If Ouamuamua were a propelled lightsail, wouldn't we have detected it?

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SUMMARY

The discussion centers on Avi Loeb's hypothesis that Oumuamua may be a propelled lightsail, utilizing sunlight or starlight for propulsion. Participants debate the feasibility of detecting such a lightsail, questioning whether light from a potential laser source, like Vega, could be observed. The consensus is that while sunlight is detectable, the notion of artificial acceleration via lasers lacks substantial evidence and is not supported by the original article. Overall, the conversation emphasizes the speculative nature of the lightsail theory.

PREREQUISITES
  • Understanding of Oumuamua's trajectory and characteristics
  • Familiarity with the concept of lightsails in astrophysics
  • Knowledge of light detection methods in astronomy
  • Awareness of the scientific method and hypothesis testing
NEXT STEPS
  • Research the physics of lightsails and their propulsion mechanisms
  • Explore the detection methods for astronomical objects, focusing on light sources
  • Investigate the implications of artificial acceleration in celestial bodies
  • Read Avi Loeb's works on extraterrestrial theories and Oumuamua
USEFUL FOR

Astronomers, astrophysicists, science communicators, and anyone interested in the implications of extraterrestrial technology and the study of interstellar objects.

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(Yes, I know how folks here like to say that I shouldn't read pop science articles because it's not correct.)

https://www.nytimes.com/2021/01/26/books/review/extraterrestrial-avi-loeb.html
... Loeb argues that it is no more preposterous to suppose that Oumuamua was a lightsail, a thin material that gets its propulsive boost from sunlight or starlight, either launched in our direction or anchored like a buoy in space, where we ran into it on our planet’s travel around the galaxy.

So if this were a lightsail, wouldn't we be able to detect the light propelling it?
 
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swampwiz said:
So if this were a lightsail, wouldn't we be able to detect the light propelling it?

Yes, we are - even with the naked eye. It's the light of the Sun.
 
swampwiz said:
(Yes, I know how folks here like to say that I shouldn't read pop science articles because it's not correct.)

https://www.nytimes.com/2021/01/26/books/review/extraterrestrial-avi-loeb.htmlSo if this were a lightsail, wouldn't we be able to detect the light propelling it?

This hypothesis is just a speculation, so we probably cannot comment it here. But to your question, we do detect the sunlight, of course.
 
No, I meant the laser coming from Vega, or wherever it came from.
 
swampwiz said:
No, I meant the laser coming from Vega, or wherever it came from.

Considering the speed of Oumuamua there is no reason to assume artificial acceleration. Even if it would have been accelerated with a laser, that would be a very long time ago. In any case there is nothing to see.
 
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Oumuamua propelled by laser is mentioned nowhere in the article.
gets its propulsive boost from sunlight or starlight,
 
swampwiz said:
Yes, I know how folks here like to say that I shouldn't read pop science articles because it's not correct.

I don't think anyone said that. What they did say is that you need to manage your expectations on what these articles are.
 
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