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Universe's Expansion Rate Is Different Depending on Where You Look
Space.com ^ | July 13, 2018 | Elizabeth Howell, Space.com Contributor

Posted on 07/17/2018 7:33:25 AM PDT by ETL

Our universe's rate of expansion keeps getting stranger. New data continues to show a discrepancy in how fast the universe expands in nearby realms and more distant locations. 

The study's researchers said this "tension" could mean we need to revise our understanding of the physics structuring the universe, which could include exotic elements such as dark matter and dark energy.

New measurements from the Hubble Space Telescope and the Gaia space telescope together showed that the rate of expansion nearby is 45.6 miles per second per megaparsec. This means that for every 3.3 million light-years a galaxy is farther away from Earth, it appears to move 45.6 miles per second faster.

But the more distant background universe, according to previous measurements from the Planck telescope, is moving somewhat slower at 67 kilometers (41.6 miles) per second per megaparsec.

In fact, the discrepancy between the two measurements keeps getting wider as the researchers refine their work. The new data shows a wider gap between the measurements that is about four times the size of their combined uncertainty — a value that reflects their level of confidence in the results — team members said in a statement.

"At this point, clearly it's not simply some gross error in any one measurement," lead author Adam Riess, a senior member of the science staff at the Space Telescope Science Institute (STScI) in Baltimore, which manages Hubble operations, said in the statement.

"It's as though you predicted how tall a child would become from a growth chart, and then found the adult he or she became greatly exceeded the prediction. We are very perplexed," added Riess, who is also an astronomy and physics professor at Johns Hopkins University in Baltimore.

Variable stars and background radiation

The universe is expanding and accelerating in its expansion as it grows, for reasons that are poorly understood. Some scientists suggest this is due to contributions from dark matter and dark energy, which are mysterious forms of matter and energy that are visible only through their influence on other objects. Others suggest there may be an undiscovered type of subatomic particle responsible for the expansion, according to the statement.

Hubble and Gaia performed their measurements by examining Cepheid variables, a type of star that brightens and dims in a predictable pattern. The pattern allows scientists to learn how far away these stars are from us. The data is then used to measure the universe's expansion rate, which is also called the Hubble constant. That constant is also used to estimate the age of the universe, which makes it a fundamental equation for astronomers.

Planck, however, focused on what the universe used to look like some 360,000 years after the Big Bang that formed our universe (which happened about 13.8 billion years ago). The echoes of the Big Bang form a microwave signature across the entire sky that is called the cosmic microwave background. Planck measures the size of the ripples, which shows information such as how much dark matter there is, how much normal matter there is, and the trajectory of the universe's expansion.

"These measurements, still being assessed, allow scientists to predict how the early universe would likely have evolved into the expansion rate we can measure today," STScI representatives said in the statement. "However, those predictions don't seem to match the new measurements of our nearby contemporary universe."

Riess and his team members have been refining their measurements of the universe's expansion rate since 2005, under an initiative known as Supernova H0 for the Equation of State (SHOES). The latest measurements have an uncertainty of only 2.2 percent, in large part due to the addition of data from Gaia — a newer telescope that can map the movements of stars to high precision.

Gaia's contribution was measuring the distance to 50 Cepheid variables in the Milky Way, while Hubble measured the Cepheids' brightness. The two telescopes' combined efforts allowed astronomers to "more accurately calibrate the Cepheids and then use those [Cepheids] seen outside the Milky Way as outpost markers," STScI said.

The collaboration aims to reduce the Hubble constant uncertainty to 1 percent by the 2020s, but as for the new results, a study based on them was published July 12 in the Astrophysical Journal.


TOPICS: Astronomy; Chit/Chat; Science
KEYWORDS: cepheidvariables; gaiaspacetelescope; haltonarp; hst; hubbleconstant; hubbletelescope; plancktelescope; redshift; stringtheory; universe
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1 posted on 07/17/2018 7:33:25 AM PDT by ETL
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My own suspicion is that the Universe is not only queerer than we suppose, but queerer than we can suppose.--J. B. S. Haldane
2 posted on 07/17/2018 7:34:53 AM PDT by ETL (Obama-Hillary, REAL Russia collusion! Uranium-One Deal, Missile Defense, Iran Deal, Nukes: Click ETL)
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To: ETL

Looks normal here..................


