how far out in space is the first broadcasted radio signal?

Answer 1

You measure it with time in a sense. Light travels a specific distance over time (hence light year) so to answer, you figure out when the first radio broadcast occurred.

The first radio broadcast is not the same as the first radio signal to be sent and received. Broadcast implies the intent of sending the signal to an wide scale audience that is assumed to be able to receive it - this discounts early studies and experiments as there was no such audience.

The first extended broadcast of the human voice was transmitted through the air on December 24, 1906 from Brant Rock, Massachusetts. A Canadian engineer, Reginald Fessenden, had worked for Thomas Edison in his New Jersey Laboratory, and later became a professor at the University of Pittsburgh. (citation - http://www.wfn.org/story.html)

At this point, its simply a matter of mathematics to figure out how far it has traveled. Using light seconds as a baseline and not accounting for rounding errors (we'll round off to the approximate at the end), the distance would be:

December 24, 1906 to March 5, 2007 = 100 years plus 70 days.

100*365.26+70 = 36596 days
36596 days = 878304 hours
878304 hours = 316189440 seconds

light travels in a vacuum (ie - space) at 299 792 458 m / s

total distance over the calculated time is:

947,912,094,112,435,200 meters - about 950 trillion kilometers.

Distance is kind of useless to measure in meters, kilometers, miles and whatnot at that scale so we use light years as a measurement. When we use light years, we end up back where we started - just over 100 light years.

Everything was just a conversion of one length measurement to another length measurement.

You may have been thinking first radio signal, but that's not what you actually asked. The answer will depend on nothing more than the definition of 'first broadcasted radio signal' everything else is just a matter of mathematic conversion.

Answer 2

Just to add:

Let's assume that our first radio signal was detected today by intelligent life approximately 100 light-years away. Assuming they could instantly decode our message and respond, it would be another 100 years for their signal to return to us. And then we would have to assume that we could detect their answer.

While this is slightly off topic, I hope this sheds a bit more light on the enormity of our galaxy, must less the universe, and the virtual impossibility of finding other intelligent life because of this.

Answer 3

It is not how far out the signal is but that it will drop 3 dB every times u double the distance . 3dB is half of what ever the signal was.

Answer 4

The transmintions are traveling at the speed of light. Light travels at 3,000,000 meters/second so just take the number of seconds from the first transmition and then just plug it in and you will have your answer except it will be really large becuase it would be in metters.

Answer 5

About 105.3 light years away.

That's if there is enough signal above the backgound noise to realize its existance.

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Answer 6

About a hundred light years. Where it would be completely undetectable.