Name – ___________________________ Don't use plagiarized sources. Get Your Custom Essay on Gravitational Waves – Essay Help Services Get an essay WRITTEN FOR YOU, Plagiarism free, and by an EXPERT! Just from $10/Page Order Essay Date – ____________ Section _______ Lab Partner – ______________________

Your Grade     __________________

 

 

 

 

 

 

 

 

Neutrinos and Gravitational Waves – Worksheet

 

2

1

Part 1: Neutrinos

A

 

 

 

D

Earth

B

 

C

4

 

 

3

 

 

 

Question 1) Each dot on Earth in the picture above is a neutrino detector. Suppose each star shown goes super nova and emits neutrinos. For each star, write detectors in order of when they would see the neutrinos arrive. (Hint: draw lines from the star to each detector and compare the lengths)

Star	1st Detector	2nd Detector	3rd Detector	4th Detector
1
2
3
4

                                                                                                                                                                    16 Points

 

Question 2) How would knowing arrival times help pinpoint the location of a super nova?

 

                                                                                                                                                                   4 Points

A

1

C

D

B

 

 

 

2

Earth

 

 

 

 

3

 

4

 

 

 

 

Question 3) Now let’s try to get a more realistic example by using arrival times to pinpoint the star that went super nova. The neutrinos are first detected by detector B, followed by A, then C, then D. Which star is it?

 

                                                                                                                                                                   5 Points

 

 

Part 2: Gravitational Waves

What can we use gravitational waves for?  Gravitational waves travel at the speed of light.  Below is a recorded signal of a gravitational wave measured in Washington state and in Louisiana.  Note the arrival times for the main signal (the brightest spot) is slightly different for the two measurements.

 

 

                       Signal at Hanford, Washington                            Signal at Livingston, Louisiana

 

 

Question 4) Measure the positions (time) for the brightest spot in each location.

 

Time signal arrives in Washington	sec
Time signal arrives in Louisiana	sec

                                                                                                                       (4 points)

Question 5) Which city received the signal earlier?

 

                                                                                                                                                                   (2 points)

Question 6) Could this tell you where the gravitational wave is coming from?  Explain.

 

                                                                                                                                                (2 points)

 

Question 7) What is the difference in arrival times?

 

sec

(2 points)

 

Question 8) Remembering that gravitational waves travel at the speed of light, and that:

 

 

Calculate the extra distance the gravitational wave would have travelled to reach the farther away detector based on the difference in arrival times. (the speed of light is 186,000 miles/second)

 

Show your work

                                                                                                                                                           (4 points)

 

 

Question 8) How close is the estimate to the actual distance between the two cities? (use Google)

 

                                                                                                                                                            (4 points)

 

 

 

 

Question 9) It can be difficult to describe how important being able to see past some physical barrier can be to science.   To help put the importance of gravitational waves into a more relatable context, consider some other discovery or invention that allowed us to see past some physical barrier. Describe the discovery/invention and how it has affected our lives. List two.

 

1)           2)

7 Points

Name – ___________________________ Date – ____________ Section _______ Lab Partner – ______________________

Your Grade     __________________

 

 

 

 

 

 

 

 

Neutrinos and Gravitational Waves – Worksheet

 

2

1

Part 1: Neutrinos

A

 

 

 

D

Earth

B

 

C

4

 

 

3

 

 

 

Question 1) Each dot on Earth in the picture above is a neutrino detector. Suppose each star shown goes super nova and emits neutrinos. For each star, write detectors in order of when they would see the neutrinos arrive. (Hint: draw lines from the star to each detector and compare the lengths)

Star	1st Detector	2nd Detector	3rd Detector	4th Detector
1
2
3
4

                                                                                                                                                                    16 Points

 

Question 2) How would knowing arrival times help pinpoint the location of a super nova?

 

                                                                                                                                                                   4 Points

A

1

C

D

B

 

 

 

2

Earth

 

 

 

 

3

 

4

 

 

 

 

Question 3) Now let’s try to get a more realistic example by using arrival times to pinpoint the star that went super nova. The neutrinos are first detected by detector B, followed by A, then C, then D. Which star is it?

 

                                                                                                                                                                   5 Points

 

 

Part 2: Gravitational Waves

What can we use gravitational waves for?  Gravitational waves travel at the speed of light.  Below is a recorded signal of a gravitational wave measured in Washington state and in Louisiana.  Note the arrival times for the main signal (the brightest spot) is slightly different for the two measurements.

 

 

                       Signal at Hanford, Washington                            Signal at Livingston, Louisiana

 

 

Question 4) Measure the positions (time) for the brightest spot in each location.

 

Time signal arrives in Washington	sec
Time signal arrives in Louisiana	sec

                                                                                                                       (4 points)

Question 5) Which city received the signal earlier?

 

                                                                                                                                                                   (2 points)

Question 6) Could this tell you where the gravitational wave is coming from?  Explain.

 

                                                                                                                                                (2 points)

 

Question 7) What is the difference in arrival times?

