This topic contains a solution. Click here to go to the answer

Author Question: How have astronomers determined the mass of the Milky Way's supermassive black hole? What will be ... (Read 86 times)

humphriesbr@me.com

  • Hero Member
  • *****
  • Posts: 550
How have astronomers determined the mass of the Milky Way's supermassive black hole?
 
  What will be an ideal response?

Question 2

Describe two experiments that provide evidence of space-time curvature by the presence of a mass.
 
  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

bigsis44

  • Sr. Member
  • ****
  • Posts: 317
Answer to Question 1

Stars near the galactic center are in elongated, high-speed orbits around Sgr A. Astronomers can use the orbit of one object around another to determine the masses of the objects.

Answer to Question 2

Two key experiments confirmed that space-time can be curved the presence of a mass: the advance of perihelion of Mercury's orbit and the motion of light near the Sun.
Each time Mercury returns to perihelion, its closest point to the Sun, it is about 29 km (18 mi) past the position predicted by Newton's laws. This is such a small distance compared with the planet's diameter of 4880 km that it could never have been detected had it not been cumulative. Each orbit, Mercury gains only 29 km, but in a century it's ahead by over 12,000 kmmore than twice its own diameter. To remedy this difference, he first calculated how much the Sun's mass curves space-time in the region of Mercury's orbit and then he calculated how Mercury moves through the space-time. The theory predicted that the curved space-time should cause Mercury's orbit to advance by 43.03 arc seconds per century, well within the range of uncertainty in the observed excess. His theory matched Newton's observations.

A second test of general relativity was related to the motion of light through the curved space-time near the Sun. Because light has a limited speed, Newton's laws predict that the gravity of an object should slightly bend the paths of light beams passing nearby. The equations of general relativity indicated that light should have an extra deflection caused by traveling through curved space-time, just as a rolling golf ball is deflected by undulations in a putting green. Einstein predicted that starlight grazing the Sun's surface would be deflected by 1.75 arc seconds, twice the deflection that Newton's law of gravity would predict. Starlight passing near the Sun is normally lost in the Sun's glare, but during a total solar eclipse, stars beyond the Sun can be seen. During the next solar eclipse, measurements were taken and they matched his predictions.



humphriesbr@me.com

  • Hero Member
  • *****
  • Posts: 550
Both answers were spot on, thank you once again




 

Did you know?

Glaucoma is a leading cause of blindness. As of yet, there is no cure. Everyone is at risk, and there may be no warning signs. It is six to eight times more common in African Americans than in whites. The best and most effective way to detect glaucoma is to receive a dilated eye examination.

Did you know?

Although not all of the following muscle groups are commonly used, intramuscular injections may be given into the abdominals, biceps, calves, deltoids, gluteals, laterals, pectorals, quadriceps, trapezoids, and triceps.

Did you know?

Nearly 31 million adults in America have a total cholesterol level that is more than 240 mg per dL.

Did you know?

Persons who overdose with cardiac glycosides have a better chance of overall survival if they can survive the first 24 hours after the overdose.

Did you know?

The toxic levels for lithium carbonate are close to the therapeutic levels. Signs of toxicity include fine hand tremor, polyuria, mild thirst, nausea, general discomfort, diarrhea, vomiting, drowsiness, muscular weakness, lack of coordination, ataxia, giddiness, tinnitus, and blurred vision.

For a complete list of videos, visit our video library