What is the Longest Wavelength Detectable ?

[BubbleGum]

How low can we go in terms of radio waves with current dishes? What produces the longest wavelength on the spectrum?


Could there be a photon with a wavelength of 1 billion light years?

?Bub

[ToSeek]

How low can we go in terms of radio waves with current dishes? What produces the longest wavelength on the spectrum?


Could there be a photon with a wavelength of 1 billion light years?

?Bub

I think anything is theoretically possible, but a photon with a wavelength that long would probably take a billion years to detect.

The longest waves in common use are those for AM radio, which are on the order of a kilometer long.

The definition of ultra-low frequency radio waves goes down to 300 Hz, which corresponds to a wavelength of 1000 kilometers, but I don't know if those are detectable.

[russ_watters]

The longest waves in common use are those for AM radio, which are on the order of a kilometer long.

The definition of ultra-low frequency radio waves goes down to 300 Hz, which corresponds to a wavelength of 1000 kilometers, but I don't know if those are detectable.

The navy uses ULF radio to communicate with submarines. I don't know the exact wavelength though (most likely classified). The antennas for those things are massive.

[BubbleGum]

Interesting.

Than you for the replies.

~Bub

[ToSeek]

The longest waves in common use are those for AM radio, which are on the order of a kilometer long.

The definition of ultra-low frequency radio waves goes down to 300 Hz, which corresponds to a wavelength of 1000 kilometers, but I don't know if those are detectable.

The navy uses ULF radio to communicate with submarines. I don't know the exact wavelength though (most likely classified). The antennas for those things are massive.

Don't they use a big chunk of land in North Dakota or somesuch for those? I mean, like square miles.

[Celestial Mechanic]

[Snip!]Don't they use a big chunk of land in North Dakota or somesuch for those? I mean, like square miles.

Actually, it's a small station in Clam Lake, Wisconsin. Periodically peace activists chain themselves to the main gates.

Back in the late 60's there was talk of turning the northern third of Wisconsin into such a radio antenna, called "Project Sanguine". To lay the gridwork of cables would have required clear-cutting huge 100-yard wide swaths through the forests. Residents were also concerned that the radio waves could induce current in wire fences. Fortunately this project went down to defeat and something a bit more modest was built instead.

[ToSeek]

[Snip!]Don't they use a big chunk of land in North Dakota or somesuch for those? I mean, like square miles.

Actually, it's a small station in Clam Lake, Wisconsin. Periodically peace activists chain themselves to the main gates.

Back in the late 60's there was talk of turning the northern third of Wisconsin into such a radio antenna, called "Project Sanguine". To lay the gridwork of cables would have required clear-cutting huge 100-yard wide swaths through the forests. Residents were also concerned that the radio waves could induce current in wire fences. Fortunately this project went down to defeat and something a bit more modest was built instead.

Maybe that project is what I was thinking of. I knew there were at least plans to build something huge.