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"Big Bang Signal" Could All Be Dust
An anonymous reader writes Scientists have shown that the swirl pattern touted as evidence of primordial gravitational waves — ripples in space and time dating to the universe's explosive birth — could instead all come from magnetically aligned dust. A new analysis of data from the Planck space telescope has concluded that the tiny silicate and carbonate particles spewed into interstellar space by dying stars could account for as much as 100 percent of the signal detected by the BICEP2 telescope and announced to great fanfare this spring. The Planck analysis is "relatively definitive in that we can't exclude that the entirety of our signal is from dust," said Brian Keating, an astrophysicist at the University of California, San Diego, and a member of the BICEP2 collaboration.
So is the Universe coming, or going?
Do not look into laser with remaining eye.
Which sounds hard, because what can you measure changes in besides the light, which would be affected by magnetic dust?
The spectral shape of the dust signal and the CMB signal are different, so multi-frequency analysis can be used to tease out the various effects. There are various technical reasons the BICEP2 team chose a single frequency (150 MHz) but additional measurements at different frequencies (353 MHz is mentioned in TFA) would allow untangling of the two, albeit with some loss in sensitivity. This sounds like the approach that will be taken in future by various teams investigating this.
The BICEP2 team got bitten by designing their experiment around a flawed theoretical understanding of the dust distribution in our galaxy, which is too bad, but this is the way science works: we publicly test our ideas, and let others see if what we've done can stand up to scrutiny. I've worked on experiments in the design phase where the design team has missed important backgrounds: it's easier than you'd think. And I once worked on an experiment that had been taking data for two years before it was found that there was a background process that precisely aped the signal (it had been missed originally because of a dropped sign in a calculation that caused two terms to nearly cancel when they should have added up.)
In the best case we find these sorts of things before we publish. In the worst case--such as this one--after.
Blasphemy is a human right. Blasphemophobia kills.
In the comments for any article related to physics, on any website, there will always be at least one comment from someone who mistakes their schizophrenia for a PhD in Physics.
I advise you, pay them no heed.
--- Generation X: The first generation to have SIG lines inferior to their parents... ---
The Planck dust measurement in pretty damning, but it is not the final word.
(1) Planck measured the dust contamination with greatest sensitivity at 353 GHz. It was not sensitive enough to measure the dust signal at 150 GHz, where BICEP was observing. They had to extrapolate the dust contribution from the higher frequency to the lower. This is actually a pretty big extrapolation, since the dust emission at 150 GHz is less than 1% of the dust emission at 353 GHz.
(2) The uncertainty in the dust emission amplitude is still pretty high, so the Planck measurement is consistent with an "all dust" model, or with a "mostly dust" model, or with a "mostly primordial, with some dust" model. It does pretty conclusively rule out a "no dust" model.
(3) They have not released the results of a joint analysis of Planck and BICEP2, which is what is necessary to actually shed some light on exactly how much of the BICEP2 signal is likely to be dust.
But it's clear that the BICEP team was being over-optimistic in their assumptions about galactic dust, which is a bummer.
Oh hey, I'll just fix that for you:
- The universe did not come from nothing. Thermodynamics prevents this.
- The universe did not create itself. Thermodynamics prevents this.
- The universe was not created.
Cheers!
I've fallen off your lawn, and I can't get up.
Oh hey, I'll just fix that for you:
- The universe did not come from nothing. Thermodynamics prevents this.
- The universe did not create itself. Thermodynamics prevents this.
- The universe was not created.
Cheers!
Thermodynamics is a theory valid for a large number of particles, and deals with the emerging phenomena based on a statistical basis, i.e. what constitutes rare phenomena. This is not enough to deal with the early universe. Even if it was, there might be an infinite "time" or "tries" before our universe exists so we can observe it.
Also, the term "create" is vague. Arguable, one can speak of creation as early inflation expands the universe and cools the soup of radiation into massive particle. In that sense some earlier state *did* create the universe as we understand it (time, space, and matter).
Also it is not true that "The universe did not come from nothing. Thermodynamics prevents this." It is possible to create a universe from nothing. What you do is borrow energy from a quantum fluctuation. You would have to give it back in a time proportional to the energy borrowed. Then inflate the universe by 10^26 so that the quantum fluctuation becomes a size-able scale, and quantum mechanics do not apply anymore. The energy borrowed obviously necessitates a balancing energy, which is stored (as negative energy) in the curvature of the universe. In a sense, enormous inflation allows you to run away with borrowed energy.
Sorry for being brief in my explanation, but the above is not a crackpot theory. It is one that is consistent with the data of the CMB and large-scale structure correlations (e.g. galaxy clusters), and commonly presented in cosmology talks. You can find some books on the subject if you search for "universe inflation", one by Alan Guth who came up with the basic theory.
The right answer is "We do not know yet where the universe came from."
and "We do not know yet if the quest for a 'cause' makes sense in the early universe or has a testable answer. But we will continue trying."
Now it is possible to call the "creation" of the universe a god, in the Greek sense of the word. The creator. A mechanism. But it is a long way from there to argue a currently present, omnipotent but willfully acting, personally addressable God.
NB: The message above might reflect my opinion right now, but not necessarily tomorrow or next year.