The Universe's missing mass - do you buy it?

[merlin wood]

That's the only explanation that makes any sense to me...

...mind you I've never heard any others

Well there's no proof that the uncertainty principle decribes any quantum behaviour beyond what can be measured from the experimental results or that dark matter exists, but rather there are good reasons to think that it doesn't and it wouldn't explain galactic rotation, anyway.

But then there isn't really any alternative academically recognised theory that's workable either.

I say the only alternative is an account that seems, so far anyway, to be too radical for any physicist to accept. In part because this would mess up a lot of the cosmological theory that has been developed for the past 25 years or so. For, in short, this alternative theory describes details of a universal cause that acts non-locally in additon to all the forces, and which also causally explains quantum mechanics, as well as much else.

 

[WouldBe]

You can't buy it, it's missing

Have you checked e-bay?


It's anti-photons. They travel round the universe absorbine em radiation. That's why we can't detect them.

 

[SpookyFrank]

Have you checked e-bay?


It's anti-photons. They travel round the universe absorbine em radiation. That's why we can't detect them.

Well then why isn't there loads of energy missing as well

 

[WouldBe]

Well then why isn't there loads of energy missing as well

That's the dark energy contained in anti-photons.

 

[goldenecitrone]

...and then, also, there is the mysterious trajectory of both the space probes Pioneers 10 and 11, which are now way outside the solar system and which have also been measured to possess acceleration rates that are close enough to the cosmic acceleration to be significant.

Thanks for that. How come this kind of stuff doesn't make headline news. Too caught up in our own little lump of rock I suppose.

 

[merlin wood]

Thanks for that. How come this kind of stuff doesn't make headline news. Too caught up in our own little lump of rock I suppose.

I predict that it will become more well known in the future because these anomolous trajectories of the Pioneer space probes are the first nonlocal effects on an astronomical scale detected from human produced objects.

 

[Johnny Canuck3]

Ever since I studied physics I've wondered about this question. Is there really a huge load of mass in the Universe out there waiting to be found, or is it actually that our fundamental theories (such as general relativity) are a bit wrong?

Astrophysicists always seem to proceed on the basis that the theories are right and the mass is out there to be found - how can they be so sure? Is it worth spending millions of research dollars trying to solve a problem that may not exist?

How will we know it doesn't exist if we don't spend the money?

 

[Jonti]

Even if we spend the money it could still be hiding somewhere else

Kinda like (what Bush said about) WMDs in Iraq, y'know!

 

[merlin wood]

How will we know it doesn't exist if we don't spend the money?

Although you could think that over 40 unsuccessful experiments carried out since 1987 trying to directly detect what's supposed to be 90% of all matter in the universe is getting a bit much now.

Except that the cosmological problems that the introduction of non-baryonic dark matter is supposed to resolve are not trivial. According to current theory the stuff is needed for the universe to have evolved at all from the Big Bang.

Time for a radically new theory? Well I can't see any sign of that happening very soon, I'm afraid.

 

[Jonti]

TAKE our best understanding of gravity, apply it to the way galaxies spin, and you'll quickly see the problem: the galaxies should be falling apart. Galactic matter orbits around a central point because its mutual gravitational attraction creates centripetal forces. But there is not enough mass in the galaxies to produce the observed spin.

Vera Rubin, an astronomer working at the Carnegie Institution's department of terrestrial magnetism in Washington DC, spotted this anomaly in the late 1970s. The best response from physicists was to suggest there is more stuff out there than we can see. The trouble was, nobody could explain what this "dark matter" was.

And they still can't. Although researchers have made many suggestions about what kind of particles might make up dark matter, there is no consensus. It's an embarrassing hole in our understanding. Astronomical observations suggest that dark matter must make up about 90 per cent of the mass in the universe, yet we are astonishingly ignorant what that 90 per cent is.

Maybe we can't work out what dark matter is because it doesn't actually exist. That's certainly the way Rubin would like it to turn out. "If I could have my pick, I would like to learn that Newton's laws must be modified in order to correctly describe gravitational interactions at large distances," she says. "That's more appealing than a universe filled with a new kind of sub-nuclear particle."

shamelessly c&p'd from #5 of New Scientist's 13 things that do not make sense

 

[merlin wood]

TAKE our best understanding of gravity, apply it to the way galaxies spin, and you'll quickly see the problem: the galaxies should be falling apart. Galactic matter orbits around a central point because its mutual gravitational attraction creates centripetal forces. But there is not enough mass in the galaxies to produce the observed spin.

Vera Rubin, an astronomer working at the Carnegie Institution's department of terrestrial magnetism in Washington DC, spotted this anomaly in the late 1970s. The best response from physicists was to suggest there is more stuff out there than we can see. The trouble was, nobody could explain what this "dark matter" was.

