back to article Boffins bend space and time to measure neutron star

Astronomers have caught three neutron stars in the act of distorting space-time, just as Einstein predicted. Bendy space-time has been seen around black holes before, but this is the first time astronomers have seen it around any other body. Sudip Bhattacharyya and Tod Strohmayer, both of NASA’s Goddard Space Flight Center, …


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  1. Graham Dawson Silver badge

    Another statistic I heard...

    I remember reading about neutron stars in some almanac years ago, where they said that if all the water in the great lakes (the in the united states and partly canada, in case someone wonders) were compressed to the density of matter in a neutron star, it would fit in your kitchen sink.

    I now feel confident enough to demand that gigatonnes per sink should be added to the lexicon of odd weights and measures as a measure of density.

  2. Crossbow

    More units

    Lets not forget Everests as a unit of weight (or maybe mass). And is that a metric or US cupful? Theres a whole 0.013411763 liter difference!

  3. DoubleD

    Size Comparison

    "It is so dense, a cupful would weigh the same as Mount Everest."

    OK, I can't resist...

    Are we talking a standard 8oz cup, a 6oz coffee cup or a demitasse?

    (grabbing my coat...)

  4. Anonymous Coward
    Anonymous Coward

    Cubic Furlongs?

    "the same as Mount Everest"

    Can we get that in Cubic Furlongs please? What is the point of standards if you don't keep to them?

  5. eddiewrenn

    Re: Another statistic I heard...

    Imagine drinking a glassful of that! I'd piss myself.

  6. amanfromMars Silver badge

    International GBIrish.

    Errr...... yes, well, if they say so. Others might just say that Skunk Works/NASA and they are 'avin' a larf.

    Keep up the good works though, we need the relief....... and boy, does it ever give heart to anyone at the leading edge of technology to know that someone must be paying them for it.

    ITs a mad, mad, mad world indeed, in Deed....... and your fifteen minutes is up, gentlemen. Don't call us, we'll call you.

  7. Anonymous Coward
    Anonymous Coward

    Neutron matter in the kitchen sink?

    That's not a bad idea. Sure, the kitchen sink would have to be pretty robust, but just think...

    "Sorry, love, can't do the washing up - it's all been crushed into neutron matter. I guess we'll have to buy new again."

  8. Neil Barnes Silver badge

    Pedant of the week

    "a cupful would weigh the same as Mount Everest."

    Surely, it would mass the same. Weight depends on local gravity, no?

    (Trivia department: an average apple masses 100 grams and weighs about a Newton...)

  9. John Browne

    So, how much would a sheep weigh...

    If it were made of collapsed matter?

    From your earlier article, (brilliant, by the way) I propose two further units of mass; the cf (cupful) for collapsed matter and the MtEv (Mount Everest) for ordinary matter. For convenience, the volume of a cf could equal 1 gf (grapefruit), as defined earlier, assuming a generous coffee mug rather than a dainty teacup.

    Oh, and how much would Wales weigh?

    Somebody else can do the maths, my brain is a bit off today.

  10. Fluffykins

    Oh, come on! be consistent.


    What's that in RegStandard Grapefruit (gf) units?

  11. Robert Ramsay

    Now all we have to do... glue a few together and keep them spinning...

  12. David Tonhofer Silver badge

    Hrmp! A neutron star is not made of neutrons only

    Here ya go:

  13. Martin

    Bendy space-time was observed 88 years ago!

    By Arthur Eddington, during a solar eclipse, in May 1919. He observed bending of starlight around our very own Sun (not a black hole!) which was twice what classical theory would have predicted, and was in fact what Einstein's theory, then only 4 years old, suggested.

    For several decades this was the _only_ experimental demonstration of general relativity (GR), a theory which had taken Einstein and a handful of collaborators 10 years to construct since his landmark 1905 papers on special relativity (SR) had left open the rather obvious question, "what happens if this relative motion of which you speak is non-uniform?".

    For an inkling of just how monumental this was, compare GR with software development. A five-person team works for 10 years coding a program which, by today's standards, is only moderate in size, but is extremely complex. They have no automated development tools, no system to run the code on, and no test cases - only peer reviews. 4 years later they identify a system and run a single test case - successfully. Several decades later, other test cases run on other systems, all successfully. The original GR program has accumulated plug-ins and applications in the 92 years since v1.0, but virtually no bugfixes. Quite amazing.

  14. Jon

    SSI standards (strange SI standards)

    Surely the density SSI should be Everests/Cupful (E/C) since Black holes and white dwarfs will have different densities and so different proportions of Mt Everest would fit into the the cup.. And since Einstein proved E=MC^2 surely E/C=MC which gives rise to a new Rapper.. MC Neutron!

    By the way, all things being equal, (which they aren't, ask Torrentspy!) it's doesn't matter which cup you choose.. Neutron Star densities fluctuate between 8x10^13 and 2x10^15 (Ask Wikipedia.. it's definitely correct on this edit!) and Mount Everest keeps growing and nobody really knows where it ends and the next mountain begins, and it's density can only be guessed at and blah blah blah.. But out of curiosity I did the maths taking the mountain as a cone with the base diameter the same as the height and you get to the right order of magnitude, I actually got to around 2 cm^3 which is about 2 grapes, but like I said, it's the right order of magnitude, it's not a mustard seed nor a watermelon!

