Not long ago, the center of the Milky Way exploded

https://phys.org/news/2019-10-center-milky.html

by dnetesn • 7 years ago

235 117 7 years ago

phys.org

a_t48• 7 years ago

Does 3.5M years ago count as “not long ago” in astronomy time scales?

quickthrower2• 7 years ago

According to the article, yes.

Aardwolf• 7 years ago

I would say so, it's even short on Earth time scale.

saalweachter• 7 years ago

Whenever timespans like this come up, it always reminds me of the opening from Now and Then, Here and There: Because ten billion years’ time is so fragile, so ephemeral… it arouses such as a bittersweet, almost heartbreaking fondness.

atoav• 7 years ago

I think 3.5M years aren’t even that long ago in geological time scales.

kozak• 7 years ago

According to https://en.wikipedia.org/wiki/Timeline_of_the_evolutionary_h..., that's when "Blue whales grew to their modern sizes". So it's fairly recent not just in astronomy scales.

rbanffy6• 7 years ago

In cosmological terms, it's more like "earlier today". Our ancestors were already walking around, talking to black monoliths and crushing skulls by then.

ifdefdebug• 7 years ago

I hate that movie.

dredmorbius4• 7 years ago

The Krell, on the other hand, were near the peak of their development.

hanoz• 7 years ago

It's very nearly 3.5 days in terms of a middle aged person's lifetime, which is an interesting rule of thumb I think I've just discovered.

lifeisstillgood2• 7 years ago

so ... wild guess

37 years * 365 days = 13,500 days

universe has existed for 13.5 billion years

So each day in a middle aged life is 1 million of the universe's years.

I like it ! :-)

* This flare: Last Friday

* Dinosaur extinction: 3rd of August

* Pangea breaks apart: about Valentines day

* Earth formed: June 2007

* Universe Born: 1982

Of course this means the Universe would have listened to Flock Of Seagulls as a kid, and loved Knight Rider.

dredmorbius4• 7 years ago

The Milky Way is ~150,000 - 250,000 light years across, and rotates -- call it a galactic year -- once every 240 million years. At that scale, 3.5 million years would be like about 5 days relative to Earth's year.

So: earlier this week, more or less.

nerdponx• 7 years ago

They said the flare lasted 300,000 years, but how quickly does something like this start? How fast does it go from "nothing" to "full strength"?

Also if there was any form of life orbiting a star in the path of this flair, is it safe to assume that said life is no longer alive? At least if that life resembles us in its tolerance (or lack thereof) for radiation.

yourapostasy2• 7 years ago

Also if there was any form of life orbiting a star in the path of this flair...

Based upon a couple other articles I read [1] [2], it sounds unlikely there were other galaxies or smaller structures in the path of this flare. I only see references to a very directional cone at the poles of the Milky Way, and the cone only intersects a trail of gases left behind by the Magellanic Stream.

Were there somehow orphaned planets, solar systems or smaller galaxies in the path of those cones not mentioned in the articles however, then the gamma rays, X-rays and highly ionizing gases in those cones of energy would certainly strip away most if not all of the atmosphere of any Earth-like planet, and kill all forms of life as we know it unless it was in some kind of weird, tidally-locked configuration that kept one side always facing the originating, ejecting side of the cone.

These flares would make a great plot device setup for a story in the Xeelee Sequence or /r/HFY. We find out the flares are deployed as weapons, used as a kind of galactic-scale sawed-off shotgun against another galaxy. Or the flares are galactic-grade energy reactor experiments gone horribly awry, and are the cause of one Great Filter at the Kardashev Type-III scale.

[1] https://www.sciencealert.com/something-in-the-centre-of-our-...

[2] https://earthsky.org/space/explosion-milky-way-center-seyfer...

jacobush3• 7 years ago

Is there a name for some kind of inverted Kardashev scale, where higher civilizations decide to slow down and go miniature, conserving as much energy and information as possible?

Possibly as a) some kind of bet to hide from other civilizations and b) to delay the heat death as long as possible.

s1artibartfast• 7 years ago

There very likely were thousands of stars in the paths of the jets as they passed through the galactic bulge at the center of the galaxy. Our galaxy gets thicker in the galactic center and the bulge is 3000+ light years thick and contains an estimated 10 million stars.

rbanffy6• 7 years ago

I guess that's why we won't be hearing radio signals from the Magellanic clouds...

Now, seriously, what would be a safe distance for an Earth like planet to be from such an unlucky event?

leemailll• 7 years ago

So for laymen as us, how far is the center from us in light years?

andyjohnson0• 7 years ago

26,490 ± 100 light years or 8,122 ± 31 parsecs

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

rwmj• 7 years ago

https://en.wikipedia.org/wiki/Sagittarius_A%2a

26000 light years

sago• 7 years ago

Give the (Monty) Python headline on today's HN, let me add that it's worth learning to sing https://youtu.be/buqtdpuZxvk I find.

