1 Welcome to My Dark Matters ! if You

8/14/2019 1 Welcome to My Dark Matters ! if You

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Welcome to my dark matters !

If you want to know what kind of person I am, just go to http://reasonable.posterous.com,

and I will tell you about my private life, different hobbies and some eccentric experiments.Meanwhile, I want to tell you what I recently learned by studying up to date articles in the

magazines Scientific American and Sky & Telescope, searching for the last news about

mysterious dark matter, dark energy and vacuum energy.And what a surprice ! The empty spaces between billions of galaxies in the universe is not an

empty vacuum, full of nothing. Its full of matter and energy, constituting about 95 % of allmass and energy. But its invisible, why is it so ? You will perhaps find the answer if you read

my little abstract, so do it now !

Dark matter, how did it start ?

In 1687 Isaac Newton s law of universal gravitation , the firstmodern scientific description of gravity, involves action at a

distance . Newton was sure there must be an acount of gravity

without this nonlocality, and even tries an unsuccessful theori inwhich tiny, invisable, jiggling particles fill all of seemingly

empty space.

Who predicted the existence of dark matter ?

The swiss Fritz Zwicky (1898-1974 measured in 1933 the mass of the Coma cluster ofgalaxies, a near galaxie cluster outside our own . He found this to be 400 times the mass of all

visible stars from galaxies in this cluster. His conclution was that it had to be an invisibelmass in the univers, gluing together the galaxis.

What kind of particles could this bee, and not beeing obserevable? Such particles could not

be any of those created in particle accelerators, such as quarks, leptons and bosons .

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The first evidence .

In the MaxPlanck institute for astronomy

in Heidelberg three-dimentional picturesfrom galaxies was scrutinized, and

especially pictures from the Hubblespace telescope revealed a peculiar

phenonmena, called gravitation lenses.

Such distortion of a picture from a starcluster could only get its explanation

from an enormous gravitation influence.The stars in this the cluster could only

contribute with a few percent of this, the

rest had to come from the dark matter.In fact, his proves the existence of dark

matter.

What is the universe made of ?


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In the picturethe scale given is 500 Mpe/h (megaparcel) corresponding to 2 billion

lightyears. White says that dark matter must be an up to now unknown type of an elementaryparticle. We believe its kind of supersymmetric particles, Wimps.

A new approach to the understanding ?

Results from two guite different groups, the one using asatellite and the other a ballon, was

published at the end of 2008. The satellite group used the European PAMELA -satellite, the

ballon group used a ballon-borne instrument known as ATIC.

In Sky & Telescope Magazine for april 2009 the author Govert Schilling published an articlewith the title Shedding New Light on Dark Matter, where he discusses the observarions

and possible explanations. An extract from this article is presentet here:


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A theory (Wulf) based on observations from ATIC is that due to the drop-offabove 800 billion

eV Wulf suggest they come from annihilating Kaluza-Klein particles. Such particles shouldexist in tiny, rolled up fifth dimensions, from where they could make there presence in our

four-dimentional space-time .

Kaluza-Klein theory is a model that seeks to unify the two fundamental forces of gravitationand electromagnetism. In 1921 Kaluza extended general relativity to a five-dimentional

spacetime. The resulting equations can be separated out into further sets of equations, one ofwhich is equivalent to Einsteins field eqations, another set equivalent to Maxwells equations

for the electromagnetic field and the final part an extra field now termed the radion. In1926 , Oscar Klein proposed that the fourth spatial dimension is curled up in a circle of very

small radius, so that a particle moving a short distance along the axis would return to where it

began. The distance a particle can travel before reaching its initial position is said to be thesize of the dimention.

Exsistance of higher dimensioned particles is a prediction in the String Theory, not yet

confirmed by observations. String Theory presuppose eleven dimentions (seven in addition toour daily four x y -z and time) and its extreemly complicated to combine all forces incoincident mathematic equations.

Other physicists express scepticism , not sure that the measurements from ATIC are due to

dark matter. There are other objects that could accelerate positrons and electrons to such high

energies, such as pulsars and suopernovas, and concludes. Well known pulsares could givesuch signals, they say.

New hopes for a solution are attached to the Fermi accelerator in USA and the Large Hadron

Accelerator (LHC) i Cern , Switzerland. See picture beneath :

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Scientists hope for seeing telltale glow of decaying particles produced by dark matter

annihilation, a faint glow that is predicted to be most conspicious in the large centered on thecore of our Milky Way Galaxy.

Dark energy, does it really exist ?

What is dark energy ?

No one knows the answer today. A full clarification will probably disclose new kind of

physics, shaking our modern comprehension of particles behaviour in their fundaments.But something seems clarified about dark energy :

It shows a repulsiv force, and is responsoble for the expansion of the universe. Dark energy is probably relayed to what we call vacuum energy

Dark energy is uniformly distributed in the , it doesnt clog like dark matter.

Whatever the location, be it in your kitchen or in intergalactic space, vacuum energy has thesame density, about 10 -26 kilograms per m3, equivalent to a handfulog hydrogen atoms. All

dark energy in our own solar system amounts to the mass of a small asteroide. So its effect

stands out only when viewed over vast distances and spans of time.

Newertheless, some kind of energy, previously unknown to science, opposes and overwhelmsgalaxies mutual attraction, pushing them apart ever faster, and adds up to the most powerful

force in the cosmos. Simultation have shown that matter on cosmic scales is distributed in acobweblike pattern, a filigree of filaments, several tens of millions of lightyears long,interspersed with voids of similar size. Therefore, both dark energy and dark matter are

needed to be explained. Common matter, so called baryons (protons and neutrons) , makes upto 4 % of all elements in the universe. Dark matter makes about 70%, and dark energy

about 26%.

What is vacuum energy ?

The quantum theory

In 1917 Albert Einstein introduced dark energy with a constant he kalled . He needed this in

his equation for the general theory of relative gravitation, making it asserting for a static

universe. Shortly after this Hubble detected the expanssion of the universe, and wasredundant. Later on the Quantum Theori showed up, and scientists believed that the empty

room virtually was full of particles, continiously forming and vanishing. The physicians nowsuspicted that vacuum necessarily had a dark form of energy, and was again introduced.

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Status for vacuum theory.

Today, physicists explain the cosmological constant as

the vacuum energy ofspace. In essence, this say

that pairs of of particles areconstantly popping into

existence throughout the

universe. This virtualpairs of one particle with

a negative charge and onewith a positive charge.

They only exist for a tiny

fraction of a second .


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