the Bekenstein bound are correct, then the "continuous" substrate of space is actually punctuated with perfect sinusoidal waves. These waves, through self interaction and superposition give rise to location, eg. points in space where some things are, and some things aren't. The chaos of this wavy interaction ends up dividing space into a "resolution", much like your computer screen has a resolution. All material objects are then constructed of these wavy interactions that are happening at the Plank resolution. However, the Plank resolution should vary directly as the "density" of space, eg, the resolution of space should be high near a massive object, and low where there is no mass.
Do I believe any of this? No, not neccessarily, as Mony Python says, "it's just a model." But I really like theories that are simpler, instead of more complex.
Although I share your skepticism about dark matter, I couldn't help thinking about the neutrino, a "hidden" particle that filled another gap in physics. It took 25 years for physicists to finally detect the neutrino.
Mea navis aericumbens anguillis abundat
QUOTE (from google "define:", entries not related to killing edited out)
0 2-a.html
m
kill intentionally and with premeditation; "The mafia boss ordered his enemies murdered"
unlawful premeditated killing of a human being by a human being
Murder is both a legal and a moral term, that are not always coincident. It may be legal to kill, but still murder in the moral sense. Opponents of the death penalty argue that it is simply murder by the state. Proponents of limited government argue that moral murder is never legal murder unless and until the government meets the limits and standards required of it, such as due process, proof beyond a reasonable doubt, trial by jury, appellate review, etc.
en.wikipedia.org/wiki/Murder
1. The unlawful killing of one human by another, especially with premeditated malice. 2. Slang. Something that is very uncomfortable, difficult, or hazardous: The rush hour traffic is murder. 3. The collective noun for crows.
en.wikipedia.org/wiki/Murder_(disambiguation)
The willful (nonnegligent) killing of one human being by another.
www.securityoncampus.org/schools/research/doe/974
The unlawful killing of a human being with deliberate intent to kill: (1) murder in the first degree is characterized by premeditation; (2) murder in the second degree is characterized by a sudden and instantaneous intent to kill or to cause injury without caring whether the injury kills or not.
brandonlclark.com/glossary.html
Includes homicide, non-negligent manslaughter, and voluntary homicide. Does not include attempted murder (which is classified as felony assault), negligent homicide, involuntary homicide, or vehicular manslaughter (which are classified as "other violent offenses").
www.pretrialrelease.com/pretrial-release-terms.ht
the unlawful and malicious or premeditated killing of a person
securityproducts.tripod.com/Glossary.html
refers to the killing of another person
www.mtholyoke.edu/offices/dps/logs/logdefin.shtml
is the intentional taking of someone's life. Manslaughter is an accidental killing or a killing in the heat of passion. Murder is punishable by life in the penitentiary, manslaughter by 20 years.
www.msda9.com/grandjury/gjterms.htm
The crime of homicide committed either intentionally or with wicked disregard for the consequences.
hjem.get2net.dk/safsaf/glossary.html
is the intentional killing of a human being. It includes causing serious physical injury leading to the death of a human being. For example, if a person attacks another person with a hammer, intending only to injure rather than kill, the attacker can be prosecuted for murder if the attack results in the victims death.
www.wierlaw.com/glossary_criminal_law.htm
ENDQUOTE.
I agree with all of the above. Killing an enemy soldier is murder, except when said enemy soldier is trying to kill someone and there is no way to stop him but use deadly force... Besides, if you don't want Iraqi people to shoot at you, you should stay clear of Iraq. Yeah, mod me flamebait/troll for that.
It's better to be the foot on the boot than the face on the pavement. ~~ tkx Kadin2048
They are both quotations from the same book.
It's better to be the foot on the boot than the face on the pavement. ~~ tkx Kadin2048
Classical physics, which includes both Newtonian and Einsteinian mechanics, is mostly descriptive math engineering. Math does not explain physics; on the contrary, it's the physics that explains the math. For examples, they do not explain why things fall or why bodies in motion remain in motion. The beef of a physical theory is the mechanism that is responsible for the observation. Where is the beef of relativity? Until someone comes up with the beef, neither theory can claim to be physical theories, in my opinion. They're just math tricks with no real physics. The best way to improve Einstein's and Newton's theories is to unravel or model the actual physics behind the math. Until then, it's not much better than ptolemaic epicycles.
PS. I already heard the usual ripost by relativists to the effect that science is not about the why of phenomena but the how. IMO, that's just a lame copout to excuse their ignorance and mental laziness. I already know that bodies fall and move; I want to know why they do it, if you don't mind. And please Brian Greene, stop preaching the nonsense about gravity being caused by the curvature of spacetime. Nothing moves in spacetime. ahahaha...
ECE is an updated theory of general relativity :-) )
that incorporates electromagnetism, the strong force,
and the weak force using anti-symmetric tensors.
It explains and predicts many optical phenomena that
are inexplicable in Maxwell-Heaviside theory.
Universities and large companies have been studying this
theory for over a year now.
Read All about it at http://www.aias.us./
(It helps, but is not necessary, to understand tensors
Should Dr. Myron W. Evans get a Nobel Prize for this achievement?
That, ladies and germs, is science. That's how you tell the crackpots from the professionals. That's what separates the good guys from the Time Cube-style guys.
I wonder if he'll accept my invitation to dinner. We'll have cake.
From the header...
This new law seeks to discover whether Einstein's theory was correct
So now we have a sudden new law that seeks to disprove an established theory? Yet this law has not even been tested? Someone has their terms mixed up. There are very few laws in science and they include very measurable and reproducible things like gases, thermodynamics, charge, resistance, gravity, and newtonian motion (I may have missed a few). Then suddenly we're into theories because our ability to measure either interferes with the results or we can only observe our results indirectly.
I keep an open mind but this guy pegged the needle on the crank-o-meter calling it (from TFA) "a new law for gravity" from day 1.
Seven puppies were harmed during the making of this post.
It really pisses me off the leeway we give theoretical physicists. If an engineer screws up on a bridge, or if a doctor screws up on a patient, people know, and they demand accountability. If astrophysicists fail to properly apply an equation for 100 years, or miss something simple for 75 years, "hey, that's science, it's tough man, cut us some slack". How many times have they changed opinions on whether the universe is expanding or contracting now? And just so you don't misunderstand, it's absolutely okay to make mistakes -- as long as they're new! Each time scientists err in a theory and "change their collective mind" about something, it should come with a fundamental re-evaluation of what practices led to the error, and what kind of evidence counts as proof. If they did that, you wouldn't see them switch opinions about some matter every third year, or, even better, admit they don't know.
