A Visiting Star Jostled Our Solar System 70,000 Years Ago | Hacker News Reader

A Visiting Star Jostled Our Solar System 70,000 Years Ago

gizmodo.com

228 pointsrbanffy86 comments

I'll take this opportunity to recommend Universe Sandbox[1], which is pretty cheap on steam and worth every penny.

Turning on projected orbital lines in an N-body simulation of our solar system and seeing what happens when you toss a star in there is really enlightening... the rings all shift in tandem in a visceral way that really helps me "feel" what happens.

There's a simulation that comes out of the box that simulates the circumstances of the book "Nomad" (I haven't read the book) where a small solar-mass rogue black hole drifts past the solar system at high speed. With orbital path projections turned on you get to watch all the paths shift like wobbling hula hoops as the unseen object drifts past. Most orbits remain stable but very deeply shifted from where they were (earth's aphelion ends up far out where Jupiter was, with its perihelion much closer than before...)

The effects described in the article are obviously less extreme, but the game helps me get a sense of just how perilous our planetary orbits are and how vulnerable to outside influences they can be.

[1] http://universesandbox.com/

Space engine http://spaceengine.org/ is also worth mentioning

Space engine doesn't have nbody or collisions yet, but if you want to explore a beautifully rendered and endlessly exolorable universe, highly recommend space engine. It's also developed almost entirely by a single guy in Russia.

> Most orbits remain stable but very deeply shifted from where they were (earth's aphelion ends up far out where Jupiter was, with its perihelion much closer than before...)

That's incredibly terrifying. Although from what I see in the book description, it focuses more on the drama aspect.

I wouldn't mind someone exploring the technical aspect in more detail, e.g. what would be possible to do to prepare for such an event (if anything) and how likely it would lead to the extinction of civilization.

Past a certain level of extreme disaster planning, every disaster plan converges on the same point: build (what amounts to) a space station. Whether your station is actually in space or five miles underground, you ultimately need to plan a fully self-contained, self-sufficient environment that will support human life.

Reminiscent of "A Pail of Air" by Fritz Leiber (1951). The image of bringing in a pail of oxygen, to melt/boil by the fire, is wild.

The scenario described is almost certainly the end of human civilization and the majority of life on earth. Assuming I’ve done the math right, an aphelion of ~5 AU and perihelion of ~0.9 AU gives a highly eccentric (e = 0.69) orbit taking 5 years.

I’m just guessing here, but I imagine each orbit would start with 6-8 months of relatively normal temperatures as we made or closest pass by the sun, a year or so worth of dropping temperatures, 2.5 years of deep, deep freeze, and a year of slow warming as we approach the sun again. Each orbit is probably going is probably going to see the planet spending at least 3 years competely outside the habitable zone. I’d expect virtually all life as we know it on the surface to die in the first orbit.

With enough warning we might be able to dig some deep facilities that could harness geothermal energy to generate power and avoid freezing. They might be able to use hydroponics or something to sustain themselves for a long time, but to what end?

There’s life beneath deep oceans that thrive on geothermal - I think it’s possible some life can survive.

if you are going to bite the bullet and get this game, Id recommend the 2nd iteration of the game, think they call it Universe Sandbox^2 (squared) . Nicer graphics and speed improvements in the second version.Its got a steam VR version too for those with VR hardware.

Looking at the link, what else are people going to buy? I'm confused as to what you're clarifying.

If you search Steam, there used to be V1 and this is V2, so there's that potential confusion.

... or if you want a casual experience for free right in your browser you can try http://www.stefanom.org/spc/

Made a gif of this from the game:

https://imgur.com/a/6NXQ7

I was going to ask if perhaps ancient humans saw this new red star and if it drove them to an elevated state of being superstitious and chaos but:

>When Scholz’s Star was in the neighborhood, it would have been a 10th magnitude star (red dwarfs are very dim). That’s about 50 times fainter than what can be seen with the naked eye at night. Under normal circumstances, it would be invisible. But because red dwarfs are magnetically active, it could have briefly “flared-up” (i.e., V-band flares) to become thousands of times brighter. The astronomers say it’s possible that the star was visible to our paleolithic ancestors for a few minutes or hours if this rare flaring event transpired at the time.

I was drawn to that passage as well. The author goes on:

> Sadly, this star’s passing likely went unnoticed by our ancestors.

I mean, I get it, but why is it sad? Is it because it feels like a "missed connection" with our ancestors? Tangential, but I feel like the answer to this question connects with why people study astronomy in the first place, and I'm just curious if others relate to this sentiment. :)

Sadly because our ancestors missed the opportunity to see such an event, as rare as we think it to be.

