A radio broadcast left Earth in 1911. How far in light years has it traveled? If there is, on average, 1 star system per 400 cubic light years, how many star systems has this broadcast reached? Assume that the fraction of these star systems that have planets is 0.50 and that, in a given planetary system, the average number of planets that have orbited in the habitable zone for 4 billion years is 0.20. How many possible planets with life could have heard this signal?

Q: Which of the following is not considered a likely solution to the question of why we are not…

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Q: A newly discovered orange dwarf star has a surface temperature of approximately 5185 K. How far…

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A: Ques: Suppose the Earth grew to its present size in 1 million years through the accretion of…

Q: Which of the following is least reasonable regarding the difficulty in contacting extraterrestrial…

A: "The spacecraft that NASA sent to Proxima Centauri a few years ago should be approaching its target…

Q: If you detected radio signals with an average wavelength of 37 cm and suspected that they came fro

A: Given: Average wavelength is  λa=37cm=0.37m  Earth's orbital velocity is v=30km/s v=30*103 m/s…

Q: Suppose we find an Earth-like planet around one of our nearest stellar neighbors, Alpha Centauri…

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Q: A 25 W speaker emits sound isotropically. What is the sound intensity level at a distance of 32 m?…

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Q: Course Contents » ... » Homework 3 » HW3-P2-PHYS240.problem Timer Notes Evaluate Feedback A ball…

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Q: TRUE OR FALSE: According to an optimistic evaluation of Frank Drake’s equation, there can be as…

A: The Drake equation may be a probabilistic argument wont to estimate the amount of active,…

Q: The Drake equation tells us that the number of technological civilizations in our Galaxy at this…

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Q: Suppose there are 12000.0 civil actions broadcasting radio signals in the Milky Way Galaxy at the…

A: Given that There are 12000 civil actions broadcasting radio signals in the milky way galaxy at the…

Q: By READING the R vs t graph shown below, determine Ro & the mean life. Ro =  ? decays/s mean life…

A: Given, Activity R vs time t graph

Q: Which of the following best represents R = A - B?

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Q: Suppose that stars were born at random times over the last 1010 years. The rate of star formation is…

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Q: The number density of air in a child's balloon is roughly the same as sea level air, 1019…

A: Number of particles in the balloon is, N=nVN=n×43πR3

Q: Suppose there are l0,000 civilizations broadcasting radio signals in the Milky Way GaIaxy right now.…

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Q: How does the habitable zone differ for a star hotter than the sun?

A: The habitable zone of a star is the range of distance from a star where water can remain in its…

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A: The milky way galaxy consists of a disk of about 100000 ly diameter and a thickness of about 1000 ly…

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A: Drake equation is a speculative equation which gives an approximate number of extra-terrestrial…

Q: If a sample of pennies had 75 heads and 25 tails out of 100, how many half-lives have passed?

A: Total 100 In first half life 100/2=50 In second half life 50/2=25

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A: For which of the following reason rover send to other planetary bodies

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Special Relativity

The theory of special relativity discusses how space and time are related to objects traveling along a straight line at a constant speed. Simply stated, as an object reaches the speed of light, its mass becomes infinite and it is unable to move faster than light. This interstellar speed limit has been the topic of much debate in astronomy, and also in science fiction when people consider how to fly over large distances.