Einstein’s Last Mystery

“God does not play dice with the Universe.” -Einstein

“Einstein, don’t tell God what to do.” -Neils Bohr (disputed, but awesome)

Einstein, the brilliant mind behind general relativity and the concept of “spacetime,” is making the news again this week. As you all know, gravity isn’t some mysterious invisible force traveling across space, it comes about because energy itself — most commonly in the form of mass — distorts the very fabric of space.

Image credit: GNU user Johnstone and NASA's Galileo spacecraft.

Of course, wrapping your head around this can prove quite difficult. Space, as we all know, is three-dimensional; how do you expect to understand it by drawing a two-dimensional surface?

Image credit: Today's XKCD.

I mean, honestly, it’s kind of the best we can do. It’s pretty easy to imagine what completely flat three-dimensional space would look like; just take a big 3-D grid, and there you go!

But put a mass in there, and then what? Well, think of mass as a high-powered vacuum cleaner. You turn the vacuum on, and it immediately sucks the carpet (or whatever unfortunate thing the vacuum touches) into it, distorting it and causing it to “pucker”.

Or like making a fish-face, right, Kerry Katona?

Well, mass does the same thing to space. And the greater and denser your mass, the greater the range and more severe the distortion of space!

Now a black hole is an extreme example, and we are (perhaps) fortunate to not have one nearby to study relativity with. But we do have the Earth, which does a pretty respectable job distorting space close to its surface. You feel it as the force of gravity, pulling you down towards the center of the Earth, of course. But the weird, relativistic, distorted aspect of space makes things just a little bit weird.

Image credit: Wired.

What do I mean, weird. It means that objects change their shape a little bit thanks to the Earth’s gravity, known as the geodetic effect. If you had a gyroscope in orbit, you’d see it start to precess because of this!

But there’s more; because the Earth is rotating, there’s an extra effect on top of this, known as frame dragging, which means that an object moving with the Earth’s rotation would go slightly faster than an object moving against it.

There was an experiment designed in the 1960s to test this.

Image credit: Resonance Pub.

But it’s only relatively recently that the technology has advanced enough to allow us to build the necessary suspended, low-temperature, precisely smooth gyroscopes necessary to test this. And, as you may imagine, we had to do it in space. The experiment was known as Gravity Probe B.

Image credit: Lubos.

Unsurprisingly, the results are in perfect agreement with Einstein’s prediction. In fact, the most (pleasantly) surprising thing to me, as a scientist, is that they are honestabout their experimental errors; they report significant confirmation of both of these effects, but did not perform as good of a frame-dragging test as they would have liked. (The geodetic effect was measured to an extraordinary accuracy, however,

So, for those of you keeping track, that’s another victory for Einstein’s general relativity, making the score about a bajillion to zero.

But there’s a reason we keep testing it in new ways: we won’t learn anything new unless we find something that general relativity is inadequate for. So we think about the most extreme situations for spacetime in the Universe, like very close to collapsed, massive object: black holes and neutron stars.

Image credit: Infovark.

The proverbial “vacuum cleaner” is turned up to an ultra-high setting in this instance, and space is severely distorted. What happens if you bring a second vacuum cleaner in, very close by, and have these two compact, heavy masses orbiting one another close by?

Video credit: John Rowe animations.

Well, according to General Relativity, two amazing things will happen:

  1. These orbits will be unstable, and will decay over time. These two objects — whether they be white dwarfs, neutron stars or black holes — will eventually spiral in to one another. And…
  2. As they do, they will emit gravitational waves!

Now, the inspiral thing is cool enough as it is. We’ve actually observed these orbits decaying over time, because we discovered a system of two pulsing neutron stars, and their orbits are decaying!

Image credit: NASA/Dana Berry, Sky Works Digital.

Yes, for those of you wondering, the discoverers of this, Russell Hulse and Joseph Taylor, did in fact win the Nobel Prize for this. But the gravitational waves coming from this? That’s something we’ve never detected before. It would require, in fact, a huge set of antennae in space, looking for extraordinarily precise patterns that change the distance between them.

Luckily for us, we’ve already started building them.

Image credit: Uri Keshet/LISA artist.

The Laser Interferometer Space Antennae (LISA), a series of three spacecraft orbiting behind the Earth, would be sensitive to these gravitational waves. It was one of the major NASA science goals of this decade, scheduled to be launched in 2015. As a joint venture between NASA and the European Space Agency, LISA was supposed to finally find these gravitational waves, being the only detector designed to achieve the necessary sensitivity.

Image credit: ESA.

And then, last month, this happened:

ESA has ended the partnership with NASA because NASA is financially unable to participate when ESA’s funding is available (in 2015). To preserve their program, ESA’s must solicit a downscaled mission concept that does not rely on the availability of NASA funding, which they are doing.

