Is recreating the Big Bang possible?

[Rage Crank]

Dark Matter
Can it be identified?

First of all let me start off by saying dark matter is only a theory, it is not proven. Dark matter is a hypothesized form of matter particle that does not reflect or emit electromagnetic radiation. The existence of dark matter is inferred from gravitational effects on visible matter, such as stars and galaxies.( stole that from ask.com, didn't feel like writing it ) All elements that are currently known by man are accompanied with a "bright line spectrum." Which is essentially a fingerprint, unique to all elements. How it works is an element is exposed to a spectrum analyzer, which will in turn reflect back a distinct and separate reflection. Now it is found to be true that dark matter does not reflect electromagnetic radiation, so my question to you is can it reflect spectra? And if it can we compare it to to the elements we already know and guess there chemical, physical, and quantum characteristics, just like Mendeleev did when he was producing the first periodic table of elements?

Pictures:

You see how every picture varies by the element. If you notice they are all distinct and unique. No two are alike. Remind you of something?

Anyways if we can get one of these spectrograph of dark matter will we be able to use it to predict its characteristics and place it on the periodic table of elements?

Just imagine. A dark matter Periodic Table of Elements. A dark hydrogen bomb?

 

[Phyisab****]

Probably not.

 

[Kevin_Axion]

Dark Matter is non-baryonic and emission spectra occur when baryonic matter like atoms, enter an excited state. The electrons occupy higher-energy orbitals but return to their stable positions while releasing line spectra. Dark matter doesn't contain this property and it couples very weakly to other matter, so if it were possible, the evidence would be as similar as ordinary emissions from other more prominent sources, therefore indistinguishable.

 

[Rage Crank]

So can you explain baryonic a little more? I'm an aspiring young physics student tring to get as much information as possible. :)

 

[Kevin_Axion]

Well, baryonic dark matter would be brown dwarfs and black dwarfs these are called Massive Astrophysical Compact Halo Objects (MACHOs). Essentially, they are composed of atoms or particles that have three quarks - neutrons and protons. Non-baryonic dark matter consists of fundamental particles such as neutrinos, axions or supersymmetric particles.

 

[Rage Crank]

so in essence non-baryonic particles are smaller than atoms?

 

[Kevin_Axion]

Essentially, they are fundamental, they aren't composed of any other particles or three quarks to be correct in this reasoning.

 

[Rage Crank]

so then the atom isn't the smallest naturally occurring building block?

 

[Kevin_Axion]

No, atoms are composed of electrons, protons and neutrons. protons and neutrons are then composed of quarks. Here is the current model of fundamental particles (right-handed, left handed and anti-matter particles must be considered, SUSY if proven)

The Standard Model relies on several assumptions, among which the existence of a certain fields, whose quanta are point-like particles, divided first in two categories : matter and force particles.

Matter particles​

Those fundamental particles are fermionic, which implies one can fill a box with them until none can be added (as long as the box is strong enough to resist electric repulsion for instance). Fermi-Dirac statistics is a deep phenomenon, linked to the intrinsic angular momentum called spin : fundamental fermions are spin [tex]1/2[/tex] (spinor) particles, and it implies that after a rotation of [tex]2\pi[/tex], their wavefunction changes sign !. This is not a real problem, since only the (hermitean) square of the wavefunction is observable, that is the probability density. Notice also that after [tex]4\pi[/tex] the double sign reverses cancel, and there are deep reasons why [tex]4\pi[/tex] rotations are always equivalent to no rotation. Let us first stare at a list of them :

First family​

Second family​

Third family​

1. electron [tex]e^-[/tex]​
   muon [tex]\mu^-[/tex]​
   tau [tex]\tau^-[/tex]​
2. electronic neutrino [tex]\nu_{e}[/tex]​
   muonic neutrino [tex]\nu_{\mu}[/tex]​
   tauonic neutrino [tex]\nu_{\tau}[/tex]
   ​
3. up quark [tex]u[/tex]​
   charm quark [tex]c[/tex]​
   top quark [tex]t[/tex]​
4. down quark [tex]d[/tex]​
   strange quark [tex]s[/tex]​
   bottom (beauty) quark [tex]b[/tex]​

