Beyond and Below Geostationary Orbit

At first I was going to rant about light being able to go around the world 7 times in one second, so why is there a lag of two seconds between interview question and interview answer from only half way around the world?

But it’s not that simple. You see the signals are sent up to satellites in geostationary orbit and then bounced around the globe to the proper far flung place. The problem is geostationary orbits are 22 000 miles above the equator. Then to get to the other side of the world, the signal is bounced around by other geostationary satellites and then down to the target. That is roughly 22 000 miles plus 22 000 miles plus half the circumference of a circle with a radius of 26 000 miles (geostationary height plus the radius of the earth). That’s 44 000 miles plus 3.14 x 26 000miles which is about 126 000 miles. It is actually less because the signal doesn’t have to go in a perfect circle around the Earth. It will also be more because the location on Earth isn’t directly below the satellite on the equator. So 126 000 miles is a good approximation.

Light travels 186 000 miles in one second. So, one way, it will take the signal over 2/3 of a second. But that’s close to one second. And to return, which is needed in a question/answer scheme, would be another second so we get the approximate 2 seconds mentioned in the opening paragraph.

But why use satellites in geostationary orbits? This is simple laziness on the part of the engineers. They just want to point their satellite dishes at the same part of the sky. But tracking dishes aren’t that hard to build, for instance almost all observatory instruments track the stars which move across the sky.

So why not put a series of satellites in orbit at say 5000 miles above the Earth. Doing the same calculations as above only with 5 000 miles instead of 22 000 miles we get about 38 000 miles. That’s less than 1/3 of the distance, so the delay would be about 0.6 seconds. That’s much better.

It is my belief that the 5000 mile high satellites (or less) have been up there for a long time and the satellite trucks can actually track them. It’s just that years ago reporters figured they could take a second or two to compose their thoughts in an interview. After all if it’s worth broadcasting by satellite, it’s worth composing your thoughts. So this sham has been foisted on the world by those no good reporters.

But ha ha, they’re stuck composing their thoughts for this week’s royal wedding. I bet it’ll be hard to wait the two seconds to keep up the sham.

And sham we know it is, else why not send the signal via under ocean cables, like with the Internet. But perhaps they’re worried because of what happened with that Grandma in Georgia cutting the Internet cable and leaving Armenia Internetless. After all, nothing is more important than Will and Kate being viewed by the voyeuristic public.

About Larry Russwurm

Just another ranter on the Internet
This entry was posted in Humour, Mathematics, Science and tagged , , , , , , . Bookmark the permalink.

Leave a Reply

Your email address will not be published. Required fields are marked *