Profile

Cover photo
Eric Sandall
197 followers|112,899 views
AboutPostsPhotosVideos

Stream

Eric Sandall

Shared publicly  - 
 
“Slim by Chocolate!” the headlines blared. A team of German researchers had found that people on a low-carb diet lost weight 10 percent faster if they ate a chocolate bar every day. It made the front page of Bild, Europe’s largest daily newspaper, just beneath their update about the Germanwings crash. From there, it ricocheted around the internet and beyond, making news in more than 20 countries and half a dozen languages. It was discussed on tel...
1
Add a comment...

Eric Sandall

Shared publicly  - 
1
Add a comment...

Eric Sandall

Shared publicly  - 
 
Sounds totally safe, too!
An anonymous reader writes: Looking more like a computer company than a car company, Hyundai ships Android Auto on 2015 Sonatas and unlocks it for owners of the 2015 Sonata with a software update. Says the article: To enable Android Auto, existing 2015 Hyundai Sonata owners outfitted with the Navig...
2
Add a comment...

Eric Sandall

Shared publicly  - 
 
 
Friday's 'Galaxy' Insight --"Why the Universe Exists"

http://bit.ly/1cSkeX4

"In the beginning there were only probabilities. The universe could only come into existence if someone observed it. It does not matter that the observers turned up several billion years later. The universe exists because we are aware of it."  

Martin Rees, British cosmologist and astrophysicist as well as Astronomer Royal of the Royal Observatory.
The active galaxy Messier 82 from infrared observations by Spitzer Space Telescope in three wavelength bands coded in red (longest wavelength), green, and blue (shortest wavelengths). This galaxy remarkable for its webs of shredded clouds and flame-like plumes of glowing hydrogen blasting out from its central regions where young stars are being born 10 times faster than they are inside in our Milky Way Galaxy. NASA/JPL-Caltech/C. Engelbracht (University of Arizona)
72 comments on original post
1
Add a comment...

Eric Sandall

Shared publicly  - 
1
Add a comment...
Have him in circles
197 people
Travis DeVault's profile photo
Dennis Durling's profile photo
Vincent Yang's profile photo
Devin Rider's profile photo
Dariusz Gołębiowski's profile photo
Chad Zanonie's profile photo
Ben Ford's profile photo
Nancy Curteman's profile photo
Piotr Zdziechowiak's profile photo

Eric Sandall

Shared publicly  - 
 
 
Einstein's Succession, Part 6
(Other parts: https://plus.google.com/collection/AP7WX)

We know, that Einstein's field equations of general relativity cannot fully describe the universe we observe today. The resolution to the paradox described in the previous parts has to be found somewhere before the time of last scattering, in the first 380,000 years after the big bang.

We can simulate the hot young universe from a second after the big bang and follow its evolution over time while it expands and cools down. The predictions of such simulations are at overwhelming agreement with detailed observations all the way to the present time. To explain the uniform CMB temperature physicists hence aim at the first fractions of a second after the big bang. This first second is poorly understood. The unexplained imbalance in baryonic matter and antibaryonic matter for example originates from the same time. The closer you get to the big bang, quantum effects become more and more important, but the theories we use to extrapolate back in time were not developed to include quantum physics. Until today, there is no “theory of everything” that describes gravity, space, time, and the shape and evolution of the universe, as well as physical phenomena at nanoscopic scales with all known quantum effects. It is impossible to tell if the properties of our universe gave birth to the laws of natural, or if there is an underlying fundamental set of rules that determines both, general relativity and quantum mechanics. Maybe the shape and nature of our universe is even somehow independent from the interactions of matter and energy within.

Currently two favored theories exist that extend the standard ΛCDM model to explain the observed uniform CMB temperature. The more conservative theory is the cosmic inflation model [30]. It postulates an inflationary epoch that lasted from 10􀀀^-36 seconds to roughly 10􀀀^-32 seconds after the Big Bang where space expanded exponentially. In this model, tiny quantum fluctuations during inflation became magnified to cosmic size, and all other inhomogeneities were smoothed out. It explains the uniform CMB temperatures including its pattern, and predicts that the total mass density equates the critical density, as can be observed today. In this model, in the beginning there was nothing. The universe started out of a singularity that expanded exponentially for a very short time span and follows the rules of general relativity ever since, including an ever accelerating expansion dominated by dark energy as shown in the figure. Inflation though was not the same for the whole universe – other parts would undergo different inflationary epochs or might even still inate today, producing many local universes with very different properties.