And they still can't. Although researchers have made many suggestions about what kind of particles might make up dark matter, there is no consensus. It's an embarrassing hole in our understanding. Astronomical observations suggest that dark matter must make up about 90 per cent of the mass in the universe, yet we are astonishingly ignorant what that 90 per cent is.

Maybe we can't work out what dark matter is because it doesn't actually exist. That's certainly the way Rubin would like it to turn out. "If I could have my pick, I would like to learn that Newton's laws must be modified in order to correctly describe gravitational interactions at large distances," she says. "That's more appealing than a universe filled with a new kind of sub-nuclear particle."

shamelessly c&p'd from #5 of New Scientist's 13 things that do not make sense

Except that no modification of Newton's laws actually works overall, at least, and it also produces unlikely complications in relativity theory.

 

[WouldBe]

Except that no modification of Newton's laws actually works overall, at least, and produces unlikely complications in relativity theory.

Do the laws need to be modified?

What if an iron nickel core isn't the norm for planets but one or more of the much heavier elements?

 

[merlin wood]

Do the laws need to be modified?

What if an iron nickel core isn't the norm for planets but one or more of the much heavier elements?

Irrelevant since, for one thing, the mass of the planets have been accurately measued and another, this would not explain the rotation of galaxies at all.

 

[SpookyFrank]

Irrelevant since, for one thing, the mass of the planets have been accurately measued and another, this would not explain the rotation of galaxies at all.

Stupid question perhaps but how?

 

[merlin wood]

Stupid question perhaps but how?

From the orbits of the planets around the sun and the moons around the planets which all do accurately obey Newton's laws, as do, up to a certain point the stars orbiting galaxies.

The problem with Newton's laws only arises when objects possess a very low rate of rotation or acceleration, which is much less than the orbit of any moon or planet.

 

[WouldBe]

Irrelevant since, for one thing, the mass of the planets have been accurately measued and another, this would not explain the rotation of galaxies at all.

No they haven't as we've only discovered a handful outside our solar system.

 

[merlin wood]

No they haven't as we've only discovered a handful outside our solar system.

Yes they have. Earth's mass having been measured to be 5.9736×10^24 kg, Mars 6.4185×10^23 kg and so on.

And your suggestion that planets are more massive cores is also irrelevant, anyway, because, as I said, Newton's laws are only measured to be disobeyed by objects with less than a certain rate of orbital motion, like the the outer stars of galaxies and the Pioneer space probes and also, the motion of whole galaxies in clusters (unless you assume the existence of dark matter, which doesn't work well for stars in galaxies, anyway).

Then, if you think about it, and forget about modifying Newton's laws by considering that the strength of gravity decreases at a different rate with increasing distance, you can say that the anomolous orbits also occur when the strength of gravity is below a certain amount.

And then you can think that a quite weak cause could act in addition to gravity, and so that the effects of this can only be measured when this cause becomes stronger than the weakening action of gravity with distance. While this hypothesis would also work for the Pioneer probes because the anomolous effect is measured to be greater than for orbiting stars, which would be the case for objects of a such a small mass as space probes.

Also as I mentioned above, there is this mysterious coincidence between the measured acceleration of stars in galaxies where the anolomoly begins to apply and the measured acceleration in the expansion of the universe, and which can't be explained either by modifying Newtons laws or by any dark matter/energy theory...

 

[jcsd]

The theory Merlin Wood is talking about is Modified Newtonian Dynamics (MOND), however the general consensus is that the theory of dark matter is preferable and has more evidence than MOND (though not substanially enough to stop MOND from being an intersting avenue). In the stronegst DM theories a large compoent of the dark mass is non-baryonic meaning it can't be completely explained by planets and the like.

 

[merlin wood]

The theory Merlin Wood is talking about is Modified Newtonian Dynamics (MOND), however the general consensus is that the theory of dark matter is preferable and has more evidence than MOND (though not substanially enough to stop MOND from being an intersting avenue). In the stronegst DM theories a large compoent of the dark mass is non-baryonic meaning it can't be completely explained by planets and the like.

Your comment above is without a quote from me, jscd. So stop putting words in my mouth.

I'm not talking about MOND but an alternative to both this and dark matter theory. Because this is what I in fact said in post #47 above:

Then, if you think about it, and forget about modifying Newton's laws by considering that the strength of gravity decreases at a different rate with increasing distance, you can say that the anomolous orbits also occur when the strength of gravity is below a certain amount.

And then you can think that a quite weak cause could act in addition to gravity, and so that the effects of this can only be measured when this cause becomes stronger than the weakening action of gravity with distance. While this hypothesis would also work for the Pioneer probes because the anomolous effect is measured to be greater than for orbiting stars, which would be the case for objects of a such a small mass as space probes.

So MOND (ie. Modified Newtonian Dynamics) is just about changing the action and effects of gravity as described by Newton's laws to fit the observations of galaxies.

