Sunday, April 26, 2015

Supervoid

Astronomers have found an enormous "void" in space 1.8 billion light-years across, the largest structure yet found in the universe. The void is aligned with a "cold spot" discovered in the cosmic microwave background. The void was found using the PAN-STARRS telescope on Maui and NASA's Wide Field Infrared Survey Explorer (WISE) in space.

Detection of a supervoid aligned with the cold spot of the cosmic microwave background

The study suggests that the void is draining light energy from the surrounding space, causing the cold spot. This supervoid may not be empty, but could be the lair of an ultra-massive black hole. Old theories of the universe can't explain a structure this large.

The void could have been formed by an ultra-massive black hole emptying the space around it. The black hole would be primordial, born of a quantum fluctuation shortly after the Big Bang. Size of a black hole is limited by a "horizon distance" related to the speed of light. This immense void is one more sign that the speed of light was once much larger.

Saturday, April 25, 2015

Type Ia Not All of a Type

Happy 25th Birthday to the Hubble Space Telescope!

Type Ia supernovae were once thought to all have the same brightness. Using these exploding stars as standard candles to measure distance, physicists in 1998 concluded that the universe is accelerating due to a repulsive "dark" energy. Speculation about an accelerating universe has occupied physics for years. Now a new study says that Type Ia don't all have the same luminosity after all.

A new study published in the Astrophysical Journal finds that Type Ia supernovae form at least two groups, distinguished by colour and luminosity. The authors used results from the Hubble Space Telescope and the SWIFT satellite. This shows that they are not standard candles, and estimates of the universe's expansion could be way off.

The paper is at:

The Changing Fractions of Type Ia Supernova NUV

The researchers conclude that differences between Type Ia supernovae could account for at least some of the apparent "acceleration". The so-called "dark" energy might not be as prevalent as thought. In the scientists' words: "Not accounting for this effect should thus produce a distance bias that increases with redshift and could significantly bias measurements of cosmological parameters". In English, what was thought about an accelerating universe could be wrong.

GM=tc^3 predicts that the speed of light has been changing. Since redshifts are roughly proportional to v/c, instead of v increasing c has been slowing down. The answer could be in light rather than imaginary "dark" energies.

Friday, April 24, 2015

The Solar System

The newest project on Kickstarter is an updated Solar System poster, including new photos of Ceres and Pluto. What is different? Most depictions of our solar system don't accurately show the distances between planets. Here we show the relative orbits, with the planet sizes depicted below. What do you think? Tell your frineds about this project!

Tuesday, April 14, 2015

"Variations in the speed of light"

More and more physicists are willing to consider that the speed of light may be changing, as predicted. From phys.org:

Physicists propose method to measure variations in the speed of light

"But in some alternative theories of cosmology, the speed of light is not actually constant, but varies throughout time and space."

The physicists from universities in Poland and Spain propose to use baryon acoustic oscillations, waves in the microwave background that can theoretically be detected and measured. Their pasper appears, behind a paywall, in Physical Review Letters:

Measuring the speed of light with baryon acoustic oscillations

The article in phys.org mentions a simple relationship: There is an angular diameter distance Da, which can be multiplied by the Hubble factor H to get the speed of light:

DaH = c

We can calculate Da, the maximum distance light has travelled from the time of highest redshift. M = R = t in Planck units, which in CGS units becomes: GM = tc^3 and R = ct

c(t) = (GM)^[1/3]t^[-1/3]

Da = \int c(t)dt = (3/2)(GM)^[1/3]t^[2/3] integrated from t = 0 (the Big Bang) to the present time.

Note that (GM)^[1/3]t^[-1/3] = c, so:

Da = (3/2)ct

Now we figure out the Hubble value H = Rdot/R

R(t) = ct = (GM)^[1/3]t^[2/3]

\Rdot(t) = (2/3)(GM)^[1/3]t^{-1/3]

H = \Rdot /R = (2/3t)

Putting it all together:

DaH = (3/2)ct(2/3t) = c

Matches perfectly, no? A simple cosmology of M = R = t fits the relation DaH = c. Why hasn't anyone noticed this before?

Monday, April 06, 2015

Project Near Funding

Funding is always an issue with science, especially in a time of darkness. The new book project, THE YEAR OF LIGHT, is tantalizingly close to being funded. thanks to all who have backed this project:

One candle can light the darkness.
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