There is no theoretical reason that a room-temperature superconductor cannot exist.
Room-temperature superconductors would be really cool. It's not clear that electromagnetic propulsion gets you to orbit, though. Once there, sure it works.
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.
So... An Osteoptath takes a "holistic" approach, and yet the treatment is only being used for certain musculosceletal conditions? How does only being useful only for that specific thing make an Osteopath more "holistic" exactly?
Of course, we haven't even gotten into the fact that osteopathy hasn't even been demonstrated to have an actual effect on musculoskeletal conditions...
What separates C++ beginners from those with 'intermediate' skills, or even masters?
Knowing when not to use templates, virtualization, [insert favorite c++ function here], etc.
Basically knowing enough about programming and problem solving with a particular language to tell a need from a want. Needing to use some language feature vs wanting to use some language feature. And being mature enough to stick to needs rather than indulge wants.
Or to state things differently
Think as a C programmer, (the kiss principal) and recast your solution into C++. Its not hard to convert structure manipulation into manipulation of an object. In effect, think simple, think about the next programmer who will be pulling his hair out trying to understand what the templates, castings, and obtuse code is doing.
Unless you want to spend several months a year of your life auditing inefficient "charity" organizations and trying to make judgments about whether they're doing it right and spending your dollars wisely...and hey if you think you're good at that you should probably start your own charity. But if you do, everyone will expect you to work for free. It's a viscous circle.
Donate your time, you'll meet people too.
Unless you're a multi-billionaire, then start a foundation and direct where the money goes.
I could be missing something, but frankly everything I read in the summery seems like reasonable changes to me.
Someone who actually is known to have purchased the item, yea, their review should be worth more than random Internet person #4827341
A review from last month is probably worth more than one from two years ago. The product may have changed.
Well, hopefully Amazon is not doing what TigerDirect was and may still be doing, re-editing or "correcting" customer reviews, particularly negative ones.
There is nothing that an anonymous person can say about someone that I will take seriously without evidence. So, if an anonymous person says that candidate X is a pedophile, but offers no evidence, I will take it as the ranting of a liar, and candidate X has not been harmed in any way, beyond registering as a person who has angered some random anonymous coward. On the other hand, if candidate X takes it upon himself to waste the court's time with crap which endangers the anonymity of legitimately fearful critics of policy everywhere, I suddenly believe candidate X is an ass, unelectable, and possibly even a pedophile.
That's you, but thats not the majority, and I bet most mothers would believe the posting, even if it was retracted. The harm has been done.
We gave you an atomic bomb, what do you want, mermaids? -- I. I. Rabi to the Atomic Energy Commission
