I've written about this before. The problem is that any critique of Musk on HN is met with extreme opposition. Almost like the other HN meme: all corporations

I've written about this before. The problem is that any critique of Musk on HN is met with extreme opposition. Almost like the other HN meme: all corporations and CEO's are greedy except for Apple and Jobs (and probably Tesla/SpaceX/Musk). Well, I'm glad people are now seeing that this is not a serious proposal. I actually think this is an elaborate marketing move. Not much Tesla news lately. While I don't have a PhD in Physics, I do have a PhD in Having Designed and Built Lots of Shit. I have touched enough disciplines outside of my EE training to have a pretty good reality meter when it comes to engineering. Thermal expansion, earthquake survivability, cost and plausibility were probably the first few issues that stood out to me. Thermal expansion is a huge problem. It is also a first year college physics problem. What is not mentioned in this article is thermal shrinking! I am surprised the author did not focus on that a bit. And then there's the more complicated problem of differential thermal effects. Put another way, you can have a portion of the tube pushing while another portion would is pulling. The bottom line is that there's a need for tube-to-tube gaps bridged with compliant material. This would localize thermal effects to a single tube and prevent propagation up and down the system. Welding is out of the question. The superficial treatment of earthquakes is also of concern. Many years ago I devoted a non-trivial amount of time to understanding earthquake physics because of a large project I was heading that required earthquake survivability. I learned just how serious these events can be. There are at least four effects to deal with: ground acceleration, structure resonance, amplification of acceleration magnitude within structures (resonant "snap"). This isn't the right venue to discuss this at length. You'd have to design for ground accelerations in excess of 5 g, ground displacement in the one to five meter range and "snap" accelerations in the 10 to 50 g range (guessing the high end). And do so for six degrees of freedom (xyz and the respective rotations). Just yesterday I drove along a 100 mile stretch of the Golden State freeway. I took note of the viability of installing support columns every 100 ft. Let's just say the very idea does not align with any imaginable reality. Great marketing though. No need to deliver anything real. Thise not equipped to understand the real engineering and business problems will surely elevate Musk to even greater genious status and recoil at the very idea of criticizing him. My prediction is that somwhere in Washington someone is trying to figure out how to throw a few hundred billion dollars at this and use it for political gain as well.