What does this mean?

Question

What does this mean?

"For the past 70 years, the powerful signals generated by radio and TV transmitters have been leaking away from our planet at the speed of light. They have already reached hundreds of the nearest stars. If ‘they’ are out there, they already know that we are here."

Answer 1

It means that while we were broadcasting signals such as tv and radio many years ago during that time alien receivers have picked up the signals by now

Answer 2

With all due respect to the answers above, it must be pointed out that only 70 years (this is clearly dated since radio communications have existed on this planet for about 100 years now) are being discussed here. In other words, our communications could only be "overheard" by an intelligent listener within 70 (100) light years of us. That is a vanishingly small amount of area covered when compared to the vastness of the universe. Our galaxy alone "The main disk of the Milky Way Galaxy is about 80,000 to 100,000 light years in diameter" is incredibly vast; it is of course only one of many billions of other galxies. The likelihood of another intelligence within "listening" range is very small. On the other hand, the US Air Force´s CrayII Supercomputer performed a calculation in the 1970s to measure the likelihood of another intelligent life form existed and it returned a 99.9999999999% success rate. The issue is not whether other life forms (intelligent and otherwise) but rather how long it will take to contact them (probably many hundreds of thousands if not millions of years.) In sum, we will eventually be detected, but almost certainly not anytime soon.

Answer 3

If there are aliens out there they already know we are here.... They would have picked up the signals already if they have been travelling at the speed of light for 70 years since with that speed and that much time spent in space the signals would have covered a trumendous distance increasing the chance for other life forms to receive them... 70 light years!!! but in terms of the universe's size this area covered is too small.. So aliens may not exist in this range. BUT! since they have UFO's that travel at very high speeds it is logical to think they live in this range if they have travelled to earth through out these 70 years. but i don't believe in their existance anyway.. Too childish. It's not a faulty quote as John R below states... Why? Because in our human minds aliens are supposed to be superior when it comes to technology levels reached.. So they must definately have receivers as we do

Answer 4

It means that the signals made by radio and television has been transmitted to different parts of the universe. If aliens truly exist, then they would known that we are here because of the said signals.

Answer 5

Start with the signal levels and then the signals is inverse as the sq. of the distance and it is continually rotated through space even if they had a super cooled maser they would see it only an instant in time ,don't worry.

Answer 6

Hmmm, this is interesting, cause if something is 'out there' you'd think that we'd pick up something. Granted, we do find cosmic disturbances but there is really no true way to pinpoint it less we just make an assumption about other life forms. Faulty quote methinks.

Not necessarily aliens....

Answer 7

The aliens are watching numerous reruns of Gilligan's island. And for that reason - and that reason alone? They have decided that we are too primitive to contact - at least not for another 10,000 years.

Answer 8

The aliens can hear us talking to ourselves and they think we are crazy. So they are going to stay as far away as possible.

Answer 9

We have lost the element of surprise.

Answer 10

that's the whole theory behind the movie galaxy quest.