back to article Astro-boffinry world rocked to its very core: Shock as Andromeda found to be not much bigger than Milky Way

The Andromeda galaxy is actually roughly the same size as the Milky Way, and may not engulf our galaxy when it is expected to collide in about four billion years time, according to new research. In other words, no, Andromeda is not the vastly larger sprawling galaxy we all thought it was. A paper published earlier this week …

  1. Stuart Halliday

    Dwarf Galaxy anyone? ;)

    1. hplasm
      Happy

      Dwarf Galaxy anyone?

      Is that a 'Fun Size' one, or have they just reduced the content size and not the price?

    2. David Harper 1

      Galaxy of restricted growth, if you don't mind.

    3. John Smith 19 Gold badge
      Thumb Up

      Showing that it's good to revisit long held assumptions every so often

      Since they might not be quite as solid as people thought.

      Excellent work, but we might be wise to wait and see if anyone else runs similar (or ideally dis-similar) calculations and comes up with a similar result.

    4. Michael H.F. Wilkinson Silver badge

      Actually, the Andromeda Galaxy has two dwarf companions easily spotted with large binoculars, and can clearly be seen in an image I took with a 200mm telephoto (about 3 h total exposure time), as a fuzzy patches (one near circular, above and to the left of the core of M31, and one elliptical, below M31). Neither are called, Glod, I should add.

      1. David Nash Silver badge
        Thumb Up

        Dwarf companions

        M32 and M110 I believe. Nice image.

        1. Michael H.F. Wilkinson Silver badge

          Re: Dwarf companions

          Indeed. There are actually a couple more satellites galaxies of M31 much further out. NGC 147 and NGC 185 are two I managed to spot much later

      2. Mayday
        Alien

        Nice photo!

        Upvote for you there!

        Question though (I'm no photographer) - How did you take a photo with 3 hours of exposure and not get the "arcs" you see when the earth rotates during that time?

        Extreme example here:

        http://www.astropix.com/images2/i_astrop/tripod/trails.jpg

        Cheers

        1. Mark 85

          Re: Nice photo!

          How did you take a photo with 3 hours of exposure and not get the "arcs" you see when the earth rotates during that time?

          They use what's called a clock drive to rotate the telescope/camera so that it cancels out the Earth's rotation. Here's link: https://en.wikipedia.org/wiki/Clock_drive

          1. dlc.usa

            Re: Nice photo!

            "They use what's called a clock drive to rotate the telescope/camera so that it cancels out the Earth's rotation."

            Which is useless unless the instrument uses an equatorial mount to provide a suitable rotational axis, one parallel to the rotational axis of the Earth itself (https://en.wikipedia.org/wiki/Equatorial_mount)--portable telescopes can be tricky to set up with adequate alignment.

        2. Michael H.F. Wilkinson Silver badge

          Re: Nice photo!

          Thanks everyone! I used a tracking mount to begin with, and this corrects for most of the earth's rotation. Without a so-called autoguider, there will be residual motion, so I combined 120 shots of 90 s exposure using so-called stacking software. I used a Canon EOS 550D with 200mm F/2.8 lens. Digital beats film by a mile for astrophotography, not just because it is much easier to combine multiple images, but also because a CMOS chip is far more sensitive to light. Film registers about 1% (at most!) of all photons hitting it, whereas a CMOS chip easily registers over 25%. Any dark current can be measured and subtracted too.

        3. Jtom

          Re: Nice photo!

          You can buy synchronous click drives that, once your lattutude is entered, will move the telescope/camera exactly counter to earth's rotation. Not expensive, not complicated, and highly accurate.

      3. jimbo60

        Is that digital or film?

  2. Anonymous Coward
    Anonymous Coward

    Films / TV-shows ever dramatize the collision of galaxies?

    What does galaxy collision look like when its happening near your home...

    Is it 'Slow-Boiling-Frog' territory, where you don't realize until its too late...?

    1. Tom 7

      Re: Films / TV-shows ever dramatize the collision of galaxies?

