This site uses cookies. By continuing to use this site you agree to our use of cookies. To find out more, see our Privacy and Cookies policy.
Skip to the content

Share this

Free weekly newswire

Sign up to receive all our latest news direct to your inbox.

Physics on film

100 Second Science Your scientific questions answered simply by specialists in less than 100 seconds.

Watch now

Bright Recruits

At all stages of your career – whether you're an undergraduate, graduate, researcher or industry professional – can help find the job for you.

Find your perfect job

Physics connect

Are you looking for a supplier? Physics Connect lists thousands of scientific companies, businesses, non-profit organizations, institutions and experts worldwide.

Start your search today


In the dark about dark matter

By Jon Cartwright

Has a European satellite detected dark matter? That’s the question on many people’s lips who attended the recent International Conference on High-Energy Physics (ICHEP) in Philadelphia, US.

Several physicists who attended the conference have told me that Mirko Boezio, a representative of the PAMELA (Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics) mission, briefly showed data depicting an excess of high-energy positrons in the ionosphere. If true, it would seem to be evidence of annihilation dark matter — an elusive substance thought to make up some five-sixths of all matter in the universe.

Unfortunately, neither Mirko Boezio nor the principal investigator of PAMELA, Piergiorgio Picozza, wants to comment on their data. They told me this was because they are planning to publish in either Nature or Science, and are therefore prohibited from talking to journalists because of those journals’ embargo policies. (Another little birdie told me that the PAMELA team is specifically aiming to submit to Nature by September, so if they fast-track it we might get to see the paper before Christmas.)

I’m going to tell you all I know about this, because frankly it’s not that much at the moment. The slides available from the ICHEP website only show positron data up to about 6 GeV, which doesn’t show much. Slightly better is this slide below from another PAMELA team member, Elena Vannucinni, who gave a presentation at the recent SLAC Summer Institute.

(Credit: PAMELA mission team)

This is a graph of the detected charge ratio — in other words, the ratio of positrons to electrons — against the particle energy. Although this PAMELA data set goes as far as 9 GeV, the satellite should be able to detect positron–electron ratios up to 270 GeV.

The line, labelled “Moskalenko and Strong 1998”, is a theoretical prediction of the positron–electron ratio without taking into account dark-matter annihilation. That means that anything above the line — anything with reasonably small error bars, that is — would indicate an unknown source of positrons, possibly dark matter. (By the way, don’t get too worried about the lower energy data falling way beneath the line — apparently Boezio said that was because the data was taken from a different time in the Sun’s 11-year solar cycle of activity.)

As I’m told, Boezio flashed up a slide like this one that had data stretching above 10 GeV while clearly going over the Moskalenko/Strong line.

“The results look okay,” Bhaskar Dutta of Texas A&M University wrote me in an email, adding: “The excess of positrons above 10 GeV is typical of dark-matter annihilation.”

Martin Perl, who shared the 1995 Nobel Prize in Physics for the discovery of the tau lepton and other contributions to lepton physics, was less keen to jump to conclusions. “If [the data] are true it would indicate an unknown source of positrons,” he wrote.

Stay tuned.

This entry was posted in General. Bookmark the permalink.
View all posts by this author  | View this author's profile


