ROCHESTER, N.Y. (WROC) — Recently, there’s been a lot going on with planet Earth. But in a new interview, a Harvard physicist named Avi Loeb said there’s a “serious possibility” that an interstellar object that passed through Earth’ solar system could be an alien spacecraft… ahead of his new book.
“Extraterrestrial: The First Sign of Intelligent Life Beyond Earth,” is the streamlined name of the book, and in it, he argues that the interstellar mystery object was likely similar to a light sail — a method of spacecraft propulsion — created by extraterrestrials.
“I would say, given everything we know, I would give a high likelihood that it could have been artificially made,” Loeb said in an interview with Salon.
Now let’s backtrack for a moment. The object he is specifically referring to is an asteroid that scientists were able to observe in 2017, which they dubbed “Oumuamua.”
But this isn’t any old asteroid. We spoke to a RIT professor who broke down why this asteroid is so unusual, why these factors might have prompted this claim by Loeb, and what he thinks of Loeb’s hypothesis.
This interview with Michael Richmond, Speaker — professor in the School of Physics and Astronomy at RIT, and the director of the RIT Observatory — has been edited for length and clarity.
So what makes “Oumuamua” unusual?
There are lots of asteroids and comets and small icy bodies that move around inside our solar system. That’s not unusual. We’ve known about them for thousands of years, and there are many, many of them. The thing that is unusual about this object is it’s one of only two or three, which have definitely come from another solar system. The ordinary objects like the earth and Jupiter and Mars and ordinary asteroids that circle around the sun in nearly circular orbits, some comets have very elongated orbits.
These start out far, far beyond the orbit of Neptune and Pluto. And then every once in a rare, while they fall in towards the sun circle around the sun, and get really bright. The sun heats them up. Lots of dust falls off them, dust and gas, the sunlight reflects off that makes a big, long tail humans in our sight: “Ooh, look pretty comet over there.”
And then those comets back into the outer solar system, they become cold. They stop releasing gas and dust, their tails disappear, and they just sit out far, far away in the distant edges of the solar system for a long, long time before they come back.
When we measure the orbits of these comets, we can tell: “that one came in through the inner solar system.” And then based on how fast it’s moving and where we see it, it’s going to head back out and it’ll turn around and come back 200 years from now.
For example, Halley’s comet comes up back every 76 years… A few comets go out, and it looks like they go out and will only come back after a thousand years or 2000 years. These have very, very long thin orbits, and two or three have been found that are on orbits that look so elongated that they wouldn’t ever come back. Like if we take their measured positions and velocities and we projected forward in time, it just keeps going and it never orbits the sun. It just goes off and escapes the solar system.
That means that if you go backwards in time, it didn’t come from somewhere deep in the outer reaches of our solar system. It came from somewhere farther away. And that’s very unusual. Like I say, only two or three out of thousands and thousands of comets that have been discovered.
This is one of those two or three objects. Astronomers measured its position and its velocity calculated its orbit, and they figured out very quickly that this thing, must’ve come from some other part of our galaxy, and just wandered into our solar system and then gets bent around by the sun’s gravity and goes out in a different direction… Now that’s one of the three reasons why people think this could be very interesting comes from another solar system, not from our own that’s reason… And everyone agrees with that.
Reason No. 2
Its shape is weird. We don’t have any pictures that show its shape explicitly. So it doesn’t look like a round ball or a potato or something. (Though we have artist renderings)
All we see is a dot of light, but a few astronomers over the brief period of time when we could measure it accurately, we only had about a week before it flew off. Several astronomers measured it over and over again, like “click, click, click, click, click, click, click.” And they saw that over a period of several hours its brightness changed: bright, faint, bright, faint, bright, faint, not exactly periodic, not a perfectly regular thing.
The changes in brightness were pretty big, like factors of two or more. For an ordinary object, if it’s slightly brighter on one side and slightly fainter on the other side when it spins around, it’ll get brighter and fainter by maybe 5% or 10%, but not a factor of two. So there are several different ideas.
People have to explain how it could get so bright and then faint. So bright then faint. And one way, one explanation is that it could have a long thin shape. So imagine the pen… So if you hold it so that it’s long ways to you, you see a lot of the pen right left to right… So it reflects a lot of light. It’s bright. If you make it point at your eyes, there you go. Small surface area. So it seems fainter.
So one way you can explain the changes in brightness of this object is that it has an elongated shape… So it’s not just like a two to one. It’s more like a three or four or five to one.
So very few objects are shaped like that. You look at asteroids and comets in our solar system. They’re more like potatoes, which are maybe two to one, two and a half to one, not five to one. So, um, what objects are really long and thin? Well, it turns out that the astronomers occasionally notice objects in the solar system that have big changes in brightness, very big, bright, faint break thing. And sometimes we discover an old rocket booster launched back in 1974.
(Richmond explains that many objects like asteroids are potato shaped because they might have come off of a bigger asteroid, creating random shapes. But the bigger an object is, the greater the force of gravity exists drawing mass to its center. Planets are round because they are massive, and gravity exerts force equally… Making it a circle. This is why something so long and thin is very strange)
Reason No. 3
We only were able to see the comet for a relatively short period of time. But when we measure its, uh, its path, as it moved out of the solar system, didn’t quite look right.