      Even in galaxies things is mostly empty space. Take two galaxies and merger them and practically all the stars will miss each other. - our nearest neighbour is 4 light years away and the solar system up to Pluto is 0.0012 light years across. Things will get a lot brighter as gasses crash into each other and start new stars off. A few more comets and asteroids will be flung about but we are at far more risk from people who will start riots in the interstellar highways complaining about Andromeda's imperialistic intentions.

      1. fedoraman

        Re: Films / TV-shows ever dramatize the collision of galaxies?

        Yes, but...

        You're right about there being very few stars smashing into each other, and the extra comets, and the hot gasses from dust and gas cloud collisions. But, depending on the geometry of the collision, one galaxy may be gravitationally disrupted - most of the stars in orbit around the central black hole will have their orbits radically altered by the approaching mass of the other galaxy. Many will end up being ejected from the galaxy collision altogether, though some do a quick out-and-back as they're recaptured by the new merged galaxies. There are some informative animations of this on YouTube. Highly speeded-up, of course ;-)

      2. kventin

        Re: Films / TV-shows ever dramatize the collision of galaxies?

        two questions:

        1/ even though all stars will _miss_ each other, they will still _feel_ each other. in fact there's gonna be so much feeling, both galaxies will emerge profoundly changed. two stars don't have to hit it off, a close encounter is enough. also, massive black hole(s) in the centre? how close will they get?

        2/ what about all the dark enigmatic stuff we're told is holding the galaxies together?

      3. Andy Non Silver badge

        Re: Films / TV-shows ever dramatize the collision of galaxies?

        "we are at far more risk from people who will start riots in the interstellar highways complaining about Andromeda's imperialistic intentions."

        On the plus side, the Vogons may have to re-route their hyperspace bypass away from Earth. Anyone checked on the planing permission status with our local office in Alpha Centauri?

        1. The Oncoming Scorn Silver badge
          Thumb Up

          Re: Films / TV-shows ever dramatize the collision of galaxies?

          Space is big. Really big. You just won't believe how vastly, hugely, mind-bogglingly big it is. I mean, you may think it's a long way down the road to the chemist, but that's just peanuts to space.

    2. Anonymous Coward
      Anonymous Coward

      Re: Films / TV-shows ever dramatize the collision of galaxies?

      Shh! Michael Bay may be reading this forum.

      1. Oh Matron!

        Re: Films / TV-shows ever dramatize the collision of galaxies?

        I'm not aware of anyone more ignorant of science than Michael Bay (with the exception of Trump, of course)

        1. Doctor Syntax Silver badge

          Re: Films / TV-shows ever dramatize the collision of galaxies?

          "with the exception of Trump, of course"

          Other politicians are available and also ignorant of science.

          1. Anonymous Coward
            Anonymous Coward

            Re: Films / TV-shows ever dramatize the collision of galaxies?

            But they are not as successful as Trump.

            1. jake Silver badge

              Re: Films / TV-shows ever dramatize the collision of galaxies?

              If you definition of "successful" includes going bankrupt financially, morally and politically, I'm awfully glad I'm not successful in your eyes.

              1. Intractable Potsherd

                Re: Films / TV-shows ever dramatize the collision of galaxies?

                Hah! Until I checked the poster's name, I thought it was someone saying that no other politician was as successful at being ignorant about science as Trump.

                1. Overcharged Aussie

                  Re: Films / TV-shows ever dramatize the collision of galaxies?

                  No they are all pretty much stupid and I mean all of them from all countries, especially the ones who think that islands will tip over from too many people and the others that think that there is a secure backdoor encryption system that IT people can just turn on.

      2. lglethal Silver badge
        Trollface

        WE'RE ALL GOING TO DIE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

        Oh wait maybe not...

        1. Ben Bonsall

          No, we will, don't worry.

        2. Alan Brown Silver badge

          Not today anyway.

    3. Anonymous Coward
      Anonymous Coward

      Re: Films / TV-shows ever dramatize the collision of galaxies?

