This topic contains a solution. Click here to go to the answer
« previous next »

Author Question: Why do stars in the central bulge have a lower metallicity than stars in the disk? What will be ... (Read 65 times)

saraeharris

  • Hero Member
  • *****
  • Posts: 546
on: Jul 27, 2018
Why do stars in the central bulge have a lower metallicity than stars in the disk?
 
  What will be an ideal response?

Question 2

Explain why the term acceleration is important to the first postulate of special relativity.
 
  What will be an ideal response?


Related Topics

Need homework help now?

Ask unlimited questions for free

Ask a Question
Marked as best answer by a Subject Expert

zhanghao

  • Sr. Member
  • ****
  • Posts: 316
Reply #1 on: Jul 27, 2018
Answer to Question 1

Stars in the central bulge formed first, out of material found early in the Universe's history that was mostly hydrogen and helium. Many stars in the disk are younger, and formed after stellar evolution had enriched the interstellar medium with heavier elements. Since metals were present in the materials that formed disk stars, disk stars have a higher metallicity.

Answer to Question 2

The first postulate states that the laws of physics are the same for all observers, no matter what their motion, so long as they are not accelerated. The word accelerated is important. If either spaceship were to fire its rockets, then its velocity would change. The crew of that ship would know it because they would feel the acceleration pressing them into their couches. Accelerated motion, therefore, is differentthe pilots of the spaceships can always tell which ship is accelerating and which is not. The postulates of relativity discussed here apply only to the special case of observers in uniform motion, which means unaccelerated motion. That is why the theory is called the special theory of relativity.


saraeharris

  • Member
  • Posts: 546
Reply 2 on: Jul 27, 2018
Thanks for the timely response, appreciate it

scottmt

  • Member
  • Posts: 322
Reply 3 on: Yesterday
Great answer, keep it coming :)

« previous next »
 

Did you know?

The use of salicylates dates back 2,500 years to Hippocrates's recommendation of willow bark (from which a salicylate is derived) as an aid to the pains of childbirth. However, overdosage of salicylates can harm body fluids, electrolytes, the CNS, the GI tract, the ears, the lungs, the blood, the liver, and the kidneys and cause coma or death.

Did you know?

Pink eye is a term that refers to conjunctivitis, which is inflammation of the thin, clear membrane (conjunctiva) over the white part of the eye (sclera). It may be triggered by a virus, bacteria, or foreign body in the eye. Antibiotic eye drops alleviate bacterial conjunctivitis, and antihistamine allergy pills or eye drops help control allergic conjunctivitis symptoms.

Did you know?

In the United States, congenital cytomegalovirus causes one child to become disabled almost every hour. CMV is the leading preventable viral cause of development disability in newborns. These disabilities include hearing or vision loss, and cerebral palsy.

Did you know?

Vaccines prevent between 2.5 and 4 million deaths every year.

Did you know?

Oxytocin is recommended only for pregnancies that have a medical reason for inducing labor (such as eclampsia) and is not recommended for elective procedures or for making the birthing process more convenient.

Relaxed ear position of a bored or resting horse. Lower lip is loose, also indicating relaxation. Th Relaxed ear position of a bored or resting horse. Lower lip is loose, also indicating relaxation. Th
Aneurysm. Photograph of the aorta, the large blood vessel arising from the heart, with a large bulge Aneurysm. Photograph of the aorta, the large blood vessel arising from the heart, with a large bulge
Motion of Stars at the Poles Motion of Stars at the Poles
Apply lotion to the foot, lower leg, and thigh if accessible. Apply strokes from distal to proximal. Apply lotion to the foot, lower leg, and thigh if accessible. Apply strokes from distal to proximal.
A very thin uniform rod, 2.40 m long and of weight 135 N, has a frictionless hinge at its lower ... A very thin uniform rod, 2.40 m long and of weight 135 N, has a frictionless hinge at its lower ...
The central nervous system is composed of the brain and the spinal cord The central nervous system is composed of the brain and the spinal cord
Video: Introduction to Heart Attacks

For a complete list of videos, visit our video library