Rank my idea: http://www.sinceslicedbread.com/node/531
This is not an improvement to Einstein's theory of gravity. It is, however, an improvement to Milgrom's Modified Newtonian Dynamics (MOND): MOND is merely an empirical correction to Newtonian gravity, so this is an improved 'empirical' gravity (well, it's got to survive a few more tests before we know if it's an improvement to MOND).
One big difference between Newton's theory of gravity and Einstein's theory of gravity is that Newton's theory says what gravity does (ie. it gives us the magnitude and direction of the force of gravity between two objects) whereas Einstein's theory says that and how as well (i.e. mass curves space-time). Einstein's theory improves on Newton's in that it is more accurate and actually provides insight (testable) into how gravity actually works.
It is likely that Einstein's theory will be improved upon at some time, and be replaced by a more enlightening theory (quantum gravity? string theory?), but for now it is the best theory of gravity we've got....
#include "cunning_plan.h"
Here is mine. The law of gravity is fine. Our calculations of the planets masses are wrong.
The sun is iron. Refigure gravity with the sun being iron.
Mecury is iron and rock, Venus is iron and rock, Earth is iron and rock, Mars is iron and rock.
Jupiter is hydrogen and helium with a liquid metal core. Saturn is gas.
Uranus is ice methane and other ice gases, neptune is of other ice gases too.
In a centerfuge the heaver elements go outward. In a spiral with gravity pulling inwardthe heavier elements get pulled in first.
The sun has much more gravity than anyone knows.
If gravity can bend light, as per Einstein, then gravity has some tug on the entire electromagnetic spectrum.
The sun is giving off huge amounts of electromagnetic energy that doesn't make it past Saturn, ie Uranus and Neptune don't recieve enough energy to be gas. The electromagnetic energy that is infared is slowed down and possible stopped by gravity.
Now something in our solar system pushed the gasses to the outskirts of our system. More than likely the gas planets are the gases from the inner planets blown off by the sun and pushed out to the outskirts of our solar system. This blowing off of gasses is more than likely the electromagnetic energy given off by the sun.
If earth had a stronger magnetic field we might have more of an atmosphere. If the moon had a magnetic core, it might have an atmosphere.
Mars once had an magnetic field and it was possible that it had water. Now theorized that it was blown off by the sun. Where did that water go??? Into dark matter?? I think not.
It was blown off to Jupiter or Saturn or the other planets. Something was pushing it. What ever was pushing the gasses has sucumed to gravity and is no longer in effect passed Neptune.
The Pioneer anomaly comes from the same thing that was blowing the gases to the outer planets. It was also pushing on the spacecraft. What ever electromagnetic energy was pushing on Pioneer 10 space craft is no longer pushing on it and Pioneer 10 is now being fully effected by the remaining gravity of the Sun and slowing down ever so slightly.
I know that I'll have thousands of people claiming that I'm wrong and stupid. But, one day, you will have read it here first.
The sun is iron and its mass calculation is entirely wrong.
Nathan W.
Does that matter?
Newton's gravity law works well on Earth. Maybe we can find a theory that works well on our solar system and even on other places we observe. But, to make really sure it works, maybe we should put an apple on space and see how it behaves.
Fine-tuning sounds great for an automobile, but in physics if a theory is fine-tuned it means that it is unnatural or unpredictive.
If you look at a reasonable plot of data, you can probably fit a curve through it. But where did that curve come from? If your theory admits any curve, then 'fine-tuning' the curve to fit the data is not much of an achievement. And if you 'modify the equations of gravity' so that rotation curves of galaxies match observation, while abandoning any fixed theorical principle for guidance, then you haven't done much. Unless of course you come up with a new theoretical principle---which is what Einstein did when he abandonded Newton's framework.
Gravity's interaction is _derived_ from general relativity. If you play around with the derived equations, you lose hope of understanding where they came from, and we're back with Newton. If you get rid of general relativity (which approximates to Newtonian theory in most reasonable every-day limits), then you also have a whole lot of new problems.
Modified Newtonian Gravity (MOND) theory has been around a long time. Dr Zhao's realisation is new, but not the idea or framework. As such, it solves the 'dark matter problem' while complicating many other things.
Evidence for the 'dark matter problem' comes from big bang nucleosynthesis, galaxy surveys, rotation curves, galaxy cluser dynamics observations, weak and strong gravitational lensing, the cosmic microwave background, and large scale structure simulations. Many of these problems are inter-related. MOND theories usually address roation curves while spoiling any hope of explaining all the rest.
I think you've hit the nail on the head. Unfortunately, with the omnipresent media that we have nowadays, they need to find little tidbits, regardless of their accuracy or proof, that can fill up a quiet hour on their 24hour news shows.
On an aside, I read somewhere (can't find it now though) that the news shows are starting to have to come up with a new phrase for breaking news because it was constanly on the screen regardless of how long the news had been broken.
"If something doesn't work first time, invent something imaginary"
This is not the first time in which an existing theory has had a part added (a fudge factor if you will...) to explain an anomalous phenomenon.
Such example include,
1. God
2. The aether
3. The cosmological constant
Each of these ideas have been used at some point to ensure that an existing theory (or foundationless preconceptions) coincide nicely with observation. In each case, they have been refuted at some point in the future.
The idea of modifying the rate of gravitational fall off with distance is not a new idea - back in the 1800s, Airy (If I remember correctly) discovered that if instead of gravity obeying an inverse square relationship, it obeyed an inverse relationship to a different power, the predicted orbit of mercury would fit the observed data. If this was proposed however, there would have been a lesser incentive to look for the more accurate theory that General Relativity provides.
I can't help but think that very rarely does true progress come from simple modifications to existing theory. When theory does not match observation, it is often a new idea entirely that is needed to resolve the problem. A modification to an otherwise elegant idea usually obscures the truth.
If this new theory really does provide highly accurate results, we should ask why and look for the underlying cause of gravity falling off faster than expected, rather be complacent with the introduction of a new constant.
Nothing sucks like a Vax, nothing blows like a PowerMac G4
First off, I want to say a few words about dark matter. I think it's kind of irritating when people rant on about how dark matter is ad hoc fudging, etc. etc. Well, "fiddling around with the laws of gravity" isn't any better on that account. The fact of the matter is that all of theoretical physics is creating new models that fit our observations, and both dark matter and MOND fall into that category. The very existence of MOND as a theory shows that it is not easy to distinguish "matter that primarily interacts gravitationally" from "modifications to the laws of gravity". Historically, both "unseen matter" and "modifications to gravity" have been valid solutions to anomalous gravitational behavior (in the cases of Neptune's orbit and the perihelion precession of Mercury, respectively).