  1. Come on, Jon, isn’t it clear that it’s but another piece of show-business (or bullshit) science serving only to “justify” its senselessly wasted billions and unmerited personal profits? It’s clear that an observed excess of practically any radiation from universe (even if it’s convincingly confirmed!) can have too many possible sources (see also my and other comments on the corresponding Nature News information). And when one is so quick to attribute its still uncertain appearance to a very esoteric, practically “magic” entity (because it appears exclusively when it’s needed to save the bankrupt establishment of official science), well, don’t you have a clear impression of being duped (together with billions of tax-payers that have no choice for their hardly-earned money investment in science)?
    Today’s scientific policy in the West appears to seriously compete with its practical-life sister in the East for the highest degree of abuse of everything “human”. There even seems to be multiple links between the two (like ambition-to-brain ratio going to infinity). But in the second case we have at least some “theoretically limiting” notions like “crime against humanity”, etc. By contrast, in today’s science disaster the abuse of the world-wide totalitarian system is unlimited, by anything and anybody. Maybe it’s time to introduce something like “crime against human intelligence”, which should even be one of the worst kind of crimes against humanity (if humans may have something to do with intelligence)?
    Needless to say, a realistic alternative without artificially inserted “magic” entities and laws (like supernatural “quantum mysteries”), as well as always persisting and growing ruptures and contradictions, is not only possible but finds its increasing experimental confirmation (see the above link for references). However, let’s be open: do they ever need a real problem solution, however objectively nice and confirmed it may be, if it will inevitably demonstrate, irrespective of details, how far from truth and elementary human logic and honesty the absolute majority of “officially great” theories and their learned “private owners” may be? The already attained, undeniable (and always growing!) departure from consistency in establishment science excludes any other kind of essential knowledge progress. When knowledge becomes officially hidden but absolutely visible private property providing huge and uncontrollable profits to its owners, there can be no objective knowledge any more, only selfish fight of private interests of low-level dealers calling themselves “scientists”…
    Just take that whole recent fundamental physics evolution, with its unlimited spectrum of any desirable “scientific magic” completing traditional, century-old “mysteries”: hidden dimensions (any needed number of totally abstract, physically meaningless dimensions as a basis for the real, tangible world structure), their yet more hidden, abstract and absolutely uncountable “landscape” variations, multiverses wholesale and retail (elves and gnomes seem so realistic now, with respect to that “objective science”!), dark mass (any number of types), dark energy (any number of candidates: it’s magic!), supersymmetric particle partners (never seen in any intentional, super-penetrating and super-expensive experiment), a special entity (Higgs particle/field) providing a universal (and remaining physically unexplained) property (inertia + related energy? and gravitation?) for all other entities (but escaping, always escaping in the last moment…), etc. ad infinitum… And it really doesn’t matter how consistent theoretically and experimentally, let alone unified in a consistent system (similar to real world structure), these magic entities may be: because science is magic, today magic is science!
    And note even a particularly magic, totally “unexpected” appearance of these recent, trillion-worth advances of official science: until a very recent moment at the end of the 20th century, everything was so nice and almost great in the same science structure (cosmology including) dreaming only about a yet greater greatness (like unified theories), but then after just a relatively minor detail refinement, suddenly everything flips from plus to minus infinity: now we don’t know anything about the real world structure, almost all matter is magically hidden, forces are governed by hidden dimensions, and we don’t even know whether we are really here or just a bad dream of a drunken guy (our real God?!) from another, real (if ever!) universe (increasingly probable, in view of the last science and politics evolution)… Isn’t it evident that a kind of knowledge showing that kind of “stability” can only be pure magic (if only slightly covered by some mathematical “justification”), even irrespective of technical details? And if you think I exaggerate, just have a look at the officially dominating concept of “mathematical (abstract) reality” behind our tangible but only “visible” one, which is supported by the most renowned science priests at the most prestigious faculties… A rigorously specified, causally complete explanation for that “magic” trickery and its realistic-science alternative appear in their intrinsic unity, but then again, who needs the consistent reality but compromising all (truly!) magic profits of officially great scientists? Obviously not them, but unfortunately it’s exclusively them who determine any real scientific activity and decision in your best of all possible worlds…