In M-theory—a unifying string theory and promising candidate for a unied theory of general relativity and quantum mechanics—a very different kind of universe is possible. This theory even raises the question if the big bang was the real beginning of our universe as it can also describe a cyclic (or ‘ekpyrotic’) universe that did not start with a singularity but with two branes moving apart [31]. Branes are higher-dimensional objects described by M-theory that exist in space-time and follow the rules of quantum mechanics. Space in between both branes cannot be accessed by any object situated in either brane—like us—but both branes can move along this extra dimension. This opens the possibility for the big bang to be a collision of both branes, caused by a spring-like force between them [32]. In this collision hot matter and radiation was created. Both branes move apart while the two universes begin to expand. M-theory predicts that the accelerated expansion cannot last forever since within this context, dark energy is associated with the spring-like force between both branes. Eventually, it will bring both branes back together again. In the subsequent collision all kinetic energy is converted to new matter and radiation and the cycle starts all over again. This is illustrated in the figure.
Strictly speaking this is not a full cycle as the universe contracts only in the extra dimension and continuously expands in all other dimensions. Thus the overall Universe becomes bigger and bigger. Nevertheless, the local universes from an observer’s perspective remain the same for each cycle. During the process of contraction – which is the alternative to inflation and lasts for about 10 billion years – the universe smooths out until quantum fluctuations take over. Consequently, the branes are slightly wrinkled and do not collide everywhere at the exact same time. Some regions of space bounce off earlier (heat up sooner) than others. Simulations predict that this would cause exactly the same uniform CMB temperature with its distinct pattern. This model also provides an explanation for the nature of dark matter: it merely is the influence of matter from the distant brane felt in our local universe.

Both models result in the universe that we observe today. The nature of the universe though is fundamentally different for both theories. In one, the CMB pattern is caused by quantum fluctuations shortly after the big bang during the time of cosmic inflation, while in the other one the same pattern arises from quantum fluctuations prior to the big bang which merely was the most recent collision of two higher-dimensional branes. The amount we already know about our universe speaks volumes of our ingenuity and science, but if we want to find answers about the origin of our universe, we need a new kind of observational cosmology. The only way to distinguish between both models lies in one single differentiation: strong gravitational waves should have been created during rapid inflation, but almost zero gravitational waves would originate from a slow collision of two branes. We just need to push today's technology a little bit further to detect these gravitational waves.

Learn what gravitational waves are in the next parts. Subscribe to https://plus.google.com/collection/AP7WX


[30] Alan H Guth. Inationary universe: A possible solution to the horizon and atness problems. Physical Review D, 23(2):347, 1981.
[31] Paul J Steinhardt and Neil Turok. Endless universe: Beyond the big bang. Broadway, 2007.
[32] Justin Khoury, Burt A Ovrut, Paul J Steinhardt, and Neil Turok. Ekpyrotic universe: Colliding branes and the origin of the hot big bang. Physical Review D, 64(12):123522, 2001.
21 comments on original post
1
1
Matthew J. Harmon's profile photo
Add a comment...

Eric Sandall

Shared publicly  - 
 
 
Read this. It is important. 
This Memorial Day weekend marks the start of another—hopefully safe—swimming season. In 2013, Mario Vittone dispelled a popular myth about how to tell when someone is struggling in the water. The original article is reprinted below. The new captain jumped from the deck, fully dressed, and sprinted through the water. A...
View original post
1
Add a comment...

Eric Sandall

Shared publicly  - 
 
HughPickens.com writes: Richard Horton writes that a recent symposium on the reproducibility and reliability of biomedical research discussed one of the most sensitive issues in science today: the idea that something has gone fundamentally wrong with science (PDF), one of our greatest human creatio...
1
Add a comment...

Eric Sandall

Shared publicly  - 
 
Sounds like an interesting approach.
HughPickens.com writes with news that Elon Musk has established "Ad Astra," a small, private school for grade-school-age kids. His goal for the school is to eliminate actual differences between the grades. The school had only 14 students for the past year, but will likely expand to 20 next September...
1
Add a comment...

Eric Sandall

Shared publicly  - 
 
 
Colorfull Nebula

Best seen from the Patagonian Clear Skyes

From the center of our Milky Way Galaxy in Sagittarius through the constellations of Scorpius and Ophiuchus, this southern field of view contains an assemblage of some of the most colorful nebulae in the sky. This beautiful area contains such notables as the Rho Ophiuchi Nebula and the Dark River, the reflection nebula vdB 99, the Cat's Paw Nebula, and the Blue Horsehead Nebula. 

Also highlighted on the right side of this image is the very faint emission nebula, Sh2-27. This nebula occupies a swath of sky of over 10 by 13 degrees. That's an area larger than 600 full Moons! 

Please Follow +Ruta a la Patagonia for more postings of this kind :-) !!
14 comments on original post
1
Add a comment...

Eric Sandall

Shared publicly  - 
 
All human beings, scientists have established, are genetically modified. Over the years, hundreds of foreign genes have jumped into human DNA through a natural phenomenon called 'gene flow.'
1
Add a comment...
People
Have him in circles
197 people
Travis DeVault's profile photo
Dennis Durling's profile photo
Vincent Yang's profile photo
Devin Rider's profile photo
Dariusz Gołębiowski's profile photo
Chad Zanonie's profile photo
Ben Ford's profile photo
Nancy Curteman's profile photo
Piotr Zdziechowiak's profile photo
Basic Information
Gender
Male
Apps with Google+ Sign-in