As it stands, dark matter models can pass many experimental tests, and they're still the way to bet. That being said, MOND is not a bad idea either. It's not as well supported by dark matter, and it has serious problems with galaxy clusters, but it can still account for a surprising amount of data (for a nonrelativistic theory!). The flaw of non-relativistic has been "corrected" by Bekenstein's TeVeS theory (the one that Zhao and Famaey's work is based on).
Unfortunately, TeVeS appears to be rather ad hoc (even compared to dark matter). Z&F's work does not appear to be much better in this regard. In addition, solar system observations appear to place serious constraints on such MOND-like theories, leading to anomalous non-inverse square forces in the outer solar system (and no, it doesn't seem to be of a form that can be attributed to the Pioneer anomaly, though the jury is still out).
The TeVeS/dark matter debate should be definitively resolved by the Planck mission, which will be capable of resolving the third acoustic peak in the the cosmic microwave background radiation power spectrum. TeVeS and dark matter make very different predictions for the structure of this peak. Of course, if TeVeS fails this test, maybe some other MOND-like theory could be put forward (if the entire class of theories hasn't already been ruled out by other means, such as solar system dynamics, by then).
Being completey undereducated I will nevertheless offer my little theory. Most of the unaccounted for gravity is due to frame dragging. The faster an object spins the more it pulls on the space surrounding it and increases its gravitational pull.
So, you're saying it's good to be the king. That's one of the best backhanded compliments I've read in a while. You must keep your standards on the lowest rung lest you fail to allow those on the highest rung in. In America, we are a little more pragmatic. We simply redefine what high standards are similar to the way torture has been redefined. It's not torture unless it causes organ failure or impairs bodily function. How else could we end up with best and brightest in our highest office?
"You'll get nothing, and you'll like it!"
A galaxy is modeled as a stationary axially symmetric pressure-free fluid in general relativity. For the weak gravitational fields under consideration, the field equations and the equations of motion ultimately lead to one linear and one non- linear equation relating the angular velocity to the fluid density. It is shown that the rotation curves for the Milky Way, NGC 3031, NGC 3198 and NGC 7331 are consistent with the mass density distributions of the visible matter concentrated in flattened disks. Thus the need for a massive halo of exotic dark matter is removed."1 0/1052224&tid=160&tid=14 0 7619.pdf
http://science.slashdot.org/article.pl?sid=05/10/
http://xxx.lanl.gov/PS_cache/astro-ph/pdf/0507/05
"... the intrinsically linear Newtonian-based approach used to this point [in the study of the motion of Galactic Bodies] has been inadequate for the description of the galactic dynamics and Einstein's general relativity should be brought into the analysis within the framework of established gravitational theory."
I guess that most Dark Matter proponents haven't yet read this important paper that debunks the need for Dark Matter. Ah, if you get the math wrong you need Dark Matter... if you don't you don't!
The article is NOT well written. It doesn't explain anything other than in vague terms. A cat chewing on a lemon would make more sense.
That paper was debunked in the same bloody thread you cite. Read the comments! Several authors have pointed out why it is in error (here, here, here, here, and here). The authors should have known better; general relativity is just not relevant on galactic scales. I expected better of Cooperstock.
Check out www.aias.us. Myron Evans has brought together all the fundamental forces of physics in a fully unified field theory.....and it's all based on Cartan geometry. As Einstein described gravity as the curvature of spacetime, Evans goes on further and describes electromagnetism as the torsion or twisting of spacetime. Unlike string theory, Evans' theory uses the four physical dimensions and produces testable predictions.
No, that's not what happens. Laws say what happens, theories say why and/or how it happens. Laws don't try to explain behaviour, they just state it. Hence the laws of thermodynamics are laws, while the theory of relativity is a theory and always will be.
:-)
And the law of gravity? Observations say what happens. Theories say why and/or how it happense. Laws are what we call theories we think will never be falsified, and it's probably a word that should be dropped from any kind of scientific discussion, since we all should have learned by now that even the most basic assumptions and most obvious conclusions drawn from the most irrefutable of observations have a way of requiring revision from time to time, as better observations are made (Newton couldn't look at gravitational motion, and we cannot yet see into the higher folded dimensions of string theory, assuming such in fact exist).
The "laws" of thermodynamics are as theoretical as relativity. Both have been observed, both are mathematically modelled to great precision, both make useful predictions, both are falsifiable, and no one outside of a few religious wackos expects either to be falsified. That doesn't mean they won't be.
Someday we might find conditions in which entropy in a closed system decreases (candidates for something like this include the time leading up to the big bang--if such is found to have existed--and certain theories of the internal workings of black holes, etc.). Not that I or anyone else realistically expects this (but then, who expected the anomalies that would lead to the dark matter/energy vs. non-newtonian gravity debate, either), but the "laws" of thermodynamics are as falsifiable as the theory of relativity and, as it turns out, the "law" of gravity.
Theories do have a habit of becoming "laws" when they are basically considered irrefutable. They shouldn't--we should probably refer to gravity as the theory of gravity, and the laws of thermodynamics as the theories of thermodynamics. It might stop the "big bang theory" and "theory of evolution" rhetorical nonsense we've all been subjected to by communications majors coasting through college with a "C" average only to become network anchors...and help all of us to think clearer. That having been said, I imagine my calls to refer to the laws of thermodynamics as the "theories of thermodynamics" would fall on my old physics professor's deaf ears. Most of us like keeping our language the way it is, no matter how cumbersome or confusing it becomes--but that's a rant for another day.
The Future of Human Evolution: Autonomy
gah
Newton couldn't look at gravitational motion
should read
Newton couldn't look at galactic motion
The Future of Human Evolution: Autonomy
New and improved: Realitivity 2.0!
Now with AJAX!
I read
Yeah, I remember the last time you posted this. Myron Evans, the chemist, no physics publications in respected journals, with a self-published "unified field theory", no part of which made it past peer review. You can find those on Usenet a dime a dozen. In fact, he coauthored a "paper" with famous Usenet crank Tom "Overunity Drive" Bearden.
For those that are interested in this, Jacob Bekenstein (the author of the first relativistic MOND paper ~2 years ago) has a paper on the preprint server today about the possible measurable effects of MOND in the solar system.
I couldn't tell if you were experimenting with poor-man's cryogenics or looking for the orange sherbet.
> I personally, have a complete dislike for the idea of dark matter. It seems like a stab in the dark, that missed, and was declared right anyway. "Wow, galaxies spin way faster than we think they should. It's almost like there are invisible halos of super heavy matter surrounding all galaxies." Oh, yeah, beyond being completely invisible Dark Matter exists in halos around galaxies. They are really really heavy but the stars don't fall into the halos or the halos into the stars. It's all magically perfect.
'Nuff said.
