This Week’s Hype

This week’s dramatic announcement of the discovery of gravitational waves was a major milestone for the fields of physics and astrophysics. The LIGO observation validates a lot of previously untested aspects of our understanding of general relativity, and promises the imminent opening up of a new field of observational astronomy, as LIGO sees other astrophysical sources of gravitational waves. Watching the announcement, the lead up to it, and the press stories that came out, many immediately as the embargo was lifted, I was struck by the general high quality of the stories in the press (I linked to a few of them in the last posting, but there are many more). Congratulations to whoever organized this, and to all the science writers who have done a great job producing enthusiastic but generally hype-free coverage of the story.

Unfortunately, those physicists brought in by major news organizations to tell the public what the significance of this is often can’t resist the temptation to indulge in the usual hype. At the Wall Street Journal today, Michio Kaku’s commentary is labeled Riding Gravity Waves to the Big Bang and Beyond, and subtitled “Once again, Einstein’s theory of relativity is confirmed by scientists. Next stop: Creation.”

There’s nothing in his piece about what else LIGO might observe and what we might learn from it about the universe. Instead, it’s all about the big bang, Creation, and before the big bang, things which as far as I can tell, LIGO data is highly unlikely to tell us anything about:

Now we are witnessing the third great revolution in telescopes, the use of gravity waves to open a new chapter in astronomy. For the first time, waves from the very instant of creation might be observed, giving us “baby pictures” of the universe as it was born. High-school textbooks may have to be rewritten to incorporate the new discoveries coming from this third generation of telescopes.

This may also have philosophical implications. Right now the big-bang theory doesn’t tell us what banged, why it banged, and what caused it to bang. It only tells us that there was a bang. But if space-based gravity-wave detectors similar to LIGO’s detectors can measure the radiation emitted an instant after the big bang, then, using mathematics, one can run the equations backward to determine what set off the big bang in the first place, in effect answering the biggest question of all: What banged and why?

When Einstein postulated gravity waves a century ago, he not only opened up an entirely new chapter in astronomy, he also opened the door to answering the most important philosophical questions of all time, including the creation of the universe.

Over at the New York Times, in the Sunday Review, Lawrence Krauss has a more sensible piece, entitled Finding Beauty in the Darkness. Multiverse mania seems though to be irresistible, as he ends up with this summary of the physics significance:

Ultimately, by exploring processes near the event horizon, or by observing gravitational waves from the early universe, we may learn more about the beginning of the universe itself, or even the possible existence of other universes.

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30 Responses to This Week’s Hype

  1. To be fair, he does mention “this third generation of telescopes”, which might refer to gravitational wave detectors in general, including those such as (e)LISA and others, which might possibly detect gravitational waves from the early universe. Though these are at best far in the future whereas LIGO is here and now.

    On the topic of good science reporting, I agree that the standard was generally very high, though an amusing failure appears in The Independent:

  2. Peter Woit says:

    Thanks, that mainly looks like a headline writer failure. On next generation experiments, the piece does have eLISA launching in 2020, whereas it seems it’s going to be much later than that. This 2014 presentation says 2034

    and it looks like the idea that even this later generation of detectors is going to tell you something about before the big bang (“Creation”) or the multiverse is, well, just hype.

  3. Sesh, referring to any detectors that look for signals from the early universe, or that just probe physics that is relevant for understanding the early universe, as time machines has (sadly) become standard. Both Planck and the LHC have been called time machines. In the former case, this was even done by ESA itself:

  4. Peter Shor says:

    One thing I haven’t seen any mention of is what this means for the supporters of MOND—Modified Newtonian Dynamics? Do they just give up and admit general relativity is correct, or do they continue supporting their theory?

    (Maybe this is off-topic, but there are certain similarities to one of the main topics of this blog.)

  5. anon says:

    eLISA is definitely not launching in 2020. As far as I know, eLISA hasn’t even been selected for launch yet. ESA has chosen gravitational waves as the science theme for the third large-class mission slot (L3), planned for 2034. But unless I’ve missed the news, the precise mission concept has not been decided, so the eventual gravitational wave telescope may not resemble eLISA plans.