This is according to Robin Stebbins, NASA’s project scientist for LISA. Steinn has more on this, but the gist of it is that, unless something gets done about this over the next six months, the last great unmeasured prediction of general relativity — gravitational waves — will go undetected for decades to come. We totally expect them to be there, but there’s a reason we do the experiments. If the ESA can’t figure out a way to make this work, it will be tragic to see LISA go down.

This is, quite possibly, now the last mystery of classical general relativity, and we were so close to making it happen. There are lots of reasons why it’s gone down this way, not the least of which is the James Webb Space Telescope going billions over budget, but I can’t believe it’s just going to end like this. I wrote about the importance of delivering what you promise about a year ago, and now we’re facing the consequences.

Sorry, LISA. Let us know if there’s anything we can do to save you!

Comments

  1. #1 Sinead
    May 6, 2011

    Was Minkowski not the mind behind the space-time approach?

    That is quite sad news about LISA. =( maybe we can talk the UK into putting the electoral reform money into it…

  2. #2 Ethan Siegel
    May 6, 2011

    Sinead,

    In many ways, yes! http://einstein.stanford.edu/SPACETIME/spacetime2.html

    (As an aside, I have an email I need to send you, either later today or tomorrow.)

  3. #3 Nate Schuknecht
    May 6, 2011

    I remember a year or so ago hearing a theory about gravitational waves on a larger scale. The theory stated that our place in the universe could be on the trailing end of a wave left over from the big bang, and that our position on this wave created a false sense of accelerated universal expansion. Curious if you have any thoughts on the subject.

  4. #4 healthphysicist
    May 6, 2011

    As general relativity becomes more certain, does that have an inverse relationship with the confidence in finding gravitons from quantum field theory?

    Or could the observance of gravitational waves provide a bridge? Might there be wave-particle duality with gravitons, such that the observance of gravitational waves links the two theories?

  5. #5 BenHead
    May 6, 2011

    I dig the haiku tweets for each new blog post. Unfortunately Twitter can’t handle my limerick reply for this one:

    There once was Gravity Probe B.
    Whose balls were as round as could be!
    It spun ‘em around,
    Then it looked and it found:
    They had shifted the slightest degree!

  6. #6 Matthew Bright
    May 7, 2011

    Space is supposed to be made up of nothing. Apparently, there’s a lot more to nothing than nothing.

    WHAT THE HELL IS IT?!!

    Peace… God bless…

  7. #7 Sphere Coupler
    May 7, 2011

    In order to see dark matter you must duplicate the conditions of an shielded expanding vacuum area with one decaying baryon contained within same vessel, and measure the gravity manifestation potential…that will be a challenge. Dark matter is a pre-meson, in other words it is both virtual quark and virtual anti quark never coupled, (not uncoupled not decoupled,)…never fully coupled. Yet if DE is reduced enough, and shielded from outside influence and at the point of NM particle decay (not radio decay), a meson can be created.

    That’s how I see it.

  8. #8 Daniel de Rauglaudre
    May 7, 2011

    For electromagnetism, there is Special Relativity.
    For gravitation, there is General Relativity.

    But what about strong and weak forces?
    Does it exist a “Relativity”, for them?

  9. #9 Eric Andresen
    May 7, 2011

    Yes, there are apparent things going on in this universe…gravity appearing to be the attraction of masses. But this is just appearances, there is something underlying this aspect. There will be no detection of gravitational waves…they don’t exist. Quantum gravity establishes, maintains, and sustains the 3d matrix to be completely perpendicular and unbiased with respect to charge, mass, and time. We see what may be termed as “higher order” effects of mass attraction. Also, there are no true forces…underlying all are superconductive arrays of charge, mass, and perhaps time.

  10. #10 Lloyd
    May 7, 2011

    It’s a shame we still have to rely on two dimensional grid depictions of waves, warping, funneling, etc. from which very few people actually have the ability to extrapolate a full three or four dimensional conceptual perception of what we think is happening. Perhaps some of the new virtual reality full feedback technology can enlighten a few lucky ones in this respect which would help move things along towards better understanding.

  11. #11 Joffan
    May 8, 2011

    … but if we are to believe relativity (which I do), there is no frame to warp, because every observer sees a different view.

    Unless we bring back the aether..

  12. #12 Anneler Günü
    May 8, 2011

    Was Minkowski not the mind behind the space-time approach?