Botanistic classification : 1 and 2 are leptons, while 3 and 4 are hadrons. Leptons do not feel the strong force (on which more latter). Etymology : "hadron" comes from a greek word sounding like "hadros" and meaning "strong, robust, bulky, thick, or stout", and "lepton" from "leptos" : "fine, thin, slender, small". To this list you could add anti-particles, or consider they are ordinary particles traveling backwards in time. Anti-particles have opposite charges except mass and spin, are denoted by an upper bar on the particle symbol, and sometimes have a special name, such as the positron [tex]\bar{e}^+[/tex]. Each of those might have a supersymetric bosonic partner (supersymetry relates bosons and fermions) but this is not part of the standard model. Although supersymetry has shown relevance in nuclei, it has not been observed for fundamental particles. Some basic facts :

1. Carry minus one unit of electrical charge : [tex]-e[/tex].
2. Zero electric charge, and at most a very small mass (zero in the standard model)
3. [tex]+2/3 e[/tex], and color charge (red, blue or green) which is "hidden" : free particles are "white", or more accurately "invariant under color rotations".
4. [tex]-2/3 e[/tex]. Also colored. It is difficult to define mass for 3 and 4 guys because they are never free, especially difficult for the lightest, first family members.

The quarks are "contained in a white bag", either they pair in mesons (quark/antiquark bound state) or in baryons (three quarks bound states). Recent proposal of "pentaquarks" seem nowadays unlikely : only intermediate energy have published low statistics evidences, high energy experiments lead to negative results. Confirmation or rejection of this hypothesis will be available soon, when the analyzing process of data from dedicated experiments will be over.

Force particles​

There are 12 bosonic fundamental particles with spin 1 (vector) in the standard model, plus one additional not yet confirmed and spin zero (scalar) particle. They are beautifully unified by a so-called gauge model, formulated entirely in terms of symmetries. One would contemplate a [tex]U(1)\otimes SU(2)\otimes SU(3)[/tex] gauge group. Let us emphasized here that gauge symmetry is not a real symmetry, but rather a very elegant mean to deal with constrained systems

• The photon is the quantum of light, it is usually denoted [tex]\gamma[/tex] and carries the electromagnetic interaction. It is massless, and this fact is related to the [tex]U(1)[/tex] Quantum ElectroDynamic (QED) part of the standard gauge group which is not broken. Broken symmetries occur when the laws have a certain symmetry, but the ground state (vacuum) does not. So all the tower of states constructed form the vacuum do not exhibit this symmetry.
• The 3 massive vector bosons [tex]W^+[/tex], [tex]W^-[/tex] and [tex]Z^0[/tex] are responsible for the weak interaction. This is for instance what causes [tex]\beta[/tex] decay of the proton into a neutron, at the quark level : [tex]d\rightarrow u + e^- + \bar{\nu}_e[/tex]. There are also so-called "neutral currents" with the [tex]Z^0[/tex] able to go from one family to another. The gauge part is [tex]SU(2)[/tex], but this symmetry is spontaneously broken, giving mass to the vector bosons by the so-called Higgs mechanism. The weak interaction is very peculiar, in that is does not respect some basic symmetries of Nature the other interactions seem to : especially [tex]P[/tex] symmetry, the parity which consists in "taking the mirror image", is maximally broken : the [tex]\nu[/tex] (if massless) is always left handed, while the [tex]\bar{\nu}[/tex] (if massless) is always right handed. So physicists first hoped [tex]CP[/tex] would not be broken, with addition of the exchange particle-antiparticle exchange [tex]C[/tex]. It appears not to be the case, but then it is only slightly broken, such as in the decay modes of the some mesons. Today, we strongly believe that by adding time reversal, the all-important [tex]CPT[/tex] symmetry is the fundamental for the theory. The spin-statistics theorem relies on this symmetry.
• The 8 massless gluons, with gauge group the color [tex]SU(3)[/tex]. Gluons are also peculiar in that themselves carry color charge : a red gluon turn blue by emitting a red/antiblue gluon absorbed by a blue quark turning red for instance. This fact makes gluons interact with each other. There are three gluons and four gluons vertices in the standard model. The non-linearity makes the equation hopelessly unsolvable until now. Also, this is likely the cause of confinement, the property that color is always hidden in color-invariant bound states. Another striking feature is asymptotic freedom, the fact that at very low distances, or alternatively at high energy, quarks look like free particles.