  6. Shantanu says:

    Peter, MOND is not a relativistic theory But any relativistic version should behave same as GR in the strong field and should produce tensorial fluctuations like in GR. Right now the signal cannot rule out scalar-tensor theories.

  7. Peter Woit says:

    As I feared with the last posting, there’s a large number of people wanting to discuss the significance of this signal for GR and black hole physics. This doesn’t work very well with my lack of willingness to moderate such a discussion, given that I know nothing much about the subject, and suspect that half of those wanting to make claims about it know as little as I do. So, unless someone has something more on topic, like an explanation of how LIGO is going to provide evidence for the multiverse, please try and find a better venue, hosted by someone who knows more about this. I’ll be very happy to advertise that here.

  8. Tim May says:

    This discovery is refreshing in so many ways.

    But the connection to this blog theme, I think, is that _experimental_ physics is again vindicated. Actually _seeing_ the waveforms, without elaborate processing and appeals to 1.5 sigma or 2.1 sigma probabilities, is refreshing. And this is far from the only case–the astronomical discoveries of dark energy (or whatever is causing an accelerating expansion of the universe) and of non-luminous or dark matter (the galaxies passing through each other), and all the results with the CMB….these need no hype by journalists or scientists themselves.

    Maybe it’s time to slow down on the theories that may be centuries (or more) from any hope of testing. (To be sure, the best mathematicians and theorists will continue to work in many areas–and may even have breakthroughs. But maybe it’s time to not have most physics departments dominated by one particular area.)

    This is an obvious theme, the costs and timelines for the MeV energy range, up through synchrotrons and linear colliders and rings past the GeV range and up to TeV and beyond. The pickings seem to be getting slimmer despite huge increases in cost. With no “surprises” to suggest new physics. A next generation collider may be the last one for a long, long time. When the next big jump in energy requires GNP-level spending, it just won’t get funding.

    Sometimes it may just be best to switch efforts to a more fruitful field. As I have been reading, the LIGO and Advanced LIGO cost well under a billion dollars. Money well spent!

    And how can “multiverse” hype compete for enticing young minds–or spending by governments– with the now dead certain detection of black holes a billion light years away spiraling in and radiating away massive amounts of energy?

    Personally, I think this puts a cork in the hype bottle for a long time.

  9. upstate_cyclist says:

    There was one bit of particle related news buried within the detection paper and one of the supplements. Using a simple Yukawa-correction, they put a bound 90% credible limit on the graviton mass at 1.2 x 10^-22 eV/c^2. This is the best dynamical bound to date but still not as “good” as the some of the others from galaxy clusters & weak lensing. But still, its another experimental bound necessary for a theory of quantum gravity, which I thought was what these folks were trying to sort out in the first place.

    And at some point, with enough sources, one is able to do some cosmology with these standard sirens, but how to get there never seems to arrive on the page. Also, space-based detectors are sensitive to super-massive black hole and white dwarf binaries, not the primordial waves (if they even exist) from the Big Bang. It looks like both Krauss and Kaku are in some wishful thinking, i.e. “if only the BICEP2 signal hadn’t been dust, then … MULTIVERSE”.

    They are perfectly welcome to do that on their own time and not muddle an article difficult subject to discuss with the public with their fatuous navel gazing.

  10. Mark Hannam says:

    The prime targets for Advanced LIGO are, as you say, astrophysical sources of gravitational waves, especially binary mergers — they are expected to produce the strongest signals.

    LISA isn’t due to be launched until after 2030, so there will hopefully be many impressive observations and discoveries long before we get anywhere near observing GWs from the big bang.

    I think one of the coolest things about this observation was that it is the closest we have ever come to measuring a signal *from* a black hole.

