The Uncensored Guide to ‘Oumuamua, Aliens, and That Harvard Astronomer • Hacker News Board

Re: The Uncensored Guide to ‘Oumuamua, Aliens, and That Harvard Astronomer

#121

Post by giantrobot » Sat, Jan 30, 2021, 6:43 AM UTC

interestica wrote: post #110

giantrobot wrote: post #80

Earlier quoted context omitted.

It's unlikely many types of exoplanets could have been detected "decades" earlier. Transit and Doppler detection methods require good seeing power and accurate intensity measurements. It takes large mirrors with good optics for good seeing power and sensitive electronics for the spectral/intensity measurements. Those two things weren't readily available until the past few decades...which surprise is when exoplanet di…

> Those two things weren't readily available until the past few decades...which surprise is when exoplanet discoveries started happening. I think the other poster might be alluding to a chicken-and-egg situation: could a stronger theoretical basis for the existence of 'Hot Jupiters' have driven development toward the goal of their detection 20 years earlier?

Hot Jupiters were unknown until they were discovered once instruments were sensitive enough to detect them. No major planetary development models predicted them. The current best explanation for them is they formed much further out from their parent stars and migrated inward. The migration phenomena is still poorly understood, it wasn't on anyone's radar in the 70s and 80s.

So until Hot Jupiters were discovered they were not predicted. No one even thought to look for them. No one was thinking about Hot Jupiter detectors that just didn't get funding.

Had billions of dollars flowed into astronomy instead of particle accelerators exoplanets (of all types) might have been discovered earlier. Then again they may not have. It's a pointless "what if".

Re: The Uncensored Guide to ‘Oumuamua, Aliens, and That Harvard Astronomer

#122

Post by wcoenen » Sat, Jan 30, 2021, 11:32 AM UTC

jula432vdf wrote: post #113

YeGoblynQueenne wrote: post #105

>> Loeb was a once-respected scientist who made important contributions to astrophysics and cosmology, particularly when it came to black holes and the first stars. But his work on extraterrestrial signatures continues to be largely unappreciated by the community — a position as justifiable as ignoring the comparable idea of Russell’s teapot — and rather than address their scientific objections, he’s stopped listenin…

I don't think many realize the seriousness of the situation. If the asteroid is just a rock, nothing happens, everything is just fine, we can continue to be the apex predator of Sol system. But if anybody is wrong and oumuamua was in fact an alien device looking for us (intelligent life), almost certainly it has found us. What happens next is entirely out of human hands, unless we can realize that event. Maybe is not…

> What happens next is entirely out of human hands, unless we can realize that event.

We would not have been able to detect this object two decades ago. So the "event" is that our observation capabilities have grown past some threshold, not that anything has changed in our solar system. Whether rocks or alien probes, these types of objects must always have been passing through our solar system with some regularity. We'll get a a chance to study others soon enough.

Edit: this video by Scott Manley helps to get a sense of how our ability to detect asteroids has grown over time: https://youtu.be/BKKg4lZ_o-Y

Re: The Uncensored Guide to ‘Oumuamua, Aliens, and That Harvard Astronomer

#123

Post by saberdancer » Sat, Jan 30, 2021, 4:14 PM UTC

vfclists wrote: post #102

saberdancer wrote: post #95

Earlier quoted context omitted.

Oumuamua changed velocity in an unexplained way. This was not expected, but there is an explanation that the object is outgassing and it increases it's velocity. This, along with strange shape made the object interesting for ET speculation.

Hasn't the outgassing theory been dismissed because there is no sign of it?

No, from what I read the theory is that Oumuamua had only frozen hydrogen/gases so the outgassing couldn't be observed as the object was small.

Re: The Uncensored Guide to ‘Oumuamua, Aliens, and That Harvard Astronomer

#124

Post by Gravityloss » Sat, Jan 30, 2021, 11:41 PM UTC

avian wrote: post #12

willis936 wrote: post #9

Oumuamua raises some questions, but the one my mind keeps wandering to is “how common are these interstellar objects?” It poses a serious existential threat to us. We are a tiny target, but we have been able to observe these objects for a very short period of time. Unlike regular solar satellites, they are only visible for a very short period of time. Like comets, if one hit us it would end life on the planet. They d…

> We can estimate how many comets are out there with orbital mechanics models, but what about objects originating from outside the solar system? We can estimate the frequency and size of impacts, regardless of the origin of the impacting body, from observing craters on the Earth, moon and other planets. Those show that the "end of life" impacts are pretty rare - the conclusion that also follows from the fact that we'…

The dinosaur killer was estimated to be 10 km diameter. Oumuamua is much smaller, maybe 0.1 to 1 kilometers long and narrow.

Re: The Uncensored Guide to ‘Oumuamua, Aliens, and That Harvard Astronomer

#125

Post by KingFelix » Sun, Jan 31, 2021, 7:06 AM UTC

thewakalix wrote: post #111

KingFelix wrote: post #106

Earlier quoted context omitted.

I agree and no longer read his articles, and I don't think he provides any value. He often uses statements like this to attack targets, he did the same thing with the last article that came across my news feed for Roger Penrose. >>Hundreds of scientists have pointed this out to Penrose — repeatedly and consistently over a period of more than 10 years — who continues to ignore the field and plow ahead with his content…

I think you may have meant to link to this page instead? https://www.forbes.com/sites/startswithabang/2020/10/08/no-r...

Yes! Thank you, copy pasted wrong tab

Re: The Uncensored Guide to ‘Oumuamua, Aliens, and That Harvard Astronomer

#126

Post by playerm1 » Mon, Feb 08, 2021, 3:23 PM UTC

dysfunction wrote: post #52

m4rtink wrote: post #34

Earlier quoted context omitted.

If you can intercept an interstellar object to land something on it you can by definition also just launch the thing to the same trajectory. Unless your payload is advanced enough to use the mass of the object for something (fuel, radiation shielding, construction materials, etc.) there is not much benefit in landing on an interstellar object if you just want to launch an interstellar probe. Maybe actually if you wan…

If you had really good shock absorbers you could intercept at an orthogonal trajectory and have the impact knock you into the desired trajectory... not practical but fun to think about.

The ultimate egg-drop challenge.

I'm imagining some Vehicle Assembly Building-sized cloud of aerogel with a paperclip-size payload at the center.