Reference no: EM131127505

Astronomy Homework Big Bang

1. Gravity is the weakest of all fundamental forces. So why is that gravity rather than the strong force keeps the planets in orbit around the sun? (hint: think strength and range)

2. Why is it that protons/anti-protons and neutrons/anti-neutrons are no longer being created by colliding photons (aka pair production)?

3. This question will require a google search.

The text mentions the other kind of hadrons called mesons as a more exotic form of matter.

• What are these particles?

• Where would we detect them?

• What is their 1/2 life?

Note, there are several different kinds of mesons so can either report average properties for the 3 questions or you can report on one type of meson.

4. Why aren't there "free" quarks (quarks not confined within a neutron or proton)?

5. For each of the following particle interactions:

I. Calculate the baryon number, lepton number and charge for each particle as was done in the text.

II. Based on your results, state whether the interaction could or could not occur.

a) 3 Protons + 1 electron → 2 Protons + 1 positron + 1 neutrino + 1 neutron

b) 2 electrons + 2 protons → 2 neutrinos + 2 neutrons

c) 1 Neutron + 1positron → 1 Proton

d) 1 Neutron + anti-Neutron → 1 Proton + 1 Neutron + 1 electron + 1 anti-neutrino

e) 1 anti-Proton + 1 positron → 1 anti-neutrino + 1 neutron + 1 proton