Archive for astroparticle physics

A New Theory of Dark Matter

Posted in Science Politics, The Universe and Stuff with tags , , , , , , on November 6, 2010 by telescoper

Since this week has seen the release of a number of interesting bits of news about particle physics and cosmology, I thought I’d take the chance to keep posting about science by way of a distraction from the interminable discussion of  funding and related political issues. This time I thought I’d share some of my own theoretical work, which I firmly believe offers a viable alternative to current orthodox thinking in the realm of astroparticle physics.

As you probably know, one of the most important outstanding problems in this domain is to find an explanation of dark matter, a component of the matter distribution of the Universe which is inferred to exist from its effects on the growth of cosmic structures but which is yet to be detected by direct observations. We know that this dark matter can’t exist in the form of familiar atomic material (made of protons, neutrons and electrons) so it must comrpise some other form of matter. Many candidates exist, but the currently favoured model is that it is made of weakly interacting massive particles (WIMPs) arising in particle physics theories involving supersymmetry, perhaps the fermionic counterpart of the gauge bosons of the standard model, e.g. the photino (the supersymmetric counterpart of the photon).

However, extensive recent research has revealed that this standard explanation may in fact be incorrect and circumstantial evidence is mounting that supports a  radically different scenario. I am now in a position to reveal the basics of a new theory that accounts for many recent observations in terms of an alternative hypothesis, which entails the existence of a brand new particle called the k-Mason.

Standard WIMP dark matter comprises very massive particles which move very slowly, hence the term Cold Dark Matter or CDM, for short.  This means that CDM forms structures very rapidly and efficiently, in a hierarchical or “bottom-up” fashion. This idea is at the core of the standard “concordance” cosmological model.

However, the k-Mason is known to travel such huge distances at such high velocity in random directions between its (rare) encounters that it not only inhibits the self-organisation of other matter, but actively dissipates structures once they have been formed. All this means that structure formation is strongly suppressed and can only happen in a “top-down” manner, which is extremely inefficient as it can only form small-scale structures through the collapse of larger ones. Astronomers have compiled a huge amount of evidence of this effect in recent years, lending support to the existence of the k-Mason as a dominant influence  (which is of course entirely at odds with the whole idea of concordance).

Other studies also provide pretty convincing quantitative evidence of the large mean free path of the k-Mason.

Although this new scenario does seem to account very naturally for the observational evidence of  collapse and fragmentation gathered by UK astronomers since 2007, there are still many issues to be resolved before it can be developed into a fully testable theory. One difficulty is that the k-Mason appears to be surprisingly stable, whereas most theories suggest it would have vanished long before the present epoch. On the other hand, it has also been suggested that, rather than simply decaying, the k-Mason may instead  transform into some other species with similar properties; suggestions for alternative candidates emerging from the decay of the  k-Mason  are actively being sought and it is hoped this process will be observed definitively within the next 18 months or so.

However the biggest problem facing this idea is the extreme difficulty of  detecting the k-Mason  at experimental or observational facilities. Some scientists have claimed evidence of its appearance at various laboratories run by the UK’s Science and Technology Facilities Council (STFC), as well as at the Large Hadron Collider at CERN, but these claims remain controversial: none has really stood up to detailed scrutiny and all lack independent confirmation from reliable witnesses. Likewise there is little proof of the presence of k-Mason at any ground-based astronomical observatory, which has led many astronomers to conclude that  only observations done from space will remain viable in the longer term.

So, in summary, while the k-Mason remains a hypothetical entity, it does furnish a plausible theory that accounts, in a broad-brush sense, for many disparate phenomena. I urge particle physicists, astronomers and cosmologists to join forces in the hunt for this enigmatic object.

NOTE ADDED IN PROOF: The hypothetical “k-Mason” referred to in this article is not to be confused with the better-known “strange” particle the  k-Meson.


There is no Zero

Posted in The Universe and Stuff with tags , , , , on October 1, 2010 by telescoper

The Incredible Shrinking Man is a science fiction film made in 1957. If you haven’t seen it before its title will probably make you think it’s a downmarket B-movie, but it’s far from that. In fact it was very well received by film critics when it was first released and in 2009 was added to the Library of Congress list of films considered to be culturally, historically or aesthetically significant. The  special effects used to portray the main character reducing in size were remarkable in its day, but for me the film is worth it for the wonderful ending shown in the clip:

I first saw this film on TV when I was at school and the final monologue made such an impression on me that it keeps popping into my mind, as it just did. The field of astroparticle physics encompasses cosmology, the study of the Universe on the largest scales accessible to observation (many billions of light years) as well as the smallest dimensions we can probe using the techniques of particle physics.  As the Incredible Shrinking Man realises, these are just two aspects of the same underlying unity. There’s nothing specifically new about this line of reasoning, however; I posted a poem a while ago that dates from 1675 which has a similar theme.

I decided to put the clip up now for two reasons. One is that the phrase “there is no zero” (which has passed me by on previous occasions I’ve watched the clip)  reminds of some stuff I wrote recently for a book that I’m struggling to finish, about how there’s no such thing as nothing in physics. Space is much more than the absence of matter and even empty space isn’t the same thing as nothing at all. Zero is also just the flip side of infinity and I don’t think infinity exists in nature either. When infinity appears in our theories it’s just a flag to tell us we don’t know what we’re doing. Many others have thought this thought: both Gauss and, later, Hilbert argued against the possibility of there being realised infinities in nature. My old friend and erstwhile collaborator George Ellis adheres to this view too.

The other reason for posting it is that, in these days of the Incredible Shrinking Science Budget, it’s important that we recognize and nurture the deep connections between things by supporting science in all its forms. Once we start trying to unpick its strands, the web of knowledge will all too quickly unravel.