3 posted on 07/17/2018 7:34:58 AM PDT by Red Badger (July 2018 - the month the world discovered the TRUTH......Q Anon)
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To: ETL

When Robert J.Ringer had gained weight once he said

“I’m thankful the universe is expanding-—I need the room!”


4 posted on 07/17/2018 7:35:10 AM PDT by frank ballenger (End non-citizen voting ,vote fraud & leftist media news censorship or we're finished.)
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more CYA gibberish from the intellectual elites who dont know jack....


5 posted on 07/17/2018 7:35:34 AM PDT by raygunfan
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To: ETL

Was he slamming Elton John and Rachel Maddow or supporting them?


6 posted on 07/17/2018 7:36:29 AM PDT by frank ballenger (End non-citizen voting ,vote fraud & leftist media news censorship or we're finished.)
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To: ETL

How can they know the distance of the most distant galaxies and then say the Red Shift is lower? They use the Red Shift to determine that distance.


7 posted on 07/17/2018 7:37:07 AM PDT by DungeonMaster (...the light has come into the world, and men loved darkness rather than light...)
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To: ETL

Maybe there were two big bangs....


8 posted on 07/17/2018 7:37:41 AM PDT by pepsionice
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To: SunkenCiv

*ping*


9 posted on 07/17/2018 7:41:48 AM PDT by fieldmarshaldj ("It's Slappin' Time !")
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To: DungeonMaster
How can they know the distance of the most distant galaxies and then say the Red Shift is lower? They use the Red Shift to determine that distance.

Redshifts are determined by estimating the distances to objects via other distance measuring techniques. Then a distance is associated with that particular redshift.

From the article: "Hubble and Gaia performed their measurements by examining Cepheid variables, a type of star that brightens and dims in a predictable pattern. The pattern allows scientists to learn how far away these stars are from us. The data is then used to measure the universe's expansion rate, which is also called the Hubble constant. That constant is also used to estimate the age of the universe, which makes it a fundamental equation for astronomers."

10 posted on 07/17/2018 7:44:56 AM PDT by ETL (Obama-Hillary, REAL Russia collusion! Uranium-One Deal, Missile Defense, Iran Deal, Nukes: Click ETL)
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To: ETL

Women and children most adversely affected


11 posted on 07/17/2018 7:46:28 AM PDT by a fool in paradise (Spygate's clock began in 2015 - what did President Obama know and when did he know it)
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To: DungeonMaster
How can they know the distance of the most distant galaxies and then say the Red Shift is lower? They use the Red Shift to determine that distance.

What do the Democrats have to say about the Red Shift within their party? Is it faster on the east or west coast? By how many light years per parsec? Drs. Schummer and Pelosie want to know as do Sheldon Cooper and George Soros.

12 posted on 07/17/2018 7:47:05 AM PDT by Don Corleone (Nothing makes the delusional more furious than truth.)
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To: All

“In physics, redshift happens when light or other electromagnetic radiation from an object is increased in wavelength, or shifted to the red end of the spectrum.

In general, whether or not the radiation is within the visible spectrum, “redder” means an increase in wavelength – equivalent to a lower frequency and a lower photon energy, in accordance with, respectively, the wave and quantum theories of light.

Some redshifts are an example of the Doppler effect, familiar in the change of apparent pitches of sirens and frequency of the sound waves emitted by speeding vehicles. A redshift occurs whenever a light source moves away from an observer.

A special instance of this is the cosmological redshift, which is due to the expansion of the universe, and sufficiently distant light sources (generally more than a few million light years away) show redshift corresponding to the rate of increase in their distance from Earth.

Finally, gravitational redshift is a relativistic effect observed in electromagnetic radiation moving out of gravitational fields.

Conversely, a decrease in wavelength is called blueshift and is generally seen when a light-emitting object moves toward an observer or when electromagnetic radiation moves into a gravitational field.

However, redshift is a more common term and sometimes blueshift is referred to as negative redshift.

Knowledge of redshifts and blueshifts has been applied to develop several terrestrial technologies such as Doppler radar and radar guns.[1]

Redshifts are also seen in the spectroscopic observations of astronomical objects.[2] Its value is represented by the letter z.

A special relativistic redshift formula (and its classical approximation) can be used to calculate the redshift of a nearby object when spacetime is flat.

However, in many contexts, such as black holes and Big Bang cosmology, redshifts must be calculated using general relativity.[3]

Special relativistic, gravitational, and cosmological redshifts can be understood under the umbrella of frame transformation laws.