Whereas my hypothesis is about a cause that would act in addition to gravity and so would alter the effects of gravity to fit the galactic observations.

Why should I think there's such an additional cause? Well, in full, that's quite a long story. But for a start you can argue that the existing theory of galaxy formation that describes the seeding of galaxies in the very early universe due to quantum fluctuations is unsatifactory because it depends on the unproven interpretation that the Uncertainty Principle describes the invisible behaviour of quantum particles.

Whereas I've found reasons to think that an explanation of large scale structure requires, in the first instance, a hypothesis based on a causal interpretation of quantum mechanics.

So you can begin by agreeing with Richard Feynman that "nobody understands quantum mechanics" and conclude that this is because, at least from any evidence found of matter or the energy it radiates on the smallest scale alone, no details can be sufficiently justified and described of a cause of, in particular, the invisible - because only indirectly detectable - quantum behaviour called wave, spin and entanglement.

And then you could just ask Might not a causal understanding of this unique quantum behaviour provide an essential key to explaining how the universe has come to possess its presently observed form both on the smallest and cosmological scale?

So for a start, don't the experimental findings indicate that all matter exists despite the forces acting within and upon it? and couldn't this be explained by sufficiently justifying and describing enough details of a cause of quantum wave, spin and entanglement? And might not the current cosmological problems be soluable by finding enough reasons to consider that such a cause could act on the astronomical scale?

And then suppose that such a detailed general theory of natural orginisation as a whole could be self supporting only from the combined evidence examined like, say, Newton's account of gravity and its various effects?

 

[WouldBe]

Yes they have. Earth's mass having been measured to be 5.9736×10^24 kg, Mars 6.4185×10^23 kg and so on.

Re-read what I put.

We don't know that our solar system is typical of all the other solar systems in the universe.

We don't know if 9 planets is typical for the size of star we have.

We don't know if an iron nickle core is typical for all the thousands of undiscovered planets in the universe. An iron nickel core probably isn't typical of the planets in our own solar system.

 

[merlin wood]

Re-read what I put.

We don't know that our solar system is typical of all the other solar systems in the universe.

We don't know if 9 planets is typical for the size of star we have.

We don't know if an iron nickle core is typical for all the thousands of undiscovered planets in the universe. An iron nickel core probably isn't typical of the planets in our own solar system.

But then, as I've been saying, your planetary theory is irrelevant because it can't be applied to the problems that the theories of MOND and dark matter have been designed to resolve. Which are the behaviour of stars in galaxies and of whole gaxies in clusters

So in fact, the the existence of dark matter was first proposed back in 1933 by the astrophysicist Fritz Zwicky to explain how the motion of whole galaxies in a cluster was possible and then it was only about 40 years later that dark matter theory was applied to the rotation of stars in galaxies. And dark matter or MOND theory need not be applied to any planetary system at all.

While I've found reasons to think that a whole new cosmology derived from a causal theory of quantum mechanics is needed to explain the behaviour of galaxies and galaxies in clusters, and also how galaxy rotation can be related to the expansion of the universe.

 

[fudgefactorfive]

Is it worth spending millions of research dollars trying to solve a problem that may not exist?

Have always been a bit split on this. The dark side of the force makes me say that astronauts are wankers, fuck off with your Moon landings while people are starving, there is a fucking hair's breadth between wankers who drive sports cars and wankers who, copiously and in public, wank over military-level space hardware, and anyway particle physics is better because (a) I like it and (b) you can do it without leaving Earth and not only use it to look at the other side of the universe but use it for useful stuff that might avoid the need for people to periodically go and murder other people, and the chances of actually cracking the planet in half by creating some exotic bundle of totally mad shit that last existed when the entire universe was still pocket-sized are actually fairly remote.

I can see the argument ... is the eventual fate of our entire galaxy what you could call a "pressing concern"? It all applies to the local scale too though, you can't deny it would be kind of useful to totally understand gravity.

Do I trust people to know how to bend space though? No. We fuck up our local environment cavalierly enough, who knows, maybe there are whole other galaxies just over the radar that are grotesquely fucked up by appallingly-scaled fountains of exotic energy that used to be the home solar system of a race of friendly iron slugs. How many of those particle jets coming from distant quasars are "slug-made"?

I say the only alternative is an account that seems, so far anyway, to be too radical for any physicist to accept

teh blind fools!!!!

 

[merlin wood]

teh blind fools!!!!

Nope, not fools. It's that modern physicists are too restricted in their methods and scope to take on what needs to be a whole new kind of physics of a cause acting universally in addition to the forces.

 

[Jonti]

... I've found reasons to think that a whole new cosmology derived from a causal theory of quantum mechanics is needed to explain the behaviour of galaxies and galaxies in clusters, and also how galaxy rotation can be related to the expansion of the universe.