Actually perhaps it's better that way. Otherwise they could base some superstitious thinking on it that would stick if we were unlucky enough and there'd be yet another case of irrational thinking to be undone.

I would chose a belief about a moving star in a heart beat compared to a talking bush and a dude walking on water.

Edit: my point being, humans are superstitious in unpredictable way; A moving star wouldn't be more surprising than an eclipse. I'm sure our cultures and religions would have been roughly the same

I have never been able to understand why so many other scientists and "rationalist" look back on humans early "superstitious" ideas with contempt. To my mind these superstitious ideas are the beginning of the rationalist mindset. These ideas are people's attempts to explain and understand how the world works. I am certain that some of the ideas that many of us hold now will be thought quite silly in a few hundred years.

> am certain that some of the ideas that many of us hold now will be thought quite silly in a few hundred years.

Yes, like the theory that we're actually living in a simulation, espoused by Elon Musk and other respected, ostensibly science-minded people.

It's basically Creationism in modern form.

It is an interest idea and a great starter for philosophical thinking, but no-one is treating it like literal gospel.

>It is an interest idea and a great starter for philosophical thinking, but no-one is treating it like literal gospel.

Of course not. "Gospel" is a religious concept. They're claiming that it's a plausible, scientifically-supportable theory.

I don't think it's an interesting idea at all, nor do I think it's a good starter for philosophical thinking. I think it's Creationist nonsense.

Okay.

A "scientifically-supportable theory"* is one that describes a phenomenon that can be observed sufficiently to form a hypothesis and then test that hypothesis by experiment.

In what way would you propose to test the simulation hypothesis by experiment?

(* I'm assuming you're using the word "theory" loosely here.)

I wouldn't think of it as a theory. More like an off-the-cuff hypothesis, based on seeing and creating simulations of systems, that we ourselves are creations of a simulation. A single universe could be host to innumerable amounts of capsuled simulations.

The point is "could" because a complete simulation of "the world" would require another world much the same way that complete map of the world would constitute another world if trying to capture a full level of detail.

It's only silly in the sense that such an explanation is just one out of infinite possible, and coherent, propositions about the mechanics of "our world". In hindsight, the timescales of Hindu and Buddhist mythology don't seem absurd.

It isn't like creationism because it is based on some otherwise currently unexplained observations such as quantum mechanical behavior and magic physical constants. The idea is that these are exactly the sort of observations you'd see if you were in a simulated universe.

Now if we were to observe new species being created in N days, for small integer N, then I suppose your assertion about creationism would also hold.

>It isn't like creationism because it is based on some otherwise currently unexplained observations such as quantum mechanical behavior and magic physical constants. The idea is that these are exactly the sort of observations you'd see if you were in a simulated universe.

Really? Why would you not simply "see" whatever the Creator(s) want you to "see"? After all, it's a simulation.

And it seems to me likely that Creationism originally grew out of a then-unexplained observation: "Hey, we're alive and we exist! How the heck did that happen???"

>Now if we were to observe new species being created in N days, for small integer N, then I suppose your assertion about creationism would also hold.

I'm not sure what you mean. My assertion about classic Creationism is that it's disproven bunk.

Are you saying that if "if we were to observe new species being created in N days, for small integer N" then my assertion that simulation-Creationism is also bunk would hold?

Wouldn't a simulation have to have a creator? Unless you are postulating that a Turing-complete simulator got itself together by random chance and, by random chance, started simulating universe(s), one of which, by random chance, happens to simulate beings that can imagine a simulator simulating themselves. It seems like a simulation is a fairly strong evidence FOR a creator. Hawking's quantum bubbles seem much more like what would happen without intervention.

Also, creationism isn't limited to only 6 day creation, that's more of a modern thing by people that insist on taking Genesis 1 (which is poetry) literally. Early Christian thinkers postulated that 1 Genesis-day was actually 1000 years. Creationism just says that God created the world; how long it took and how he did it are implementation details.

By definition, aren't all attributes of our Universe exactly what we would expect to see if we were in a simulation of a Universe with those attributes?

> the theory that we're actually living in a simulation, ... It's basically Creationism in modern form.

It's not even modern. It is basically Plato's Cave, which is classic Greek philosophy.

https://en.wikipedia.org/wiki/Allegory_of_the_Cave

The religious touch of that idea did not become popular until the movie "The Matrix", which originally had allusions to many different religions, but specialized to Christianity / Creationism with the second and especially the third movie "The Matrix Revolutions".

That is not the meaning of the Allegory of the Cave at all! The metaphor is that human experience is limited by our senses (like living in the cave) and so to understand eternal, absolute truths you need to use pure reason (leaving the cave), not experience.