    And stop calling me Shirley!

  15. Jon

    By the way Martin

    Computers have been around for 80 years or so and we've come along a hugely long way.. The versioning we see is more of a response to the changes in hardware that we've had (Babbage to Quantum Computing).. We've been studying the cosmos for 2000 years or more.. Einstein was a genious, I grant you, but his flash of inspiration is the end of a VERY long journey, and still he managed to deliberately put in some padding for some bits and bob's that he didn't understand or couldn't account for (The cosmological constant GR was really v2 of the Newtonian Laws, which stood well for 300 years or so, so 88 years is quite a short time in relative terms so to speak! And we're hardly on v2.0 what with the Standard model, and the developments in string theory and now Membran theory.. Einstein had an excellent start, but if the new LHC in CERN is able to show supersimmetry in the Universe, let's not underestimate the impact of modern day physicists!

  16. Anonymous Coward
    Anonymous Coward

    Neutron stars may be dense...

    But not as dense as some of the computer users I have had the misfortune to look after over the years.

    When you next hear an IT sys admin call someone a "star" now you know what type of star they are thinking about.

  17. Morely Dotes

    @ David Tonhofer

    Frank Shu said, "A sugarcube of neutron-star stuff on Earth would weigh as much as all of humanity! This illustrates again how much of humanity is empty space."

    Frank was obviously thinking of the generous distribution of intellect across the entire species - a few anomalous concentrations of high intellect, like raisins in a pudding, with a large volume consisting mostly of vacuum.

    However, NASA has the size of the neutron star as around 5 miles. That's only 8 km, or roughly 25% of the measured size of Serpens-X1

    No wonder the USA keeps losing spaceships. Simple math seems to escape our engineers. :-(

  18. Luther Blissett

    Hrmp! A nucleus is not made of neutrons only

    Neutron stars into troilsm - whatever next? Unicorns on roller skates?

    If Einstein ever shouted anything, it was because someone else said it first.

    Ignore this: - like the BBC it is selective with its reporting. See here: for a fuller account.

  19. Jon

    @ Morely - Only you know what you're talking about!!

    If you take the average male weight to be 80Kg and female to be 75Kg, ( and ignore the fact that some are children (because that's always a good thing to do with them) then the 6 billion population would weigh 465,000,000,000 kg or 4.65*10^14 grammes. Pile them all into 1cm cube resmbling sugar, and you get what David's reference shows as the core density of a neutron star to within 5% so there! :-D

    I don't care if my calculations might be a little off, I feel like I've achieved something tonight, and any descrepancies we can just wash away with the cosmological constant.. Oh, wait, that's already been done!

  20. Kevin


    "Lets not forget Everests as a unit of weight (or maybe mass). And is that a metric or US cupful? Theres a whole 0.013411763 liter difference!"

    I'm confused. In the US, lite is the opposite of heavy. Or it means "low in calories" (found that out the hard way. You shouldn't be allowed to call that stuff beer). So a liter difference must be the obvious of a heavier difference. Or maybe a fattening difference. Or is that some kind of US pseudo-imperial-pretend-metric unit El Reg hasn't yet catalogues? :-)

    Which leaves the question: If you have a cubic decimeter of milk, and it says "Liter" on it. Is that low in calories like the beer? Or is it a reference to volume?

  21. Aubry Thonon

    Which cup?

    "It is so dense, a cupful would weigh the same as Mount Everest."

    Is that an A cup or a B cup? Surely we're not talking DDs, right?

    <where's me coat?>

  22. Adrian Esdaile

    As dense (or at least as intelligible) as a neutron star...

    ... is Fear, uncertainty and DoubT.

    Sorry, I just HaD tO use amanfromMars' icy-1337-hot random capitalisations, because it just shows you KNOW things, dunnit?

    Try Googling he/she/it/they - amanfromMars likes trolling other sites too.

    My favourite theory is a spam-bot farming for text.

    My second favourite theory is someone who really needs to just grow up. Acting out Gibson-esque cyber-warrior fantasies of trying to 'muddy' intelligent comments only is just so 1990s. Why is it so afraid of names? Bill Gates gone rampant? Superman? (DON'T start on the Nietzsche quoting!)

    Why 'amanfromMars' anyway? Why not 'Neo' or 'Tyler Durden'; both were very fashionable amongst the spammers in the early-to-mid boom, and have so much cyder-chic.

    Whatever, definitely one of the Great Important Misty-eries (oh, its SO damn easy!) of teh Intarwebs, right up there with HamsterDance.

    Adrian Esdaile. Not afraid to use my name.

  23. Pascal Monett Silver badge

    Re: Adrian

    Oh come now, not nice to pick on him when he's having a bad day, now is it ?

