Title: James Webb founds galaxies that could challenge modern theories!
The James Webb Space Telescope is the largest ever built. It was designed by researchers
from NASA, ESA, and CSA (the Canadian space agency). An international collaboration that
could mark a milestone in space observation. There are several images captured by the Webb
telescope, and they concern various bodies: planets, asteroids, and clusters of galaxies.
But there is a very particular one.
The galaxy that you see has a tiny red blob in this image has been dubbed GLASS Z13.
It is thought to be the most distant galaxy ever known, and it was spotted by the James
Webb Space Telescope. It lies at approximately redshift 13, that's where its name comes from.
This discovery was presented in July 2022, but now, only a few days later, some papers
came out, claiming that even more unusual galaxies – and more extreme – were found
among the data provided by the amazing James Webb Space Telescope.
This new chat is currently going on on Twitter despite the studies being still preliminary
and not peer-reviewed. Of course, in the next months we will have a more precise idea, but
why don't we talk about what the papers say?
You'll see that, if they got it right, they suggest the existence of galaxies that sort
of break modern theories.
Follow me in this video to get to know about the oldest galaxies in the universe, and more!
===================================================== As we've already said, the new discovery we
are going to discuss is still absolutely preliminary, but could forever change the way we see the
universe, especially the way we see the early universe, when the first objects, such as
stars and galaxies, were forming.
What these data basically suggest is that we might have underestimated the age by which
galaxies formed. But if this turns out to be true, we might also have underestimated
the age of the first forming stars. This discovery is breaking all the rules,
and if the results are confirmed, we are in trouble.
For example, they contradict a lot of the early predictions and a lot of modern understanding
when it comes to the evolution of the universe. But why?
Let's start from the basics, from what our theories predict about the early phases of
the universe. Let's only see the key points.
1) The Big Bang happens and the universe appears everywhere as a very
hot, very dense, single point in space. The afterglow of light and radiation left
over from the Big Bang is contained in the so-called cosmic microwave background, which
we can still observe and study in great detail.
Then, in a very small fraction of a second,
the universe undergoes an incredible growth spurt. This is known as inflation. During
the inflation phase, the universe doubled in size at least 90 times.
As the universe expanded, it got cooler and less dense. This allowed the matter to form.
3) Light elements are created within the first three minutes.
In fact, as the universe expanded, protons and neutrons collided to make deuterium, which
is an isotope of hydrogen. Much of this deuterium is combined to make helium.
Up to this point, however, the universe was still too hot to shine, because atoms at high
temperatures were colliding, forming a plasma of protons, neutrons, and electrons that scattered
light as a fog.
4) Then, at an estimated age of about 380.000 years after the Big Bang, the universe still
expanding, and matter cooled enough for electrons to combine with nuclei, to form neutral atoms.
This is the so-called recombination phase, and at this point, the fog finally went away,
and the universe became transparent. Photons were finally free to travel. But this
era was soon followed by a period of darkness.
5) Dark ages After recombination, about 400 million years
after the Big Bang, the universe went dark again. This period is called re-ionization,
and we don't know exactly what happened and which objects were responsible for the reionization,
but during this period, clumps of gas collapsed enough to form the very first stars and galaxies.
6) After the re-ionization, stars and galaxies were still forming.
This is something that we know, and Hubble Space Telescope has proved it right.
For example, this image taken by HST shows a cluster of galaxies residing 10 billion
light years away.
This is basically what we need to understand the new discoveries. Let's see how they contradict
this scenario, which seems actually strong and based on solid ground.
From the big bang theory, we know that stars formed first, and then galaxies. We also know
that the recombination epoch came first, and then it was time for the re-ionization.
But the big problem with this scenario is that we have a little bit of uncertainty between
the dates these events happened, and we don't exactly know for sure when the first stars
formed stars started forming galaxies also why they
started doing so and what led them to form more complex structures.
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What scientists are trying to do in order to
answer some of these questions, is to look for the so-called population III (population
three) stars. Such stars are hypothetical stars because
scientists didn't seem to have found any of them until now. Population III stars are basically
the first stars to have formed, and therefore if they exist, they should be composed entirely
of primordial gas, hydrogen, helium, and very small amounts of lithium and beryllium.
