Harvard Prof: Aliens visited us in 2017

laptop shop wrote:

“On 4 November 2013, astronomers reported, based on Kepler space mission data, that there could be as many as 40 billion Earth-sized planets orbiting in the habitable zones of Sun-like stars and red dwarfs within the Milky Way. 11 billion of these estimated planets may be orbiting Sun-like stars.”

First, they're lying. They know the only way to get others to pay their salaries is by creating E.T. frenzy. Personally, I'm sold. But they're lying.

Second, you're lying. You intentionally altered the statement. It said "Sun-like stars and red dwarfs". You cut off the part about red dwarfs. They're too cool, which requires a planet to orbit too closely to be in the habitable zone. And then they're too magnetic, which means huge solar flares.

Third, I said "conditions ripe for the development of intelligent life" not just Earth-sized in habitable zones. You also need lots of water (nobody knows where our water came from), a molten core (generates a magnetic field), a moon (creates a stable axis of rotation), a third generation star or later (for elements heavier than hydrogen or helium), located in the galactic habitable zone, a non-binary or non-triary star, a rotating non-tidally locked planet, tolerable wind speeds, an ozone layer (protects against UV rays), lightning (creates the organic molecules), tectonic plates, a planetary system with massive stars like Jupiter and Saturn, a central star with 5-10 billion years of fuel, and probably ten other factors we don't know about. And many of those factors are independent of each other.

Lots of physicists wonder if there's even a single other planet like that in the Milky Way.

I get that life is hard but a lot of these seem overly stringent. e.g. Plenty of ways to block UV that don't require ozone to start -- like evolving at the bottom of an ocean, or under dense clouds, or any number of things.

Point is, you don't need a duplicate of Earth for life to arise.

laptop shop wrote:

Bound4Glory wrote:

Planets with conditions ripe for the development of intelligent life are exceedingly rare.

“On 4 November 2013, astronomers reported, based on Kepler space mission data, that there could be as many as 40 billion Earth-sized planets

True, but it's a moot point anyhow. Either

1) The aliens already had an Earth-like planet, the one they came from, and would far more easily stay right there than go schlepping across vast interstellar spaces to find another one, or

2) The aliens are so high tech they don't really need Earth-like planets anymore. That's a basic prerequisite of long-term interstellar travel.

Since they were here, we can deduce the latter is the case and should assume they wouldn't pay us any attention. And obviously they didn't, or they would have stopped. They used the sun for a gravity-assisted acceleration just like our own space probes do with Jupiter, on their way to somewhere else.

I am runner and a astronomer. And let me tell you, this guy is infamous for his far fetched and bordering on insane theories. We all just roll our eyes when we see his publications. So please do take this with a grain of salt. All he wants is to sell books and create public interest.

runningchick wrote:

I am runner and a astronomer. And let me tell you, this guy is infamous for his far fetched and bordering on insane theories. We all just roll our eyes when we see his publications. So please do take this with a grain of salt. All he wants is to sell books and create public interest.

I don't think anyone here thinks it was an aliens in a spaceship. But on that note, neither did Avi Loeb. I think he was just speculating that it might be a piece of Alien technology. Let's say it was a large broken off light sail? That could explain the slight acceleration. There's nothing in the observational data that rules it out. All the pictures show an elongated asteroid, but that's just an artist's guess. Nobody knew about this object until it was 20 million miles away and leaving the Solar System. Even in our best telescopes, the object still appears as a point source of light.

Does it really matter so long as there is not an Immodium Q36 Explosive Space Modulator aimed at the Earth?

runningchick wrote:

I am runner and a astronomer. And let me tell you, this guy is infamous for his far fetched and bordering on insane theories. We all just roll our eyes when we see his publications. So please do take this with a grain of salt. All he wants is to sell books and create public interest.

Says a lot about the hiring standards at Harvard I suppose. Not worth the price of admission to that clown show.

CrispyChicken wrote:

runningchick wrote:

I am runner and a astronomer. And let me tell you, this guy is infamous for his far fetched and bordering on insane theories. We all just roll our eyes when we see his publications. So please do take this with a grain of salt. All he wants is to sell books and create public interest.

Says a lot about the hiring standards at Harvard I suppose. Not worth the price of admission to that clown show.

Btw here is a good blog post by an astronomer who know their stuff:

runningchick wrote:

I am runner and a astronomer. And let me tell you, this guy is infamous for his far fetched and bordering on insane theories. We all just roll our eyes when we see his publications. So please do take this with a grain of salt. All he wants is to sell books and create public interest.

Unless you can explain the oddities of this object (and it appears astronomers can't), the fact that you are an astronomer seems irrelevant. It becomes more a question of philosophy and logic.

not how that works wrote:

xczvzxcv wrote:

The sum total of the argument mentioned in the article was that it's an unusual shape and it slightly accelerated, instead of slowing down, in leaving the sun.

I see no reason why there would not be irregularly shaped small interstellar objects like that one, where their gravity is too small to form them into a more spherical shape. The latter could either be a slingshot effect or a measurement error.

The 'slingshot effect' would not cause it to accelerate while moving away from the sun.

Correct. One initial explanation of its supposed acceleration was that it was "out-gassing," losing mass, in other words, from its approach to the sun. Imagine, similarly, an ice ball continuing to melt after passing the sun, and hence, possibly accelerating as its mass decreased.

Coevett wrote:

Unless you can explain the oddities of this object (and it appears astronomers can't), the fact that you are an astronomer seems irrelevant.

I think she's just trying to say that she's been familiar with this guy and he has a long history of being a quack. That's relevant.

My guess is he's just playing this game: lets think of the most far-out, but plausible, explanation for whatever unexplained phenomenom that can not be ruled out by the observational data.

runningchick wrote:

Btw here is a good blog post by an astronomer who know their stuff

I'd like to see a better critique of the idea that the object was a broken off piece of a light sail that randomly drifted through the Solar System. Their answer was this: "statistically speaking, each star would need to toss out more than one quadrillion (that’s one million billion) of these alien probes for us to find one.

Really? 10^15? There's 10^10 stars in the Milky Way. So in order for us to find one, there would have to be 10^25 of them? No way that is true.

Bound4Glory wrote:

Really? 10^15? There's 10^10 stars in the Milky Way. So in order for us to find one, there would have to be 10^25 of them? No way that is true.

The funny thing is I just calculated this, and I came up with the exact same number they did. So, good for them.

A chunk of debris from an alien ship would have a random path i.e. not targeted at Earth. So we would have to be insanely lucky to see one.

xczvzxcv wrote:

One initial explanation of its supposed acceleration was that it was "out-gassing," losing mass, in other words, from its approach to the sun. Imagine, similarly, an ice ball continuing to melt after passing the sun, and hence, possibly accelerating as its mass decreased.

In before astronomer chick explains why losing mass wouldn't accelerate it. Might reduce deceleration.

Strictly speaking, of course, a change in velocity in any direction is an acceleration, so it was being accelerated the whole time it was under the influence of Earth's gravity.