If you had taken an ordinary rock subject to the gravity of the sun and you threw it in a path that matched the incoming orbit of this thing, it would have gone out of the solar system in a slightly different direction, not a giant different direction, slightly direction. And so what could cause something to move, not according exactly to gravity…
Comets of ice, when the ice heats up little geysers form on the surface, they act like engines. Other people said, why use fake engines? Why not use real engines? If it had been an ordinary comet, like the ones in our solar system, when those comets emit gas and dust, because they heat up, we often can see the gas and the dust that’s come off. People looked hard, they didn’t see any evidence for carbon dioxide or carbon monoxide, which are very common molecules in the sort of gas given off by ordinary comets for technical reasons.
It turns out carbon based molecules like carbon monoxide, carbon on are easy to see. And in the brief time we had people look at telescopes that could have seen it. Funny if it had been outgassing we would expect a lot of carbon monoxide, but we don’t see carbon oxide.
So some people said, well, if it isn’t an ordinary outgassing comet, but it has things like engines, maybe it’s because they’re real engines.
So those are the three pieces of evidence that people quote when they say maybe this is extra terrestrial. Spaceship comes from other solar system has a funny shape probably, and it moves in a way that means it’s not just an inert rock.
Do you have any thoughts on why it took four years for Loeb give this hypothesis?
So that is a very good question. And I can’t answer it because I am not Avi Loeb. I have not asked him, but I can give you some possibilities, but again, I’m just speculating.
Astronomers had more time to analyze the data that they collected and some of the calculations are pretty difficult… Maybe it takes a long time to check them all out. Another, um, thing is that observations were made over a short period of time… But it was probably a year, maybe even a year and a half before most of the observations were finally released.
Someone comes up with an explanation. Someone gives a counter explanation is pure water ice. And then someone else has to come up with a counter counter explanation. Oh no, wait, you’ve come up with this counter explanation. And now I’m going to think about what that would imply and tell you why it can’t be right. And every, when you go through cycles like that, there there’s just time someone has to write the first paper or someone has to read it. Then someone has to write the second paper, then someone has to publish it and read it. And so it can take several years for a bunch of scientists to go back and forth three or four times.
So sciences are pretty slow.
What do you think of Loeb’s take, then?
Is it reasonable to conclude that if one object flies through your solar system from another solar system, you know, randomly, should it be the one that’s one in a thousand and really long and thin rather than most of the potato we ones? At some point, this boils down to the question of what is more probable: that we have an unusual shaped ordinary naturally formed comet, or that it’s a spaceship, right?
That would be a very unusual comet. Yes. True. Absolutely very unusual. Is that more or less probable than it is a spaceship? And I don’t know how to answer that question. That’s, that’s two improbable things.
Some people have claimed that that one could apply Occam’s Razor (the simplest solution is often the most accurate). Which is simpler, this is a one in a thousand shaped comet, or this is an alien spaceship?
Let’s think from a suppose that it were an artificial construction. It definitely came from out of the solar system. It definitely went through the inner regions of our solar system.
But if I were in charge of an alien spacecraft, having it go to another stellar system would make sense, unless I just want to spend all my life out in between the stars, because I’m some sort of weird wandering poet, I guess. But so you would think, okay… If you’re the captain of an alien spaceship and you’re like, let’s go in close and get a look at this solar system. You’re going close and get a look. What do you do then?
If you’re like Captain Kirk, you slow down. You know, study the planets like, “Oh, there is a planet over there with oceans, oh, that’s a planet with mountains, and there is a planet that’s got lots of rings around it.”
You know, we should spend a couple of weeks taking data, going closer, look to getting a look… (But Oumuamua) didn’t do that. So maybe they came in close and looked around quickly and said, “no, there are no planets that are of interest to our species. So we’re just leaving.”
I guess that’s possible. But if it were a spaceship that was under a current control, I would’ve thought you spent millions of years getting here (wouldn’t) you want to at least spend a couple of weeks looking around on the other hand.
Maybe you say another explanation might be that it’s a spaceship formed by aliens, but it they’re all dead, and it’s like a derelict. And so it was just, it was just random chance that it came in through our solar system. That’s kind of depressing.
But the thing is, if one tries to figure out the psychology of alien creatures, you will always face the objection: “Oh, that’s only what a human would think. They have their own inscrutable reasons.” And therefore trying to attack the problem that way is pointless.
Seems like a pretty convenient defense for something that you want to propose.
I can’t deny that it’s very difficult to make counter-arguments that can disprove that… But when you’re talking about alien psychology, there’s basically nothing you can say that can’t be hand waved away.
It’s sort of like the a, we all live in a simulation argument. Like anything you say to counteract that argument is like, well, that’s what the simulation program does to say or something exactly right… So Ouamuamua. Is thing moving in a straight line? Or is it tumbling? How does that affect Leob’s “solar sail” thought?
It’s definitely tumbling. It’s not rotating in a perfectly regular manner as far as we can tell. And if you say this is a, an artificial spacecraft, that’s like got a solar sail that that’s, it’s probably not a good idea for your solar sail to tumble, right? You want to keep the solar sail pointed. So the sunlight hits it from one direction and it pushes you in other direction.
Perhaps the tumbling behavior, would be an indication that either it’s a solar sail, but created by aliens whose minds are far beyond ours, (like) they’re using 16 dimensional chess. And so tumbling is actually the best way to make a solar sail, because we can’t understand it cause our brains aren’t big enough… Or that it was an artificial spacecraft, but it’s derelict and the people that made it are dead, and it’s just going to keep tumbling.
Dan Gross
No comments:
Post a Comment
Note: Only a member of this blog may post a comment.