And others think that perhaps f=ma does not exactly hold over intersteallar distances.

This may or may not matter to you, depending on how you feel about the Big Bang theory of cosmology. I'm just not so sure that time is so simple as to be submit to the idea that "just as there's nothing norther than north so there's no before the big bang".

 

[merlin wood]

...So, in short, the proposal is that it takes more than push or pull causes to make a universe both on the small scale and the cosmic scale. And more than such causes that can be described as surrounding objects in 3D space.

Whereas without recognising that or understanding how there is more than matter, energy and the forces acting in 3D space, no sensible answers will be found to questions such as how radiation and matter particles possess wave, spin and entanglement behaviour or how any form of matter can exist and persist given the action of the forces or how the universe evolved from a Big Bang origin to galaxies of stars and planetary systems, clusters of galaxies and cosmic voids.

Nor indeed will it be found out whether or not or if so how human beings and other living organisms consist of more than matter, energy and the forces or how it is they experience the world.

But rather, it seems, with their restrictive methods, theoretical scope and interpretaton of quantum mechanics, physicists will be forever stuck with their matter/energy/forces only view of the world, where the only solutions that can be sought to their big theoretical problems are bunging in vast amounts of matter and energy that cannot be directly detected by any means - from virtual particles to dark matter and then dark energy - and developing hugely complex theories that can't be adequately supported by observable evidence.

 

[Jonti]

Dark energy a furphy, says new paper

Here's an interesting take on the problem, from abc.net's "News in Science". In a nutshell, the theoretical need to postulate "dark-energy" just goes away if one drops a couple of unrealistic assumptions from the calculations.

"Dark-energy" protagonists use sums that assume the universe is both isotropic (same in all directions), and homogeneous (uniform everywhere). It makes the sums easier, you see. Thing is, we can now make observations that demonstrate that neither of these assumptions is good. We can now see that the universe is neither isotropic nor homogeneous. Instead, there is a tendency towards a bubble-like structure with large empty spaces surrounded by thin "filaments" of galaxies.

But, the standard model which requires dark energy ignores these differences. Take them into account and the need to postulate dark energy just disappears!

There's also a great slashdot post on the subject (which I lightly pillaged for this post).

 

[kyser_soze]

So basically, cosmologists have been doing what astronomers used to have to do when the Earth was centre of the universe, and make stuff up to fit the existing theory, and not make the theory fit observation then?

Quelle surprise over this TBH...

 

[Brainaddict]

So basically, cosmologists have been doing what astronomers used to have to do when the Earth was centre of the universe, and make stuff up to fit the existing theory, and not make the theory fit observation then?

Quelle surprise over this TBH...

To be fair, it behooves them to stick with the current model until there is an overwhelming weight of evidence to support a new model, but we as non-scientists have the luxury of being able to speculate before that point is reached, and I speculate that there's more missing from scientist's brains than there is from the Universe

 

[merlin wood]

Here's an interesting take on the problem, from abc.net's "News in Science". In a nutshell, the theoretical need to postulate "dark-energy" just goes away if one drops a couple of unrealistic assumptions from the calculations.

"Dark-energy" protagonists use sums that assume the universe is both isotropic (same in all directions), and homogeneous (uniform everywhere). It makes the sums easier, you see. Thing is, we can now make observations that demonstrate that neither of these assumptions is good. We can now see that the universe is neither isotropic nor homogeneous. Instead, there is a tendency towards a bubble-like structure with large empty spaces surrounded by thin "filaments" of galaxies.

But, the standard model which requires dark energy ignores these differences. Take them into account and the need to postulate dark energy just disappears!

There's also a great slashdot post on the subject (which I lightly pillaged for this post).

However, the amount of evidence for the overall acceleration in the universal expansion is now quite large. eg. see here.

You can insist, too, that there needs to be a definite explanation for the particular type of "lumpiness" of the universe that has been observed - ie Galaxy walls and filamentary clusters around vast cosmic voids - for which, at least without the experimental direct detection of any non-baryonic dark matter, there's still no such explanation.

 

[merlin wood]

However, the amount of evidence for the overall acceleration in the universal expansion is now quite large. eg. see here.

You can insist, too, that there needs to be a definite explanation for the particular type of "lumpiness" of the universe that has been observed - ie Galaxy walls and filamentary clusters around vast cosmic voids - for which, at least without the experimental direct detection of any non-baryonic dark matter, there's still no such explanation.

...but then I've found what I feal are enough reasons from the natural and experimental evidence to conclude that this alledged missing non-baryonic dark stuff is the Emperor of the Standard Model's invisible suit of clothes that won't be patched up by any peculiar modification of Newton's laws.

But instead what is needed is the natural magic of a nonlocally acting cause that also produces the quantum wave, and the truth of which can only be revealed by a real world revolutionary scientific explanation that describes how the universe really is: infinite.