## Physics Questions People Ask Fermilab

Particles and their properties
Quarks, leptons and bosons, spin and mass, antimatter

1. Particles and Vacuums
Do you think it is possible that the velocity of an object in space determines the force of the vacuum it travels through?

2. Movement of the Electron Around the Nucleus
Why does the electron have to move around the Nucleus? Why does it not lose energy moving around it?

3. Particles and Their Properties
How do I figure out the number of protons, the number of neutrons, and the number of electrons of a particular atom?

4. Is a quark a sound particle?

5. Why is a proton like a blueberry muffin?

6. Fermilab's Antimatter Production Rate

7. The Importance of Antimatter Research

8. Definition of Matter

9. Results of Tevatron Run II

10. The smallest building block
I would like to receive information on the smallest parts of matter to date.

11. Particles from Batavia to Soudan
I have been reading various pages on the Fermi website and I'm unclear how the particles to be tested get from Batavia to Soudan. Is there a physical connection like a pipeline or is this something that just happens through the earth?

12. Isolating quarks
The question that one of my students stumped me with was whether or not the scientists at fermi lab have isolated any quarks yet.

13. Vacuum
Is it possible to increase the probability that virtual particles will appear in a vacuum?

14. Radiation from particle annihilation
How much energy is created when the particle-antiparticle annihilate? Does it release a large amount of radiation? If so, about how many rads?

15. Patterns in CP violation
I was wondering if there were any mathematical patterns noticed in CP violation experiments, especially in regard to relationships between matter and antimatter, the rate of decay and so forth.

16. Jets of particles
When you talk about "jets" of particles, what are you meaning? Lots of particles?

17. How is momentum defined for a photon?
"Photons are said to have no mass, but how is that possible? The momentum equation is m=velocity*mass, therefore photons would have no momentum."

18. Why is the top so massive?
"I am a high school senior researching theories of why the top quark is so massive. I'm having trouble finding any theories. Most articles that I encounter simply state that the top quark is extremely massive for unknown reasons. Do you have any theories?"

19. Particle Speed
"What is the exact speed a particle can be accelerated to?"

20. Charge, Spin and Mass of Fundamental Particles
"I've been searching the web for some kind of list of the rest mass, charge and spin of the most fundamental particles. Also I am wondering if the electron is "colorless" in the same way as a proton is, as the proton is built up out of particles with color and and electron is not."

21. Higgs Boson
"How does the Higgs boson generate the masses for all other particles? Is it the carrier of a force?"

22. Bosons/antiparticles
"Is there a negative energy state for the boson in relativistic quantum mechanics? What is the antiparticle of a boson?"

23. Charged objects and virtual photons.
"What is the difference between real and virtual photons? When two charged objects interact (electromagnetic force), which photons do they exchange?"

24. Do electrons ever "fall" into the nucleus of an atom?
"Could you please tell me if electrons ever " fall " into the nucleus of an atom ? When the temperature is extremely low electrons should be moving very slowly and hence should " fall " into nuclei."

25. What is spin? How can neutrinos be detected?
"What is spin 1/2 and 2/3? Can you see this in a chamber of some detector? Or is it are theoretical concept? How do you determine exactly the spin of a neutrino? Can I make a detector to look for neutrinos from the sun?"

26. What are experiments confirming the existence of gravitatonal mass of elementary particles?
"What are experiments confirming the existence of the gravitational mass of elemetary particles (e.g.protons, electrons, neutrons ect.)? Where can I find the detailed dscriptions of these experiments?"

27. Do tachyons exist?
"I'd like to know if there are any proofs of the existence of the tachyons ... "

28. In an atom, how does an electron move?
"In an atom, how does an electron on a 2p (bell shaped) orbital cross the node of the nucleus (a region of zero probability)? Does it have something to do with the wave properties of an electron? ..."

29. Antimatter and Virtual Photons
• What is antimatter?
• Are there other properties/quantum numbers besides the charge that are different?
• Why is the charge the key parameter?
• Why do particle-antiparticle annihilate when they meet?
• Why is that we cannot see the photons that mediate the electromagnetic force?

30. Neutron Decay
"Why is the neutron an unstable particle?"

31. Proton lifetime, annihilation and shell electrons
"Has proton decay been successfully accomplished?
What would happen if an antiquark is shot at a proton?
Is it even possible to isolate a single quark?
Is the distance from the first electron shell and the center of the nucleus of an atom always the same?"

32. What are virtual particles?
"What are virtual particles? What does "virtual" mean?"

33. How can you tell what a particle is made of?
"How can you tell what a particle is made of? For example, H2O--how do you know the shape of the molecule if it is so small?"

34. Is the antineutron the same as the neutron?
"In my physics book I have come across the idea of antimatter. Antimatter seems to be the same as matter but it has an opposite charge. Since the neutron has no charge what makes its antiparticle different?"

35. Mass of the neutrino
"I think that neutrinos have mass. The electron neutrino mass is .789 MeV. I figured this by subtracting the mass of the proton from the mass of the neutron, then subtracting the electron mass from the difference. Can you tell me whether the NuMI experiment can verify my result?"

36. Non-resonant energy absorption by atoms
"Why is the cross section for compound nucleus formation not zero between resonances? How can an atom absorb energy that does not correspond to an allowed excited state?"

37. Quarks and Auras
"Do you think that quarks are what ghosts may be made of? Has Fermilab done any studies with auras?"

38. Question about Radioactive Decay
"What is the actual 'event' that causes an unstable isotope (like Carbon 14) to decay?"

39. Neutrinos: spin and collisions
"How does one determine the spin of neutrinos since they have no charge? Using a computer, has anyone generated what a neutrino collison might look like?"

40. Particle vs. Wave, etc.
"Are quarks particles and waves? What about photons? I have heard from a friend that experiments proved them to be both particles and waves."

41. Radiation Direction
"What is the direction of radiation emitted from an atom?"

42. Double slit experiment with protons
"Since electrons exibit wave behaviour in a twin slit experiment, I would like to know if protons exibit the same behaviour."

43. Mass of weak bosons
"Why are the masses of the W and Z bosons, which are responsible for the weak nuclear force, non-zero and in fact quite large?"

44. Color of Atoms
"What color is an atom and how could you see what it is?"

45. Electron Transfer
"How do scientists know which atoms can give electrons to other atoms?"

46. Antihydrogen as power source
"What is the next logical step in the development of antihydrogen as a power source?"

47. Neutrons in Nuclei
"What happens when you vary the number of neutrons in an element?"

48. Virtual Photons
"What are virtual photons?"

49. Antimatter as power source
"How could antimatter be used as a power source, and what major technological problems must be solved before such a source could be developed?"

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