Matter and Anti matter?
919946
There is no reason to believe that there weren't equal amounts of matter and antimatter after the big bang. However, there is a difference between the way matter and antimatter interact. It has to do with a complex symmetry in physics called CP (charge-parity).\nThe difference allowed abut one in every billion matter particles to avoid annihilation.
1090798
Actually astronomers and physicists are really quite puzzled by the whole universe.  They have absolutely no idea what the dark matter is.  Some postulate that it is neutrinos, even though they have not be able to show that neutrinos have mass. And they do not know if the expansion will stop or not.  At the moment it appears that it will not but they are not certain. They do not know even why the matter of the universe has congealed into galaxies instead of a uniform soup. They have concocted elaborate hypotheses as to why, but they are still puzzled.\n\nAnd best of all is why is there no anti-matter except in labratories?\nWhy did it not cancel out all the matter to begin with?
298027
The most obvious reason is that you need a huge load of energy to create anti-matter in the first place. Anti-matter does not exist in a stable condition anywhere close and we have to create it. We can't just harvest it from the environment. It's also true that storing it is a major pain in the a$$.\n\nFusion is a much more realistic possibility. Try searching the internet for ITER (the first fusion reactor to be built in France by an international collaboration, currently under design).
769964
The definations wanted by you are given below-\n\nIn physics, matter is commonly defined as the substance of which physical objects are composed, not counting the contribution of various energy or force-fields, which are not usually considered to be matter per se (though they may contribute to the mass of objects). Matter constitutes much of the observable universe, although again, light is not ordinarily considered matter. Unfortunately, for scientific purposes, "matter" is somewhat loosely defined.\n\nMass is a property of a physical object that quantifies the amount of matter and energy it is equivalent to. Mass is a central concept of classical mechanics and related subjects, and there are several forms of mass within the framework of relativistic kinematics (see mass in special relativity and mass in General Relativity). In the theory of relativity, the quantity invariant mass, which in concept is close to the classical idea of mass, does not vary between single observers in different reference frames.\n\nAn elementary particle is a particle with no measurable internal structure, that is, it is not a composite of other particles. They are the fundamental objects of quantum field theory. Elementary particles can be classified according to their spin, with fermions having half-integer spin and bosons integer spin.\n\nSpace has been an interest for philosophers and scientists for much of human history. The term is used somewhat differently in different fields of study, hence it is difficult to provide an uncontroversial and clear definition outside of specific defined contexts. Disagreement also exists on whether space itself can be measured or is part of the measuring system. (See Space in philosophy.) Many fields use an operational definition in which the units of measurement are defined, but not space itself.\n\nIn chemistry and physics, an atom (Greek  átomos meaning "indivisible") is the smallest particle of a chemical element that retains its chemical properties. \n\nA chemical element, often called simply an element, is a substance that cannot be decomposed or transformed into other chemical substances by ordinary chemical processes. All matter consists of these elements and as of 2006, 117 unique elements have been discovered or artificially created. The smallest particle of such an element is an atom, which consists of electrons centered about a nucleus of protons and neutrons.\n\nIn chemistry, a molecule is an aggregate of two or more atoms in a definite arrangement held together by chemical bonds. Chemical substances are not infinitely divisible into smaller fractions of the same substance: a molecule is generally considered the smallest particle of a pure substance that still retains its composition and chemical properties. Certain pure substances (e.g., metals, molten salts, crystals, etc.) are best understood as being composed of networks or aggregates of atoms or ions instead of molecular units.\n\nIn particle physics, antimatter extends the concept of the antiparticle to matter, wherein if a particle and its antiparticle come into contact with each other, the two annihilate —that is, they may both be converted into other particles with equal energy in accordance with Einstein's equation E = mc2. This gives rise to high-energy photons (gamma rays) or other particle–antiparticle pairs-.