The gas from which Pop III stars formed had not been ‘recycled’ (incorporated into,
and then expelled) from previous generations of stars, but was pristine material left over
from the Big Bang.
The only problem is that Pop III stars are entirely hypothetical at present. Despite
intense searches, no Pop III star has ever been observed. But maybe the James Webb Space
Telescope could help us find one.
In fact, JWST is supposed to be really good at finding Pop III stars, because of its ability
to see the infrared light, and infrared light, in this case, is very important because at
these distances all of the original ultraviolet light from all these very powerful stars has
actually been ratcheted into very specific infrared frequencies.
We were actually able to detect some of these frequencies with the Hubble Space Telescope,
but its limit was set at approximately 400 million years after the beginning of the universe,
instead, James Webb Space Telescope is able to see much much further! In terms of redshift,
Hubble was able to reach z = 11, while James Webb reaches z = 13.
For example, for GLASS Z13, the redshift of 13 gives us the age of about 330 million years.
What the new papers claim to have found is a bunch of objects in the iconic cluster Smacs
0723-73. This image came out in July, it was one of the first 5 Webb images to come out.
As we've said in a previous video, this cluster is also gravitationally lensed. This can be
seen from the unusual warping of the galaxies. As with every other lens, the gravitational
lens allows scientists to see much farther than would be otherwise possible.
What the teams did was analyze the raw data from all observations of this cluster, in
order to find some potential new record holder objects.
The first team basically found 55 highly redshifted galaxies and 44 of them seem to be entirely
new, but more importantly, six of them were at the redshift of over 12, and one of them
had a redshift of 16.7. This number is huge. If confirmed, it would make it the new record
holder! This would be a very young galaxy, only 230 million years old! This is of course
in contradiction with the scenario we have discussed before. Let's understand why.
If we are able to detect this light coming from such a distant galaxy, this would imply
that some of the neutral hydrogen present at that time absorbed the ultraviolet light
coming from the early stars, but would instead allow other light to pass through! This means
that such ancient galaxies already existed during the dark ages! This is something completely
unexpected, and in a certain sense, scientists hope these results are wrong!
For example, astrophysicists wouldn't know how to explain the presence of such a high
mass content in the early universe.
The second paper instead identified 88 candidates, and they say that at least one of their candidates
is at the redshift of 20. This is a huge distance and tells us that this galaxy formed when
the universe was only 180 million years old.
So, are these the final results? Of course not, they are very preliminary, and we just
need to wait for more studies to be done and peer-reviewed, but if this turned out to be
true, we would be in serious trouble! In that case, we would need a new scenario, and this
scenario has to be able to match the observations.
When it comes to science, one of the most important requirements for theory is to always
match the observations. When this doesn't happen, it probably means it's time to go
for a better theory. Or maybe our instruments and ways of measurement need to be improved.
Who knows? Anyway, I'm pretty sure that in the next months
we will hear about new discoveries: the James Webb Space Telescope Era has just started,
and the revolution is already coming...we had no doubt!
However, to confirm that the galaxy is as old as its redshift suggests it is, astronomers
will use spectroscopy to analyze the magnitude of light across a range of wavelengths for
all the galaxies Webb's Near Infrared Spectrograph instrument has found so far. This device uses
tiny, 0.1 millimeter-long, 0.2 millimeter-wide adjustable mirrors that only let in light
from target galaxies, tuning out background radiation so that astronomers can break down
a galaxy's stars by color. This will reveal both the age of the galaxies' light but also
their chemical composition, size, and temperatures. This, again, is important to test our theory,
because astronomers think the first stars, were composed mainly of lighter elements,
such as hydrogen and helium. Also, g
Given the stunning rate of Webb's discoveries, along with its ability to look as far back
as 100 million years after the Big Bang, it's highly unlikely that this is the farthest
galaxy we will see. The telescope will probably break its own
records a lot more in the coming months! Are you ready?
This video ends here! Do you think James Webb will revolutionize our understanding of the
universe? Let us know in the comment below! And if you enjoyed the video, don't forget
to share it, and I'll see you next time on the channel