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s2w6 Flipped classroom - implications of the doppler effect

Last updated 6 months ago

11 questions

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Question 1

1.

Draggable item		Corresponding Item

Question 2

2.

watch this video which will remind you about the doppler effect

do you have any questions?

Question 3

3.

Hubble noticed that not only were the vast majority of distant galaxies were redshifted, but the further they were the more redshifted they are. He determined this meant

The universe was expanding, and the

Light from distant galaxies was being absorbed and re-emitted by interstellar dust, causing a progressive reddening effect that increased with distance due to more dust being encountered.

Galaxies were rotating around a central point in the universe, with more distant galaxies moving at faster speeds, causing greater Doppler shift effects.

Ancient galaxies formed in an earlier, cooler universe had different chemical compositions that naturally produced redder light, and we see more ancient galaxies at greater distances.

Question 4

4.

A common misconception about the concept of the expanding universe is that stars and galaxies are moving away from the earth into empty space that surrounds the universe. That is not the theory. Go find a rubber band and make three marks somewhere in the center. make two marks reasonably close together, and another one a little farther away. then stretch the rubber band. which of the following is true?

the second two dots have moved the same distance from the first dot as a result of the stretching. 

the third dot (the one farther away in the first place) moved further away from the first dot than the second dot did.

The third dot did not move as far away from the first dot as the second dot did

Question 5

5.

Remember that speed is just measured as change of distance over time, if something moves a larger amount over a set amount of time compared to another moving object, it is moving

faster

slower

the same

Question 6

6.

we have talked about the speed of light as the speed limit of the universe, and there is a lot of fairly complicated math that explains why nothing can move through space at speeds greater than the speed of light. so a couple questions - without doing any research - just using your gut instinct: how would you try to measure the speed of light?

Question 7

7.

Watch the following video. It is pretty long, but I want you focus on the things you do understand, and don't fret too much if you don't understand some of it.
write any questions you have here.

Question 8

8.

What method made the most sense to you?

Question 9

9.

What method made the least sense to you?

Question 10

10.

should we try the american cheese in the microwave method?

yes

no

Question 11

11.

Come to class ready to discuss one or two of the methods of measuring the speed of light, and discussing the nature of the "speed limit of the universe". One of the things I did want to note is that the speed of light has been measured to be 299,792,458 m/s. The earth moves at 29,780 m/s.
we do not believe the speed of light reaching us is 299,792,458-29,780 when we are moving away from the light source or that it is 299,792,458-29,780 when we are moving towards the light source. be ready to consider why this is.

Now that exhibition is over we are going to start putting aspects of light together. so first - some review: below is a list of things we can glean from light from a star. From what you already know, try to match the aspect of a star we can learn

Age of a star

pattern of the light tells us the makeup of the outermost layer of the earth

size of the star

whether the star is moving towards or away from the earth

the mass of a star

how much light is observed from earth

spectral analysis of the light

light output of the star based on light observed from earth and calculated distance to the star

luminosity of the star

parallax, speed of doppler shift, 

doppler shift of the spectral analysis

uh... we can't really tell that about an individual star. we have theories about stars in general.

distance of the star

angular diameter, and then calculate the linear measurement with the distance found with parallel. (there are other methods of making more precise measurement as well)

Brightness of the star

from measuring the speed of the orbits of the stars planets