A fine illustration of what a chaotic system can do

Science geeks may want to check out this article in Ars Technica. Basically, a bunch of scientists attempted to do a principled simulation of the orbital mechanics of the inner solar system -- a very complex system, because of all the large elements in it and how they can interact. They ran the simulations out, making *tiny* modifications to the size of Mercury while doing so. The article sums it up:

Out of the 2,500 runs that were performed, only about one percent resulted in a major disruptions in Mercury's orbit. This result is in agreement with prior works that had not taken general relativity or the lunar effects into account. However, when Mercury's orbit did become highly perturbed, large variations could occur, some of which saw disturbances in the dynamics of the entire inner Solar System—all of these using variances no larger than one meter.

Those "variations" wound up producing scenarios ranging from Mercury falling into the Sun, to the Earth and Mars having a near-collision of less than 1000 km.

Most of us think of the Solar System as very tidy and orderly, with things going around the Sun in near circles indefinitely. So it's fascinating to hear about simulations that show it to be a lot less simple than that. None of this is destiny, of course -- the system is quite difficult to simulate with real accuracy, and most results didn't get wonky -- but it does illustrate the range of possibilities...

ETA: On rereading this, I realize that it makes it sound like the changes are sudden and dramatic. I should note that the simulations are for the next five billion years...

A fine illustration of what a chaotic system can do

Science geeks may want to check out this article in Ars Technica. Basically, a bunch of scientists attempted to do a principled simulation of the orbital mechanics of the inner solar system -- a very complex system, because of all the large elements in it and how they can interact. They ran the simulations out, making *tiny* modifications to the size of Mercury while doing so. The article sums it up:

Out of the 2,500 runs that were performed, only about one percent resulted in a major disruptions in Mercury's orbit. This result is in agreement with prior works that had not taken general relativity or the lunar effects into account. However, when Mercury's orbit did become highly perturbed, large variations could occur, some of which saw disturbances in the dynamics of the entire inner Solar System—all of these using variances no larger than one meter.

Those "variations" wound up producing scenarios ranging from Mercury falling into the Sun, to the Earth and Mars having a near-collision of less than 1000 km.

Most of us think of the Solar System as very tidy and orderly, with things going around the Sun in near circles indefinitely. So it's fascinating to hear about simulations that show it to be a lot less simple than that. None of this is destiny, of course -- the system is quite difficult to simulate with real accuracy, and most results didn't get wonky -- but it does illustrate the range of possibilities...

ETA: On rereading this, I realize that it makes it sound like the changes are sudden and dramatic. I should note that the simulations are for the next five billion years...

Add just a *little* (very important) weirdness, get solutions?

And another very interesting article in Ars today, on a possible new approach to a Theory of Everything. For the most part it goes way too far over my head, but the high concept seems to be that, if you tweak one fundamental assumption of physics, you seem to wind up with a universe that looks very much like ours. The high concept seems to be that time and space have to be considered more separately than usual, and you can treat space as the same in all directions, but *not* time.

I'm intrigued and curious, but have only the slightest idea of what they're talking about. (My math isn't nearly up to physics at this level, not to mention that reading the underlying papers appears to cost Real Money.) Hopefully, if this has any legs at all, someone will come up with a better layman's summary of the concrete implications of the idea...

Add just a *little* (very important) weirdness, get solutions?

And another very interesting article in Ars today, on a possible new approach to a Theory of Everything. For the most part it goes way too far over my head, but the high concept seems to be that, if you tweak one fundamental assumption of physics, you seem to wind up with a universe that looks very much like ours. The high concept seems to be that time and space have to be considered more separately than usual, and you can treat space as the same in all directions, but *not* time.

I'm intrigued and curious, but have only the slightest idea of what they're talking about. (My math isn't nearly up to physics at this level, not to mention that reading the underlying papers appears to cost Real Money.) Hopefully, if this has any legs at all, someone will come up with a better layman's summary of the concrete implications of the idea...