Any physics nuts out there?

[dshans]

Anyone?

1. Suppose we look at a distant quasar. If an inhabitant of the host galaxy of that quasar looked at the Milky Way at the same time we looked at their galaxy, what kind of object might they see? Explain. How would the color of light they observe be different than the color of light emitted by the Milky Way?



2. What is Hubble’s Law and how can it tell us the distance to a galaxy? Hubble’s Law contains a constant (labeled H, the slope of a line). How is the value of the constant determined? Suppose the accepted value of the constant was found to be incorrect in the future. Would we have to change our ideas about the evolution of galaxies? Why or why not? Would it change our estimate of the age of the Universe?

A million vbucks for a legit answer, per QU.

Way beyond my pay grade. Not even close to grammar, spelling, syntax or provable coherency.

I'll give you a million vbucks if you make my headache (a result of pondering your questions) go to a galaxy far, far away ...

 

[MNIrishman]

On my phone, so please forgive the brevity. One can presume that the inhabitants of the quasar host galaxy will have a symmetric view of our galaxy. Since the universe is expanding, this would mean that they would see a red-shifted Milky Way. This red shift is related to velocity by hubbles law (v=HD), where h is hubble's constant. I think H is determined using standard candles to have a separate determinant of distance. If it were found to have a different value, it would change this relationship. In other words, the universe would have been shown to have a different expansion rate, and thus a different age than what we think. That would dramatically affect our theories of galactic evolution since it alters the time scale of development.

 

[koonja]

Way beyond my pay grade. Not even close to grammar, spelling, syntax or provable coherency.

I'll give you a million vbucks if you make my headache (a result of pondering your questions) go to a galaxy far, far away ...

This is way better than what I could come up with .

On my phone, so please forgive the brevity. One can presume that the inhabitants of the quasar host galaxy will have a symmetric view of our galaxy. Since the universe is expanding, this would mean that they would see a red-shifted Milky Way. This red shift is related to velocity by hubbles law (v=HD), where h is hubble's constant. I think H is determined using standard candles to have a separate determinant of distance. If it were found to have a different value, it would change this relationship. In other words, the universe would have been shown to have a different expansion rate, and thus a different age than what we think. That would dramatically affect our theories of galactic evolution since it alters the time scale of development.

I don't know enough about physics to refute you, so vbucks on the way! Thanks!

 

[goldandblue]

On my phone, so please forgive the brevity. One can presume that the inhabitants of the quasar host galaxy will have a symmetric view of our galaxy. Since the universe is expanding, this would mean that they would see a red-shifted Milky Way. This red shift is related to velocity by hubbles law (v=HD), where h is hubble's constant. I think H is determined using standard candles to have a separate determinant of distance. If it were found to have a different value, it would change this relationship. In other words, the universe would have been shown to have a different expansion rate, and thus a different age than what we think. That would dramatically affect our theories of galactic evolution since it alters the time scale of development.

Lol... Wut???

 

[dshans]

Head. Exploding. Must drink more Burgundy. So. Many. Many. Variables.

Is "at the same time" an absolute function, irrespective of the speed of light? Would "color" be affected by inherent limitations in wave length perception? If the universe is expanding or contracting, is "distance" a valid metric?

You're only as old as your heart is young.

 

[koonja]

Head. Exploding. Must drink more Burgundy. So. Many. Many. Variables.

Is "at the same time" an absolute function, irrespective of the speed of light? Would "color" be affected by inherent limitations in wave length perception? If the universe is expanding or contracting, is "distance" a valid metric?

You're only as old as your heart is young.

I don't what to tell you because I don't know anything, but all I can say is this is an introductory physics class, so I doubt it's supposed to be too in depth.

 

[MNIrishman]

'At the same time' is an idealized notion, to be taken in the colloquial context in this instance, because as we all know, time is as mutable as position. Color in the physics sense transcends the visual range and generally only refers to deviations from normal in the increased frequency direction (blue shift) or decreased frequency direction (red shift) in accordance with the Doppler effect. Distance is a valid metric because the relative magnitude of velocity dwarfs the magnitude of distances involved, especially over the time of the measurement. Think less 'measuring a car driving away' and more 'measuring a continent move.'

 

[condoms SUCk]

On my phone, so please forgive the brevity. One can presume that the inhabitants of the quasar host galaxy will have a symmetric view of our galaxy. Since the universe is expanding, this would mean that they would see a red-shifted Milky Way. This red shift is related to velocity by hubbles law (v=HD), where h is hubble's constant. I think H is determined using standard candles to have a separate determinant of distance. If it were found to have a different value, it would change this relationship. In other words, the universe would have been shown to have a different expansion rate, and thus a different age than what we think. That would dramatically affect our theories of galactic evolution since it alters the time scale of development.

The red shift is due to what is known as the Doppler Effect this principle states that as waves move towards you they are compressed and as they move away from you they elongate. Think of a train that is sounding it horn. It has a higher pitch as it moves towards you peaks as it is in front of you and then the tone gets lower as it moves away from you. With light similar principal as light moves towards you it will have a “blue shift” and as light moves away from you it will have a “red shift”. This is how astronomers figured out that they universe is expanding because galaxies had a red shift which means they are moving away and the space between the galaxies are expanding.
To the reference of “Standard Candles” this is a way for astronomer to judge distance. This is done by using type 1A Supernovas since all supernovas emit the exact same about of energy and light astronomers can tell how close or far away a distant galaxy is by looking for a Type 1A supernova and determining its light magnitude.

 

[condoms SUCk]

Anyone?

1. Suppose we look at a distant quasar. If an inhabitant of the host galaxy of that quasar looked at the Milky Way at the same time we looked at their galaxy, what kind of object might they see? Explain. How would the color of light they observe be different than the color of light emitted by the Milky Way?



2. What is Hubble’s Law and how can it tell us the distance to a galaxy? Hubble’s Law contains a constant (labeled H, the slope of a line). How is the value of the constant determined? Suppose the accepted value of the constant was found to be incorrect in the future. Would we have to change our ideas about the evolution of galaxies? Why or why not? Would it change our estimate of the age of the Universe?

A million vbucks for a legit answer, per QU.

The standard candle is the way the constant is determined. If Hubble's Law is found to be incorrect then the ability to judge distance will be lost and since the distances between galaxies are so vast astronomers would be more or less guessing how far away galaxies are.
Now to the question of would this change our ideas of the evolution of galaxies I would say yes and no. We can see galaxies progressing through various phases of development now to get a good idea of how they form, but if the distance is factor is taken out that means it would be hard to figure out the age of those developments.
Why I say that is the further distant a galaxy is the older the galaxy from our view point due to light taking time to reach us. For instance light from the sun takes 8 minuets once the photon leaves the surface of the sun to reach Earth, so we see the sun as it was 8 minuets ago. If a star is 10 light years away (or about 60 Trillion miles) it would take light 10 years to reach us. So we view that star as it was 10 years ago. A galaxy that is 100 million lit years away we see it as it was 100 million years ago and so on an so forth.
So if we couldn't figure out how far away the furthest galaxies are we couldn't figure out old the furthest galaxies are hence determining the age of the universe would be extremely difficult if not impossible.
Hope that helps.