Not sure what you argue against, but exactly that aspect, "human experience is limited by our senses", means that everything could be a simulation. Plato named those "shadows", but that's only because people weren't used to good simulation technologies back then. Today we have 3D cinemas, flight simulators, VR headsets, etc.

But if you still don't like that example, here's another historic example of a philosopher who published the idea that everything could be a simulation.

The evil daemon by René Descartes:

https://en.wikipedia.org/wiki/Evil_demon

So my point still stands: The idea that everything might be a simulation is as old as humanity. It is neither modern nor based on creationism.

Plato's shadows have absolutely nothing to do with living in a simulation. He was talking about degrees of true knowledge and their alignment with his idea of a multi-layered existence.

No multi-layered metaphysical construct in the ancient world discussed simulations. There isn't even a vocabulary that could describe an abstract simulation rather concrete reenactment, like drama or a physical model.

Some ancient religions spoke of the physical world as an illusion, but that too does not mean anything like a simulation.

A simulation is a virtual reality created by a higher intelligence in a real-world environment with great real-world power. Plato's forms weren't discussed as beings who did anything, and in the end were just reifications of predicates.

Descartes' skepticism is the foremost example of a simulation issue, but in addition to the great flaws in his arguments in the Discourses, saying you can't absolutely prove that your senses are not an elaborate deception is no indication that it is.

Profound ignorance and misunderstanding of philosophy is, for me, the most salient feature of the latest discourse on world-as-simulation.

2 weeks of an intro to philosophy college course would correct most peoples' thoughts on the matter, as examining Descartes is the most basic first step in learning philosophy.

If people fear responsibility to acting immorally, the probability of becoming an inter-planetary species likely increases.

So it makes sense for Musk.

I would suggest that any contempt of early superstitious ideas has to do with the fact that many live on today.

People work with the best hardware and software they can. And for a lot of people, both components are shit beyond coexisting with other members of a "tribe". A lot of people absolutely suck at abstract thought, although "suck" is a relative term.

If AI flourishes, it'll consider even the smartest human as a hillbilly swamp creature, a mockery of the possibilities of intelligence.

> I have never been able to understand why so many other scientists and "rationalist" look back on humans early "superstitious" ideas with contempt. To my mind these superstitious ideas are the beginning of the rationalist mindset.

First of all, pstuart nailed it: "I would suggest that any contempt of early superstitious ideas has to do with the fact that many live on today.". Also, one could argue that not all modes of thinking eventually lead to rationalist mindset, at least not directly - one problem with superstitions is that people don't have or need proofs for them and that they as memes fight the same space truth does.

True concept of, for example, evolution still is fighting with creationism because they solve the same problem, but one of them was made completely made up and people still believe in it because it was here earlier. I think it would be better if we had no answers rather than ones that are utterly wrong. Especially since people who make them up and believe based on "faith" alone are so convinced that their concept is true that they actually harm the actual, proven truth.

Well astronomy is very much time travel in the search for knowledge. There's all this stuff going on/has been going on out in the multiverse, but it is just so damn far away most of the time. Some people figured out that a star visited our solar neighborhood only 70K y/a and at that time there were proto-humans on the cusp of grasping a better understanding of themselves and eventually the universe. It puts into perspective our fragile existence.

"Artist’s depiction of a spear-wielding human gazing up at Scholz’s Star — a scene that probably never happened, given the red dwarf’s low luminosity."

If humans then were anything like us, they were looking up at night. If it happened at night, I bet someone saw it.

Thought this might be Nemesis:

(https://en.wikipedia.org/wiki/Nemesis_(hypothetical_star))

....but the dinosaurs died much, much earlier than this dawrf star passed by.

Isn't that around the time of the Homo Sapiens genetic bottleneck?

What does that mean?

https://en.wikipedia.org/wiki/Population_bottleneck ?

This is the coolest part of that page:

"A 2005 study from Rutgers University theorized that the pre-1492 native populations of the Americas are the descendants of only 70 individuals who crossed the land bridge between Asia and North America."

https://www.livescience.com/289-north-america-settled-70-peo...

this is even cooler: https://en.wikipedia.org/wiki/Mitochondrial_Eve

You learn everyday this is awesome find.

That's a disputed claim.

https://www.nature.com/articles/nature19085.epdf

I'm amazed at this coincidence, too.

It can't have had sufficiently fast impact on Earth by disturbing orbits to create impactors, given the distance.

Isn't the article mostly about how it did influence Oort cloud object orbits? Thirty-six identified.