Sheesh, evil *and* a jerk. -- Jade
E = mc^2 + 0.9999999999999999
Precisely what I thought when reading it. It reminds me why I respect science and scientists, toiling to provide a shared understanding of our universe. There is an essential aspect of humility to science - submitting your ideas to live or die under the scrutiny of the community. Not that it's always so gracefully exemplified.
Lots of posters here seem to have no problem referring to dark matter as some sort of crackpot theory, or some fudge, when its really not. There is alot of evidence for it:
1) Rotation curves for galaxies - The measured rotation curves of galaxies don't seem to match up with the mass distribution we see the "ordinary" matter. If we add dark matter, things seem to work out.
2) Structure formation - Given the rate of expansion of the universe, there doesn't appear to be enough ordinary matter for the tons of clusters of galaxies that we see to form. If we add dark matter, things seem to work out.
3) Abundances of the light elements - Nearly all of the Helium (and a few others) in the present universe, was formed during a process/time called "Big Bang Nucleosynthesis". The fraction of the light elements produced from the initial hydrogen plasma depends very strongly on the fraction of normal matter and the fraction of dark matter. In order to agree with the observationally measured abundances, we must add dark matter.
4) Cosmic Microwave Background - There is remnant radiation left over from when the universe was an ionized plasma. The appearance of this radiation is very sensitive to the contents of the universe. In order to agree with observations, we must add dark matter.
5) Expansion History - We can reconstruct the expansion history of the universe by many methods. The most currently favored uses type Ia supernova, which have a calibratible brightness ("standard candle"). In order to reproduce the observed expansion history, we must add dark matter.
The important things about these distinct observations are (and this is why we thing dark matter is right):
1) introducing dark matter explains all of them
2) they all agree on how much dark matter we should add and what its properties should be
The problem with all of these alternative theories being suggested (believe me, everyone wants to be the one who goes beyond einstein), is that none of them explain all of the observed properties listed above (many of them in fact produce observationally ruled out discrepencies).
The problem is that as a result physicists really, really like very elegant theories when there's no particular reason to believe that the Universe itself has the same bias. Similarly, we like to take theories that work on scales and locations that we know and can easily interact with, and assume that they smoothly apply in the places that we can't get to know quite so easily. It's reasonable even if it isn't logical - we have to go with what we already have. It's a decision born of practicality.
In Cosmology, there's even a phrase for this: we assume homogeneity and isotropy. That is, that there's nothing special about where and when we are, and that the universe is pretty much the same (in physical laws) everywhere. The first time I heard about "dark matter," it was in the context of closure of the Universe. Physicsts really really wanted the universe to have enough mass/energy in order to be "closed," but we simply weren't finding enough matter. There was no reason to believe that the universe is closed (curvature 1.0), but it just seemed more elegant. So, they started to look for the "missing mass."
These are not logical assumptions, they're just assumptions that we have to make in order to get anywhere. Again, there's no reason that the universe will cooperate on this matter.
My own bias is to reject dark matter in favor of a revised theory of gravity, but that's just my own love of elegance - a different gravity feels more elegant than dark matter and dark energy, and in fact would hint at much more interesting cosmologies. But that's just how I am seduced by elegance...
"It is our blasphemy which has made us great, and will sustain us, and which the gods secretly admire in us." - Zelazny
If one keeps looking for presence of something that seemingly should be there but yet doesn't seem to be, perhaps it's time one considers that perhaps a lack of something might be responsible for the same effect? Nature abhors a vacuum and all that.
Hey, it's Tuesday: The day of the Tues! Happy Tuesday to you.
Everything in the Universe sucks: It's the law!
Except that work was horribly flawed and was debunked in the very Slashdot story you refer to. See also here.
Use a little common sense. While individual scientists make mistakes, the collective scientific community as a whole is not so stupid as to neglect the application of the known laws of gravity for 30+ years for no good reason. In fact, it is well established that general relativity has no significant effect on galactic scales and cannot account for rotation curves. Cooperstock and Tieu were embarrassingly careless.
Then God condemned them for disobeying him.
According to Numbers 36, they got a slap on the wrist for it. Further, Moses did allow them to keep the virgin girls for themselves, and his priests affirmed the order. God never condemned them for that part.
Genocide isn't bad as long as it's he right kind of genocide, and they are Bad People. I'll keep that in mind next time I want to exterminate an entire population.
"The impossible often has a certain integrity that the merely improbable lacks" - Dirk Gently
I am, having spent 4 years in gravity research and having taught university general relativity.
Then why hide behind "Anonymous Coward"?
Oooo, let's cover up your profound ignorance of the evidence for and against dark matter by calling it "magical". That neatly obviates the necessity for you to muster any scientific arguments against it.
I understand the arguments for Dark Matter and they don't make it sound any less Magical. Besides, it's incumbant upon those (i.e. you) who propose an "Extraordinary Theory" (such as Dark Matter) to provide the extraordinary evidence for it.
The Extraordinary Evidence standard is applicable to Theories of God (really Theologies of God) as well those of Science. Dark Matter may or may not be proven; while it might be falified by someone, as a proponent of it it's up to you to prove that Dark Matter correlates with Reality and to offer the extraordinary evidence of it's existance.
It's not relevant whether or not I like Dark Matter. The evidence just isn't conclusive. Where is the extraordinary evidence for it's existance? Where is a jar of the stuff (so to speak assuming it can be held in a jar in your hand)?
What is interesting about this discussion and the large number of new "theories" to explain the anomolies in galactic motions is that it's the cutting edge of human understanding. Oh, by the way a writing style that borders on insults (e.g. your profound ignorance comment) and ad hominem methods isn't needed and just reflects upon your abilities to argue.
Who's hiding behind "Anonymous Coward"? I don't have an account. If I posted under an anonymous alias such as "CuttingEdge", would that change my qualifications, my arguments, or make my name known to all? Sorry, dude, you are not improving your position here.
Yeah, right. Please summarize them (to a greater extent than what you can copy and paste from my own summary of the arguments). I would be interested to see how much you know about the subject.
I already summarized the evidence for it in the link that you ignored. If you want to know more, you may read any of the thousands of papers on the subject. I can point you to some good review articles if you want.
Dark matter is not proven, but there is a hell of a lot of evidence for it. Nobody claims that it has been "conclusively" proven, though; that's why alternatives such as MOND still exist. Dark matter does significantly better than alternative gravity, but not so much better that alternative gravity can be ruled out.
There never will be a jar of "dark matter" you can hold in your hand, by its very nature. That has nothing to do with the conclusiveness of the evidence in its favor.