      Well, there's the anime Gurren Lagann, in which giant (and I mean REALLY giant) robots use galaxies as weapons and throw them at each other in a fight that can be seen throughout the universe. Which violates more laws of physics than I want to think about.

      1. Michael Thibault

        Re: Films / TV-shows ever dramatize the collision of galaxies?

        "anime Gurren Lagann"

        That's just silly! How can you throw something in spaaace, with any accuracy, when you aren't standing on anything?

    4. jake Silver badge

      Re: Films / TV-shows ever dramatize the collision of galaxies?

      A '64 Ford Galaxy hit an old oak tree just up the road from here a year or so ago. Made a right proper mess, it did. The tree didn't survive, the car is still driveable. I wouldn't want to get hit with a Galaxy, regardless of what I was driving.

      1. Mark 85

        @jake -- Re: Films / TV-shows ever dramatize the collision of galaxies?

        Well done. But to do this properly, we'll need to find two Ford Galaxys and have a head on collision to see how they merge.

        1. jake Silver badge

          Re: @jake -- Films / TV-shows ever dramatize the collision of galaxies?

          They don't merge. I drove in a Demolition Derby at the old Fremont Raceway Park once[0]. My Chrysler Imperial was the odds-on favorite to walk away with it, but I was knocked out early. The last two cars driving were Galaxys. They bashed each other for about another 20 minutes before settling on a draw ... And both drove down the street to the junkyard after the event.

          The track is now a disused NOLF, and the former junkyard now houses several auto dealerships. And they wonder why so-called "sideshows" are such a problem in the East Bay ...

          [0] I think this should be a requirement for receiving a license to drive. It's a real eye opener as to the laws of physics with regard to automobiles.

          1. Alan Brown Silver badge

            Re: @jake -- Films / TV-shows ever dramatize the collision of galaxies?

            "It's a real eye opener as to the laws of physics with regard to automobiles."

            There's a standard joke that most automobiles understand the laws of physics far better than the monkeys driving them.

      2. The Nazz

        Re: Films / TV-shows ever dramatize the collision of galaxies?

        But did the yellow ribbons survive?

    5. Anonymous Coward
      Anonymous Coward

      Re: What does galaxy collision look like when its happening near your home...

      xlock -mode galaxy

      (but only if you have the right sort of OS :)

    6. Anonymous Coward
      Anonymous Coward

      Re: Films / TV-shows ever dramatize the collision of galaxies?

      Headlines blaming it on climate change should now commence.

    7. jelabarre59

      Re: Films / TV-shows ever dramatize the collision of galaxies?

      "Final Yamato" (one of the later Space Battleship Yamato/StarBlazers movies).

      https://youtu.be/-HmgbAVuyW8?t=3m44s

  3. Cranky_Yank

    The nanny state

    Now every telescope in the U.S.A. must have the warning "Objects in your reflector's mirror are smaller than they appear." engraved on it.

  4. david 12 Silver badge

    4 billion years...

    and if we survive that, only another billion years until the death of the sun

    1. DropBear
      Trollface

      Re: 4 billion years...

      I'm sure we'll be screwing in some sort of eco-saver replacement in its stead long before that...

    2. Anonymous Coward
      Anonymous Coward

      Re: 4 billion years...

      Actually, the Earth is predicted to lose its oceans in a billion years or so. I wouldn't be concerned about anything happening much later.

      1. jake Silver badge

        Re: 4 billion years...

        The only things that give a shit about a billion years in the future, give or take a few hundred million, are tardigrades and Keith Richards.

      2. Yet Another Anonymous coward Silver badge

        Re: 4 billion years...

        to lose its oceans in a billion years or so.

        Unless we can arrange for G*d to send another flood.

        Everybody start sinning has hard as you can now, we only have a billion years !

      3. Alan Brown Silver badge

        Re: 4 billion years...

        "the Earth is predicted to lose its oceans in a billion years or so. "

        It will become too hot for life in about 500 million years. We'll be long-gone by then. In one way or another.