 

sec

(2 points)

 

Question 8) Remembering that gravitational waves travel at the speed of light, and that:

 

 

Calculate the extra distance the gravitational wave would have travelled to reach the farther away detector based on the difference in arrival times. (the speed of light is 186,000 miles/second)

 

Show your work

                                                                                                                                                           (4 points)

 

 

Question 8) How close is the estimate to the actual distance between the two cities? (use Google)

 

                                                                                                                                                            (4 points)

 

 

 

 

Question 9) It can be difficult to describe how important being able to see past some physical barrier can be to science.   To help put the importance of gravitational waves into a more relatable context, consider some other discovery or invention that allowed us to see past some physical barrier. Describe the discovery/invention and how it has affected our lives. List two.

 

1)           2)

7 Points

University of Colorado – Colorado Springs
Most things we have considered so far have been detected through extensions of our senses, sight in particular. We can do things like measure temperature, identify molecules, and measure distances, all by using light. However, to truly understand our universe, we need to go beyond things our senses can handle. In this lab we will learn about two such things, neutrinos and gravitational waves.
Neutrinos
Neutrinos are sub-atomic particles that are produced in important astronomical events, from everyday nuclear reactions that take place in our sun to supernovas. Our sun produces so many neutrinos that 65 billion of them pass through each square centimeter of our body every second! Thankfully, these tiny particles hardly ever interact with matter, so we are not affected. In fact, we need giant underground chambers lined with detectors and filled with 50,000 tons of ultra-pure water just to detect them. These detectors look for tiny bursts of light that indicate a neutrino has interacted with some of the water in the chamber. Neutrinos also play a very important role in supernovas. When a massive star explodes at the end of its life, it sends out an even greater number of neutrinos.
Figure 1: The inside of the Super-Kamiokande neutrino detector in Japan when it was drained for repairs. Each dome-like thing lining the wall and floor is a detector
Neutrinos and Gravitational Waves – Detecting things our senses miss
University of Colorado – Colorado Springs
But what exactly are neutrinos? Since they do not interact strongly with light or matter
and they are not part of the building blocks of matter like protons, neutrons, and electrons,
they are difficult to relate to everyday life, and we can only describe their properties. (And even
some of those properties are bizarre!) The most normal part about them is that they do not
have an electrical charge. They are smaller than electrons. They were once thought to be
massless but are now known to have one of three tiny values of mass and can switch between
those values over time! They also come in three “flavors”: electron neutrinos, muon neutrinos,
and tau neutrinos (in particle physics, “flavor” is more like a new type of electrical charge than
anything you would taste).
Despite rarely interacting with our everyday world, neutrinos give us important
information for understanding the workings of our universe. Most things produced by the Sun,
such as light and solar winds, are produced at or near the surface. Since neutrinos pass though
matter so easily, they can give us insight on the internal workings of our sun that other particles
cannot. We can also use the large burst of neutrinos produced in supernovas to pinpoint the
location of the super nova. We do this by comparing when the neutrino burst arrives at
detectors across the globe. Currently we have a network of 7 neutrino detectors installations
working together in the “SuperNova Early Warning System” (SNEWS) to detect local (this and
nearby galaxies) super nova. Super nova are rare events and SNEWS has only been active since
2004 so it has not found a supernova yet.
Gravitational Waves
Gravitational waves are
literally waves in the fabric of our
universe, called space-time.
Einstein’s theories of special and
general relativity unite space (as in a
direction you can walk rather than
outer space) and time together into
space-time. General relativity states
that gravity is a warping of a spacetime
around a massive object such
as a star, planet, black hole, or
galaxy. Waves can be produced in
space-time when two of the massive
objects orbit each other very closely.
Since these waves are propagating within space-time itself, they are not stopped by matter.
Gravitational waves are a promising way to study the early Universe. Right after the Big Bang
(14 billion years ago) the Universe was very hot and dense. Because of this, any light that was
emitted would almost always be absorbed by something. This means that the Universe was
Fi gure 2: An example of two dense objects orbiting each other
very quickly to produce gravitational waves in space time.
University of Colorado – Colorado Springs
optically dense; light could not pass through it. As the universe expanded and cooled, it became
less and less likely for emitted light to get absorbed. Around 370,000 years after the Big Bang,
light was no longer likely to get absorbed and the Universe became optically transparent.
The light emitted when the Universe became transparent is the oldest light in the universe and
is now known as the Cosmic Microwave Background (CMB). Since the CMB is the oldest light,
we ca not use telescopes to “see” what happened in the time between the Big Bang and the
Universe becoming transparent – all that early light was absorbed long ago. One way we can
get information about the early universe is by using gravitational waves! Unlike light,
gravitational waves can travel through matter and could travel through the early, dense
Universe. By studying ancient gravitational waves, we hope to learn more about how the
universe developed before the CMB was emitted.
Figure 3: An ariel view of one of the LIGO facilities where gravitational waves are detected. The long lines
radiating out from the buildings are for the kilometers long lasers needed to detect the tiny variations of
distance caused by a gravitational wave.