    I wrote about what we saw here,

    and a bit about the experience of the last few months and the final announcement here,

  11. vmarko says:

    Folks, there seems to be some confusion about which kind of gw-detector would be able to look for CGB (the gravitational analogue of CMB), so just a short note: neither ground-based detectors (such as LIGO or the most advanced idea of ET), nor the space-based detectors (such as LISA or the most advanced idea of BBO) would be able to see anything even remotely in the range of CGB frequencies (and this despite the name of the BBO).

    The way we *can* look for CGB signals is using the pulsar timing arrays (IPTA and SKA). Only those types of gw-detectors would be useful to “look at Creation” (pardon the language), or at least somewhat close to it. 🙂

    A nice map of what kind of detector can see what can be found here:

    The map is interactive, so you can choose which sources, which detectors and which observable will be plotted. The CGB (aka the “stochastic background”) goes from 10^(-7) Hz and downwards. So there is no chance for any Solar-system sized detector to catch this signal, aside from the nature-provided detection with the PTA.

    GW community has so far been very good at steering clear from hype, so we should help them keep it clean in the future as well.

    Best, 🙂

  12. HarrisTeter says:

    Hello all,

    Starting around 37 minutes into the NSF video here:, Kip Thorne states that LIGO will see gravitational waves from cosmic strings–listen to the LIGO video and you will hear: “Giant Strings that reach across the universe. They’re thought to have been created by the inflationary expansion of the fundamental strings that are the building blocks of all matter that expanded through inflation at the beginning of the universe.”

    This probably has a greater influence on the perception and direction of things than Kaku and Krauss.

    Also, might anyone know when a second signal might be detected by LIGO? Thanks! 🙂

  13. Anonymous Mathematician says:


    The rumors are that a second signal has already been detected by LIGO (although nowhere near as strong as the first signal). The press conference said they expected at least a handful each year.

  14. Thibault Damour, one of the people who predicted gravitational waves from cosmic strings (in work with Vilenkin), told me that even if such signals are discovered by LIGO/Virgo, we wouldn’t know if these strings were generated by the fundamental strings of string theory or some other mechanism.

  15. Peter Woit says:

    Hype about this has been going on forever, and I’ve written several times about it on the blog. For an early example, see

    which was about a 2004 press release from UCSB claiming that LIGO would within two years “test” string theory and possibly confirm it, by seeing evidence of cosmic strings.

    What’s going on here is that there is a long story about one-dimensional configurations in the Higgs fields of certain GUT models, which you might expect to be created in some early universe models. At some point certain string theorists started pointing to some fundamental string theories that also had such solutions and started up a hype campaign about them. As always, the story about string theory “predictions” is that you can get any “prediction” you want out of string theory: no cosmic strings, cosmic GUT strings, fundamental strings that look like cosmic GUT strings, or whatever.

    I’ve been glad to see that the press coverage of the LIGO discovery has generally ignored this nonsense.

  16. John says:

    As an interested “lay person” I was disappointed in many of the headlines and quotes. I read that this was the “Holy Grail of physics” and that the discovery “fundamentally changed our perception of the universe”. Hype isn’t limited to the multiverse it seems. It’s a great achievement in experimentation but it verified not changed our perception of the universe.

    I do have what I think is an interesting question. Right now we measure distance using the light from “standard candles”. Light is subject to lensing effects but I read that the gravitational waves are not “hindered” in any way. They also based the distance to the 2 black holes strictly on the properties of the gravitational waves.

    So do you think that gravitational waves can or will be used to verify distance to far off objects? Or at least be used to verify if the “standard candle” method is accurate?

  17. Chris W. says:

    Gravitational waves should be subject to lensing effects. For example, see arXiv:1309.5731.

  18. upstate_cyclist says:

    @Peter — While there was a search for string cusps in the previous science run before the upgrade began (, I expect that cluster resources are going to be allocated such that a repeat of this effort is very far down the priority list. So at least from the instrumental/search side of things, the best bet is continued silence.

    Though if primordial B-modes truly recede into the background, one may see another flare-up of interest in this source as theorists grasp for old-new straws as aLIGO reaches design sensitivity and new machines come online.