  2. Alastair Carnegie

    Well sometimes a good rant gets one’s frustrations off one’s chest. I do it myself often. Science needs to remind itself now and again that knowledge, like a chain, is only as strong as it’s weakest link. I am constanly reminded of the good old Royal Society Motto, Now in it’s 350th celebration year. I quote:-
    The Royal Society’s motto ‘Nullius in verba’, roughly translated as ‘Take nobody’s word for it’, dates back to 1663, and is an expression of the determination of the Fellows to withstand the domination of authority (such as in Scholasticism) and to verify all statements by an appeal to facts determined by experiment. The Latin words (see below) are taken from a passage of Horace in which the poet compares himself to a gladiator, who, having earned peace and retirement, is free from control.
    ‘Nullius in verba’ was chosen to accompany the arms given to the Society by Charles II in the second charter of 1663. John Evelyn had sketched a variety of possible ‘Armes and mottoes proposed for ye Royal Society, 1660′, which included the motto eventually chosen and still used today. Designs which failed to make the final cut included a vessel under sail with the motto ‘Et augebitur scientia’, a hand issuing from clouds holding a plumb-line with the motto ‘Omnia probate’ (1 Thess. 5.21), two telescopes extended in saltire with earth and planets, motto ‘Quantum nescimus!’, and a shield bearing the sun in its splendour inscribed ‘Ad majorem lumen’, plus on one side of the shield ‘Quis dicere falsum audeat?’. A final design, a shield charged with terrestrial globe and human eye, is headed ‘Rerum cognoscere causas’ from Virgil’s Georgics, alongside which is the word ‘Experiendo’ and a repetition of ‘Nullius in verba’. All were rejected, with the exception of the latter, and the arms were entered into the official volume, ‘Royal Concessions in the College of Arms’, approved by the King on 22 April 1663 and entered into the record by Elias Ashmole on 30 June 1663.
    Ac ne forte roges, quo me duce, quo lare tuter,
    Nullius addictus iurare in verba magistri.
    (Horace, Epistles I.i, 1.13-14)
    You shall not ask for whom I fight
    Nor in what school my peace I find;
    I say no master has the right
    To swear me to obedience blind.
    (trans. C.T. Carr)

  3. Anton Szautner

    Oh my. You certainly have the gift of the blah blah, don’t you? Why not just tell us what you REALLY think?
    I guess you really do mind if the rest of us are impertinently curious. Pardon us all for stepping on your delicate toes.

  4. Edwin C Smith

    The 3 particles of a naturally occurring atom are 1: Bosons (call it the Higgs), 2: electrons, 3: positrons. The Higgs resides in the center of the unperturbed atom at ambient atmospheric temperatures and pressure. The Higgs Boson cannot be sensed with the 5 senses or with technologically available sensing devices. The Higgs Boson is responsible for mass and gravity. Mass can be sensed as a force operating through the space time to give a measurable force “weight”. Weight is the measurable attractive force of gravity operating between entities.
    Neutron stars are perhaps the source of the recently encountered positron plasma regions of space. If neutrons are built with positrons and electrons together with a Boson then a progressive gravity collapse would lead to expulsions of electrons then by expulsions of positrons from the neutrons collapsing in the corona like sphere of a neutron star. Perhaps this accounts for the puzzling source of the positrons found by the Alpha Magnetic Spectrometer.
    The Bohr/Rutherford atomic theory has served well for the last about 2 centuries but I think it is time to examine whether the proton is fundamental in nature.

Leave a comment

Your e-mail address will not be published. Required fields are marked *


  • Comments should be relevant to the article and not be used to promote your own work, products or services.
  • Please keep your comments brief (we recommend a maximum of 250 words).
  • We reserve the right to remove excessively long, inappropriate or offensive entries.

Show/hide formatting guidelines

Tag Description Example Output
<a> Hyperlink <a href="">google</a> google
<abbr> Abbreviation <abbr title="World Health Organisation" >WHO</abbr> WHO
<acronym> Acronym <acronym title="as soon as possible">ASAP</acronym> ASAP
<b> Bold <b>Some text</b> Some text
<blockquote> Quoted from another source <blockquote cite="">IOP</blockquote>
<cite> Cite <cite>Diagram 1</cite> Diagram 1
<del> Deleted text From this line<del datetime="2012-12-17"> this text was deleted</del> From this line this text was deleted
<em> Emphasized text In this line<em> this text was emphasised</em> In this line this text was emphasised
<i> Italic <i>Some text</i> Some text
<q> Quotation WWF goal is to build a future <q cite="">
where people live in harmony with nature and animals</q>
WWF goal is to build a future
where people live in harmony with nature and animals
<strike> Strike text <strike>Some text</strike> Some text
<strong> Stronger emphasis of text <strong>Some text</strong> Some text
WordPress Appliance - Powered by TurnKey Linux