There exist other physical processes that can lead to a shift in the frequency of electromagnetic radiation, including scattering and optical effects; however, the resulting changes are distinguishable from true redshift and are not generally referred to as such (see section on physical optics and radiative transfer).”

https://en.wikipedia.org/wiki/Redshift


13 posted on 07/17/2018 7:49:20 AM PDT by ETL (Obama-Hillary, REAL Russia collusion! Uranium-One Deal, Missile Defense, Iran Deal, Nukes: Click ETL)
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To: raygunfan
”more CYA gibberish from the intellectual elites who dont know jack...”

If you mean posts like yours, yes.

14 posted on 07/17/2018 7:49:23 AM PDT by mlo
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To: Don Corleone
What do the Democrats have to say about the Red Shift within their party? Is it faster on the east or west coast? By how many light years per parsec? Drs. Schummer and Pelosie want to know as do Sheldon Cooper and George Soros.

Not to be confused with red states which is a good red. Red is so confusing!

15 posted on 07/17/2018 7:49:30 AM PDT by DungeonMaster (...the light has come into the world, and men loved darkness rather than light...)
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To: DungeonMaster
They use the Red Shift to determine that distance.

The red shift is just a first-order way to estimate the distance. If the Hubble Parameter (which used to be called the Hubble Constant when people thought it was constant) was a simple constant, that's a straightforward calculation. When it became more complex it becomes more of a table lookup, but as a first order it's still fairly valid. By that, it means that for items without some better way to estimate their distance, it's a good start.

The best way to estimate the distance to some deep space object is by measuring the apparent brightness of something with a known absolute or intrinsic brightness. The article mentions Cepheid variables which are a very good way to do that, and form the basis for Edwin Hubble's first recognition that the universe was much larger than the Milky Way, and eventually to identify the Hubble Constant. However, in detail it is known to have limitations because some galaxies are influenced by galactic clusters and so their relative motion is not solely due to the expansion of the universe. For example, Andromeda galaxy is approaching us, not receding.

Type 1A supernovae are the most distant distinctly observable phenomena for which we believe we know the intrinsic brightness and enough about the spectrum that we can determine both their absolute distance (from apparent versus intrinsic brightness) and relative velocity (from red shift of the spectrum). They are the main reason we now think the Hubble "Constant" is not really constant, but drops off with distance (or, conversely, increases as you get closer in distance and time). That accelerating expansion is not explained by gravity - in fact, it contradicts the expected effect of gravity. Since the velocity (and hence energy) of observed objects seems to be increasing, they call the mechanism we can't otherwise detect "dark energy."
16 posted on 07/17/2018 7:53:11 AM PDT by Phlyer
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To: ETL
From the article: "Hubble and Gaia performed their measurements by examining Cepheid variables, a type of star that brightens and dims in a predictable pattern. The pattern allows scientists to learn how far away these stars are from us. The data is then used to measure the universe's expansion rate, which is also called the Hubble constant. That constant is also used to estimate the age of the universe, which makes it a fundamental equation for astronomers."

I suspect that is a bit misleading. I don't think they are measuring Cepheid variables at 14,000,000,000 light years.

Well, I guess they don't need to. If they can measure them at 10,000,000 light years and see the redshift variation nearby and then extrapolate.

It is a lot like we are not at the center of the Big Bang which I don't believe in.

17 posted on 07/17/2018 7:53:14 AM PDT by DungeonMaster (...the light has come into the world, and men loved darkness rather than light...)
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To: pepsionice

two big bangs....


the origin of TV series re-runs.


18 posted on 07/17/2018 7:55:35 AM PDT by frank ballenger (End non-citizen voting ,vote fraud & leftist media news censorship or we're finished.)
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To: ETL

I still theorize (though the geniuses have said I’m wrong) that the stream of particles leaving every galaxy (light among them) is pushing on every other galaxy, thus removing the need for “dark” anything to accelerate universe expansion.

It wouldn’t be the first time I’ve theorized something and later been found right, so I’ll stick with it till I am.


19 posted on 07/17/2018 7:56:29 AM PDT by TheZMan (I am a secessionist.)
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To: Don Corleone

Research CEPHEID VARIABLES.


20 posted on 07/17/2018 7:57:30 AM PDT by TexasGator (Z1)
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