The exact numbers are not quite exact, although they are usually in the right ballpark. "We are 30,000 light-years from Galactic central point." But I found it so useful knowing that song over the years.

mannykannot• 7 years ago

When this was first noticed (2013) I recall statements (possibly speculative) that the irradiated part of the Magellanic Stream might have glowed brightly enough to be visible in the night sky. If so, it would have subtended about half a degree, about the same width as the moon and the sun.

ianai• 7 years ago

And here we are stuck with just a sun and moon!

andyljones• 7 years ago

Paper: http://www.physics.usyd.edu.au/~jbh/share/Papers/JBH-Ionizat...

keyle• 7 years ago

They said it would have been a massive event, but what would our ancestors have seen?

jwr• 7 years ago

For those of us who read Larry Niven's sci-fi novels, this headline is… both amusing and somewhat scary.

flyGuyOnTheSly• 7 years ago

And for those of us who do not, can you elaborate as to why exactly?

drdeadringer• 7 years ago

I believe the story referenced is "At The Core", where stars at the core of the galaxy have gone supernova and thereby started a supernova chain reaction expanding outward from the core into the surrounding stars of the galaxy.

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

ceejayoz2• 7 years ago

The galactic core exploding is a major plot point driving the Known Space series.

simonh2• 7 years ago

In one of Niven's short stories an alien corporation hires a Human pilot to fly to the galactic core. It's a publicity stunt to demonstrate the speed and range of a new FTL drive. When he gets close to the core, his ship is almost fried by the radiation wave front coming from a chain reaction explosion of suns in the galactic core. This drives events in many of Niven's later stories.

The devastation won't reach 'Known Space' for thousands of years, but the alien Puppeteers that funded the trip are paranoid herbivores. They immediately start a mass exodus of their whole species out of the galaxy, causing a massive economic crash along with many effects on other plot lines.

Niven's Known Space future (and past) history is an amazing and incredibly influential achievement. Highly recommended. Most of it consists of collections of short stories and novellas written over decades, so it's very digestible.

sliken2• 7 years ago

There another short story by Niven where someone gazing at the moon sees it get as bright as the sun. They quickly come to the conclusion that some horrific event will end life on earth as soon as the earth rotates towards whatever made the moon so bright.

It's a fun little romp.

FrameworkFred2• 7 years ago

Given that we're able to aim telescopes at things that are billions of light years away, I wonder how close we are to being able to see the reflection of such a thing when it actually happens on some celestial body 3.5 million light years away.

raattgift• 7 years ago

You might be interested in the examples section of https://en.wikipedia.org/wiki/Light_echo

ljf• 7 years ago

I remember as a child thinking I had fixed time travel (in a very limited sense) when I wondered why we didn't just stick a bunch of mirrors far far away, and then aim them back at the earth and use telescopes to look back at the dinosaurs etc.

While that wouldn't work for heaps of reasons, I like your idea. I guess the issue would be discerning 'when' such a thing happened, and finding the right item to look back at, which would be a difficult challenge...

smudgymcscmudge• 7 years ago

I had the same idea. I forgot about it before I was old enough to reason about it. At the time I thought the size of the mirrors would be the biggest issue. I guess I thought faster-than-light travel was easy.

indigo747• 7 years ago

I have a distant childhood memory of a book based on this concept, in which the protagonist is projected back in time through light beams bounced off of distant mirrors. I think I stopped reading because I could tell the science was completely impossible, and ultimately just an excuse to write an historical fiction book which I didn't feel like reading. Perhaps I judged it too harshly?

jandrese• 7 years ago

Ignoring the problems with resolution, the big issue with this is you would need FTL travel to position the mirrors ahead of the light.

And this in turn is one of the big reasons why FTL is probably impossible: It is in essence time travel.

jerf3• 7 years ago

You need natural mirrors, because as others have pointed out, they have to already be there, you can't get ahead of the light to put them there.

It has been suggested that black holes could provide this mirror, but it requires resolving not just something the size of Earth, but something much smaller, at a distance of 30 million light years +. Unfortunately you actually start hitting up against the limits of spacetime's resolution itself fairly quickly. But at least in principle, it is possible that some lucky photon has bounced off a dinosaur, and has traveled all the way out there, and all the way back to Earth, just now, that if you knew where to look in the sky, perhaps such a photon might even enter your eye now. Or perhaps there is some human out there who really has "seen" the dinosaurs. But you'd never really know.

jakeogh• 7 years ago

:) https://news.ycombinator.com/item?id=9161967

iamgopal• 7 years ago

Bit turnoff is, we couldn't even take photograph of human size on moon, things far away are mind blowing huge. Every data is blurred out.

mirimir2• 7 years ago

We already have: Clavel et al. (2013) Echoes of multiple outbursts of Sagittarius A[star] revealed by Chandra.[0] Here's the abstract:

The relatively rapid spatial and temporal variability of the X-ray radiation from some molecular clouds near the Galactic center shows that this emission component is due to the reflection of X-rays generated by a source that was luminous in the past, most likely the central supermassive black hole, Sagittarius A[star]. Studying the evolution of the molecular cloud reflection features is therefore a key element to reconstruct Sgr A[star]'s past activity. The aim of the present work is to study this emission on small angular scales in order to characterize the source outburst on short time scales. We use Chandra high-resolution data collected from 1999 to 2011 to study the most rapid variations detected so far, those of clouds between 5' and 20' from Sgr A[star] towards positive longitudes. Our systematic spectral-imaging analysis of the reflection emission, notably of the Fe Kalpha line at 6.4 keV and its associated 4-8 keV continuum, allows us to characterize the variations down to 15" angular scale and 1-year time scale. We reveal for the first time abrupt variations of few years only and in particular a short peaked emission, with a factor of 10 increase followed by a comparable decrease, that propagates along the dense filaments of the Bridge cloud. This 2-year peaked feature contrasts with the slower 10-year linear variations we reveal in all the other molecular structures of the region. Based on column density constraints, we argue that these two different behaviors are unlikely to be due to the same illuminating event. The variations are likely due to a highly variable active phase of Sgr A[star] sometime within the past few hundred years, characterized by at least two luminous outbursts of a few-year time scale and during which the Sgr A[star] luminosity went up to at least 10^39 erg/s.

0) https://arxiv.org/abs/1307.3954

Edit: Older image: https://www.chandra.harvard.edu/photo/2007/gcle/

FrameworkFred2• 7 years ago

WOWWW...that's super cool. If you could find multiple reflections of the same source [edit: after a second look, that's actually what they did which is even more amazing], you could start piecing together a sequence.

But, darn it, now we're going to have to map the cosmic background light pollution. :)

facethrowaway• 7 years ago

I am guessing this would lead to solar system-scale destruction? Putting a base on Mars doesn’t seem like it would do much to counter such an event if it headed our way?

michannne2• 7 years ago

My opinion is that the idea of a base on Mars is not to somehow secure humanity's position in the Solar System, but to give us something to aim for so we have a reason to pump money into space exploration and aerospace research

jp5552• 7 years ago

Don't you think two self-sufficient instances of a civilization separated by a ~dozen light-minutes decreases the risk of species extinction events?

ekianjo• 7 years ago

A Mars base would do a lot to prevent extinction of human life because of an "unlikely" but "it's just a matter of when, not if" situation where we get hit by a massive rock.

eloff• 7 years ago

Actually there's only a period in time where we're vulnerable to such things. Eventually we'll know of all the potential threats with enough advanced warning and have the capabilities to deflect them. Maybe we're vulnerable for another hundred years, but not likely still vulnerable in a thousand. Given the rarity of such events, we should be fine.

hoorayimhelping• 7 years ago

From my understanding, something that can wipe out the entire solar system at once is highly unlikely.

Huge bursts of concentrated energy coming out of black holes are usually tight beams of high energy particles and light (x-rays, gamma rays) moving very fast and aligned with the object's poles. The focused beam of energy is what is deadly to life. If it's not tight and focused and moving fast, the energy dissipates out into space.

The solar system is huge and extends in three dimensions. A burst of energy that hit earth directly could miss Mars (or the moon, or the space around the earth and the moon) entirely. To sterilize a specific planet, the event has to be close (within like 10,000 light years I seem to remember reading) and the poles of the object undergoing the event have to be pointing at the planet.

simonh2• 7 years ago

If the black hole was only 1,000 light years away, and the angle of divergence of the beam was only 0.1 degrees, by the time the beam hit our solar system it would be about 2 light years across, or 126,000 AU.

Compared to interstellar distances, our solar system is tiny.

FuckButtons• 7 years ago

intensity is proportional to the inverse square of the distance, anything exploding that far away will be but a pinpoint in the sky by the time it gets here, even if it was a cataclysm when it occurred.

Yuval_Halevi• 7 years ago

So basically we are not on the way of bursts exploding from the poles of the center, we are perpendicular to the bursts trajectory?

tejtm• 7 years ago

normally

_bxg1• 7 years ago

They probably would've mentioned this in the article were it the case, but I wonder if it was visible at all in the night sky? We can see part of the Milky Way, after all. I guess there wouldn't have been writing yet but could such a thing have made it into oral history? Was there even oral history yet?

windsurfer• 7 years ago

Dust and gas surrounding the galactic center blocks almost all visible light. Sadly most events simple wouldn't be visible.

onychomys• 7 years ago

No oral history, sorry. 3.5MYA, we were still Austropithecenes, basically as smart as a modern day chimp or gorilla, but bipedal. The little numbers in the tree here show divergence time:

https://en.wikipedia.org/wiki/Australopithecus#Phylogeny

kristianp• 7 years ago

No mention of what observations they made to come to this conclusion. Not in the press release I guess.

Faction• 7 years ago

They said the flare lasted 300,000 years, but how quickly does something like this start? How fast does it go from "nothing" to "full strength"?

Not long ago, the center of the Milky Way exploded

Related Stories