        1. Al Black
          IT Angle

          Re: 4 billion years...

          The Sun will swell into a red giant, either swallowing Earth or at least completely scorching it, around five billion years from now. However, as the Sun grows gradually hotter (over millions of years), Earth may become too hot for life as early as one billion years from now. But Civilisation will be wiped out in less than 8000 years by the Y3K bug, assuming it cannot be averted by adopting a 5 or 6 digit Year....

  5. Anonymous Coward
    Anonymous Coward

    If the mass is 800 vs 700...

    ... how the escape velocity is lower?

    1. Duncan Macdonald

      Re: If the mass is 800 vs 700...

      The escape velocity depends on the size of an object as well as its mass. The black hole left after the collapse of a giant star is so much smaller than the original star that the escape velocity increases from a few hundred kilometres per second to the speed of light. Less dense objects have a lower escape velocity than dense objects of the same mass.

      1. IanRS

        Re: If the mass is 800 vs 700...

        Wrong. The escape velocity from a given body is sqrt(2GM/r), where M is the mass of the body you are trying to escape from, r is the distance from the centre of mass that you start at, and G is 6.67E-11. Density does not matter. Size does not matter other than letting you start from nearer the centre of gravity, but if you try and escape from two different size bodies with the same mass, starting at the same distance, then the escape velocity will be the same.

        If you start at planetary orbit distances then the escape velocity required to get away from a black hole is the same as from a star of the same mass. It is only because the mass of a black hole is in such a small space that you can start closer which changes the escape velocity.

        1. Duncan Macdonald

          Re: If the mass is 800 vs 700...

          The escape velocity from an object is normally defined as the velocity required to escape starting from its surface. For two objects of the same mass but different densities, the denser one will be smaller so r in the term sqrt(2GM/r) will be less leading to a higher escape velocity.

        2. Anonymous Coward
          Anonymous Coward

          Re: If the mass is 800 vs 700...

          Wrong. The escape velocity from a given body is sqrt(2GM/r), where M is the mass of the body you are trying to escape from, r is the distance from the centre of mass that you start at, and G is 6.67E-11. Density does not matter.

          Tell me about it. I find it impossible to get away when annoying fat colleagues start talking shit to me. Doesn't matter whether they extremely dense, or quite bright but exceptionally annoying, so density is not important. I can also confirm that it is more difficult to achieve escape velocity from those buggers who invade your personal space and poison your air, proving that distance is important.

      2. Alan Brown Silver badge

        Re: If the mass is 800 vs 700...

        "The black hole left after the collapse of a giant star is so much smaller than the original star that the escape velocity increases from a few hundred kilometres per second to the speed of light. Less dense objects have a lower escape velocity than dense objects of the same mass."

        Wrong on a number of levels.

        Firstly, only a small amount of the mass of the original star actually forms the black hole. The rest blows off into space.

        Which means that anything orbiting will see its escape velocity _at that orbit_ decrease dramatically.

        But if you setup shop in orbit close to the event horizon, then yes your escape velocity will be high. That orbit will be well inside the diameter of the original star. (gravity follows the inverse square law of distance)

        Fun quiz for the day: If you were to go straight up from earth to the distance of the moon's orbit, then you'll experience a gravitational pull from the earth of about 1/3 G - and start coming straight down again as soon as you stop counteracting that pull and lose any outward momentum you had. It's a long way to fall. At times like this, how long will you have to consider all those things your mother told you before you discover if the ground will be friendly?

  6. Pascal Monett Silver badge

    "By measuring the escape velocity, scientists have recalculated the galaxy’s mass and size."

    Um, I don't get it. How can they get a proper escape velocity measure if they've gotten the mass wrong in the first place ? Seems to me that those two things are related in a specific way. It's like throwing a ball four feet and then saying it was a bowling ball.

    Doesn't make sense.

    1. fedoraman

      Re: "By measuring the escape velocity, scientists have recalculated the galaxy’s mass and size."