The Glashow-Weinberg-Salam model has already unified the first two in the so-called electroweak unification [tex]U(1)\otimes SU(2)=U(2)[/tex]. This leads us to the Higgs mechanism : for each broken symmetry, a massless Goldstone boson appears. The Higgs mechanism permits this degree of freedom to be "eaten" by the massless gauge boson thus acquiring mass. We can even refine the model to make all fundamental particles massless acquiring mass by interaction with the Higgs scalar boson. This particle should soon be discovered at the LHC facility (Geneva)

Additional informations :​

A good source of general information is wikipedia

Another specifically on physics, somewhat at lower level but good illustrations is hyperphysics

The http://particleadventure.org/particleadventure/ is the source of the link provided by Marlon, and this link leads to the gateway to it, a very friendly introduction.

The http://public.web.cern.ch/Public/Content/Chapters/AboutCERN/WhyStudyPrtcles/WhyStudyPrtcles-en.html is the main European research center.

Of course, the Particle Data Group has a reference site with all particles informations, and more, quite up-to-date and reliable,
The less technical particle adventure is also from the PDG.

http://laser.physics.sunysb.edu/~wise/wise187/janfeb2001/weblinks/physics_words.html

This quote derives from the thread "Elementary Particles Presented", within the High Energy/Nuclear/Particle Physics general sub-forum

 

[Rage Crank]

Well i tried to keep up best I could. Basically what I got from that was kind of a description of the inner workings of the atom, but a lot of it was just jargon to me. And I'm going to make the assumption that, that was a pretty simplistic model of what we believe to be true?

 

[Kevin_Axion]

It is the Standard Model, don't worry about the [tex]U(1)\otimes SU(2)\otimes SU(3)[/tex] nomenclature, that's just something called gauge symmetry and isn't really necessary to understand the basics of particle physics. Just tell me what you don't understand and I'd be happy to help you.

 

[Rage Crank]

Mainly I'm having truoble understanding the first. second, and third family of the matter particles. To my basic understanding these are the sub-atomic particles? Could you please explain this subject a little more in depth?

 

[Kevin_Axion]

Mainly I'm having truoble understanding the first. second, and third family of the matter particles. To my basic understanding these are the sub-atomic particles? Could you please explain this subject a little more in depth?

Okay, so let's look at the family of particles:

First family​

Second family​

Third family​

1. electron [tex]e^-[/tex]​
   muon [tex]\mu^-[/tex]​
   tau [tex]\tau^-[/tex]​
2. electronic neutrino [tex]\nu_{e}[/tex]​
   muonic neutrino [tex]\nu_{\mu}[/tex]​
   tauonic neutrino [tex]\nu_{\tau}[/tex]
   ​
3. up quark [tex]u[/tex]​
   charm quark [tex]c[/tex]​
   top quark [tex]t[/tex]​
4. down quark [tex]d[/tex]​
   strange quark [tex]s[/tex]​
   bottom (beauty) quark [tex]b[/tex]​

Yes these are all fundamental particles therefore sub-atomic but they don't all create atoms. The families define different mass levels, family 1 being the least massive and family 2 being the most massive. Now there are two different types of fermions (matter particles - bosons are carriers of force particles) leptons and quarks. The first family of leptons contains the electron ([tex]e^-[/tex]) and the electron neutrino ([tex]\nu_{e^-}[/tex]). The electron neutrino a neutrally charged electron with a very small mass and similarly has the same spin of [tex]1/2[/tex]. The up ([tex]u[/tex]) quark and the down ([tex]d[/tex]) quark are the main components of neutrons and protons and combine in triplets to make baryons and couplets to make mesons. A proton is composed of [tex]u[/tex],[tex]u[/tex],[tex]d[/tex] and a neutron is composed of a [tex]d[/tex],[tex]d[/tex],[tex]u[/tex]. As the generations (Families) progresses the masses increase therefore the stability of the particle decreases which is why we only see their lowest energy (least massive) particles. It is just symmetrical how the masses correspond to create ordered generations

 

[physalpha]

Then, which method we can identify dark matter in the collider?
No interaction with matter, no electromagnetic interaction.
Only rely on energy loss, other particles behavior?
No interaction makes no trajectory, I suppose?
Do the researchers have any good ideas?

