Voyager Clue Points To Origin of the Axis of Evil 293
KentuckyFC writes "Cosmologists have been scratching their heads over the discovery of a pattern imprinted on the cosmic microwave background, the radiation left over from the Big Bang. This pattern, the so-called Axis of Evil, just shouldn't be there. Now an independent researcher from Canada says the pattern may be caused by the boundary between the Solar System and interstellar space where there is a sharp change in pressure, temperature and density of ions in space. Known as the termination shock, astronomers had thought this boundary was spherical. But last year, data from the Voyager spacecraft which have crossed the boundary, showed it was asymmetric. The new thinking is that the termination shock acts like a giant lens, refracting light that passes through it. Any distortion of the lens ought to show up as a kind of imprinted pattern on an otherwise random image. But the real eye-opener is that as the shape of the termination shock changes (as the Solar Wind varies, for example), so too should the pattern in the microwave background. And there is tentative evidence that this is happening too (abstract)."
Wikipedia (Score:4, Informative)
Re:Why should we care? (Score:5, Informative)
Re:too (abstract) (Score:5, Informative)
Short version: You know how stars twinkle because of the Earth's atmosphere? Something similar happens at the boundary of the solar system. The difference there is that the boundary is due to the solar wind as opposed to an atmosphere.
The actual distortion is similar to the ripples of light you see on the bottom of a swimming pool due to ripples in the surface of the water. Because the surface is uneven, the light gets bent unevenly and bunches together in some places and spreads out in others. So, instead of even lighting across the bottom of the pool, you see a pattern of light and dark areas.
Same thing's happening to the cosmic background radiation. It should be evenly distributed, but instead it's brighter and darker in places, and they think it's due to the uneven surface of the termination shock.
Epoch Fail (Score:4, Informative)
I hardly know where to begin, but the physics, as described in the original post, is wrong. I am going to read the article now, but just remember that Arxiv articles are not peer reviewed before they are posted.
Re:Why should we care? (Score:5, Informative)
Re:Why should we care? (Score:2, Informative)
Re:Why should we care? (Score:3, Informative)
Re:Fascinating stuff (Score:1, Informative)
It's obsolete here on Earth, but the key reason for using it was that the playback mechanism was easily reproduced. They put a diagram showing how to assemble a record player on the vehicle.
Including a CD plus all the necessary 'stuff' to build the player would have been a little harder to explain.
Re:Why should we care? (Score:1, Informative)
http://lmgtfy.com/?q=Before+the+big+bang
This idea is pretty well accepted by our current understanding of physics.
Re:Voyager (Score:5, Informative)
I completely agree - and it's worth noting that we're talking about a spacecraft launched in 1977 - so it's flying tech is even older.
Not only that - our ground tech is truly incredible.
The power received at an earth antenna is 1e-16 watts - imagine finding and holding that signal in the cosmic background noise!
http://voyager.jpl.nasa.gov/mission/didyouknow.html [nasa.gov]
Re:So? (Score:5, Informative)
Not necessarily, we just need glasses. Knowing our observations are being altered by what is in effect a lens is the first step. Once we know the actual shape and properties of that lens we can mathematically apply alterations to our observations to correct for the distortion and end up with representations of our galaxy, other galaxies, and the background photons and radiation of the universe with much more accuracy than ever before.
Of course, stationing observatories beyond the field would be the best option, much like observatories like Hubble that are outside our atmosphere are better than ground-based telescopes. It is possible that not everything is actually making it through this lens, so even applying corrections won't yield a 100% perfect picture.
Re:Fascinating stuff (Score:2, Informative)
Re:too (abstract) (Score:5, Informative)
I don't think that's quite right. You are describing small-scale fluctuations in the "surface" of the termination shock. But the main effect being considered in the scientific paper [arxiv.org] is a large-scale anisotropy in the termination shock.
The termination shock (TS) is usually assumed to be spherical: the sun emits supersonic solar wind in all directions; the point at which this solar wind is slowed by the interstellar medium should be the same in all directions. But what if it's not? The paper considers what effect a termination shock shaped like a "prolate ellipsoid of revolution" would have on an otherwise isotropic (at large scales) cosmic-microwave-background (CMB).
They quickly calculate that a prolate TS could lead to the observed quadrupole in the CMB. The authors suggest that the coupling between TS and CMB may be due to refractive index effects (basically as if the solar system is inside a gigantic lens), or possibly differences in scattering at different parts of the TS. Either way, some types of light reaching us should have a corresponding signature of the anisotropy.
Note that this isn't the first time the CMB had to be corrected. A very significant dipole in the full-sky map has to be removed to account for the relative motion of our planet in the galaxy, the motion of our galaxy with respect to the rest frame of the CMB, etc.
The authors end their paper by mentioning that if this effect is real, then small-scale fluctuations in the surface of the TS may also affect the smaller-scale fluctuations we see in a map of the CMB [wikipedia.org]. Those fluctuations are normally thought to be an imprint of the randomness in the early universe. The authors suggest that the fluctuation spectrum may be altered by, or possibly even totally an artifact of, ripples in the TS. But as the authors note this is very, very speculative at this point. (We've been mapping the CMB for many years and the maps seem roughly consistent, so any time-varying rippling in effect would have to be subtle and/or slow...)
Re:Fascinating stuff (Score:2, Informative)
It appears they stopped trying to contact the Pioneers. They couldn't detect any signals on the last tries. Whether this is due to signal weakness or hardware failure is unknown. They are around the threshold of detection even if they still broadcast.
Even if they received a signal, the probes no longer generate enough power for any of the sensors to work properly. Thus, they can no longer "sniff space". At best, the signals could be used to check the actual trajectory against predictive models for gravity-related studies. But the signals may be too weak for that also.
Re:Why should we care? (Score:3, Informative)
The current robot mission (New Horizon) to Pluto should provide better answers in the future. The New Horizon mission is going to reach Pluto in 2015, so it should be at the boundary at 2020 or 2025, I am not sure about the exact date in that manner. But it is somewhere along those years.
http://pluto.jhuapl.edu/ [jhuapl.edu]
Re:Why should we care? (Score:3, Informative)
A replicator (ST) could be used to make a replicator (SG).
Correct me if you have an encyclopaedic knowledge of startrek, but self-replicating machines only seem to have featured in the form of the mines in DS9.