My ability to argue is summarized by the fact that I have actual arguments and evidence supporting my position, whereas you have nothing but deriding dark matter as "magic". What reflects on your ability to argue is, as I said, your profound ignorance of the subject. I mean really, where do you get off telling the entire dark matter community that they "did the math wrong" and were trivially disproved by two guys with a rejected paper that was debunked six times over? You are in serious need of a reality check. I'm sorry if it hurts your feelings to be told you're ignorant, but you are, and you need to realize it.
In the game of Nomic, the rules of the game include rules for changing the rules. However, there are initially two rulesets, mutable and immutable. An immutable rule must be voted into the mutable class before it can be changed. This is essentially, I think, the same situation we see in the discussion of Laws vs. Theories.
The utility of having a special class of theories we call "Laws" is that they make science more stable, and essentially frame the direction of investigation and new theorizing. What Dr Hong Sheng Zhao and his collabators are doing is essentially calling for the Law of Gravity to be moved into the mutable class.
He who refuses to do arithmetic is doomed to talk nonsense.
'Dark Matter' really describes the problem more than anything. I don't think that when the solution is found anyone will refer to it as 'Dark Matter' any more.
Please sign petition to restore sanity to our banking system!!!
http://financialpetition.org/
I thought this whole mess was cleared up back in 1977.
The Force is an energy field created by all living things. It surrounds us, it penetrates us, it binds the galaxy together.
Based on the information in the article, it's not clear what physical principles he's appealling to that would justify adding more parameters to the gravitational model.
I could generate a bicubic mesh from a bunch of random data and claim that I had a "theory" that explained it all. Noone would ever be able to "invalidate" my claim that a polynomial fitting function matched all available data.
But no matter how complicated my polynomials become, my curve-fitting exercise will never reveal that the random data is created by radioactive decay.
It doesn't smell like Physics to me...
The original text, in the Torah, is written without vowels. What you were seeing, with vowels, is known as a Chumash - an individual book that is used for daily reading of the Torah's text. The actual scroll(s), known as "A Torah Scroll" in english, is written without any vowels at all and has been that way for thousands of years - google "The Dead Sea Scrolls" for more evidence.
Your assertion that I'm ignorant about Dark Matter is not more than an irrelevant opinion and is an ad hominem attack; as is much of your above posting. I request that you take up a writing style that avoids ad hominem person attacks starting with your very next posting.
Not having a Slashdot account makes it difficult to know if you are the same poster from post to post. At least a Slashdot account let's others know that it's likely the same person posting or responding to a post.
The point about Dark Matter being magic isn't intended to "deride" the hypothesis of dark matter; it is what it is. The hypothesis will stand or fall as people examine it over time and find the beyond doubt conclusive and extraordinary evidence for it or not. Dark Matter makes extraordinary claims and while there is some evidence for it so far there isn't extraordinary evidence for it. Some of the claims just seem magical, unreal and not related to everyday experience; while that characteristic is common in much of physics it's especially true of the Dark Matter hypothesis (and others such as the String Hypothesis).
I didn't ignore your link to what you assert is your list of Dark Matter evidence. It simply wasn't relevant to my posting. The linked posting was well written I might add just so you know that I read and considered it.
By your own statement you assert that "Nobody claims that [Dark Matter] has been 'conclusively' proven"; so how can you attack my request for "extraordinary evidence"? It's not only a reasonable request, it's at the core of the Scientific Method that those who make (or support) the extraordinary claims find the extraordinary evidence and present it.
I make the same requests of those who support or proport the notion that God or the FSM exists. Where is the proof? Where is the reality based extraordinary evidence?
As to the paper "General Relativity Resolves Galactic Rotation Without Exotic Dark Matter", by Cooperstock and Tieu, which suggests that physicists have got their math wrong it's very probably the case; whether or not Cooperstock and Tieu are right with their math is a different question. If you look at the various hypothesis being proposed, Dark Matter, MOND, Strings, M-Branes, etc... they for the most part exist in the world of mathematics (the questions are how and if they correlate with Reality). So it's not a stretch or an insult to question the accuracy of the mathematics involved. In fact that's the basis of the papers that you presented attacking the "Cooperstock and Tieu" papers - that they got their math wrong. So it's common for physicists to assert that the others have got their math wrong. Since we've yet to hear further from Cooperstock and Tieu bowing to these newer papers assertions about their work it's not a dead subject yet - they (or someone else) may still come though with additional adjustments to their hypothesis taking into account any valid critisms. That's the nature of the process of progress in science.
Your statement I mean really, where do you get off telling the entire dark matter community that they "did the math wrong" and were trivially disproved by two guys with a rejected paper that was debunked six times over? is an ad hominem attack against Copperstock and Tieu since you assert that they are simply "two guys" when compared to the "dark matter community". Let's see now, Copperstock is a professor with the University of Victoria's Department of Physics and Astronomy which makes him a little bit more than a run of the mill guy. It also makes him someone who is qualified (by his peers) to assert that the entire dark matter community did their math wrong; and that's exactly what he did in his paper. That is also exactly what the rebuttal papers said of him. That's the process of science. By the way, in case you think that "two guys" can't trivially disprove the entire physics community there was this unknown guy with the name of Albert Einstein who worked at a patent office...
The "Torah", the laws written on large scrolls, do not have vowels on them. "Torah", meaning "Law", is the basis of the Hebrew Testament. They are copied from scroll to scroll by a scribe who needs to do it PERFECTLY - one mistake, which may include ink from one letter touching another, renders the entire thing void and invalid (and requires its destruction, no less). Fortunately, Torahs are written on multiple pieces that are stitched together (with ligaments, if memory serves) and the 'offending' piece can me taken out and replaced.
The vowels that people here are talking about are in the Chumash, a book that was created so that the Torah can be followed along with. The Chumash also contains insightful commentary from one or more sources, explaining certain ideas and translations more fully. Also, a Chumash will often have Hebrew on one page, and English (for example) on the opposite page, so that people can learn the stories without requiring Hebrew as a primary language.
The "Hebrew Testament" was translated into Greek, and then into Latin, if memory serves. These translations often contained errors that have made it into the Christian 'mainstream' ("Splitting the Red Sea" never happened, for example. It was the "Sea of Reeds", according to the original Hebrew).
Ergo:
killing without religious sanction - bad
mass murder whenever God changes his mind about the whole 'sanctity of all life' thing - good
Procrastination Man strikes again!
if its got one of those egg shaped door knobs im letting it hit me
oooh baby!
It's not an irrelevant opinion, it's the entire content of this thread: you made a dumb assertion and got called on it. Nor is it an ad hominem attack; an ad hominem attack is one that uses personal attacks to prove some argument. But in this case, I actually have proven my argument: you were totally ignorant of the rebuttals of Cooperstock and Tieu's paper even while citing their paper as dispensing with dark matter.
