Question

Which of these is the best method to estimate the speed at which a star is moving away from Earth?


measure the star's red shift

calculate the pitch due to changes in frequency of light

calculate the parallax due to changes in Earth's position

measure the star's blue shift

Answer 1

sorry but i'm not sure about it ..

Answer 2

Its ok

Answer 3

I believe it's pitch due to changes in frequency of light.

Answer 4

red shift...light from the star will appear to have a longer wavelength if moving away.

Answer 5

Isn't a red shift a description of a galaxy moving away?

Answer 6

I mean a description of the distance of a galaxy when moving away?

Answer 7

I think it also applies to stars in general

Answer 8

options 1 & 2 seem to be saying the same thing really, and we can rule out option 4 for sure..

Answer 9

Hm I see, can you help me on a couple more questions?

Answer 10

I'll try

Answer 11

Ok thank you here is one:

The Big Bang Theory was supported by the discovery of the
Answer

gravitational force between planets

red shift in electromagnetic spectrum

galaxies in the universe

temperature of the universe

Answer 12

I know that the most definite proof of the big bang was the discovery of the cosmic microwave background radiation. This relates mostly to option 4, since the cooling of the thermal radiation from the big bang was predicted and measured in the cosmic background microwave radiation. My guess would be option 4..

Answer 13

Ok thank you very much. What about this one:

Which of these is the most likely reason why the Steady State Theory has been rejected by the scientific community?
Answer

scientists worldwide do not agree with its results

its results remain unchanged over a long period of time

scientists need expensive equipments to verify its results

its experiments contradict the old theories about the universe

Answer 14

This is a weird set of options...! I have to admit I'm stuck, but from what little I know I would guess option 1

Answer 15

Haha yeah these questions are tricky plus I suck at science :/

Answer 16

Do you think it would be option 4?

Answer 17

I mean the observations contradict the predictions of the SST. But I don't see that option as one of the possible answers

Answer 18

Hm cause in my lesson they said that "scientist realized that it did not follow the rules of physics" can you get anything from that?

Answer 19

The answer to your first question is to measure the redshift, that's correct. Blueshift is not so crazy an answer though, since that's what happens when stars move toward the earth rather than away. The electromagnetic doppler effect applies to any light emitting body, and is most commonly applied to stars. It can by extension be applied to galaxies by averaging.

I would argue that the Big Bang theory was supported by the discovery of the expansion of the universe, which corresponds to a near-universal redshift. Which is not to say that stars are not also coming towards us sometimes, but on average everything is getting farther apart, which implies that it was closer together in the past and suggests that it may have been all together in one little lump at the beginning.

The fundamental principle of science is that any theory that disagrees with experiment is wrong, and that's the end of the story. The Steady State theory does not agree with experimental evidence, and so it has been largely discarded.