At the end of my trip in Western Australia, we went to see a sunset at a place called Cable Beach. And at the moment, all I was focused on was the beautiful scenery. I mean, look at that sunset and the crazy cloud above the town!

But then later, I was curious about why it was named Cable Beach. And a quick online search showed me that it was the location of the underwater communications cable that had connected Australia with the island of Java in Indonesia between 1889 and 1914. And while that cable is no longer in operation, there are currently over 400 underwater cables connecting various cities, countries, islands, and continents. In fact, you can see a map of these cables at https://www.submarinecablemap.com/

When I first learned about these cables, I wondered why they were still necessary now that we have satellites circling the planet. But these cables are better than satellite connections for a few reasons:

• Because satellites orbit so high in the sky, data sent via satellite must travel significantly farther than data sent via undersea cables.
• Satellite communications are susceptible to weather conditions, which can slow down connection speeds.
• Each underwater cable contains up to eight optical fiber cables, each of which has the capacity to transmit data at speeds of around 3,800 gigabits per second. This is nearly 1,000 times faster than a communications satellite can transmit data.

It's amazing that a cable under the sea can function so much better than a satellite in the sky! They truly are essential for society to function as it does!

Sample Problems

1. Use Google Maps (right-click to toggle the tool to measure distance) to find the distance (in km) between Broome, Australia and Banyuwangi, Indonesia. Round UP to the next 50 km. This can be used to approximate the length of cable that connected Australia and Java, though the actual length would be longer due to various underwater obstacles.

2. How much cable would be required to connect Madagascar to the continent of Africa via an underwater communications cable? In other words, find the shortest distance between Madagascar and the continent of Africa. Round up to the next 50 km.

3. How much cable would be required to connect Tasmania to the rest of Australia via an underwater communications cable?

4. How much cable would be required to connect Australia and New Zealand via an underwater communications cable? Give one answer that includes Tasmania (assuming that it was already connected to the rest of Australia) and one answer that does not include Tasmania (in case that cable were to malfunction).

5. In all actuality, these shortest distances are rarely used. In fact, one can see that there are many cables wrapping their way around the edges of continents. What are some reasons why it might not be best to simply use the shortest distances between land masses?