Yeah, I am so terribly concerned with pleasing you, Mr. Anonymous CuttingEdge.
Of course it is intended to do so, because it certainly is not remotely "magic": it is well supported by the observational evidence, and there are independent lines of reasoning from particle physics that require the existence of particles that fit the role of dark matter.
The hell it isn't. You ask for evidence supporting dark matter, I gave it.
I didn't attack your request for "extraordinary evidence". In fact, I gave you quite a bit of evidence. However, there is no reason for the evidence in dark matter's favor to be "extraordinary", because, as I said, dark matter has not been conclusively proven. Dark matter, however, is a well supported idea, and the evidence, while not "extraordinary", is proportionally strong to the credence lended to dark matter.
It is very probably the case that physicist don't know exactly how to account for our observations; there are multiple theories. It is not at all likely the case that dark matter is nonexistence because of some calculational error. The existence of dark matter will be resolved by a new theory driven by new experimental evidence. It won't be because physicists have been misapplying existing theories all along due to math errors.
If it's a different question, than why did you cite C&T in support of your claim regarding physicists making math errors?
As I said before, it is easily possible for individual physicists to make errors. To believe that the entire physics community collectively forgot to apply a modern theory of gravity (general relativity) to the problem is beyond absurd.
No, it's not. No matter how eminent an individual physicist, their work has to be judged and reviewed by others; they made an extremely careless mistake, and got called on it.
E = mc^2/69 dude
It's a nice article abouw a new formula, but they forgot one minor detail: the formula. Or is it patented already?
"an idiot of the highest order" isn't an ad homenim attack eh?
While you might seem to know something about physics you also evidently have a need to personally attack those who argue and challenge your statements by reverting to the time honored practice of name calling.
The Magic of The Amazing Randi has more reality to it than Dark Matter.
I suppose that you believe in God as well as Dark Matter?
I agree with the grandparent, and disagree with you.
There's no governing body of scientific terms, but I've seen many proposed laws with no prior history of being called a theory. In my physics experience, laws are almost always a mathematical model of observed behavior with no attempt to explain the underlying reasons or mechanics of said behavior.
Laws are theories as they fit all the definitions of a theory, but they don't become laws by extra proof, rather by their initial limited nature. For example, there is a law of gravity ( F = G Ma Mb / r^2 ) and there are separately various theories of gravity such as general relativity.
-Ryan C.
No, it's an insult. (Not that I claimed that it wasn't to begin with.) Look up the difference, idiot. Hell, I even explained the difference to you.
Wow, that's a convincing argument. I cited both experimental and theoretical support for dark matter, and you in return respond with little more than "it's magic
Nope.
Face it dude, you lost. Save some face and admit you've been making a fool out of yourself. You're not going to hide your ignorance by attacking me.
Dark Matter exists, and in my opinion it is here for good. The attempts to come up with alternative theories of gravity are quite noble, but they only work on certain scales, and the proponents of these theories sometimes neglect examples that invalidate their theory. It would be quite elegant to be able to account for dark matter via a modification of gravity alone, but I am afraid that it will not be possible.
One of the most compelling pieces of evidence for the existence of dark matter is the "bullet cluster of galaxies" discovered by Maxim Markevitch and collaborators. Their 2004 peer reviewed article shows a small cluster of galaxies passing through much more massive one. As the cluster passes through, its gas is stripped, but the dark matter stays behind, detected via weak gravitational lensing. This effect is impossible to reproduce using alternative theories of gravity, because there is a visible separation between the total mass peak and the observable mass peak.
There are dozens of other peer-reviewed articles that argue against these alternative theories of gravity. What about the cosmic microwave background? The CMB is one of the underpinnings of modern cosmology and basically made the big bang the widely accepted theory that it is today. This recent analysis of the CMB show that the kind of alternative gravity proposed here is strongly disfavored by the CMB spectrum, and that it would imply too high a neutrino mass.
I challenge you to look through the literature for yourself. Here is a list of papers discussing modified newtonian gravity and its derivatives... You will find that yes, these alternative theories do work quite well at describing the rotation curves of galaxies, as TFA suggest. But on larger scales, such as in cluster of galaxies and the cosmic microwave background, they seem to fail convincingly.
The Universe is very, very old. --More than old enough for lots of stars to have burned out like this.
I really don't see a problem with the Dark Matter theory. In fact, I don't really understand why a theory is even required here. All which is being said is that, "Maybe it's still there even if it doesn't glow in the dark!"
Duh.
But then that seems to be largely the main problem with mixing science with the muggles; "Until I see it, I won't believe it!" People seem to have a lot of trouble recognizing that sometimes there are things affecting the world which don't immediately register on the 5 senses. Gee whiz. Perhaps it's time to graduate from kindergarten.
-FL
you made a dumb assertion and got called on it
There you go again with the personal attacks and name calling. If I was to stoop to your level I'd have to say something like "wash your mouth out with some dark matter". However, I won't stop to your low level.
I actually have proven my argument: you were totally ignorant of the rebuttals of Cooperstock and Tieu's paper even while citing their paper as dispensing with dark matter.
You've not proven your argument. You are assuming that the rebuttal papers are conclusive in dispensing with the Copperstock and Tieu line of reasoning. That's a big leap. They have opened a new door, a new possibility that others have rejected. Maybe it will lead nowhere but it's an open possibility that will need to be fully explored and a few rebuttal papers are NOT necessarily the end of it.
"Yeah, I am so terribly concerned with pleasing you, Mr. Anonymous CuttingEdge."
I already addressed the advantages of Slashdot accounts that do provide some identity presense which you seem to reject out of hand Anonymous Coward.
You assume that a comparison of Dark Matter with Magic is bad.
The Amzaing Randi can present conclusive proof that Magic is real, which is a lot more than you can say about Dark Matter with it's "strong evidence".
Your linked posting, which you can't prove is yours since you've posted it anonymously, wasn't relevent to my posting since the linked posting didn't provide conclusive and extraordinary proof.
I didn't attack your request for "extraordinary evidence". In fact, I gave you quite a bit of evidence.
But you didn't present extraordinary evidence. As Carl Sagan said "extraordinary claims require extraordinary evidence."
Dark Matter doesn't need to have been "proven" to require the production of extraordinary evidence. The fact that the Dark Matter hypothesis makes extraordinary claims is enough to trigger the requirement for extraordinary claims.
"The existence of dark matter will be resolved by a new theory driven by new experimental evidence. It won't be because physicists have been misapplying existing theories all along due to math errors.
Maybe, maybe not. You don't know that for sure unless you can travel into the future or see into a crystal ball. In fact your statement is a belief.
"If it's a different question, than why did you cite C&T in support of your claim regarding physicists making math errors?
