Question

answer the following question :

1. Say we live in another galaxy. We observe the galaxy's globular clusters and they appear to be uniformly spread out in all directions. What would this tell us about where we are in the galaxy and why?

2. Why do we think that large elliptical galaxies result from the merger of spiral galaxies?

3. You are in a windowless box. You feel yourself pressed to the floor. What are the two things that could be causing this? How does general relativity explain this? What would an outside observer notice about your watch?

Answer 1

1. Say we live in another galaxy. We observe the galaxy's globular clusters and they appear to be uniformly spread out in all directions. What would this tell us about where we are in the galaxy and why?

Answer: There won't be much difference in our observation when we observe the macroscopic large scale structures in universe. This is assumed the the principle of Isotropy of Cosmological principle.
If our assumed galaxy is a spiral galaxy, then it would possible for us to determine the galactic rotation curve and hence our relative position in the galaxy with respect to the central core of the galaxy.

2. Why do we think that large elliptical galaxies result from the merger of spiral galaxies?

Answer: Elliptical galaxies are those galaxies which have a central bulge of huge gravitational strength as well as radiative emissivity which looks almost like an ellipse with eccentricity. However, Spiral galaxies are those which has a central core, but the angular speed of rotation of the galactic disk varies with distance from centre to periphery. As the speed gradually reduces, the arms split and form spirals.
When two spiral galaxies merge, and if their average angular speed of rotation of the galactic disk is almost same there is a chance for them to equally cancel their spiral nature and creates uniformity after the merging of the nuclei of the two spiral galaxies.

3. You are in a windowless box. You feel yourself pressed to the floor. What are the two things that could be causing this? How does general relativity explain this? What would an outside observer notice about your watch?

If you inside a windowless floor and you feel yourself pressing towards the floor the two things that would be happening will be:

1. The windowless box containing you would be accelerating upwards
2. The windowless box containing you would be under a gravitational pull towards the bottom direction.

In general relativity theory, Albert Einstein have proved that Gravity brings the effect equivalent to what an acceleration would bring in the opposite direction. This is what we refer to as Principle of Equivalence.

If you are inside the box you would never know whether it is the gravity or acceleration that is making you pressing towards the bottom. However, an observer outside your frame of reference would observe that the windowless box is going upwards towards you, rather than you pressing downwards.