We all know about the existence of antimatter; that is an otherwise equivalent particle but of opposite charge of every sub atomic particle that you are aware of, including Neutron. Yes. even neutron that is a neutrally charged particle has an anti-neutron. How is it possible is your google based homework for tonight.
But other than the charge, an anti-particle has same physical properties and would behave just like its counterpart. One thing that scientist could not test (and tell for certain) if a table made of anti-matter (an anti-table i.e) would fall down or fall up. They believe that it would fall down but could not test the theory.
Of course when a particle and its anti counterpart would hit each other, they would annihilate with a burst of energy. That means that if a galaxy made entirely out of anti-matter gets on to the collision course with our galaxy, we would never know that its made out of anti matter, till it actually collides with us, and then it will be too late.
What do you mean by "could not tell if a table made of anti matter will fall up or down"
How does a table fall up or down. You mean it will rise from earth surface. Like anti gravity. If so how high it an rise. Till it reached ht where gravitational "push" is small?
What I was saying Southie is that scientists dont know how gravity would work on anti matter. Right now they were able to create sub-atomic anti particle in the labs and few anti-atoms - but at that sub-atomic level, other forces (nuclear, electro-magnetic) are so high that gravity dont work on these particles.
Yes, by falling up, I meant rising up, or levitating. If gravity could make you levitate, then you can only go up till the point where gravity can influence your body. More mass you have, higher the distance would be before gravity would give up on you. That means that if you are made out of anti-matter, and gravity works the opposite way for objects made out of anti -matter, then heavier you are, further up you would go
I am not saying it will. I am saying only if gravity works in the opposite way with anti matter, though most of the scientists think that gravity would attract the abut matter the same way
Here is what I recall from Google assignment done 1.5 hrs ago.
Anti neutron has one anti quark. Which is one anti quark in up direction and two in down direction.
While neutron has quarks.
Exactly. Neutron has 1/3,1/3 -2/3 quarks, while anti-neutron has -1/3, -1/3, 2/3 quarks (or maybe its opposite). Both end up being neutral, but the signs of quarks are opposite.
For the anti gravity part, the force of attraction due to gravity between you and earth is
F = G m1m2/R^2
where G is the gravitational constant, m1 is your mass and m2 is the mass of the earth, R is the distance between the center of both bodies. You can see that heavier you are , higher the F is going to be. If that force is attraction, then you feel that F as your weight on the ground (which is nothing but ground pulling you down with more intensity). If that force is of repulsion, then the ground will shoot you away with higher force if you are heavier, hence pushed you further higher.
Exactly. Neutron has 1/3,1/3 -2/3 quarks, while anti-neutron has -1/3, -1/3, 2/3 quarks (or maybe its opposite). Both end up being neutral, but the signs of quarks are opposite.
For the anti gravity part, the force of attraction due to gravity between you and earth is
F = G m1m2/R^2
where G is the gravitational constant, m1 is your mass and m2 is the mass of the earth, R is the distance between the center of both bodies. You can see that heavier you are , higher the F is going to be. If that force is attraction, then you feel that F as your weight on the ground (which is nothing but ground pulling you down with more intensity). If that force is of repulsion, then the ground will shoot you away with higher force if you are heavier, hence pushed you further higher.
If the atmosphere had no resistance, regardless of repulsion force magnitude, the anti matter may keep flying higher and higher. Or farther and farther from earth. Force equals mass times acceleration. Force proportional to mass and inversely prop to r^2. Hence acceleration (away from earth) is inversely prop to r^2
Due to finite air resistance, the acceleration with which particle moves away from earth is reduced. But the acceleration away from earth always remains finite. So in the long run, the anti matter will escape earth. Once in space, it may follow a path based on the velocity when it escaped the earth.
So bottom line, if repulsion theory correct, the anti matter will escape earth?
Above not entirely correct. Yes, with zero drag, the anti matter moves away from earth with acceleration inversely proportional to square of distance from the earth.
The drag force I think increases with density. So more drag on heavier antimatter. The drag also increases with velocity. Same effect. Buyoancy more for lighter antimatter. Here Buyoancy serves to move it to earth - reverse.
Drag plus Buyoancy counteract movement away from earth. Till terminal velocity reached. Depending on drag vs Buyoancy magnitude, one or the other particle maintains higher acceleration for longer time. Eventually both escapes.
Except for one factor - wind. Wind direction has a sideways and downward component. So antimatter may never get to leave earth atmosphere. Unless we have anti wind.
Good argument Southie, but your assumption is this that the anti matter object is on earth and then started to levitate upwards. The fact is this that if gravity repels anti matter, then you will never have an air drag/wind situation as you will never find an antimatter object within earth atmosphere to begin with. An anti matter object based on it velocity may try to enter the atmosphere from outside. If the entry attempted velocity is less than the terminal velocity, then earth gravity will push the object back in the space. Higher velocity object will keep penetrating the atmosphere, till very heavy and very high velocity objects will hit the ground and annihilate.