      I think it might have been a case of estimating the mass of Andromeda, from its brightness and assumed star population, and deriving an escape velocity from that. Now its a case of looking at high velocity stars in Andromeda (from the article), and seeing how their velocity distribution fits with the old and new escape velocity figure.

    2. S4qFBxkFFg

      Re: "By measuring the escape velocity, scientists have recalculated the galaxy’s mass and size."

      Assuming the object doing the escaping is much less massive than the object from which it's escaping, escape velocity is independent of the mass of the escaping object.

      So, you can observe the speeds of stars that actually have escaped the galaxy, and those that haven't.

      e.g. if star A is going at 1000km/s and has escaped, and star B is going at 500km/s and hasn't, you can say the escape velocity is between 500 and 1000km/s and therefore the galaxy's mass (strictly speaking it'll be a combination of mass and size/density) is between some two values.

      Better explanations welcome.

      1. Pen-y-gors

        Re: "By measuring the escape velocity, scientists have recalculated the galaxy’s mass and size."

        Sounds plausible. To be honest, the article isn't exactly clear.

        1. Tom 7

          Re: "By measuring the escape velocity, scientists have recalculated the galaxy’s mass and size."

          TBH the 'escape' velocity of a galaxy is probably not that easy to calculate - given the velocity of stars in galaxies has required the invention of dark matter to try and get the rotational velocities into some sort of agreement with Newton let alone Einstein.

      2. Doctor Syntax Silver badge

        Re: "By measuring the escape velocity, scientists have recalculated the galaxy’s mass and size."

        "So, you can observe the speeds of stars that actually have escaped the galaxy, and those that haven't."

        I'm not sure whether they'd spot the stars that have escaped but the maximum measured velocities of stars in the galaxy is likely to be just under escape velocity.

      3. This post has been deleted by its author

    3. steelpillow Silver badge
      Boffin

      "It completely transforms our understanding of the local group,"

      And it will completely transform the mystery of Dark Matter. Up to now, only about a third of the calculated dark matter has been identified (gas, dust, rocks, rogue planetoids, etc). The remaining two-thirds is a topic of hot speculation about New Physics. Now, in Andromeda at least, that missing dark matter is, well... totally missing. There is no problem to solve. I wonder how other galaxies will now stack up.

    4. mr.K

      Re: "By measuring the escape velocity, scientists have recalculated the galaxy’s mass and size."

      I have no idea on what they actually did, but if you can determine the orbital speed you can also determine the escape velocity. This is since both only rely on the mass of what you orbit and the distance to the centre of it. You have to assume the orbit to be circular, or establish the entire orbit and with galactic years tending to be long years I don't think they have waited for that.

      You also have the assumption that you orbit something where the mass is in the centre. Witch is of course not true for galaxies. The neat thing about calculating gravitational pull from within an object is that you can disregard all the mass situated further out from the centre than yourself, assuming the mass is symmetrically placed i.e. in rings or shells around the centre.* Thus when you start to escape you start to pass more and more of the mass further out to you that adds to the gravitational pull.

      But I assume that if you manage to map the average orbital velocity on objects far enough out then you should be able to determine the entire mass. And if you map for enough orbits then you should be able to map the mass profile distribution. So easily I thought that I wonder why they either have gotten it wrong with that method or why they havn't done it before.

      *Among other things enabling the fun fact that inside a hollow planet if it is a sphere you are weightless, regardless of where you are in it.

  7. Anonymous Coward
    Anonymous Coward

    Galaxy say...

    "No, Andromeda, you are NOT fat! Wanna do that collision thing?"

  8. AndrueC Silver badge
    Joke

    Damn. That totally destroys the credibility of the Blake's 7, "Star One" episode.

    1. The Oncoming Scorn Silver badge
      Coat

      A lot of things totally destroy that episode to be fair (the opening few minutes & quelle surprise the opening few minutes of the space battle in Aftermath).

      Somethings do make up for it however like.....

