Multiple-Tesla fields that are changing their orientation rapidly in time aren't particularly healthy to be around. Induced currents in your nerves, heating, etc. That MRI field is acceptable because it's DC. That is, if you don't have any ferromagnetic objects on you.

No, the superconductors are not simple magnets.

What's on the tele then?

Rockets being the only solution does not automatically mean rockets are a viable solution. Please quit ignoring the real challenges presented.

Unfortunately, this can't be approached as an engineering problem and get the result you would like. It needs to be approached as a problem in fundamental research of the physics underlying our world.

There were lots of efforts to miniaturize the vacuum tube. They only resulted in smaller tubes. It took new insights in fundamental physics before people could understand how to make a transistor. There were many experiments with germanium (a natural semiconductor) that could have led to the transistor before 1947 if anyone had understood what was happening.

Some steel. Not all of them. That's why the refrigerator magnet doesn't stick to that silver door.

A field strong enough to work on water would kill you first.

Look at the amount of money made on oscillococcinum, and you might agree it's a successful hack to make money from the stupidity of others.

This would be cool if it was more than a stage trick. The superconductor needed to do this used to be mail-ordered from Edmund Scientific. So lots of hackers were doing levitation demonstrations in the 90's. People think it's cool because they've not lived through that, or have forgotten it.

It works on the principle of superconductors excluding a magnetic field. When they are cooled to liquid nitrogen temperatures. Steel is low in ferromagnetism and isn't as good a conductor as copper so it's not as good for making electromagnets.

Well, I did that once with a bottle of liquid nitrogen from Airco and a superconductor I bought from Edmund Scientific. This was before there was a Slashdot. So, no, not impressive.

Before someone makes a working hoverboard, we will first hear about the principle that makes it possible. Because one that's practical is almost guaranteed to get someone a Nobel Prize. And certainly Lexus would go for that if they could.

No new principles lately. There is an existing principle of magnetic repulsion that would work only in an extreme condition. One requiring really special stuff buried in the street, and probably including liquid nitrogen to keep it working for even a short time and a few feet.

So, it's a gimmick.

Hey, I hang out with a lot of creative people. Not Elon Musk, but Steve Jobs for more than a decade, and lots of people at least as smart that you don't know. They can be really brilliant, and successful, and they can still make really stupid mistakes and sell them to the rest of us pretty well because they believe in themselves completely and they have a track record. I've done that too.

That's the hyperloop. Something Elon never meant to stand behind (and still really isn't), just put out there to torpedo a worthy project that he didn't believe in.

Anyone who looks at the hyperloop design can see it's not a no-brainer. It has safety issues up the wazoo :-) It's going to take a long time to get right.

Meanwhile, little Switzerland can have incredible trains everywhere and the United States can't get it together, and unlike with rockets and cars Elon's not helping this time. And I am not sure that the "lease" part of his solar business is a great thing for the world either.

Although the hyperloop is possible and might even be practical someday, let's please be honest about the reason it was created. Elon Musk just wanted to kill the California high-speed rail.

That might have been OK if there was a hope that we could actually replace it practically with a hyperloop. But given the history of bleeding-edge rail - ride any maglevs lately? We haven't even had much success with monorails outside of theme parks and Las Vegas - we don't really have any working system to replace high-speed rail. Hyperloop should really be called "Pipes that carry People" and we need decades of work on it before considering intercity lines.

Russia would like for us to continue gifting them with cash for 40-year-old missle motors, it's our own government that doesn't want them any longer. For good reason. That did not cause SpaceX to enter the competitive process, they want the U.S. military as a customer. But it probably did make it go faster.

Also, ULA is flying 1960 technology, stuff that Mercury astronauts used, and only recently came up with concept drawings for something new due to competitive pressure from SpaceX. So, I am sure that folks within the Air Force wished for a better vendor but had no choice.

This ends a situation in which two companies that would otherwise have been competitive bidders decided that it would cost them less to be a monopoly, and created their own cartel. Since they were a sole provider, they persuaded the government to pay them a Billion dollars a year simply so that they would retain the capability to manufacture rockets to government requirements.

Yes, there will be at least that Billion in savings and SpaceX so far seems more than competitive with the prices United Launch Alliance was charging. There will be other bidders eventually, as well.

No-fault is about taking money away from lawyers, who used to litigate each and every auto accident as a lawsuit in court before the insurers would pay. Eventually the insurers decided that they spent more on lawyers than accident payments, and they had no reason to do so.

If you want to go back to the way things were, you are welcome to spend lots of time and money in court for trivial things, and see how you like it. I will provide you with expert witness testimony for $7.50/minute plus expenses. The lawyers charge more.

In general your insurer can figure out for themselves if you were at fault or not, and AAA insurance usually tells me when they think I was, or wasn't, when they set rates.