If the atmosphere had no resistance, regardless of repulsion force magnitude, the anti matter may keep flying higher and higher. Or farther and farther from earth. Force equals mass times acceleration. Force proportional to mass and inversely prop to r^2. Hence acceleration (away from earth) is inversely prop to r^2
Due to finite air resistance, the acceleration with which particle moves away from earth is reduced. But the acceleration away from earth always remains finite. So in the long run, the anti matter will escape earth. Once in space, it may follow a path based on the velocity when it escaped the earth.
So bottom line, if repulsion theory correct, the anti matter will escape earth?
That would make sense since we don't find antimatter in space as much as we expect to find. We would see a lot more antimatter if gravity affected it the same it affects matter and if gravity repels antimatter then we shouldn't see antimatter on earth at all, right? I don't know. We don't even understand how gravity works yet and we don't know much about antimatter. I have no clue and can't imagine why one is more likely than the other.
Maybe the dark energy (which is responsible for the continuous expansion of the universe) is some form of anti matter. Mind it that we call it energy, only because we don’t have any other proper word to describe it.
There are two observations which scientists are making, that dont compute well.
The movement of stars within a galaxy, and the movement of galaxies within a cluster of galaxies is because of the gravitational pull of all the matter that exists in that region of space that we are observing. The problem that scientists face again and again is that all the observable matter in any region of the universe is not enough to explain the tug and movement of the stars and galaxies of that region. In fact the observable matter only accounts for a fraction of what is needed to keep that cluster together. The missing matter is dubbed dark matter.
On a flip note, the way universe is expanding, or the space between those clusters of galaxies is increasing is also confusing. For what is visible in the universe, and the calculation based on big bang theory and other theories, universe should be slowing down. Instead it seems to be speeding up. For the lack of better term, the mysterious force that is causing the universe to speed up, is known as dark energy.
The neutron is made up of 1 up and 2 down quarks ... These have charges ... (2/3)e - (1/3)e - (1/3)e = 0
Likewise ... The anti-neutron is made up of anti-quarks ... With charges ..
-(2/3)e + (1/3)e + (1/3)e = 0
neutrons are hadrons which means they are built up with 3 quarks ... Mesons only have two quarks ... And leptons are tiny, they are more fundamental and do not contain quarks - electrons are a type of lepton. For their size they carry a hefty charge.
Matter and anti-matter are distinguished by charge only ... And the various colliders and accelerators only use charge to create the collisions ... Gravitation should be uniformly expressed ... i.e. A neutron star will have a pulling force and so will an anti-neutron star ... But the final collision may be very different between like for like particles to those of like for unlike particle collisions ... The latter being potentially more spectacular.
In fact if we work this through ... Anti-matter will be made up of anti-compounds, which are anti-molecules made from anti-atoms ... So an isolated neutron to anti-neutron collision is highly unlikely. It is more likely to have a positron and electron collision. As leptons usually form the outer surface of a material ... Atomic nuclei are held by other forces in a field preventing them for coming into contact with anything. Electrons in atoms do not collide with their nuclei ... Despite them being oppositely charged ... However, given energy they will collide and interesting things will happen ... Exchange particle formation (bosons) and the proton becomes a neutron ... One of the up quarks with +(2/3)e charge gets converted to a down quark -(1/3)e ... Because the -e charge on the electron delivers that on impact.
Anti-matter is essentially charge opposites, but not gravitational opposites ... i.e. The mass of proton is the same mass as an anti-proton ... And it is the magnitude of the mass that determines the gravitation of that particle. Mass warps space which is the effect of gravity ... And it is only possible to warp space or not warp space for i.e. All deltas are negative ... E.g. There is no possible way travel minus 15 metres away from a point ... Because all directions away from that point are 15 metres from it ... You can only move away from a point ... You can't move more towards a point when you are already on it.
If what TLK is saying about anti-gravity, is true ... Should we therefore not get gravitational cancelling as evidence of this? Where two bodies one with F and the other with -F gravitations have a net attraction of zero between them ... ?
Anti-gravity will only work between two bodies of anti-mass ... m1M1 are both bodies with gravity they attract each other ...however, m'1M'1 will repel each other because they are BOTH anti-gravity bodies.
Presumably ... m1M'1 or m'1M1 interactions are more complicated to work out.
I am using ' to represent "anti" or may have no effect on each other at all.
Also we might have to invent more quarks ... +(2/3)e = up
but we assume it has gravity +ve
we may have to say that
-(2/3)e = up'
but with gravity -ve
which then opens the possibility of having a
+(2/3)e up which has gravity -ve and a -(2/3)e up' which is gravity +ve.
Psyah, I did not think of that gravity attraction/repulsion would work only inside the same domain (matter+matter > =attraction, anti-matter+anti-matter=repulsion, anti-matter+matter=0 Force). Excellent point. Now I feel like a stupid person :k:
Of course this is all based on assumption (as you said) that only if gravity works in opposite direction when in case of anti-matter. And if that is indeed the case, then we will never see might see small anti-matter bodies but never an antimatter planet or moon, cause at that level gravity is the dominant force.
About the quarks, I dont think that we need more of that for anti-matter, cause scientist have already seen anti particles in the particle accelerators, but i never read anything about more than 6 quarks. But I will read about antimatter more.
Instead of having more quarks, why cant we just have an anti-graviton particle, a negative counter part of graviton i.e.