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3 years ago

How do scientists use the Doppler effect to understand the universe?

2 answers:

6 0

There's a very subtle thing going on here, one that could blow your mind.

Wherever we look in the universe, no matter what direction we look,
we see the light from distant galaxies arriving at our telescopes with
longer wavelengths than the light SHOULD have.

The only way we know of right now that can cause light waves to get
longer after they leave the source is motion of the source away from
the observer. The lengthening of the waves on account of that motion
is called the Doppler effect. (The answer to the question is choice-c.)

But that may not be the only way that light waves can get stretched. It's
the only way we know of so far, and so we say that the distant galaxies
are all moving away from us.

From that, we say the whole universe is expanding, and that right there is
one of the strongest observations that we explain with the Big Bang theory
of creation.

Now: If ... say tomorrow ... a competent Physicist discovers another way
for light waves to get stretched after they leave the source, then the whole
"expanding universe" idea is out the window, and probably the Big Bang
theory along with it !

Now that our mind has been blown, come back down to Earth with me,
and I'll give you something else to think about:

It's true that when we look at distant galaxies, we do see their light
arriving in our telescopes with longer wavelengths than it should have.
And then we use the Doppler effect to calculate how fast that galaxy
is moving away from us. That's all true. Astronomers are doing it
every day. I mean every night.

So here's the question for you to think about ... maybe even READ about:

When the light from a distant galaxy pours into our telescope, and we
look at it, and we measure its wavelength, and we find that the wavelength
is longer than it should be ... how do we know what it should be ? ? ?

djverab [1.8K]3 years ago

3 0

Answer: The correct option is (c).

Explanation:

In Doppler effect, there is an apparent change in the frequency when there is a relative motion between the source and the observer or the source or the listener.

When the source and the observer are approaching each other then there is increase in the frequency.

When the source and the observer are moving away from each other then there is decrease in the frequency.

Therefore, Scientists use the Doppler effect to understand the universe to determine motion of object.

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Two or more velocities add by ____?<br><br> Plz help

VladimirAG [237]

By vector addition.
In fact, velocity is a vector, with a magnitude intensity, a direction and a verse, so we can't simply do an algebraic sum of the two (or more velocities).
First we need to decompose each velocity on both x- and y-axis (if we are on a 2D-plane), then we should do the algebraic sum of all the components on the x- axis and of all the components on the y-axis, to find the resultants on x- and y-axis. And finally, the magnitude of the resultant will be given by
$R= \sqrt{(R_x)^2+(R_y)^2}$
where Rx and Rx are the resultants on x- and y-axis. The direction of the resultant will be given by
$\tan \alpha = \frac{R_y}{R_x}$
where $\alpha$ is its direction with respect to the x-axis.

3 0

3 years ago

Read 2 more answers

Math skills would fall under which category?

vekshin1

It would fall under Mathematics

5 0

3 years ago

Is a football tackle an elastic or inelastic collision and why?

QveST [7]

If the kinetic energy of an object changes, then the collision is considered inelastic. This is regardless of whether the objects sticks together or not.

My best answer for this question would be D) inelastic, because kinetic energy is not conserved.

We can tell from the collision that it is not elastic.

Momentum is is conserved, it transfers to the other player.

Kinetic energy is not conserved, at it turns into internal friction.

I hope this helps! :)

3 0

3 years ago

You know that you sound better when you sing in the shower. This has to do with the amplification of frequencies that correspond

Elena L [17]

Answer:

Explanation:

For first overtone

Standing waves will be formed lengthwise and breadth-wise in the enclosures having dimension of .75m x 1.5 m

A ) For the formation of lowest two frequencies formed by standing waves along the breadth , fundamental note and first overtone may be considered.

For fundamental note ,

the condition is

wave length λ = 2L = 2 x 0.75 m

λ = 1.5 m

frequency n = v / λ

= 343 / 1.5

= 229 Hz approx

For first overtone

λ = L = 0.75m

frequency n = v / λ

n = 343 / 0.75

= 457 Hz approx

For the formation of lowest two frequencies formed by standing waves along the length , fundamental note and first overtone may be considered.

For fundamental note ,

the condition is

wave length λ = 2L = 2 x 1.5 m

λ = 3 m

frequency n = v / λ

= 343 / 3

= 114 Hz approx

frequency n = v / λ

n = 343 / 1.5

= 229 Hz approx

3 0

3 years ago

All living organisms reproduce by a live functioning baby leaving the mother's body.

algol13

Answer:

there is no question

Explanation:

4 0

3 years ago