An inconstant Hubble constant? Research suggests fix to cosmological cornerstone
More than 90 years ago, astronomer Edwin Hubble observed the first hint of the rate at which the universe expands, called the Hubble constant.
Almost immediately, astronomers began arguing about the actual value of this constant, and over time, realized that there was a discrepancy in this number between early universe observations and late universe observations.
Early in the universe’s existence, light moved through plasma there were no stars yet and from oscillations similar to sound waves created by this, scientists deduced that the Hubble constant was about 67. This means the universe expands about 67 kilometers per second faster every 3.26 million light-years.
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More than 90 years ago, astronomer Edwin Hubble observed the first hint of the rate at which the universe expands, called the Hubble constant.
Almost immediately, astronomers began arguing about the actual value of this constant, and over time, realized that there was a discrepancy in this number between early universe observations and late universe observations.
Early in the universe s existence, light moved through plasma there were no stars yet and from oscillations similar to sound waves created by this, scientists deduced that the Hubble constant was about 67. This means the universe expands about 67 kilometers per second faster every 3.26 million light-years.
But this observation differs when scientists look at the universe s later life, after stars were born and galaxies formed. The gravity of these objects causes what s called gravitational lensing, which distorts light between a distant source and its observer.
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IMAGE: Schematical representation of the expansion of the Universe over the course of its history. view more
Credit: NAOJ
An international research team analyzed a database of more than 1000 supernova explosions and found that models for the expansion of the Universe best match the data when a new time dependent variation is introduced. If proven correct with future, higher-quality data from the Subaru Telescope and other observatories, these results could indicate still unknown physics working on the cosmic scale.
Edwin Hubble s observations over 90 years ago showing the expansion of the Universe remain a cornerstone of modern astrophysics. But when you get into the details of calculating how fast the Universe was expanding at different times in its history, scientists have difficulty getting theoretical models to match observations.
Date Time
Charting Expansion History of Universe with Supernovae
Schematical representation of the expansion of the Universe over the course of its history.(Credit:NAOJ)
An international research team analyzed a database of more than 1000 supernova explosions and found that models for the expansion of the Universe best match the data when a new time dependent variation is introduced. If proven correct with future, higher-quality data from the Subaru Telescope and other observatories, these results could indicate still unknown physics working on the cosmic scale.
Edwin Hubble’s observations over 90 years ago showing the expansion of the Universe remain a cornerstone of modern astrophysics. But when you get into the details of calculating how fast the Universe was expanding at different times in its history, scientists have difficulty getting theoretical models to match observations.
Home > Press > 3D design leads to first stable and strong self-assembling 1D nanographene wires
Schematic illustration of hierarchical structures of carbon nanofiber bundles made of bitten warped nanographene molecules.
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NINS/IMS
Abstract:
Nanographene is flexible, yet stronger than steel. With unique physical and electronic properties, the material consists of carbon molecules only one atom thick arranged in a honeycomb shape. Still early in technological development, current fabrication methods require the addition of substituents to obtain a uniform material. Additive-free methods result in flimsy, breakable fibers until now.
3D design leads to first stable and strong self-assembling 1D nanographene wires
Tokyo, Japan | Posted on April 6th, 2021