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Through all the ads on those sites, I still saw nothing about orbit. The reusable part of a Falcon (assuming it actually lands undamaged)[0] doesn't go into or

Through all the ads on those sites, I still saw nothing about orbit. The reusable part of a Falcon (assuming it actually lands undamaged)[0] doesn't go into orbit either. Edit: Stay classy HN. [0] "I don't expect the Falcon 9 to have a reusable upper stage" http://shitelonsays.com/transcript/elon-musk-at-mits-aeroastro-centennial-part-1-of-6-2014-10-24 http://shitelonsays.com/transcript/elon-musk-at-mits-aeroast...

stingraycharles 11y ago
You're missing the point. The media is basically doing an apples/apples comparison with BO and SpaceX. The tweet was necessary to point out that they're not competing in the same space.
ChrisClark 11y ago
You are focusing on the word 'orbit' and not the overall meaning. The forest for the trees. You are being downvoted for arguing about something completely pointless.
- jsprogrammer 11y ago
  If my comments are pointless arguing, so are Elon's. Worse, Elon's are just factually incorrect (e.g. "The energy needed is the square, i.e. 9 units for space and 900 for orbit.") [and, yet, it remains, uncontested, at the top of this thread]. >It is, however, important to clear up the difference between "space" and "orbit", as described well by https://what-if.xkcd.com/58/ https://what-if.xkcd.com/58/ is a non-sequitor because no one seems to have confused space and orbit. Additionally, the comparable part of SpaceX's machines (the first stage of the Falcon 9) doesn't go into orbit (it is supposed to land not far from the launch site and does not loop around the Earth to do it). What is the import of "orbit"? Elon is the one that brought the word into the conversation, not me. >You are focusing on the word 'orbit' and not the overall meaning. Then, please, what is the overall meaning of those tweets?
  - ChrisClark 11y ago
    Everyone else has already told you, but I'll tell you again. The media is saying Elon was just beat at his own game. Elon tweeted to point out that it's a horrible comparison, what he's been trying to do is much harder. End of story. If you can't see that, I don't care any more. I was just trying to help.
    - jsprogrammer 11y ago
      >The media is saying Elon was just beat at his own game. The media is not a single, conscious entity. Some Gizmodo blog may have claimed as such, but I think you'll have a very hard time producing any other person who would claim that what a Gizmodo blog says is what the entire media is saying. >Elon tweeted to point out that it's a horrible comparison Not really. There are comparables: stick goes up, stick goes down without crashing. Elon only appears to have made a non-sequitor argument (unless someone shows where the media made the claim that space and orbit were the same thing). Ultimately, this is probably a defect of Twitter's character limit. It is extremely difficult to put a fully reasoned argument into a single tweet.
      - mikeash 11y ago
        > There are comparables: stick goes up, stick goes down without crashing. SpaceX did that years ago: https://en.wikipedia.org/wiki/Grasshopper_(rocket) https://en.wikipedia.org/wiki/Grasshopper_(rocket)
  - dtparr 11y ago
    Regarding the factually incorrect bit, could you elaborate? I was under the impression that the energy required was proportional to the square of the velocity, so a 10x increase in velocity (from ~Mach 3 to ~Mach 30) would result in a 100x increase in energy required, which seems to be what he's saying. Is my understanding inaccurate?
    - InclinedPlane 11y ago
      Energy is proportional to the square of the velocity, but the fuel required to reach a given delta-V scales exponentially.

stingraycharles 11y ago

You're missing the point. The media is basically doing an apples/apples comparison with BO and SpaceX. The tweet was necessary to point out that they're not competing in the same space.

ChrisClark 11y ago

You are focusing on the word 'orbit' and not the overall meaning. The forest for the trees. You are being downvoted for arguing about something completely pointless.

jsprogrammer 11y ago
If my comments are pointless arguing, so are Elon's. Worse, Elon's are just factually incorrect (e.g. "The energy needed is the square, i.e. 9 units for space and 900 for orbit.") [and, yet, it remains, uncontested, at the top of this thread]. >It is, however, important to clear up the difference between "space" and "orbit", as described well by https://what-if.xkcd.com/58/ https://what-if.xkcd.com/58/ is a non-sequitor because no one seems to have confused space and orbit. Additionally, the comparable part of SpaceX's machines (the first stage of the Falcon 9) doesn't go into orbit (it is supposed to land not far from the launch site and does not loop around the Earth to do it). What is the import of "orbit"? Elon is the one that brought the word into the conversation, not me. >You are focusing on the word 'orbit' and not the overall meaning. Then, please, what is the overall meaning of those tweets?
- ChrisClark 11y ago
  Everyone else has already told you, but I'll tell you again. The media is saying Elon was just beat at his own game. Elon tweeted to point out that it's a horrible comparison, what he's been trying to do is much harder. End of story. If you can't see that, I don't care any more. I was just trying to help.
  - jsprogrammer 11y ago
    >The media is saying Elon was just beat at his own game. The media is not a single, conscious entity. Some Gizmodo blog may have claimed as such, but I think you'll have a very hard time producing any other person who would claim that what a Gizmodo blog says is what the entire media is saying. >Elon tweeted to point out that it's a horrible comparison Not really. There are comparables: stick goes up, stick goes down without crashing. Elon only appears to have made a non-sequitor argument (unless someone shows where the media made the claim that space and orbit were the same thing). Ultimately, this is probably a defect of Twitter's character limit. It is extremely difficult to put a fully reasoned argument into a single tweet.
    - mikeash 11y ago
      > There are comparables: stick goes up, stick goes down without crashing. SpaceX did that years ago: https://en.wikipedia.org/wiki/Grasshopper_(rocket) https://en.wikipedia.org/wiki/Grasshopper_(rocket)
- dtparr 11y ago
  Regarding the factually incorrect bit, could you elaborate? I was under the impression that the energy required was proportional to the square of the velocity, so a 10x increase in velocity (from ~Mach 3 to ~Mach 30) would result in a 100x increase in energy required, which seems to be what he's saying. Is my understanding inaccurate?
  - InclinedPlane 11y ago
    Energy is proportional to the square of the velocity, but the fuel required to reach a given delta-V scales exponentially.