      Technician: What is it?

      Avon: Unfriendly. Which is fortunate, they'd be difficult to love.

  9. Elmer Phud

    Father Ted time?

    The bigger ones are closer.

    1. David Nash Silver badge

      Re: Father Ted time?

      Closer - or just VERY big.

  10. Anonymous Coward
    Anonymous Coward

    What a waste of time and money

    Get a grip guys and gals. 700, 800 times the number you first thought of.

    WTF is the point in this Sh*t.

    It's 4 billion years away and the politicians will probably destroy the planet within a 100 years. Isn't there something more useful that we can spend the money on?

    1. fajensen

      Re: What a waste of time and money

      Isn't there something more useful that we can spend the money on?

      Dunno - Destroying the planet faster, perhaps?

    2. Hollerithevo

      Re: What a waste of time and money

      The point is that our monkey brains can actually understand and grasp entities so large that we can only use mathematics to understand the immensities. The point is that our minds can grapple with the universe. The point is that knowledge makes us more than beasts. The point is that we can, with our reason, go beyond the daily cares and understand a future we will not be part of. The point is that we love to stride across starry space and almost unfathomable energies, because we are human.

      1. Doctor Syntax Silver badge

        Re: What a waste of time and money

        The point is that our monkey ape brains

        FTFY

        1. Alan Brown Silver badge

          Re: What a waste of time and money

          Modified monkey brains

          Which are modified insect eater mammilan brains

          riding on reptile brains.

          riding on fish brains.

          And we're all riding on a large rock hurtling through the universe in in the general direction of the Great Attractor.

          What that is, nobody knows. If we name it, do the stars start going out, silently, one by one?

    3. Doctor Syntax Silver badge

      Re: What a waste of time and money

      "Isn't there something more useful that we can spend the money on?"

      Back in the C17th people took to puzzling about these things. I suppose if you'd have been alive back then you'd have said much the same thing. It was one of the things which lead to our understanding of Newtonian mechanics which has served us well ever since.

      People didn't stop thinking about such things and noticed a few discrepancies that didn't quite fit with the Newtonian view. Maybe if you'd been alive you'd have said the same thing then. Out of that came the theories of relativity and out of those came a whole lot of other stuff from nuclear energy to the clock corrections necessary for GPS to work.

      But in your view it's still a waste of time and money. Me? I wonder what's the next lot of useful stuff that's going to come out of it.

    4. Helena Handcart

      Re: What a waste of time and money

      Science was wrong, now it is less wrong. And will never be more wrong (or less right) than it is now. This is clearly A Good Thing.

      As a bonus, the now less wrong science poses more questions; the answering of which will make science even less wrong as they get answered (wrongly or rightly).

    5. Yet Another Anonymous coward Silver badge

      Re: What a waste of time and money

      Don't worry the people doing this research will be moving on to jobs as derivatives quants next year when their grant runs out - or they might get a job doing 'useful work' in data mining algorithms for a web ad slinger

    6. Anonymous Coward
      Anonymous Coward

      Re: What a waste of time and money

      There is good science - like antibiotics, space probes to identify - and warn of - solar flares, cancer research, satellites to monitor the planet - and a thousand other branches.

      And then there are the people who do completely pointless research into stuff that no one really has any interest in - except the other people doing the research into the same crap.

      I'm not suggesting we don't expand our knowledge - I just don't see what the value is of knowing the weight of a galaxy that we will only ever encounter in episodes of Star Trek or Star Wars. Even with this latest announcement, the scientists aren't sure about the calculations - perhaps they are right, maybe, possibly - er, but it will definitely be worth investing another $50m to check. And it will keep them all in jobs for the next 20 years.

      Now if someone has a specific scientific benefit that they can demonstrate from this research - I'm fully prepared to reconsider my view. Until then, all I can see is a couple of Bruce's with a cooler of stubbies sitting in Oz laughing at how easy it is to get money under the pretext of doing research. Bruce number 1 is in charge of Dark Matter research - he looks after the dunny, and Bruce number 2 looks after the light matter - the beer. Anyone for a Fosters (other beers are available).