    That is quite sad news about LISA. =( maybe we can talk the UK into putting the electoral reform money into it…

  13. #13 Keçiören Nakliyat
    May 8, 2011

    Einstein’s capability of observation is seemless.
    And “tought expriments” he imagined helped us come up to here.
    He has always been my favourite person on Earth.
    Thanks…

  14. #15 frantischek
    May 9, 2011

    This graphic is about S.E.T.I., but matches also this article:
    http://www.scienceblogs.de/astrodicticum-simplex/2011/05/02/seti-info.jpg

    Makes me very sad, i wish i had a few billions to spend. Lisa should be affordable for the price of a few of the new F-22s.

  15. #16 OKThen
    May 9, 2011

    Very nice science.

    Regarding frame dragging: At any particular radius from a rotating obeject (e.g. the earth or outside the event horizon of a black hole); can frame dragging be thought of as an accelleration perpendicular to the radius and parallel to direction of rotation?

    Does this mean that the general relativity GEM equations are essentially correct? (i.e. the gravitomagnetism theory analogous to Maxwell’s equations)

    I assume yes to both questions; but I’m not totally sure.
    Thanks for any insight.

  16. #17 Tim
    May 9, 2011

    NASA should open up a Kickstarter account…

  17. #18 OKThen
    May 10, 2011

    I misspoke; this is not “Very nice science”; this is science at its most excellent, most dedicated and most fundamentally important.

    NYTimes reports, “52 Years and $750 Million Prove Einstein Was Right: In a tour de force of technology and just plain stubbornness spanning half a century and costing more than $750 million, a team of experimenters from Stanford University reported on Wednesday that a set of orbiting gyroscopes had detected a slight sag and an even slighter twist in space-time.”

    Now before (some of you) conclude that such research is a waste of money. Consider these benefits of basic science http://public.web.cern.ch/public/en/about/BasicScience3-en.html

    We are fortunate to have men and women who dedicated their scientific and technical careers to such research. Thank you. As well, read the NYTimes article for a sense of the funding battles that were fought and won to achieve this result. http://www.nytimes.com/2011/05/05/science/space/05gravity.html
    Well done Dr. Francis Everitt and team.

    And of course, well done Einstein!!!

  18. #19 herky stubby
    May 12, 2011

    There are so much more of this universe then?
    It’s exciting that scientists discover new informations. But somehow it is scary.

  19. #20 herky stubby
    May 12, 2011

    Oh. i forgot to comment on the stick figures. That is so true! But when it is explained simply, that would be very interesting.

  20. #21 Tim Symonds
    UK
    January 13, 2014

    The real last Einstein mystery -
    Sherlock Holmes And The Mystery of Einstein’s Daughter by Tim Symonds

    In his later years Albert Einstein came to be considered a secular saint for proclamations like “Nothing that I can do will change the structure of the universe. But maybe, by raising my voice, I can help in the greatest of all causes – goodwill among men and peace on earth.” His younger years were different.

    In late 1903 Einstein’s illegitimate daughter ‘Lieserl’ disappears without trace in Serbia aged around 21 months. As Holmes exclaims in the Mystery of Einstein’s Daughter, “the most ruthless effort has been made by public officials, priests, monks, Einstein’s friends, followers, relatives and relatives-by-marriage to seek out and destroy every document with Lieserl’s name on it. The question is – why?”

    Publication date January 2014
    ‘Lieserl’s fate shadows the Einstein legend like some unsolved equation’ Scientist Frederic Golden Time Magazine

    Sherlock Holmes And The Mystery of Einstein’s Daughter is available at http://www.mxpublishing.co.uk/engine/shop/product/9781780925721 or http://www.amazon.co.uk/Sherlock-Holmes-Mystery-Einsteins-Daughter/dp/1780925727. Review copies contact Steve Emecz at mxpublishing@btinternet.com.

    Tim Symonds was born in London. He grew up in Somerset, Dorset and Guernsey. After several years working in the Kenya Highlands and along the Zambezi River he emigrated to the United States. He studied in Germany at Göttingen and at the University of California, Los Angeles (UCLA), where he graduated Phi Beta Kappa in Political Science. Sherlock Holmes And The Mystery Of Einstein’s Daughter was written in a converted oast house in ‘Conan Doyle country’, near Rudyard Kipling’s old home Bateman’s in East Sussex and in the forests and hidden valleys of the Sussex High Weald.
    The author’s other detective novels include Sherlock Holmes and The Dead Boer at Scotney Castle and Sherlock Holmes and The Case of the Bulgarian Codex.
    He is a Fellow of the Royal Geographical Society.

  21. #22 evden eve nakliyat
    http://www.evdeneve.org
    May 8, 2014

    That is quite sad news about LISA. =( maybe we can talk the UK into putting the electoral reform money into it…

    Einstein’s capability of observation is seemless.
    And “tought expriments” he imagined helped us come up to here.
    He has always been my favourite person on Earth.
    Thanks…