Because it would violate the laws of physics as we know them. Any small part detached from this supposed probe would still have the same velocity and trajectory of the probe. The velocity was quite high and that trajectory did not come close to Earth. And a small object has no way to change its velocity to come near Earth unless you’re going to postulate a miraculous means of propulsion. It’s just going to keep going out of the Solar System.
Too many people don’t understand this about space travel. They tend to think it works like vehicles here on Earth. You toss something out of your car and it quickly slows down. That doesn’t happen in space. There’s no air to slow the object down. It just keeps going as fast as it was when part of the vehicle modified by whatever force was used to detach it.
Note the multiple layers of hypotheses the pro-aliens people have to add on: “What about this? Well aliens might have the ability to …” Lather, rinse repeat.
If you have to posit multiple guesses as to alien technology, you are in woo territory.
It’s regular Physics folks. We don’t know all the details yet but that doesn’t mean you automatically play the aliens/deity/magic card.
Bear in mind that we did not even see it until it was already outbound. It had been within the bounds of the central Solar System (inside the heliosphere) for well over a decade (Earth frame of reference), approaching almost perpendicular to the ecliptic, giving it a very good view of the system. Earth is a tad larger than Oumuamua and probably would have seemed interesting to the putative aliens/drone in it: they had quite a long interval to detach a small device to the inner system, and early changes made to a trajectory can have amplified effects later on. But if it released a small study probe, it would almost certainly not arrive near Earth for years yet.
Personally, I find the idea of a chunk of something from outside the Solar Sytem to be compelling in and of itself. Artificial or natural, whatever, it is awesome to see shit from unthinkably elsewhere zipping by.
But the proposal that kicked off this thread was calculating what properties of photonic solar sail would lead to the unexpected speed increse, meaning that the calculations apply in exactly two ways to a magnetic sail–jack and shit. But you have already concluded that it was aliens from the moment that you knew that it existed–open your mind to the possibility that it is not.
A magsail would be a giant (some number of kilometers in radius) hoop of superconducting wire, so would be mostly empty space. And would be absolutely incompatable with either surrounding or towing a rapidly tumbling object–if it was surrounding Oumuamua it would have been instantly torn to shreds the moment the object was knocked into it’s tumble, and if it was towing Oumuamua the cable would have been reeled up around the object and then the magnetic coil would be torn to shreds.
Solar sails are big relative to their payload. But maybe this thing has a small payload.
Or, as others mentioned, is a torn off scrap of sail.
I don’t think you can conclude that it’s not a sail (or sail material) from its size. You can conclude that it’s not, say, a (human-sized) manned vessel, but so what.
I think it’s pretty unlikely that it’s a manufactured sail, but it’s not impossible.
Please remember that all this speculation is based on an extremely thin dataset. We have a light curve that can be interpreted as a long, cigar shaped object tumbling around two axes, but that’s just an interpretation. I suspect you could come up with a similar light curve of a rotating spherical object with radical differences in Albedo on its surface, too.
The bottom line is that this is all the data we will ever have on this object and it’s not enough to even definitively determine its shape. Optically we have never seen this thing with enough resolution to see it as anything other than a pinpoint.
EastUmpqua, as I look out my window right now, I can see a black SUV. Should I conclude that it’s an alien spacecraft? Should I even bother to entertain the possibility that it might be an alien spacecraft? After all, it being an alien spacecraft could explain every detail of what I’m seeing.
The only reason to even hypothesize that Oumuamua might be an alien spacecraft is that it behaves in some ways as though it is using a solar sail. If we explain away our aliens to the point that we’re positing that they don’t need solar sails, then there’s no reason at all to hypothesize that it’s a spacecraft.
Oh, and there’s also another argument against it being a solar sail: Solar sails are flat (or at least, there’s no reason for them not to be), and very thin. Unless it were deliberately taking measures to mislead us, the plane of the sail would at some point have crossed us, at which point its light curve would have dipped to zero. We didn’t see that.
And if it is taking deliberate measures to deceive us, we can’t conclude anything at all, because any alien capable of sending probes across interstellar space would be capable of complete deception (including complete stealth, if that’s what they wanted).
Your choice. Suppose I show you a 3cm-diameter metal sphere, in my office, on Earth. You hold it in your hand, and you can tell it has inertia. But when you let go of it, you can tell it’s not affected by gravity. Is that technology or magic. Your choice.
Chronos - you might have missed the part about magsails. And if I were you I’d be concerned about that black SUV out front. I came to the MISIMS list to have fun and not get called a pink unicorn if I think c changes near a black hole.
Now we’re talking. If the stupid thing hadn’t accelerated away from the Sun, the Harvard study wouldn’t have happened. And there would have been no clicks for the media. But it did accelerate. That’s why it’s fun. Yeah I’m not buying the 3-km super-conductor wire thing. There might be a more efficient technology for a magsail.
The operation of magnetic sails using plasma wind is analogous to the operation of solar sails using the radiation pressure of photons emitted by the Sun. Although solar wind particles have rest mass and photons do not, sunlight has thousands of times more momentum than the solar wind. Therefore, a magnetic sail must deflect a proportionally larger area of the solar wind than a comparable solar sail to generate the same amount of thrust. However, it need not be as massive as a solar sail because the solar wind is deflected by a magnetic field instead of a large physical sail. Conventional materials for solar sails weigh around 7 g/m2 (0.0014 lb/sq ft), giving a thrust of 0.01 mPa (1.5×10−9 psi) at 1 AU (150,000,000 km; 93,000,000 mi). This gives a mass/thrust ratio of at least 700 kg/N, similar to a magnetic sail, neglecting other structural components.
But we do not have an object disobeying the known laws of Physics!!
We just don’t have enough data. Lack of data = aliens or magic is a completely absurd statement.
It’s just like the “God of the Gaps” argument Creationists make. “There’s a gap in the fossil record between A and B. Therefore … God.” “Here’s a new fossil between A and B.” “Oh, now you have two gaps you can’t explain. Again … God.”
I don’t understand how people keep promoting the aliens idea by proposing Yet Another Magic Alien Tech when someone points out a flaw with their argument. How many amazing new things are too many too swallow before giving up the idea???
There’s an incredible number of astronomical objects that baffle us. E.g., stars or galaxies with odd colors/radiation/patterns. Is every single one of these aliens?