Obviously you need to re-read the paragraph untill you understand what it's saying. Let me be very clear: You are assuming that the rebuttal papers are conclusive in dispensing with the Copperstock and Tieu line of reasoning. That's a big leap. They have opened a new door, a new possibility that others have rejected. Maybe it will lead nowhere but it's an open possibility that will need to be fully explored and a few rebuttal papers are NOT necessarily the end of it.
You "believe" that they made errors. Reading the papers it looks that way. However it's not the end of that line of reasoning you'll have to admit.
For a time people thought that Einstein made a big mistake with his Comological Constant, he also beleived that it seems. Now it could be that he was on to a line of reasoning that while not entirely correct is reaping large rewards. Who are you to judge Cooperstock and Tieu and dispense with their work with a lot of sound, fury and insults? Aspects of thieir work could prove valuable.
Belittling them is an ad hominem attack. Belittling them lowers the quality of your work. It's a favorite method of arguing of yours. It's likely that you use it in your life with many of the people around you. Satisfying is it?
My response to ad hominem attacks is too point them out to the person who makes them rather than replying in kind. Please raise the quality of your discussion.
By stating that Cooperstock and Tieu are just "two guys" you do them a diser
"No, it's an insult.
Embedded within an argument or not an insult is a form of personal attack. It simply indicates the low quality of your arguments.
I laid out the extensive scientific support for the theory -- and, as I offered earlier, I can point you towards review articles with much more evidence.
As you yourself stated the evidence isn't conclusive.
Wow, that's a convincing argument.
Obviously you missed the point about the comparisons with Magician's Magic being real and Dark Matter being a hypothosis.
The scientific basis for calling the Dark Matter mythical magic is that it's not yet been proven conclusively. It's still a theory in the works, a hypothosis without substantial evidence of the extraordinary kind to support the extraordinary claims made by it's Dark Matter hypothesis.
You've won nothing. You've missed the point completely. It seems that since you don't get what I was saying you revert to calling me names rather than asking pertinent questions. Up the quality of your discussion, stop insluting people. Reread what I've written and see if there are other meanings that you missed on prior readings. You might learn something.
Save some face and admit you've been making a fool out of yourself. You're not going to hide your ignorance by attacking me.
I'm not attacking you. I'm pointing out where you are attacking me. Am I a fool for pointing out that Dark Matter is still simply a hypothesis with some evidence and in that regard it has aspects of similarity with Magicians Magic and Mythical Magic? Am I a fool for pointing out that you are using personal attacks in your arguments? Am I a fool for letting you know that it's possible that there could be alternative explainationsof reality that don't resort to the use of what is essentially Magical Dark Matter (remember it's not yet been proven that Dark Matter exists)?
Could it be that you missed the points that I've been making? Yes it could be.
Okay. I shall henceforth refer to it as the Commandment of General Relativity.
Time to go poke at Wikipedia I guess...?
I also speak hebrew, and a good portion of the first testimant was taught to me in public school in Israel. The exact words in the bible are "buttafucco". The current usage of the word means "breakdance", not "hambone". I am quite sure that the word for hambone(ereg) existed during the time the bible was written.
As a side note, the "ancient language" remained very consistant for a very long time. There is very little difference between the hebrew spoken then versus now. Only when you get far enough in the past to aramaic (spelling??), you get an actual different language but I find it funny that you think it does assface.
Just to clarify:
* Today many Bible scholars assume that the"Red Sea" of the Old Testament should be translated "sea of reeds," and therefore must refer to a freshwater lake.
* The translation of "yam suph" into "sea of reeds" violates the context of Exodus 2:3, as well as other usages of the word "suph" in the Old Testament.
* "Yam suph" would be more correctly translated "sea of seaweed," and could refer to any body of water - freshwater or saltwater - in which aquatic weeds flourish.
* Numerous other biblical references indicate that "yam suph" is the Red Sea proper with its two gulfs, most frequently the Gulf of Aqaba in particular.
* Biblically speaking, "yam suph" can refer only to the Red Sea proper.
* The later terminology, "Red Sea," probably arose from the Gulf of Aqaba's association with "Edom," which in Hebrew means "Red."
From: http://www.baseinstitute.org/yamsuph.html
It seems you'll stoop to the lowest level of continuing to provide utterly content-free postings. In all these responses nothing you've said has actually address the scientific content of either dark matter theories or their alternatives.
I am not assuming that, I know that, because I am capable of following their arguments and those of the rebuttals, even if you are not.
Specious argument. People thought that because there was no observational evidence in its favor. (There was none falsifying it, either, so Occam's Razor was applied.) Cooperstock and Tieu, on the other hand, simply proposed a flawed model that was already falsified by existing data the moment it was proposed.
I can dispense with their work in any fashion I please, and unlike you, I know what I'm talking about when I do it.
No, it isn't, it's an insult. You still don't comprehend the difference, despite having had it explained to you.
Logical fallacy. In fact, that statement of yours is precisely the ad hominem fallacy. But then, since you don't know what the ad hominem fallacy is, why should I expect you to identify it in this case either?
No, I don't. That's exactly what they are. And what they did was foolish. They should have known better, because they've done good work in the past.
Again you are applying the ad hominem fallacy. Let me explain it to you again: insulting someone, or personal attacks, are not ad hominem arguments. Insults or personal attacks are ad hominem arguments when they are used to attack the logical credibility of someone else's argument. Saying "You're a name-calling coward" is an insult, but not an ad hominem. Saying, "You're a name-calling coward and therefore your scientific statements are questionable" is an ad hominem argument. Saying "Cooperstock and Tieu were foolish, and their paper is flawed" is not an ad hominem argument. Saying "their paper is flawed because they are foolish" is an ad hominem, but I didn't say that. I said it was flawed for completely different reasons, summarized in the rebuttal papers I linked.
There is never proof in science, only evidence of varying strengths. And the strength of the evidence in favor of dark matter is much closer to the "conclusively proven" side of things than the "mythical" side of things.
Go read what I wrote again. I said there is not a need for extraordinary evidence, because that kind of evidence is only required to justify "conclusively proven" claims. Dark m
That's an ad hominem on your part, but you're still too stupid to realize it. The validity of my scientific argument has nothing to do with the language in which it is couched.
And therefore it doesn't require "extraordinary proof", because extraordinary claims aren't being made about it. If I said "dark matter is definitely true", that would require extraordinary support to back it up. If I merely say, "dark matter is more likely than not to be true", I only need strong support — which dark matter has.
More idiotic semantics. Saying something is "mythical magic" implies that it has no scientific basis. It is a far stronger claim than something something is merely "not conclusively proven".