  19. I’m guessing that anything that travels along geodesics should be subject to lensing effects. What’s more surprising to me is that the positive cosmological constant might produce dispersion (with no need for gravitons to be massive) and thus chromatic aberrations in the gravitational waves — in other words different wavelengths refracting at different angles. This is apparently one consequence of the work by Ashtekar’s team

  20. Ethan says:


    Isn’t the LIGO result at least some sort of refutation of the Munich symposium on the necessity of experimentation to validate scientific theories? String theory might not have been able to come up with falsifiable experiments of its own, but the detection of gravitational waves one hundred years after being predicted shows that what Richard Feynman said about what science is remains true: , namely, it doesn’t matter how beautiful a theory is or how smart is the guy who proposed it. Unless you can correctly predict outcomes in falsifiable experiments, your theory is not scientific.

  21. Navneeth says:

    For what it’s work, Rainer Weiss though the NYT article was bad. 🙂
    (Don’t remember the exact moment he said that.)

  22. Daniele V says:

    Personally, what I find really upsetting is the sentence “High-school textbooks may have to be rewritten”: new discoveries in science add chapters to textbooks, do not throw away anything (of well-established theories, of course). Classical mechanics has continued to be normally taught in schools and universities after Relativity and Quantum revolutions, nobody uses Einstein’s Equations to make an airplane fly. It may seem just a fussy detail, but in this way people are driven to think that scientific knowledge is not trustworthy at all, because “today scientists assert something, next century the opposite” (heard from a friend of mine) as it were a matter of pure opinions.

    P.S.: it’s my first post here, I thank the blog master for his hospitality and his interesting blog.

  23. Peter Woit says:

    I don’t think the gravitational wave result has much to do with the problems of string theory, or of that part of theoretical physics in general which suffers from not having any prospect of getting relevant data. It’s a wonderful example of the canonical scientific method in action, but doesn’t change the problems that have led people down roads divorced from experiment (and I need to keep pointing out that there’s not anything necessarily wrong with that, the question is how you go about it).

    Daniele V.,
    Thanks! I think you’re right that that’s a problem. Possibly what people writing something like that have in mind is something more sensible (that the LIGO experiment will make in into the textbooks as a confirmation of GR, beginning of new kind of astronomy), can’t quite help themselves from embracing the trope of a “revolution” overturning the old.

  24. Shantanu says:

    Peter Shor: Let me add something to your MOND question. Eight years ago we proposed that if the relativistic MOND theories are correct then the galactic Shapiro delay of GWs should be much smaller than that of photons/neutrinos (see arxiv:0804.3804). So one acid test
    would be comparison of relative arrival time between GWs and photons/neutrinos.
    If the Fermi GBM detection at 0.5 seconds is confirmed to be due to this GW signal, then such theories are dead.
    Another way is to look for vector modes of GWs. This was suggested by Eva Sagi (See
    arxiv:1001.1555) and references therein. As mentioned in the LIGO tests of GR paper, right now they cannot rule out extra polarization states. of course these are just one class of relativistic MOND theories. If MOND is due to modified inertia or something, then at its still an open question.

  25. Venp says:

    Most impressive discovery based on a single event since Omega-minus some 50 years ago.

  26. Shantanu says:

    Peter: something else about this result directly connected to particle physics.
    if the Fermi GBM signal seen 0.4 second after the LIGO event is confirmed to be due to
    this GW signal, then brane world models are ruled out (as they predict GWs arrive much earlier.) See Fig 1 of

  27. Nathalie says:

    On LISA:
    It is sad to see how LISA has been treated up to now, both by NASA and ESA. Much work was done on the project already in 1990s, see for example
    and now I see that the plan is to launch it in 2034. I know that many scientists have devoted their scientific lives to it. Can someone tell me what has been going on?

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  29. Michael R. Sabino says:

    Yes, I think you’re right that LIGO isn’t the appropriate experiment to detect gravitatational relic radiation. There are several experiments looking at higher, more thermal frequencies for that. Some of them use tiny resonant masses, others like the holography detector at Fermilab use lasers.

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