Question

1. What does the fact that most starburst galaxies are irregular galaxies tell us about what is happening to cause such a flurry of star formation?
2. How does general relativity explain gravity differently than Newton?
3. What does the overall reddish colour of globular clusters tell us? What are blue stragglers and why are they an anomaly?

Answer 1

What does the fact that most starburst galaxies are irregular galaxies tell us about what is happening to cause such a flurry of star formation?

A Starburst galaxy is a galaxy as the name suggests, It bursts out more stars or it gives birth to a lot of stars in short period of time. They during their lifetime consumes almost all of their gaseous ingredients which was used to make new stars and hence their life span is too short comparing the other galaxies. Such galaxies would always be accompanied with the interaction with an another galaxy or would be undergoing a merging phenomenon. Due to this fact, the highly violent and unstable behaviour they fail to achieve any particular shape and structure; which is some of them are irregular in nature. So, the stars born in them would be distributed non-uniformly and hence they forms a flurry.

How does general relativity explain gravity differently than Newton?

General relativity theory considers the Space and Time to be a single entity named Space-time where the geometry of the space-time and mass have a correlation, which is what that defines the mechanism of the phenomenon of gravity; In that theory gravity has a finite range of influence and it is not a force of attraction.
However in Newton's theory of gravitation, the phenomenon of gravitation is a fundamental attractive force in nature which has an infinite range. It also assumes the Space and Time to be seperate and absolute.

What does the overall reddish colour of globular clusters tell us? What are blue stragglers and why are they an anomaly?

When we draw the Hertzsprung–Russell Diagram we might find a numerous amount of red giant stars among them. The enormous amount of red giants will outperform when we take a visible spectral image of the cluster. That is why they seem to be reddish. Blue stragglers are those stars which have an exceptional high mass and temperature comparing other normal stars. They are considered to be formed as a result of the interaction between two or more stars. They are also considered to be binary stars on the process of merging or those which finished their merging. It is their high luminosity that makes them bluer in the Hertzsprung–Russell diagram.