Naked Science Forum
Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: timey on 04/04/2017 12:19:04
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Does anyone have anything to say about Eric Lerner's study?
http://www.sci-news.com/astronomy/science-universe-not-expanding-01940.html
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Does anyone have anything to say about Eric Lerner's study?
http://www.sci-news.com/astronomy/science-universe-not-expanding-01940.html
The light we see from a galaxy 100 million light years away, this tells us what the galaxy did one hundred million years ago. It does not tell you what it is doing today. We do not know what it is doing today since today's light will not reach us for 100 million more years. If it started to go the other way 50 million year ago, we won't know for 50 million years. This seems to create conceptual problems for cosmologists.
When we look out at the universe, it is similar to looking through a photo scrapbook. For example, say you have a new baby. Starting from birth, you take pictures, each week, and add it to the scrap book. You do this all the way until the child become 21 years old.
Although we can compare the 1 month old baby pictures, with the sweet sixteen birthday party pictures, side-by-side, in terms of light, color, size, these two pictures do not coordinate in time, even though we try to make these comparisons coordinate in time by looking side by side.
This confusion is an artifact of the photography used to collect data in different wavelengths. I can take the two pictures out of the scrapbook; 1 month old baby and sweet 16, and then photograph these together so they now have the same time stamp, so they now appear to be of the same time. Then we compare data, that does not coordinate in original time, but only in term of the time of the new photo. Time is needed for velocity and all motion assumptions, yet the time is not coordinated, but rather it is sequenced, in the original scrapbook. This confusion in time can be misleading and is now leading to the paradox of many alternate explanations.
For example, say we had a picture of the oldest physical structure of the universe. Common sense would tell us, since this event, is from 15 Billion years ago, the light needed to come from a place very close to the origin of the BB universe. It is very old, and did not have the time to move very far away from where it originated. It has to be close to the origin. It does not have 14 billion years to move, even if the light took that long to reach us. The light from 14 billion years ago is a baby picture before it could crawl. It is still stuck in the crib. If we use a picture of a picture, to misrepresent the time sequence, we can make it appear to move away from the BB center, so there is no center or origin to the BB universe.
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Well, against that study you have this.
"Hubble finds proof that the universe is expanding
1929
The two keys to Edwin Hubble's breakthrough discovery were forged by others in the 1910s.
The first key, the period-luminosity scale discovered by Henrietta Leavitt, allowed astronomers to calculate the distance to variable stars from Earth. Hubble had already used this knowledge in his 1924 discovery that the Andromeda nebula, containing a variable star, was more than 900,000 light years from Earth -- way beyond our own galaxy -- a surprise to everyone at the time. With this scale and other tools, Hubble had found and measured 23 other galaxies out to a distance of about 20 million light years.
The second key was the work of Vesto Slipher, who had investigated the spiral nebulae, before Hubble's Andromeda discovery. These bodies emit light which can be split into its component colors on a spectrum. Lines then appear in this spectrum in particular patterns depending on the elements in the light source. Yet if the light source is moving away, the lines are shifted into the red part of the spectrum. Analyzing the light from the nebulae, Slipher found that nearly all of them appeared to be moving away from Earth. Slipher knew that a shift toward red suggested the body was moving rapidly away from the observer. But he had no way to measure the distances to these reddish bodies.
Hubble's brilliant observation was that the red shift of galaxies was directly proportional to the distance of the galaxy from earth. That meant that things farther away from Earth were moving away faster. In other words, the universe must be expanding. He announced his finding in 1929. The ratio of distance to redshift was 170 kilometers/second per light year of distance, now called Hubble's constant. The numbers were not exactly right, and refinements in measuring techniques and technology have changed all of Hubble's early figures. But not the basic principle. He himself kept working on the problem and collecting data throughout his career."
Now in their study they define that "the Big Bang theory tells us that in an expanding Universe objects actually should appear fainter but bigger. Thus in this theory, the surface brightness decreases with the distance. In addition, the light is stretched as the Universe expanded, further dimming the light."
So how did we define what objects Galaxies etc that are the farthest away from us?
"Distances to remote objects, other than those in nearby galaxies, are nearly always inferred by measuring the cosmological redshift of their light. By their nature, very distant objects tend to be very faint, and these distance determinations are difficult and subject to errors.
An important distinction is whether the distance is determined via spectroscopy or using a photometric redshift technique. The former is generally both more precise and also more reliable, in the sense that photometric redshifts are more prone to being wrong due to confusion with lower redshift sources that have unusual spectra. For that reason, a spectroscopic redshift is conventionally regarded as being necessary for an object's distance to be considered definitely known, whereas photometrically determined redshifts identify "candidate" very distant sources. Here, this distinction is indicated by a "p" subscript for photometric redshifts."
Which then leaves us to wonder how those guys now reached a different conclusion. Well, it seems they used the luminosity.
" Luminosity, L, is a measure of the total amount of energy radiated by a star or other celestial object per second. This is therefore the power output of a star. A star's power output across all wavelengths is called its bolometric luminosity. Astronomers in practice also measure an object's luminosity in specific wavebands so that we can discuss an object's X-ray or visible luminosities for example. This is also used to measure a star's colour..... What properties determine the intrinsic power output or luminosity of a star? Temperature and size of the star. Fundamentally there are just two key properties - the effective temperature, T and the size of the star, its radius, R. "
And yes, if they are correct it is weird.
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And then the question becomes, what would change in astronomy, physics and mathematics if the universe wasn't expanding the way we've defined it so far. What would a cosmological redshift consist of? Would the same reasoning hold for all objects 'expanding' away in a sphere like manner from any randomly picked object?
"Einstein's theory also suggested the expansion of the Universe, but Einstein didn't believe this could be correct. In 1917 he added a new term to his equations, the "cosmological constant." This constant was designed to avoid the possibility of an expanding universe. Hubble's recent observations remove the need for this term. While Einstein has examined the data and believes Dr. Hubble's paper to be sound, he is still not convinced the universe is expanding.
In 1922, Soviet scientist Alexander Friedman developed his own solutions to the general relativity equations. He described two possibilities for the Universe: either it was expanding or contracting, but it was not staying the same.
Abbe George Lemaître, a Catholic priest and astronomer released a paper in 1927. This paper said a homogeneous universe of constant mass has to be expanding to account for the speed of spiral nebulae moving away. He described a possible universe that was expanding from an initial single point. Lemaitre believed that before this expansion began, the Universe did not exist."
Presumably this too would then be put into question.
"Previously, astronomers had estimated GN-z11's distance by analysing its colour in images taken with both Hubble and the NASA Spitzer Space Telescope. Now, for the first time for a galaxy at such an extreme distance, the team has used Hubble's Wide Field Camera 3(WFC3) to precisely measure the distance to GN-z11 spectroscopically by splitting the light into its component colours.
"Our spectroscopic observations reveal the galaxy to be even further away than we had originally thought, right at the distance limit of what Hubble can observe," explains Gabriel Brammer of the Space Telescope Science Institute and second author of the study.
This puts GN-z11 at a distance that was once thought only to be reachable with the upcoming NASA/ESA/CSA James Webb Space Telescope (JWST).
"We've taken a major step back in time, beyond what we'd ever expected to be able to do with Hubble. We managed to look back in time to measure the distance to a galaxy when the Universe was only three percent of its current age," says Pascal Oesch of Yale University and lead author of the paper."
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The assumption that redshift is wholly due to motion may be invalid.
If the universe is infinite, then there is more matter outside the Schwarzchild radius than inside it, so light from distant galaxies will be gravitationally redshifted to a greater extent than from nearby ones.