It also discusses how there was almost certainly no impact on Earth's surface or our ancestors. Apparently the star was unlikely to even have been visible in the night sky.

...except for the potential Oort object impacts? I'm not sure they discounted that. And further: we can't track the objects that did impact something because, well, they're gone now. Statistics doesn't work well for them.

That's a minuscule number and "influenced" doesn't necessarily mean "aimed them at the Earth." There's a lot of space out there which it takes things a lot of time to move through. It takes the Earth a year to go around the Sun. And the Oort Cloud is, like, 100,000 times further away from the Sun than we are.

Even if you ignore possible asteroid impacts, there's no telling what kind of issues having red dwarf star & its brown dwarf companion so close can create.

They went into 'v' orbits, which as I understand it, means steep highly elliptical orbits that come inside the Earth's orbit? Its a lot more crowded in here.

I'm no space science maker person. So take this all with a grain of salt. But.

Halley's Comet takes 75 years to make an orbit. It goes out to about 35AU. Let's call that 1 year per AU. That rough, rough number would lead one to conclude that anything from the Oort Cloud moving at a similar speed could take, say, 100,000 years to get here even if it was aimed at us. If triggered by something 70,000 years ago, we'd still have a bunch of millenia to prepare.

Anyway. I'm sure I'm completely wrong.

There doesn't need to be any physical impactors for there to be a significant effect on climate and life. Ice ages can start and end due to tiny changes in the Earth's orbital wobble.

https://phys.org/news/2016-12-ice-ages-linked-earth-orbitbut...

So it may be, that our fate was decided by the stars.

"However, subsequent research, especially in the 2010s, appeared to refute both the climate argument and the genetic argument." [0]

https://en.wikipedia.org/wiki/Population_bottleneck#Toba_cat...

Even thinking about all the sci-fi plots that could link these events is so exciting. Reminds me of a lot of different stories, from Pern to Chrono Trigger.

Too bad that in our dull and rational reality it's just a coincidence.

Wikipedia says this is 17-23 light-years away. So it moved between 16.2 and 22.2 light years in 70k years. This means relative to us it is moving an average of 0.0231% to 0.0317% the speed of light.

Reminds me of an Ask Ethan where solar systems can get slingshot out of their galaxy with planets in tact: https://medium.com/starts-with-a-bang/ask-ethan-can-stars-es...

> Around the same time our ancestors left Africa, a dim red dwarf star came to within 0.8 light-years of our Sun

So that's within the Oort cloud. If this happened again should we be more concerned about the star disturbing our Oort cloud or about us travelling through the other stars Oort cloud?

Again: as sooner we start our resettlement to other star systems - the better.

What about the opportunity cost? What about the long-term?

Maybe we should make our ecological footprint steady-state sustainable, first.

I think your idea is more practical, given the state of spaceflight technology - BUT, should it succeed, then little incentive would exist to leave Earth.

Given the impulses of people in power now, coupled with whatever steps the future takes to make Earth sustainable, it's hard to imagine a future government allowing people to leave. It would, after all, be setting up a competitor. Paranoid, you say?

Imagine an English king c. early 1600s having a vision of the descendants of his loyal colonists rebelling 170 years later. And the nation founded by the rebels eclipsing England 130 years after that. History might have turned out differently.

The good news is that thanks to France and Spain, the English king had little choice - he had to oppose France and Spain everywhere he could, or risk losing strategic advantage.

>It would, after all, be setting up a competitor

There is nothing paranoid about that.

Evolution is not some magical 'forward' direction where every species becomes more technologically capable, or even more dignified.

It might be true that our species' now has a limited opportunity to become multi-planetary.

The first person to get to the moon was Korolev, and he would have continued rotting in a gulag had the urgency for a space program not been there.

And before you say the US is so much unlike Russia--our competing Vanguard program should, from an industrial standpoint, have won, but it was a massive failure, and embroiled in politics of its own.

Humanity needs competition to keep us honest, in the same way that the veracity of ideas needs to be tested by experiment to keep them honest.

Why either one of options? Why not to do that at the same time?

Just take resources from military spendings and put them on both tasks. But right, humans need to learn first how to trust each other...

As one wise gentlemen in Russia once said "большая беда нужна" / "we need a big trouble" for all of us to work on such global task. Is this the only option for creating humanity deserving motivations? Not a star but [relatively] small asteroid on crash course with Earth, are we ready?

The one event that would unite humanity like no other (even taking advantage of our xenophobia) would be contact with other intelligent life.

If we will survive until that moment.

We already know at least 5 extinction events on the Earth : https://en.wikipedia.org/wiki/Extinction_event#Major_extinct....

