Question

In: Physics

We often use telescopes to capture beautiful pictures of the planets and distant galaxies. If optical...

We often use telescopes to capture beautiful pictures of the planets and distant galaxies. If optical telescopes like the Hubble telescope can capture pictures of galaxies millions of light years away, why can’t we get detailed photos of stars and planets in our own galaxy that are only a few hundred light years away?

Solutions

Expert Solution

The apparent size of an object is a result of just two numbers, its true size (diameter) divided by its distance: A 10-foot object located 100 feet away appears the same angular size as a 100–foot object located 1,000 feet away. And the bigger an object is relative to its distance, naturally, the larger it will appear: a 20-foot object at 100 feet will look twice as big as a 10-foot object at that distance.

Consider a prominent nearby galaxy, the Andromeda Galaxy. It is approximately 150,000 light years wide and 2.2 million light years away. The ratio of its size to its distance is 1:15, and the full Andromeda galaxy (if you could see all the way out to its dim edges) stretches nearly 4 degrees in the sky. It’s actually much larger in the sky than the sun or moon. It is so large that the Hubble Space Telescope had to take 7,398 separate images to make this partial mosaic portrait.

Now let’s consider Pluto. It has a diameter of 1,473 miles and is currently located just over 3 billion miles from Earth. The ratio of its size to its distance is about 1:2,000,000. Put another way, the Andromeda Galaxy appears more than 100,000 times as wide in Earth’s sky as Pluto does. It is, roughly speaking, the difference between looking at a poster on your living room wall and trying to look at a bacterium on the wall next to it.

That is why Pluto is so hard to see clearly from Earth.


Related Solutions

3. Radio telescopes are often much larger in diameter than optical (i.e. visible light) telescopes; some...
3. Radio telescopes are often much larger in diameter than optical (i.e. visible light) telescopes; some of the larger ones have diameters of 100 meters, while the largest optical telescopes are only about 10 meters in diameter. Assume that radio telescopes observe at wavelengths around 1 cm, which is about 20,000 times longer than the wavelengths of visible light. a) Explain why these large radio telescopes have much greater light-gathering power than large optical telescopes. Explain what quantities light-gathering power...
Research indicates that we often form more positive impressions of beautiful people than of those who...
Research indicates that we often form more positive impressions of beautiful people than of those who are physically unattractive. Explain how advertisements, movies, and children's fairy tales might encourage this tendency. Use your knowledge of the factors that facilitate interpersonal attraction to suggest how people could be influenced to feel more positively about those who are physically unattractive.​
1. Accounting information systems capture transaction data, often through the use of source documents – some...
1. Accounting information systems capture transaction data, often through the use of source documents – some paper-based, some electronic. The design of a source document can impact how easily and accurately it is used. For example, when user name is captured, it should be clear to document users whether they should enter their first name first or their last name first. When a date is required, a computerized system can utilize the current system date. Describe one or more source...
Often times, we are not told to use a mean or a proportion, but we should...
Often times, we are not told to use a mean or a proportion, but we should know which is the best method for measuring our data. Explain, what type of data would it be most appropriate to use a mean and what type of data would it be most appropriate to use a proportion?
M 12: Why can we not use visible light (and optical microscopy) to study nanoscale materials?...
M 12: Why can we not use visible light (and optical microscopy) to study nanoscale materials? What instruments are better suited and why? Explain your answer.
Often we would like to make the user think we like him/her so we use a...
Often we would like to make the user think we like him/her so we use a friendly prompt to get them to decide if they want to continue a loop. One can make a sentinel using an integer value outside of the expected input range but a more delightful way is to ask politely if: System.out.println("Do you want to play again?); In order to do this we will need a scanner and a do-while loop. For the scanner sometimes the...
In policy analysis we use triangulation in situation specific scenarios to evaluate metric options. Often we...
In policy analysis we use triangulation in situation specific scenarios to evaluate metric options. Often we have the benefit to propose a new dependent variable and by new we mean one that other researchers (to your knowledge) have not used as a “y”. You just said that to an arts major. Her face is blank. Explain what you meant in English.
At my work, we often have multiple & different components from multiple suppliers that we use...
At my work, we often have multiple & different components from multiple suppliers that we use to solve it down to tubing to make IV administration sets for hospitals. Each component supplier has its own unique set of dimensions where we are to bond to the tubing. We have tried to standardize the outside diameter of the tubing so that we have universal dimensions that work for three tiers of dimensions and components. It is important to take into consideration...
We often use sampling in conjunction with deciding the quality of entire shipments. Suppose a shipment...
We often use sampling in conjunction with deciding the quality of entire shipments. Suppose a shipment of 400 components contains 68 defective and 332 non-defective computer components. From the shipment you take a random sample of 25. When sampling with replacement (so that the p = probability of success does not change), note that a success in this case is selecting a defective part. The mean of this situation is? 12.500 8.173 2.500 4.250 2. The P(X<6)=?          a. 0.242...
Question: One criticism often heard about economics is that the models we use are unrealistic: in...
Question: One criticism often heard about economics is that the models we use are unrealistic: in seeking t... One criticism often heard about economics is that the models we use are unrealistic: in seeking to keep the scope of our work more manageable by making certain assumptions or ignoring certain details, we may oversimplify the situation. Write one paragraph on whether you agree or disagree with this criticism. Why do we use models at all, and how should we balance...
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT