List members , this is mouth watering...sorry , but I can't contain my excitement as more such findings keep coming to light from the JWST . Trust me - we are going to WIN this battle that's raging at the core of science !
Regards
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Here's the transcript for the video if anyone is interested in reading or skimming instead of watching:
[Music] Have you ever wondered how fast the universe is expanding?
And why different methods of measuring this expansion rate give different results?
This is one of the biggest mysteries in cosmology, known as the Hubble Tension.
But what if I told you that a single supernova, observed by the most powerful telescope ever built, could help solve this mystery?
And not just any supernova, but a supernova that appeared in three different images due to a cosmic phenomenon called gravitational lensing.
Sounds amazing, right?
Well, that's exactly what happened recently, when the James Webb Space Telescope made a remarkable discovery that could change our understanding of the universe.
In this video, we will explore this discovery and explain how it can help us resolve the Hubble tension.
We will also learn about the details of the supernova and the galaxy cluster that caused the gravitational lensing effect.
And finally, we will discuss how James Webb and other telescopes can use this supernova to test various cosmological models and reveal the secrets of the universe.
So buckle up and get ready for a cosmic adventure.
Let's start with the discovery itself.
When did it happen, and how did James Webb observe it?
Well, it happened on January 12, 2023, when James Webb was pointing at a patch of sky in the constellation of Leo.
One of Webb's main goals is to study the formation and evolution of galaxies, stars, planets, and even life.
As Webb was scanning the sky, it detected a bright flash of light that lasted for a few seconds.
This flash was a type 1a supernova, which is a type of exploding star that occurs when a white dwarf star accretes too much mass from a companion star and reaches a critical point.
A white dwarf is the remnant of a low-mass star that has exhausted its nuclear fuel and collapsed into a dense sphere about the size of Earth.
Type 1a supernovae are very bright and emit a lot of energy in the form of light and radiation.
It can outshine an entire galaxy for a brief period of time.
But what made this supernova so special was not just its brightness, but also its appearance.
When James Webb looked at the images it took, it noticed something very strange.
The supernova appeared in three different places in the same image.
How is that possible?
Well, this is where things get really interesting.
The reason why the supernova appeared in three different images was because of a cosmic phenomenon called gravitational lensing.
It is an effect that occurs when a massive object bends the space-time around it and and acts like a lens that magnifies or distorts the light coming from behind it.
This massive object can be anything from a star to a galaxy to a cluster of galaxies.
In this case, it was a cluster of galaxies that was located between James Webb and the supernova.
This cluster, named Max J 1149, has a mass equivalent to about 10 trillion suns and contains hundreds of galaxies.
It is so massive that it creates a huge gravitational field that warps the spacetime around it.
As the light from the supernova traveled through this warped spacetime, it followed different paths depending on its angle and distance from the cluster.
Some of these paths converged at Webb's position, creating multiple images of the same source.
This is similar to how a glass prism splits white light into different colors, or how a water droplet creates rainbows.
The result was that James Webb saw three images of the same supernova at different positions and magnifications in its field of view.
This triple-lens supernova was named Supernova Hope by its discoverers, who were part of an international team of astronomers led by Dr.
Stephen Rodney from the University of South Carolina.
The name "Hope" refers to both Hope and H0, which is the symbol for the Hubble constant, which measures the expansion rate of the universe.
Why did they choose this name?
Because this supernova could help solve one of the biggest mysteries in cosmology, the Hubble tension.
So what is the Hubble tension, and how can this supernova help solve it?
Well, as you may know, our universe is not static but expanding.
This means that distant galaxies are moving away from us at a certain speed that depends on their distance from us.
The farther away they are, the faster they move away from us.
This relationship between distance and speed is known as Hubble's Law, named after Edwin Hubble, who discovered it in 1929.
The Hubble Constant, or H0, is the proportionality factor that relates distance and speed in Hubble's Law.
It tells us how fast the universe is expanding at the present time.
But here's the problem.
Different methods of measuring H0 give different results, and these results are not just slightly different, but significantly different, with a discrepancy of about 10%.
This discrepancy is known as the Hubble tension, and it implies that either our measurements are wrong, or our understanding of the universe is wrong, and neither option is very appealing.
One way to measure H0 is to use the Cosmic Microwave Background, CMB, which is the oldest light in the universe that was emitted about 380,000 years after the Big Bang.
The CMB contains tiny fluctuations in temperature and density that reflect the initial conditions of the universe.
By analyzing these fluctuations, we can infer the properties of the universe, such as its age, composition, geometry, and expansion rate.
This method gives a value of H0 of about 67 km/s per megaparsec, which means that for For every megaparsec, about 3.
3 million light-years of distance, galaxies are moving away from us at 67 km/s.
Another way to measure H0 is to use standard candles, which are objects whose brightness or luminosity is known or can be calculated.
By comparing their apparent brightness, how bright they appear to us, with their intrinsic brightness, how bright they actually are, we can estimate their distance from us.
And by measuring their redshift, which is the amount by which their light is stretched or shifted towards the red end of the spectrum due to their motion away from us, we can estimate their speed from us.
By combining these two measurements, we can apply Hubble's law and calculate H0.
One of the most commonly used standard candles are 1A supernovae, which have a very consistent luminosity that can be calibrated by observing them in nearby galaxies.
This method gives a value of H0 of about 74 km/s per megaparsec, which is much higher than the CMB method.
So which method is right and which one is wrong?
Or are they both wrong?
Or are they both right, but there is something else going on in the universe that we don't understand?
These are the questions that puzzle cosmologists and challenge our current models of the universe.
This is where supernova H0P comes in.
Because this supernova was gravitationally lensed by a galaxy cluster, it offers a unique opportunity to measure H0 in a new and independent way.
How?
Well, remember that gravitational lensing creates multiple images of the same source at different positions and magnifications.
But it also creates another effect.
Time delay.
Time delay is the difference in arrival.
Time between different images of the same source due to their different paths through space-time.
the longer the path, the longer it takes for the light to reach us.
This means that we see different images of the same source at different times, as if we were watching a movie with multiple screens that are not synchronized.
By measuring this time delay between different images of the supernova, we can infer how much space-time is warped by the galaxy cluster and how far away it is from us and from the supernova.
And by knowing these distances, we can apply Hubble's law and calculate H0.
This method has been used before with other lensed supernovae and quasars, which are very bright and active galaxies powered by supermassive black holes.
But Supernova H0P is special because it has three images instead of two, which gives more information and reduces uncertainties.
It also has very high quality data from James Webb and other telescopes that can measure its brightness and redshift with great precision.
By using this method, Dr.
Rodney and his team estimated a value of H0 of about 71 km/s per megaparsec, which is closer to the standard candle method than to the CMB method.
This suggests that there may be something wrong with the CMB method, or that there may be some new physics involved in the early universe that affects its expansion rate.
But this is not the end of the story.
Supernova H0P still has more secrets to reveal and more tests to undergo.
Because it is so rare and so well observed, it can also be used to test various cosmological models and parameters that affect the expansion rate of the universe.
One of these parameters is dark energy, which is a mysterious form of energy that makes up about 70% of the universe and causes its accelerated expansion.
It is usually described by an equation of state parameter called W, which relates its pressure and density.
The simplest model of dark energy assumes that W is constant and equal to -1, which corresponds to a type of dark energy called cosmological constant or vacuum energy.
But other models allow W to vary over time or space, or have different values in different regions of the universe.
By measuring the brightness and redshift of H0p and comparing it with other type 1a supernovae, we can constrain the value of W and test these models.
Another parameter is the curvature of the universe, which describes its shape and geometry.
The simplest model of the universe assumes that it is flat, which means that parallel lines never meet and that the angles of a triangle add up to 180 degrees.
But other models allow the universe to be curved, either positively, like a sphere, or negatively, like a saddle.
By measuring the angular size and distance of supernova H0P and comparing it with other lensed sources, we can constrain the value of the curvature and test these models.
And there are more parameters and models that supernova H0P can help us test, such as modified gravity theories, early dark energy models, interacting dark matter models, and more.
Each of these models tries to explain the Hubble tension in a different way, either by introducing new physics or modifying existing physics.
But they also make different predictions for other observables, such as the growth of cosmic structures, the formation of stars and galaxies, and the distribution of matter and radiation in the universe.
By comparing these predictions with the data from this supernovae and other sources, we can rule out some models and favor others.
In conclusion, Supernova H0P is a remarkable discovery that could change our understanding of the universe.
It is a rare and well-observed Type 1a supernova that appeared in three different images due to the gravitational lensing effect of a massive galaxy cluster.
It offers a unique opportunity to measure the expansion rate of the universe in a new and independent way, and to test various cosmological models and parameters that affect this expansion rate.
It could help us solve one of the biggest mysteries in cosmology, the Hubble tension.
It could also reveal new physics or challenge existing physics in the early or late universe.
It is a cosmic treasure that JWST and other telescopes will continue to study and explore for years to come.
Thank you for watching this video.
I hope you enjoyed it and learned something new.
If you have any questions or comments, please feel free to share them below.
And don't forget to subscribe to this channel for more videos like this one.
See you next time.
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Thanks a lot @Soretna ! Our world is distracted so much by wars , pandemics and socio-economic turmoil that such news never hits the headlines . This is truly in the "BREAKING NEWS" Category :))
This has tremendous implications for the DEEPLY FLAWED scientific paradigms that are being taught to all kids in schools , colleges and even to PhD scholars !
Before the science establishment "blacks out" findings from the JWST too , let us spread the awareness about these rare insights that are somehow trickling into the public domain .
Regards