Can You Get The Moon Into Orbit?

This is a Rather cool SVG demo (requires Firefox 1.5). View source and see how simple it is; twenty lines of embedded SVG and then some maths implemented in JavaScript to bring it to life. Would it be more work in Flash? I don’t know…

6 thoughts on “Can You Get The Moon Into Orbit?

  1. I first saw this demo shortly after Firefox 1.5 came out, I think; it is absolutely a cool use of SVG. But at the risk of being a party pooper, the scientific position that the text on the page is trying to advocate is unfortunately bunk. The page author seems to believe that the moon couldn’t have formed in its orbit by natural processes, but he doesn’t seem to understand the models that he’s arguing against.

    The clearest example of this is his description of the “asteroid smashing into the Earth” model (which is close to the history that scientists consider most likely today). His simulation overlooks the fact that if a large enough chunk of the Earth were launched into orbit, both the remaining Earth and the chunk would orbit around a center of mass displaced significantly from the center of the (remaining) Earth. (As an extreme example, if the collision split the Earth exactly in half, both pieces would orbit around the midpoint of the system.) Once this subtlety is taken into account, the collision theory can work just fine. (And the same goes for all of the other models that have been seriously considered in the scientific literature: physicists aren’t perfect, but we’re usually clever enough to notice holes in our ideas as massive as this fellow thought that he’d found!)

  2. Yes; he also hasn’t taken into account the possibility of atmospheric drag (which is how, for example, satellites launched from earth get into stable orbits around Mars).

    But it’s still a nice piece of SVG.

  3. Impact forces, atmospheric drag, tidal forces, the fact that the Earth isn’t a point mass in an otherwise null space (i.e. it orbits the Sun along with +/- 8 other planets and numerous other solar bodies)…

    Take your pick, he ignores them all and then some.

    SVG + Javascript = Impressive

    Trying to use a browser demo to imply a static universe = Medieval bunk

  4. Were it not for the existence of Planet Mozilla, this post would be one ten thousandth as disingenuous as it is. Of course I’d rather that even people whose beliefs I disbelieve entirely presented their statements in a standards-compliant way, so the author is to be commended (expecially given that this was probably the first example I ever saw in the wild of the Power of SVG™).

    – Chris

  5. How’s this really showing the power of SVG? The things drawn are very simple items: circles with gradients. Can’t the same thing be done with bitmaps whose position is manipulated by the javascript?

  6. Chris Cunningham: What is disingenuous about my post? To be honest, when I posted it I didn’t even read the instructions which suggest that this proves the moon started in the orbit it’s in now. I only heard about that when I asked Vlad whether he’d seen this demo, and he said yes, but he got flamed when he blogged about it.

    As you will note from my comment #2, I also agree that his physics is flawed.