    And how do I know that, you ask ? Obvious ! Not only is he low on capital letters, but what he wrote actually almost made sense.

    <exit stage left>

  24. Jon

    OK, This is getting really obscure

    I understand what you might be trying to say Adrian, and you could hardly call me a noob after 15 years in IT, but The Reg is the first place I've come accross comments with that signature, I've come accross lots of other trolls, but never this one, maybe I have not been paying enough attention to inane comments, I don't know..

    amanfromMars ismost likely more than one individual.. Probably started out as one person who liked just winding people up, and now other people are trying to ride the wave (I'm Brian and so's me wife!) so I'm not gonna bother googling them 'cos I really have better things to do, honest.. So the rest of your comments have completely gone over my head..

    What's with SPAM bot's anyhow.. Having spent a good few hours tweaking mail filters, you can imagine how many SPAM emails I've seen.. I still don't get their point.. Yes, I understand the concept of selling off the percentages, and buying shares, sending millions of SPAM saying these shares are about to hit the roof, and waiting for the shares to rise, but honestly, what's the point of sending an email with an embedded picture and some random text at the end.. How's that going to earn anyone any money? I really am lost in this world where people do seemingly random things just because they can.. SPAM-bots.. Evil pointless things.. Yes, if you're a SPAMmer, you should realise that you're universally hated, that nobody likes you and you have no friends, that your £ or $ or € is tainted and that really you should go and throw yourself off the nearest high precipice!

  25. Anonymous Coward
    Anonymous Coward


    The measurements Eddington performed did demonstrate curvature of light in a gravitational field. The measurements reported on the in current article are looking at finer detail, namely asymmetric perturbation of the light. The same general phenomenon as what Eddington observed, but at a much more detailed level, showing that the effects of a spinning mass on light is not exactly the same as the effects of a non-spinning mass on light. This isn't the first time the effects of spinning mass have been observed; just the first time they were observed around a neutron star.

  26. Dave

    Seriously, why do we need to know..?

    Clearly there are some very eductaed people writing some of these notes so it should not take long to get a serious, sensible answer.

    Why do we need to know what is surrounding these things in space, what are we hoping to gain from the knowledge?

    Will it be anything to beneft mankind in the next millenia or is mankind paying for the continuance of a great hobby for a few at the huge expense to all?

  27. amanfromMars Silver badge

    A little Bit of Sugar for the Medicine

    "Will it be anything to beneft mankind in the next millenia or is mankind paying for the continuance of a great hobby for a few at the huge expense to all?"

    That appears to be the fashion, Dave, right across the board. Pathetic, isn't it.

    However, now there is IT which doesn't follow fashions at all..... IT can even think for itself in the full glare and scorn of Luddites.

    Adrian Esdaile, a little more Research would have uncovered a preference 4 Dan Dare 2 Win Win. Superman is so ....... Yesterday's Man.

    When you know what you are doing though, it is as well to be very careful what you wish for, for you will always get IT .....

  28. Dave

    Seriously, because we need to know...

    Does asymmetrically bent light reduce the incidence of SPAM? Does asymmetrically bent light increase the IQ of the average caller to a help desk?

    Does asymmetrically bent light affect the price of fish? or chips? No to all of these

    To have observational verification of a theoretical construct about the way stuff works at a fundamental level yet on a gigantic scale is a wondrous event; it confirms that we are able to theorise, analyse, design, observe, test and conclude - in summary to 'engineer'.

  29. BobApril

    If we knew, we wouldn't have to look.

    Dave and the Martian - d'you think science is all about picking a selected improvement to technology and then researching the topic to build the gizmo? Hardly. The whole point of science, in all its fields, branches and offshoots, is to try to find out how the universe works. Frequently, that knowledge becomes useful. Not always, and not always immediately, but frequently and eventually. Historically, pure science has always paid off in the long run - but the order of things is normally "find out what's happening, THEN find a use for it".

    We don't know what this research may lead us to. We can guess at possibilities - a better understanding of gravity, mass, and energy could lead to fusion power, anti-gravity, better energy transmission - or it could lead to something totally unexpected. It might even lead to nothing - but you have to buy the ticket to get a chance to win the prize.

  30. Anonymous Coward
    Anonymous Coward

    40% of the speed of light?

    Can't the police do something to stop these speed contests? What the hell do we pay taxes for! It has to stop before someone gets hurt.

  31. Aubry Thonon

    @Adrian Esdaile

    "Why not 'Neo' "

    Beggin' your pardon, yerronour, but that's been my Net-monicker since about 1987 (contraction of Neoculture). Prior art. ^_-

    And before anyone asks - ex-hacker, IT geek, strongly believes one's memories define one's self, decent shot with a handgun (on a target range at least)... and I look NOTHING like Keanu Reeves. (I kept on getting ribbed after Matrix came out, *&^%-it)

  32. Martin


    Thanks for clarifying what's new here.

    Should've acknowledged in my first post really ... observable asymmetric broadening needs pretty extreme conditions, so seeing it elsewhere than a black hole is really very interesting.

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