Hyperloop One says it can get you from Helsinki to Stockholm in 30 minutes

The proposed super-fast transport system would run underwater and cut travel time by three hours.

While it's far from a reality, many startups, consultants and industry prognosticators are talking up the possibilities of Hyperloop travel, the concept for ultra-fast transport proposed by Tesla Motors founder Elon Musk.

Hyperloop One is one of the startups trying to bring this technology to life, and in a presentation put together by consultancy KPMG, the company claims it can cut the travel time between Helsinki and Stockholm from about 3.5 hours (including travel time to the airport) to about 28 minutes, as part of an ambitious plan that could cost as much as $21 billion.

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Where will that money come from? According to a new blog post from Hyperloop One, "governments at the city, regional, national and EU level may choose to fund the project or provide loan guarantees to a private entity based on the wider economic benefits."

Building a Hyperloop won't be cheap.

Hyperloop One

The tunnel for the system would be installed along the floor of the Baltic sea, and use "pressurized capsules [that] ride on an air cushion driven by linear induction motors and air compressors."