1166578
There is no such thing as negative matter.\n\nYou may be referring to 1 or 3 things:\n\nAnti-matter: Anti-matter is the "anti" particle to various particles. You have the antiproton, antineutron, positron, etc etc. They are basically particles with opposite charges but similiar other characteristics. \n\nExotic matter: Exotic matter is a hypthetical class of matter that violates current particle physics. Such matter hypothetically can have negative mass, have negative kinetic energies while in motion, or even be repelled by gravity. Some 'wormhole' theories rely on such particles.\n\nDark matter: Dark matter is matter of unknown properties that is being theorized to solve many problems associated with our current understanding of the universe. Such mass does not emit or re-absorb light.
338341
Anti matter is negative version of matter.To differentiate the matter and antimatter we consider the atomic levels of matter.Our own matter is made with atom of centraly proton of positive charge & charge less neutron called nucleus.And a negative charged electrons revolving around it.But in antimatter nucleus is  negative charged proton(anti proton)& electron of positive charge (anti electron) revolving around it.\nI think that matter and antimatter repell each other,have a negative gravitation.
1150780
In fact, there is a great deal of evidence showing it is not. What little we know of the dark matter and energy is that they are not composed of baryons. But anti-protons *are* bosons. There are some candidates for the dark matter (axions are a good bet) but anti-matter in the usual sense is ruled out by observation.
805625
Time is completely relative.  It bends with the curvature of space.  Space is the absence of matter and is what separates matter from matter and matter from anti-matter.  Anti-matter is the opposite of matter and is responsible for anomalies like black holes and is believed to be the center of galaxies.  Anti-matter and matter form energy when they combine.  So far as we can tell, it looks like a giant flash of light when this occurs.\n\nTo answer your question:\nWhen time is removed from the equation, everything comes to a standstill.  It would be the same if you took away energy.  There would be nothing but stuff standing motionless.  When space is removed from the equation, all matter and anti matter are combined and as a result, pure energy is given off as a byproduct.  If matter is removed from the picture, the only thing that would be left is anti matter, space and energy.  Everything would be dark because there wouldn't be anything to give off light, but there would still be gravitational forces at work.
1159688
The density, the atomic structure, and the state of matter it is in.
475670
All normal matter is composed of particles such as protons, neutrons and electrons, and all of these have the fundamental property of quantum mechanical spin. Spin gives each one of these particles an associated magnetic field. Because of this, and the fact that the average microscopic piece of matter contains huge numbers of these particles, it would be expected that all matter would be magnetic. Even antimatter would have magnetic characteristics. However, everyday experience shows that this is not the case.\n\nWithin each atom and molecule, the spin of each of these particles is highly ordered as a result of the Pauli Exclusion Principle. However, there is no long range ordering of these spins between atoms and molecules. Without long range ordering, there is no net magnetic field because the magnetic moment of each one of the particles is cancelled by the magnetic moment of other particles.\n\nPermanent magnets are special in that long range ordering does exist. The highest degree of ordering exists within magnetic domains. These domains can be likened to microscopic neighbourhoods in which there is a strong reinforcing interaction between particles, and as a result, a great deal of order. The greater the degree of ordering within and between domains, the greater the resulting field will be.
595584
the spontaneous creation and destruction of particles goes on all around us all the time.  but antimatter does not seem to be part of that process in our "timeframe" and it could be that if time is viewed as a dimension only we will find the antimatter at another point on that dimension.  If antimatter did appear annihilation would occur on a vast scale.  I believe that matter and antimatter have a weak repulsing force to each other, or utterly neutral, as the antimatter has a "reverse gravity" (perhaps because it's moving backwards on the time dimension).\n\nOur Universe, all the parts that count to us, is all matter.  The antimatter resides next to us, but not in our universe.
1066558
Anit-matter is related to the atomic bomb? How?  The "atomic" bomb was a device that created a nuclear fission chain reaction.  No anti-matter was used.  The modern "nuclear" or "hydrogen" bombs are fusion devices (which create the energy needed for the fusion reaction by first detonating an atomic fission device), but still, no anti-matter involved.  \nNow, a positron (or the anti-electron) can come about under certain circumstances of a photon interacting with things such as carbon or fluorine and a couple others causing beta particle decay, but none of the right elements was used in any bomb.