 

[Kevin_Axion]

Here's an awesome article I just found: http://gizmodo.com/5639981/the-ultimate-field-guide-to-subatomic-particles.

 

[Rage Crank]

So i just heard that its a theory that a nuetron is a proton and elctron stuck together.

when beta decay occurs we get electrons being emmited from the atom right? or something like that. and then we have this random proton appear? if so can that mean the nuetron is a proton and an electron stuck together

 

[Kevin_Axion]

No a neutron is two down quarks and an up quark combined by gluons, [tex]\beta[/tex] decay is the conversion of a proton to a neutron by the [tex]W^-[/tex] boson which emits a high energy electron ([tex]\beta^-[/tex]) and an electron antineutrino ([tex]\overline{\nu}_e[/tex]).

 

[physalpha]

Dark matter identification is not easy, I suppose.
Direct measuring is very difficult. Only used method is searching WIMP.
How about this?
Indirect method for searching Dark Matter.
Using Big Bang Condition.

If Big Bang occurred in one point, it would emit matter particle and Dark Matter.
At very high temperature created the matter particles would escape that point, and the some of similar property Dark Matter would also escape, too.

Some of Dark Matter would remain there.
If we did short period operation continuously, The Dark Matter wold concentrated at that area.
As a result of that concentrated Dark Matter effect, the detected particle intensity would decrease or increase.

Important thing is the other conditions must be keep constant .
And the remain Dark Matter would luckily low diffusivity.

 

[JoaoPais]

It's an interesting point, but all theories for the detection of dark matter are based in the assumption that it exists in the known dimensions. The only "proof" of dark matter is that it's needed for the mass in rotating galaxies. Well, as far as i know, there is a theory where gravity (which is the mass problem) can be interacting in other dimensions that's why it's so weak and it's hard to explain in agreement with the other know forces. That being, dark matter could be the effect of some kind of matter that is present only in other dimensions, but its effect is noticeable throw gravity, once it can exist in more than 4 dimensions.
This being a possibility, the actual experiments being done would prove unsuccessful, because there’s nothing to interact with, because dark matter can be “touched” in this dimensions! Maybe the best way to prove it, could be through gravitational fields fluctuations or something like this…

Is this idea absurd, or has this been discussed somewhere?
Thanks

 

[physalpha]

My point is focused on collision phase.
At that phase something happened.
High temperature plasma phase was made, many particles was created.
And, recently called Dark Matter was created.
So how to detect the Dark Matter.
Best way is to detect it directly.
But there is no reasonable way to detect it, because they have no interaction with matter.
How to prove the Dark Matter was made at the beginning of the Universe, and Dark Matter existence?
Most research to now is established the emitted particles trajectory or energy intensity.
If Dark Matter had some interaction with matter, some different trajectory or energy behavior would appear.
But they said before, "no interaction with matter".
So alternative other method is "change collision phase, and some different phenomena which we can measure will happen".

 

[JoaoPais]

So alternative other method is "change collision phase, and some different phenomena which we can measure will happen".

I don’t think I’m understanding what you’re saying. =P
It’s about recreate the big bang?
If it is, well, I don’t think we’ll be able to do that in a long time, not so much because energetic limitations, but because we can’t even understand the true initial conditions! But even assuming that M theory is correct and we understand it, still there are dimensions where we cannot operate… it would be a real shot in the dark.
And, still, about what I previously said, the dark matter created could still be created in other dimensions, so that the detection would still be impossible…
Hope this is an “answer” to your post =)