      1. jake Silver badge

        Re: What a waste of time and money

        With that kind of attitude, humanity would still be hoping to find road-kill in East Africa ... and nipping back into the trees when the actual predator came back to recover the kill. For values of "living" that includes death before age 25, no need for a dunny, and a great fear of our their own shadow.

        But you go ahead. Enjoy your beers, secure in the knowledge that you can find your dunny (hopefully!). The rest of humanity will continue to explore the horizon. It's one of the things that makes us human. Care to join us?

  11. Rocket_Rabbit
    Joke

    Don't panic

    This was all written in the book of bibles where is was clear from the start that the M31 Galaxy was 800 billion Solar Masses. PS the earth is flat too...

  12. JeffyPoooh
    Pint

    Science is proudly self-correcting

    Science is proudly self-correcting, some fields much more often than others.

    An extreme example is the ever-changing (nearly pseudo-science) field of Dietary-Health Advice. I once had to cough up some half-swallowed eggs in the middle of breakfast, because somebody had left the radio on, and The News mentioned that eggs had just been re-categorized as a carcinogen, again.

    Astronomy has had its ^h Moments™. Remember Hubble (the person)? Crikey, he added orders of (numerical) magnitude to most of the basic assumptions.

    An important conclusion is that the Scientific 'facts' du jour have a Half-Life. For eggs-as-food, it's about 18 months. Astronomy facts seem to typically last more than a decade.

    This obvious conclusion has massive implications. It's horrifying when some people have too much 'Faith' in any particular Scientific result.

    (Annoyingly necessary disclaimer: No, don't guess that I'm a Climate Skeptic. Wrong guess. Skeptic yes, on Climate not so much. That this disclaimer is necessary is actual a monumental problem with global impact.)

    1. Yet Another Anonymous coward Silver badge

      Re: Science is proudly self-correcting

      It's hardly a revolutionary reversal of a scientific fact.

      A difficult to measure parameter of a distant object is 10% different from previous estimates.

      If the depth of some part of the ocean was re-measured to be 10% different to what we have now - you wouldn't be running round saying water isn't real

  13. Anonymous Coward
    Devil

    So what's the escape velocity of the local group, I wonder?

    Actually nevermind that, I want to know the escape velocity of the universe. Let me outta this thing!!

  14. x 7

    Dark stuff?

    So does this mess up the dark matter calculations even more?

  15. WaveyDavey

    From father Ted

    This is small ...

    Those are far away ...

    D'you see, now, Dougal ?

    Aaah, no.

  16. Ugotta B. Kiddingme

    dodgy maths?

    I generally suck at maths so I could be all wet, but it seems to me that there is a problem of accuracy in Kafle's statement.

    Kafle FTA: "Our home galaxy, the Milky Way, is over a trillion times heavier than our tiny planet Earth..."

    Space.com: "Recent measurements have weighed the galaxy at between 400 billion and 780 billion times the mass of the sun. "

    Swinburne Uni: solar mass is "about 333,000 times the mass of the Earth."

    quick back-of-the-napkin calc: Milky Way is roughly 1x10^17 Earth masses.

    That makes the article statement off by several orders of magnitude. That scale of error is like saying "more than 1000 people live in China." It's technically true but not realistically close to accurate.

    UPDATE: Ah, I see my error now. Long form trillion, not "American trillion". See? Told you I suck at maths.

    1. PghMike

      Re: dodgy maths?

      Do people still use British trillions?

      1. mr.K

        Re: dodgy maths?

        https://en.wikipedia.org/wiki/Long_and_short_scales#Long_scale_users

      2. jake Silver badge

        Re: dodgy maths?

        I hear that a small percent of the folks living on a little group of islands in the North East Atlantic insist on using long trillions just to prove how superior they thought they were a century ago. These are the same people who invented Imperial Units, and then stole the Metric system from the French and try to lord it over those who choose not to.