1172316
f there were plenty of these, gamma and x-ray astronomers would long since have detected the annihilation 'lines' at 511 kev and 1 Gev of electron-anti- electron, and proton-anti-proton annihilation. This is not seen, so that means that at some time after the Big Bang, any matter and anti-matter managed to segregate itself ( No known way to do this UNLESS matter and anti-matter are affected by gravity in different ways), or that starting from time zero, there has always been an asymmetry in the mater/anti-matter abundance. We know that K mesons decay into more matter than anti-matter end particles, so nature doesn't really treat matter and anti-matter the same way even though these forms are produced in equal numbers during 'pair creation' events. In a previous question I also discussed this.\n\nAs to WHY this is so, so that we only see matter galaxies, we have to say that this is simply the way Nature is. Just as the speed of light is fixed at the particular value it has. No explanations seem possible or likely in the future.
1001442
This is an interesting question, for which I can't claim to know the answer, but I'm going to take a guess anyway. \n\nThe crucial qualifier in your question is that matter and anti-matter cannot interact in your example. Otherwise, your matter person would be instantly annihilated. But since you eliminated the possibility, the answer is that you would feel gravity just the same as in a matter universe.\n\nHere's why. Anti-matter is still composed of the same materials as matter,  just with opposite charges (i.e.--electrons are positive, protons are negative). Presuming that your "anti-gravity" is not repulsive by nature (otherwise your world couldn't exist) then it's effects on the "matter" in your body would be the same as for the anti-matter because your anti-gravity would have no mechanism by which to distinguish between your electrons and its positrons, etc.
699842
In particle physics, antimatter extends the concept of the antiparticle to matter, wherein if a particle and its antiparticle come into contact with each other, the two annihilate —that is, they may both be converted into other particles with equal energy in accordance with Einstein's equation E = mc2. This gives rise to high-energy photons (gamma rays) or other particle–antiparticle pairs. The resulting particles are endowed with an amount of kinetic energy equal to the difference between the rest mass of the products of the annihilation and the rest mass of the original particle-antiparticle pair, which is often quite large.\n\nAntimatter is not found naturally on Earth, except very briefly and in vanishingly small quantities (as the result of radioactive decay or cosmic rays). This is because antimatter which comes to exist on Earth outside the confines of a suitably equipped physics laboratory would inevitably come into contact with the ordinary matter that Earth is made of, and be annihilated. Antiparticles and some stable antimatter (such as antihydrogen) can be made in minuscule amounts, but not in enough quantity to do more than test a few of its theoretical properties.\n\nThere is considerable speculation both in science and science fiction as to why the observable universe is apparently almost entirely matter, whether other places are almost entirely antimatter instead, and what might be possible if antimatter could be harnessed, but at this time the apparent asymmetry of matter and antimatter in the visible universe is one of the great unsolved problems in physics. Possible processes by which it came about are explored in more detail under baryogenesis.
214575
It is true that nobody knows. It is false that theories on the origin of matter are wild speculations. See an earlier post I did today on an almost identical question for a reasonable theory for the origin of matter out of nothing.\n\nIn short, the fact is that matter appears out of nowhere all the time. There's is no reason to think it could not do a slightly more extreme version of the same thing if the vacuum state were changed a little bit, ie. its energy density was increased.
919735
In physics, matter is commonly defined as the substance of which physical objects are composed, not counting the contribution of various energy or force-fields, which are not usually considered to be matter per se (though they may contribute to the mass of objects). Matter constitutes much of the observable universe, although again, light is not ordinarily considered matter. Unfortunately, for scientific purposes, "matter" is somewhat loosely defined.\n\nSee http://en.wikipedia.org/wiki/Matter for more information on matter.\n\nGood Luck!!!