Britain's A2 hypersonic (Mach 5) passenger plane, 2.5 times the speed of the supersonic Concorde, can travel under 5 hrs half way around the world (Europe to Australia, for instance). And it's an eco-friendly vehicle as it runs on liquid hydrogen than conventional fuel. Though it post concerns as the plane will require to fly close to the ozone layer altitude and could potentially damage the atmosphere.
Hmmm, quite interesting indeed. I would gladly see it and fly in action. Heck! I would gladly be one of the test passengers as long as someone is willing to pay for my ticket. Ha! From London to New York it'll cost me 6,800 euros (equivalent to ~$10k). And that's the price of the Concorde! If A2 can cut down half of the time of travel of that of a Concorde, it'll definitely be more expensive. Do the math, it's probably twice more than the already retired Concrode (i.e. ~$20k, "one" way). Damn! If only I'm born with money. Unfortunately, it wasn't so for me. But one of these days I sure will be trying these sonic planes. Maybe when I'm 50...XD