Cosmic inflation: 'Spectacular' discovery hailed

las.

las.

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http://www.bbc.com/news/science-environment-26605974

Excerpt from reddit:

Today it was announced that the BICEP2 cosmic microwave background telescope at the south pole has detected the first evidence of gravitational waves caused by cosmic inflation.

This is one of the biggest discoveries in physics and cosmology in decades, providing direct information on the state of the universe when it was only 1e-34 seconds old, and energy scales near the Planck energy, as well as confirmation of the existence of gravitational waves.

Quick run down for those not in the field: The BICEP telescope measures the polarization of the Cosmic Microwave Background (CMB).

The CMB is light that was released ~380,000 years after the Big Bang. The Universe was a hot dense plasma right after the Big Bang. As it expanded and cooled, particles begin to form and be stable. Stable protons and electrons appear, but because the Universe was so hot and so densely packed, they couldn't bind together to form stable neutral hydrogen, before a high-energy photon came zipping along and smashed them apart. As the Universe continued to expand and cool, it eventually reached a temperature cool enough to allow the protons and the electrons to bind. This binding causes the photons in the Universe that were colliding with the formerly charged particles to stream freely throughout the Universe. The light was T ~= 3000 Kelvin then. Today, due to the expansion of the Universe, we measure it's energy to be 2.7 K.

Classical Big Bang cosmology has a few open problems, one of which is the Horizon problem. The Horizon problem states that given the calculated age of the Universe, we don't expect to see the level of uniformity of the CMB that we measure. Everywhere you look, in the microwave regime, through out the entire sky, the light has all the same average temperature/energy, 2.725 K. The light all having the same energy suggests that it it was all at once in causal contact. We calculate the age of the Universe to be about 13.8 Billion years. If we wind back classical expansion of the Universe we see today, we get a Universe that is causally connected only on ~ degree sized circles on the sky, not EVERYWHERE on the sky. This suggests either we've measured the age of the Universe incorrectly, or that the expansion wasn't always linear and relatively slow like we see today.

One of the other problems is the Flatness Problem. The Flatness problem says that today, we measure the Universe to be geometrically very close to flatness, like 1/100th close to flat. Early on, when the Universe was much, much smaller, it must've been even CLOSER to flatness, like 1/10000000000th. We don't like numbers in nature that have to be fine-tuned to a 0.00000000001 accuracy. This screams "Missing physics" to us.

Another open problem in Big Bang cosmology is the magnetic monopole/exotica problem. Theories of Super Symmetry suggest that exotic particles like magnetic monopoles would be produced in the Early Universe at a rate of like 1 per Hubble Volume. But a Hubble Volume back in the early universe was REALLY SMALL, so today we would measure LOTS of them, but we see none.

One neat and tidy way to solve ALL THREE of these problems is to introduce a period of rapid, exponential expansion, early on in the Universe. We call this "Inflation". Inflation would have to blow the Universe up from a very tiny size about e60 times, to make the entire CMB sky that we measure causally connected. It would also turn any curvature that existed in the early Universe and super rapidly expand the radius of curvature, making everything look geometrically flat. It would ALSO wash out any primordial density of exotic particles, because all of a sudden space is now e60 times bigger than it is now.

This sudden, powerful expansion of space would produce a stochastic gravitational wave background in the Universe. These gravitational waves would distort the patterns we see in the CMB. These CMB distortions are what BICEP and a whole class of current and future experiments are trying to measure.

Discuss. Religious sceptics welcome too.
 
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I dont know what youre saying, i dont know any of the terminology, and i dont even know what to be thinking, but damn, thats sick.
 
After reading this, the rapid expansion at the beginning before the CMB totally makes sense, because energy levels would have been way higher. At least that makes sense in my mind I guess but all this stuff is crazy to think about and even crazier to calculate.
 
So what does this provide for our knowledge of the universe exactly? Is this just simply conformation that the universe is expanding, a better way to measure the expansion and possibly the recession, does it have any direct impact on our current way of life? You might have said it in that giant paragraph but honestly I just skimmed I'm no physics major(yet/possibly/idfk).
 
It means that we now understand the early universe with a higher degree of certainty than ever before. This is extremely good evidence supporting the Big Bang theory.
 
They discovered evidence of massive gravitational waves that could have only have been formed by a huge event like the Big Bang. Great stuff.
 
Cool. We are one step closer to confirming the Big Bang Theory. Not like we more important issues to focus on. Like the fact that we are on the edge of WWIII right now.
 
Not a big fan on studying the Big Bang but this is really interesting. Science surprises us with new things every day. Good thread OP.
 
The ‘smoking gun’ is a basic, but concise analogy.

We knew these gravitational waves (which rippled through our infant universe during an explosive period of growth called inflation), or the 'smoke', existed (from observing energy loss of pulsar binary systems), yet we've never been able to directly see them. BICEP2 has just confirmed the existence of these waves, which is essentially a monstrous piece in the puzzle to decrypt where we came from, how it all began and what the universe looked like and consisted of in it’s beginnings.

These findings have momentous importance, and I really hope they’re verified. Worthy of a Nobel, no doubt.
 
If you actually think some shitty peninsula on Ukraine is going to send us into WWIII, then you are an idiot. On a related note, this shits awesome.
 
that's definitely not why you were banned. they would not ban you for challenging beliefs. Scientists love that shit.

It's like opposite of NS. you will get banned for being an idiot, not for challenging/criticizing ideas in a polite way.
 
the big bankd if dumnb because its stupid so shut ip dude you8 jist dont het a tree from a bang stipded. they say there is no suvij thing as time before the big nang wekk thats a load of shit nothing just explode and nbamg caboom univetse
 
At least in philosophy, the big-bang theory was seen as a win for theists and atheists were resistant to accept it. This will definitely help William Lane Craig's Kalam Cosmological argument.
 
Physics forums doesn't allow speculative discussion for very good reason, its job is to help people understand physics, having a bunch of undergrads or high school kids challenging current theories is not a part of that goal.

On topic though, I'm waiting for this to be peer reviewed first. It sucks when the media publishes these as discoveries before the rest of the scientific community can fully look at the data and confirm it. This is what happened with the "faster than light neutrino".

I am also blown away at how accurate Einstein's work has been, 98 years after he predicted gravitational waves we're starting to find very concrete evidence (if this discovery isn't disproven in the future of course).
 
well what point is there to argue about free will on a physics forum? arguing if the laws of nature are deterministic is not the same thing about arguing about free will. what the fuck is free will anyways? is randomness "free will". That's philosophy shit really.

but you can't just straight up say that the laws of physics are totally deterministic. I mean there are a lot of very smart people who think that it might not be...
 
For everyday life? Right now not much, however as with almost all technology it is born out of physics. This discovery could lead to new technology possibly being developed down the road.

A very exciting thing about this is that by studying gravitational waves we can gather evidence of how the universe worked while it was very small and quantum mechanics and general relativity worked somewhat on the same scale, this could lead to us eventually being able to link these two theories that as of right now don't like to work together.
 
For the "what practical implication might this have" kid: I think pure scientific pursuit and theoretical science has just as much value if not more than the practical outcomes of science. We mustn't just memorize the formulas, but actually understand how they work, etc. Facilitates progress.

That being said this is so damn cool. I think the coolest part is the gravitational waves being a result of the bang.

On free will: He's right in saying it's a scientific question but there are other ways (scientific ones too) to prove man has little to no free will. We've found that human neurons fire to do something A SECOND BEFORE the person even decides to do anything for one.
 
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