      3. Fruit and Nutcase Silver badge
        Joke

        Re: dodgy maths?

        @PghMike

        Do people still use British trillions?

        I just think of the US government debt and feel infinitely superior

      4. Alan Brown Silver badge

        Re: dodgy maths?

        "Do people still use British trillions?"

        I hear Zaphod Beeblebrox does.

        1. The Oncoming Scorn Silver badge
          Thumb Up

          Re: dodgy maths?

          That's Trillian to you.

  17. Kaltern

    We're absolutely right. Until we're wrong.

    Oh look, science people have once again had to admit they're wrong about things.

    Now I absolutely respect science. And I respect that some things are more certain than others. However, I am still surprised when people adamantly refuse to accept that some things may be wrong, even after millennia of being shown otherwise.

    Now, while I understand how peer review, scientific method and confirmation bias are all part of today's better way of sciencing. However, it's clearly evident that more and more scientists and other folks of reknown are always quick to belittle and outright deny the possibility of something being wrong. I wonder how much scoffing of the calculations for Andromeda's size is already happening, and how many are trying desperately to refute the proof?

    It's small wonder us humans have come to an evolutionary stand still, when all that seems to matter is how much money we have, and how people cannot possibly be wrong.

    1. jake Silver badge

      Re: We're absolutely right. Until we're wrong.

      You seem to have a precarious grasp on the meaning of science. Any scientist would relish the thought of finding a major flaw in the general scientific consensus.

    2. Richard 12 Silver badge

      Re: We're absolutely right. Until we're wrong.

      Any new theory must be in agreement with all the observations recorded by humankind, as well as better predict observations at the edges of existing theories.

      If the theory predicts that eggs fall upwards, it is wrong because they don't.

      The reason why it is really hard to come up with a new theory of anything, is because we've made a rather large number of observations to a really high precision and accuracy over the last few decades.

      Your new theory must predict that the measurement apparatus would give the same results that it actually did.

      And again for all the other known experiments.

    3. Destroy All Monsters Silver badge
      Thumb Down

      Re: We're absolutely right. Until we're wrong.

      I wonder how much scoffing of the calculations for Andromeda's size is already happening, and how many are trying desperately to refute the proof?

      Proofs exist only in completely made-up structures like mathematics and IT.

      The world: not a video game where you can just query the mass of your opponent.

  18. Brian Allan 1

    Not confirmed yet!

    Let's wait for the peer review of this research before downgrading Andromeda! A lot of things can happen between original opinions and final reviewed results...

  19. GX5000
    Pint

    We've merged at least once before remember?

    Wow so much confusion for a Booty call we already had once....

  20. Anonymous Coward
    Anonymous Coward

    "mainly made up dwarf galaxies."

    Fake news then?

  21. David Roberts

    Dark matter?

    So someone just found out we didn't need to fiddle the numbers for Andromeda quite so much because our estimate of light (as in non-dark) matter was wrong.

    How long before we sort out the rest of the dodgy estimates and don't have to add a correction at all?

    1. David Roberts
      Facepalm

      Re: Dark matter?

      Doh!

      Our estimate of total matter was wrong. So our estimate of dark matter was wrong.

  22. Al Black
    Black Helicopters

    Super Galaxy Andromeda

    but, but...97% of Astronomers agreed on the consensus that Andromeda was a Super-Galaxy! Does that mean scientific consensus is meaningless and actual data is required? That could be the start of a belated return to the Scientific Method and an acceptance that saying it in a Peer-reviewed magazine article doesn't necessarily make it so.

  23. The Oncoming Scorn Silver badge
    Go

    A- For Andromeda Then

    Showing my age sum what (Not the 2006 remake).

  24. Qwertius

    No doubt all this shrinkage of Andromeda is all due to Man Made Climate Change.

  25. Extreme Aged Parent

    I think Monty Python summed it up nicely with the 'Galaxy Song'

    https://www.youtube.com/watch?v=buqtdpuZxvk

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