But no proven contact with extraterrestrials.

Probably because life forms on other planets didn't care at their time - didn't pass the Great Filter : https://waitbutwhy.com/2014/05/fermi-paradox.html

I think it's highly unlikely that we'll be able to move off this rock and survive, much less thrive. We are super-duper fragile. Space is extremely inhospitable, living on a space station for prolonged periods of time would wreck our bodies, potentially habitable planets are light-years away, and it's in our nature to be short-sighted.y

Perhaps one day our technology will advance to where we can create some kind of AI or AI/Human hybrid with a non-fragile body that can withstand zero gee and space radiation, but then you get into this deep existential thought of what it even means to be "human". I mean maybe Humans were never meant to colonize space, maybe our "job" as a species is to "create" a species that can, though.

I love this stuff.

Do large, bright stars ever pass that close? What would that look like?

> Do large, bright stars ever pass that close?

Yes, but it's extremely rare.

> What would that look like?

Not much. The Scholz flyby was at 0.6-0.8 light years, the same order of magnitude as the distance to Alpha Centauri. It would just look like a star, probably not even a particularly bright one.

The rate at which it was drifting with respect to the other stars might have been noticeable under long-term observations. 20 ly in 70k years means its doing about 85 km/s. At its point of closest approach, 0.6 ly, this translates to 1 radian per 2100 years, or 1 degree per 37 years. (The full moon is 1/2 a degree.) The Scholz star was too dim to see, but a brighter star following its trajectory would have noticeably moved in a constellation over the course of a human lifetime.

Alpha Centauri is 4.37 light years away. Or did I misunderstand your comment?

Hard to say. Yes, Alpha Centauri is indeed 4.37 LY away, though that kind of precision is irrelevant when talking about orders of magnitude (OOM). Two numbers are considered to be the same OOM if the absolute difference of their base-10 logarithms is less than 1.

The truly large bright stars don't really "live" long enough in that state to travel great distances on an astronomical scale, and if there was one in our area we'd be in trouble[1].

Large stars smaller than that but large enough to be significantly bright would probably look a lot like a planet, but long-term could also be bad for us if they were close enough and massive enough to even slightly destabilize orbits - the impact might take thousands of years to truly materialize, but climate change has nothin' on orbit change.

Also, anything both large/bright enough to be easily visible AND headed in our direction would likely have been noticed at this point. It may happen someday, but the descendants of the cockroaches are the ones who'll have to deal with it.

[1] http://earthsky.org/astronomy-essentials/supernove-distance

Immediately upon clicking this, I typed Ctrl-F followed by "artist's depiction". The page didn't disappoint. :)

I wonder what its velocity is in relation to the sun. Twenty two light years in 70,000 years seems rather fast!

That would be 20/70000 c ~= 300000 km/h ~= 200000 mph

It seems to be quite fast, but not exceptionally. Lets do a quick calculation, and neglect all aspects of proper stellar kinematics -- Our sun has traveled quite some distance itself during the 70000 years, I don't properly described that motion itself, so take everything with a grain of salt:

Lets call the speed difference of the star with respect to our sun `Δv`

   Δv = 20 [ly] / 70 000 [y] = 0.000285714 [ly/y]

Now, lets convert the unit `ly/y` into a unit that we can relate to, to get a grasp on it: 1ly = 63241.08AU[1].

   Δv = 0.000285714 [ly/y] = 18.0688 [AU/y]

18 AU is about the perihelion of Uranus, a bit smaller still. So the star traveled on average, with respect to our sun, about the smallest distance between the Sun and Uranus in 1 year. To put that in perspective:

   Δv = 18.0688 [AU/y] * 149597900 [km/AU] / 31557600 [s/y] 
      = 85.6550 [km/s]

The LSR[2] is about 220 km/s. The Suns deviation from this value is about +14 km/s[3]. So an object with Δv of about 85.6 km/s is quite fast in comparison. But this is still nothing compared to hypervelocity stars, wich can be more than 1000 km/s faster and are exceeding the escape velocity of the galaxy.

------

[1] : 1 AU (Astronomical unit) is the average distance from Earth to Sun.

[2] : Local Standard of Rest -- average speed of our stellar neighborhood through the galaxy.

[3]: https://arxiv.org/abs/1411.3572

I have a problem clicking on Gizmodo ever since I read an article on what was essentially a moto perpetuo machine presented as a breakthrough. Do we have a better source for the news?

Nice information

My guess is that the Oort Cloud is where the mothership turned off its interstellar drive.

> orbits that are very exaggerated, and with a characteristic v-shape

v-shape, we all know where this will go to...

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