1 open questions in physics tareq ahmed research assistant physics department, kfupm. 7, jan. 2007
Post on 18-Dec-2015
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TRANSCRIPT
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Typical Questions
1. Where and what is dark matter?2. How massive are neutrinos?3. What are the implications of neutrino mass?4. What are the origins of mass?5. Why is gravity so weak?6. Why is the universe made of matter and not antimatter?7. Where do ultrahigh-energy cosmic rays come from?
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Classical Mechanics
• Indeterminate behavior in the collisions of point particles.
Before After
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θθ
Before After
v
v’
v’
0.5 m v2= 2*0.5 m v’2 2/v'v
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Conservation of Kinetic Energy
Conservation of linear momentum
m v= 2*m*v’ * cos(θ)
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•Three equations
Conservation of Energy (1)
Conservation of Momentum (2)
•And Four parameters !!
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The interaction between the particles have to be included to treat collisions between point particles. The laws of classical mechanics alone are not sufficient.
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Quantum Mechanics( A theory of observers)
I think I can safely say that nobody understands quantum mechanics. -Richard Feynman
Anyone who is not shocked by quantum theory has not understood it. -Niels Bohr
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A single wavefunction of the Universe!
If [quantum theory] is correct, it signifies the end of physics as a science. Albert Einstein
What is it?
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The Concept of Superposition
• Any model for the particle (or system) being in a superposition of different eigenstates?
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The Collapse of the wavefunction
• How does the wavefunction collapse upon measurement?
The "spooky action at a distance."
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14The theory of quanta can be likened to a medicine that cures the disease but kills the patient. Hendrick Kramers
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•The uncertainty principle allows conservation of energy to be violated for a very short period!
Violation of the conservation of EnergyConserved or not conserved? This is the question !
•Photons of frequencies not resonant with the atomic transition frequencies can still excite the atom for a very short periods !!
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The Nature of Quantum Jumps
• Do there exist phenomena that are truly spontaneous? Or do all phenomena, when investigated in depth, turn out to be deterministic?
"If we have to go on with these damned quantum jumps, then I'm sorry that I ever got involved!” E.Schrodinger
Are there quantum jumps ?
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• What is the source of randomness in quantum mechanics?• Can the world be deterministic but only our description is indeterminist?
Quantum Mechanics and Randomness Does Randomness Exist?
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"We choose to examine a phenomenon which is impossible, absolutely impossible, to explain in any classical way, and which has in it the heart of quantum mechanics. In reality, it contains the only mystery.“ R.Feynman
The Most Beautiful Experiment in Physics
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Fundamental Constants in Physics
• What is the number of the truly fundamental constants
How Many?
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The identity of particlesDo quarks have a well defined identity?
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•"If you cannot - in the long run - tell everyone what you have been doing, your doing has been worthless." - Erwin Schrodinger, Science and Humanism
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And the result…..
"I don't like it, and I'm sorry I ever had anything to do with it." - Erwin Shrodinger, speaking about quantum mechanics
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Why two fields to describe the force between moving charges?
• No single expression that describes the force between two charges in arbitrary motion.
v1
q2
q1
rv2
Gauss
What is the nature of magnetic fields?
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Vacuum FluctuationsSo much fluctuations!!
• Any model better than vacuum fluctuations?• Each theory has its own vacuum!!
Is this a beautiful universe?
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2. Transition between different atomic states
3. Transition between different vibrational or rotational modes of molecules
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Behind it all is surely an idea so simple, so beautiful, that when we grasp it - in a decade, a century, or a millennium - we will all say to each other, how could it have been otherwise? How could we have been so stupid for so long? - John Archibald Wheeler
Conclusion
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Acknowledgment
I would like to thank Dr. Hucine Bahlouli, Dr. Abdulaziz Aljalal and Abdallah Baziyad for their valuable comments