Tube Travel Futurama

Can you travel The Tube 'Futurama' style?

Set in the year 3000, the series Futurama features one of the most interesting forms of personal travel—pneumatic tubes. These were used primarily in the late 19th to the early 20th century to transport small packages over short distances, typically within a building or city. Though it is in very limited use today, there has been renewed interest with Elon Musk's Hyperloop as a conceptual high-speed transportation system in which pressurized capsules ride on a cushion of air.

Riding a Column of Air

Tube travel diagram
The pressure differential pushes a person along the tube and voila!

Futurama travel likely works by sucking people through the tube. A vacuum pump sucks the air out inside the tube. If the difference between the pressure from the outside to the pressure inside the tube is great enough, the resultant force can push someone along the tube.

Tube travel physics equation
The force on a body due to a pressure differential

Let's assume we will be sending an "average" man through the tube—kicking and screaming if we have to. His mass, m, is about 70 kg (154 pounds) and his effective area, A, is about 0.135 square meters (1.45 square feet). The k in the equation is the drag coefficient which tells us how much friction there is.

tube travel sky diver
Figuring how fast someone can travel through the tube uses the same equation as a skydiver.

We really do not know how fast people can travel through the tube in Futurama but we can figure out their maximum speed or terminal velocity based on the physics of skydiving. There are some differences to consider. For one, skydivers tend to fall vertically with arms and legs spread out. Tube travelers travel lengthwise but the skydiver's terminal velocity gives us an upper limit to work with. Here's the terminal velocity equation:

The Tube Terminal Velocity Equation

We could solve the second equation but instead, we just plug it into the first. This makes things easier.

Tube travel Fry Tube travel
You say it's easy but is it really?

This gives us a new equation that we can use to determine if tube travel is possible. It also gets rid of most of the other nasty variables and makes calculation less problematic.

Tube Travel Final Equation
It's algebra. It's really that simple.

The entrance of the tube, P1, is open so the pressure is just atmospheric pressure, about 101 kilo Pascals (14.6 pounds per square inch). We can work out P2, the pressure inside the tube, using our new equation to find this is about 91.1 kilo Pascals or 13.2 pounds per square inch. As it turns out, from an engineering perspective, this is an easy pressure to attain, making it is possible to move a human being along a tube.

Other Considerations of Tube Travel

Tube Travel Futurama
Tube travel on Futurama is very complex

Before we get excited and start building our own Futurama-style tube network, we need to keep in mind our "back of the envelope" calculation only considers a person traveling horizontally through a tube. As we can see, Futurama's tubes are far more complex; travelers can change direction and move from one tube to another to get to their destination. This requires a system of valves to quickly push a person into a new tube, as well as the need for controllers to constantly monitor traffic and ensure accidents don't happen.

Tube Travel Kingsman
Maybe Kingsman's tube travel is more feasible than Futurama's

A more feasible form of tube travel might be found on Kingsman: The Secret Service. In fact, this is pretty close to Elon Musk's Hypertube as it just connects two points; a person can travel between the two points very quickly. The real question is, if Futurama style tube travel was invented, would you use it?

Also published on Medium.

David is the founder of the Science vs. Hollywood website and is a major science and sci-fi geek who loves to communicate science to a (sometimes) interested audience.

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