The existence of dark matter is not an extraordinary claim. In fact, it is predicted by several theories of particle physics. It's also not extraordinary to claim that dark matter can account for observations. It is merely extraordinary to claim that dark matter definitely exists and accounts for all our observatoins. But that claim is not made.
Yes. The justification for dark matter is far stronger than "myth".
"Not proven" != "Magical". "Magical" is simply an insult. "Mythical magic" does not have strong scientific support: that is, in fact, precisely what distinguishes myths from consensus science.
But let's drop the semantic games about "extraordinary" amd "magical" and crap like that. Yes or no: "The observational evidence and theoretical lines of argument in favor of dark matter make its existence (a) plausible, or (b) not only plausible but likely".
I said there is not a need for extraordinary evidence, because that kind of evidence is only required to justify "conclusively proven" claims.
Yes, it's obvious that you said there is no need, however that's nonsense. The Dark Matter hypothesis makes claims that require extraordinary evidence beyond the "strong evidence" obtained so far.
Obviously this is a point where we disagree.
In your other points you are simply repeating yourself or stating obvious facts about science and the Dark Matter hypothesis. Oh, ya and you continue with your insulting ways. You also seem to enjoy twisting statements to extreme points of view that do not actually reply to what I said, in essense taking the points out of context.
You also seem to be shifting your point of view on the "strength" of the Dark Matter hypothesis stronger and stronger.
My posts have been appropriate responses to what you've posted. However, you keep missing the points in the posts and are constantly using insults, belittling statements, ad hominem attacks (contrary to your statements that you've not used them), personal attackes, etc... against me and the scientists mentioned. By any assessemnt you would be well servered to alter your approach.
If you look at the forum history you will see that you are using personal attacks. All I did was point out that fact. Pointing out that you use personal attacks is not a personal attack since I'm repectfull, have not called you names, and have asked that you stop such comments in the discussion. Your counter that these comments are themselves personal attacks against you is silly since it's clear that you are the one making the insults and attacks.
I hope that you will reconsider your usage of the illegimate argument devices and stop using them. Then maybe we can continue a civil discussion.
First, and glaringly....you said:
about scales, from TFA:
A non-Newtonian gravity theory is now fully specified on all scales by a smooth continuous function.
so, this yet to be reviewed theory claims to have overcome your first objection, and you cannot prove them wrong until April.
you said:
ok, so no theory that you have seen can explain gravity better than dark matter without being REALLY contradictory to observations. Yeah, you know what I'm going to say...it is possible this new theory can do what you say it can't...which brings me to:
overall, i think you're wrong when you say dark matter absolutely must exist. Supposedly, this theory can explain gravity in a way that somehow changes predictably on different scales.
IANAA, but judging from the new kuiper belt object xena, I think the Oort Cloud may be the beginning of a new understanding of what it is exactly that lies between us and our nearest neighbors...on all scales. I think it's possible we will eventually observe many more such objects. While it may sound as if I'm supporting a dark matter theory, no...I am merely stating that neither dark matter nor this new theory will be the last, simplest theory of gravity. Dr Fameay from TFA would agree:
It is possible that neither the modified gravity theory, nor the Dark Matter theory, as they are formulated today, will solve all the problems of galactic dynamics or cosmology. The truth could in principle lie in between, but it is very plausible that we are missing something fundamental about gravity, and that a radically new theoretical approach will be needed to solve all these problems. Nevertheless, our formula is so attractively simple that it is tempting to see it as part of a yet unknown fundamental theory. All galaxy data seem to be explained effortlessly
Thank you Dave Raggett
"Preferred" does not mean "stand back and get beaten up", it means what it says. If there is an option by which nobody gets hurt, that should be considered (not "required", considered) first.
"Well, yes," you might say, "so if we all drive around in armoured, bullet-proof cars, wore chainmail armour and had a forcefield generator in a pocket, we'd be a lot safer. And how likely is that?"
With the exception of the forcefield, I don't see anything there that is so totally impossible that it simply cannot be done. You wouldn't use medieval chainmail, but you don't need medieval materials or design requirements, there not being many people with broadswords and maces walking around, and material science is a damn sight more advanced today. I'm also talking about a direction, not a specific point in time. If it's not viable today, then do your best today and see what you can do in ten years time, or a hundred years time. The idea that offence is the ONLY defence is not going to be valid for all time and may not be valid in many situations today.
I see no reason why society persists in limiting itself to 12th century methods, using 16th century tools, of handling 21st century threats which are likely as bad as they are due to 1st century attitudes. There almost has to be better methods of dealing with things, regardless of whether those methods are known today.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Eintein's theory certainly have improved the understanding of universe but since then, he did not really care about the gravity afterwords because he wa busy fighting and biting against Neils Bohr and other quantum Physicist in Europe. If there is any theory that uses Einstein's version of gravity (space time fabric), that would be String Theory. Remember, G(mu)(nu) is equal to 8(pie)-1/2 times g(mu)(nu).
What about option #3?
:)
3) Steve Jobs
Firstly, I'd been under the impression that some galaxies behaved differently ( because the "dark matter" had been stripped out from them, or otherwise relocated, or something, in intergalaxy-collision ), and this was part of the validation of the "dark matter" idea, AND
Why in hell does everyone call it Dark Matter, when it is Dark Mass, but with n-1 .. 1 ( or 0? ) dimensional branes ( assuming n dimensions ), rather than "particles", so the term "matter" builds assumptions that enbogify our understanding from the get-go?
Eh?
IPTables enhancement Fail2Ban bans cracker-login's
And we have a winner. I was cringing while waiting for this arrogant remark, though hoped nobody would be dumb enough to present it. (And when I say "arrogant", I am referring to the human condition as a whole rather than individual myopia.)
Gravitational microlensing only works if there happens to be a lighted star between the observer and the subject, (a tiny little degree just off to one side, to be precise). Observational constraints indeed! Gravitational microlnsing is a clever way to prove the existence of brown dwarfs, not a way to perform a full spectrum 'scanner' sweep capable of mapping the heavens.
There is a whole lot of matter out there which is simply not illuminated. Period. The "Missing Matter" needn't be described by magical non-particles which, (ahem) have never been observed, and which make a lot less sense than the lights simply being out.
It strikes me that this is further evidence that it is the social acceptability of an idea which determines its Lemming-Magnet factor rather than the actual rationality, or in this case, the irrationality behind it.
That is, I thought serious scientists looked down their noses at things like ghosts. (Which is, of course, equally short-sighted of them.)
-FL
I read that line and immediately pictured astronomers flying around randomly.
Then I imagined a silly thought experiment. If a bunch of non-Einsteinian gravity astronomers were in an elevator and it dropped, would they just fly/bump around the elevator in random directions?