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#213 - Cosmic Web and Rocket Flips

This Week Chris joins Matt to talk about Cosmic Webs and the mind, Italian Astronomers and Neutrino Detectors, Moon landings, and Elon's Shenanigans.



“The sun, the bright sun, that brings back, not light alone, but new life, and hope, and freshness to man--burst upon the crowded city in clear and radiant glory

Charles Dickens, Oliver Twist


Thank you to Spodcats who tuned into my other Podcast Recovering Queen and put that to #1 in the Itunes Music Commentary Podcast Chart!!!


Space Legend of the Week


Marta Burgay (30 November 1976, Torino) is an Italian radio astronomer whose initial claim to fame was being the discoverer of the first double pulsar (two pulsars orbiting each other), through using the 64-metre Parkes radio telescope in Australia. This was in her 2005 PhD paper that won the Pietro Tacchini Prize, awarded by the Italian Astronomical Society. Asteroid 198634 Burgaymarta, discovered at Vallemare di Borbona in 2005, was named in her honour



Chang’e5


This week was great for looking up at several conjunctions of Mars and the Moon, and thinking ...crikey China has space crafts currently winging their way to both!!!



So 5 days after taking off, Chang’e 5 is now in Orbit around the moon and moving into the position needed for a descent to the surface.

following a lunar orbit insertion burn at 12:58 UTC saturday. After three 8-hour orbits a 2nd burn will put CE-5 into a ~217 km circular orbit.

The landing could take place in the second half of Sunday (UTC). A CCTV report showing a mission rehearsal screen with a landing time of 20:30 UTC Sunday as we speak



I’ve noticed the Nasa congratulations on this are always followed by a slightly snide remark about, “We hope the Chinese share like we did” ...in a clear display of not understanding human psychology.


First time in 44 years, Nine missions have returned moon samples to Earth, six Apollo missions, and three robotic Luna spacecraft of the Soviet Union. Luna 24 was the last time in 1976. A few months before Marta Burgay was born.



Elon Musk has become the second richest person, after Jeff Bezos. Quite literally the Rocket men are the richest people on earth now. ...coincidence? I think not!

Yet more Starlinks went up this week, making 955 launched and 895 in orbit, The booster carrying the Starlinks was the 100th Falcon 9 launch!!! and the seventh time this 2-year-old booster has flown and landed. From September 2018!! Telstar 18, final Iridium mission, and then 4 Starlink missions, and finally this one!!!


The incredible looking Starship SN8, with amazing footage coming out of Boca Chica recently of the mating of these constructions. It’s so big and shiny.

After a few issues, SN8 had a good static fire with all three of the Raptor Engines firing perfectly and Elon says he is aiming to do a 15km Hop this week. Testing 3 Engine Ascent, the body flaps (powered by Tesla motors and batteries) the transition of using the header tanks to do the landing burns and almost the most unbelievable bit ...the landing Flip. He rates the chance as 30%, but Musk has a history of hedging his bets, as he did with Falcon Heavy. If this happens ant his shiny bird lands, this will be MIND BLOWING!!! And will overtake the Chang’e 5 moon mission as space event of the year.


Interplanetary Podcast Voter Awards


  • Best Space Event

  • Best Space Legend

  • Best rocket

  • Best bit of Science


So get your nominations in this week, then next week we can start voting, and then we’ll announce the winners on the last podcast of the year



Breakthrough in the Sun!!


The Borexino Collaboration has finally seen evidence of a process in the Sun that was theorised but never observed.

Borexino is a particle physics experiment to study low energy (sub-MeV) solar neutrinos.

The detector is the world's most radio-pure liquid scintillator calorimeter. It is placed within a stainless steel sphere which holds the signal detectors (photomultiplier tubes or PMTs) and is shielded by a water tank to protect it against external radiation and tag incoming cosmic muons that manage to penetrate the overburden of the mountain above.


Neutrinos that are emitted in fusion processes in the Sun’s core are the only direct probe of the deep interior.


Stars pretty much are fuelled by the fusion of hydrogen into helium. This fusion is understood theoretical in great detail, to happen via two processes, the proton– proton (pp) chain and the carbon–nitrogen–oxygen (CNO) cycle.


The Neutrinos are released by both processes, but 99% of the suns energy comes from the pp chain.

The neutrinos from this process have been observed comprehensively by the Borexino, but they have never spotted the neutrinos from the 1% CNO cycle. ...until now.

They have been incrementally improving the sensitivity of the detector over 5 years, this has been done by thermal stabilization, which has allowed them to compensate for noise in the signal (caused in this case by bismuth-210 decay contamination).


They are only counting a few neutrinos a day associated with the CNO, so this noise had to be reduced for this tiny signal to make it over the noise floor.

AS the name of the CNO suggests it is dependant on Carbon, nitrogen and Oxygen, and this now has become a feasible route to measuring the abundance of those atoms in the solar core, the solar metallicity. Even though in the sun the CNO is ly 1% in massive stars it actually is the dominant process. This is the first time that CNO has been experimentally observed despite it being the primary mechanism for the conversion of hydrogen to helium in the universe. ….possible Nobel prize here?


Space Word of the Week

THE COSMIC WEB



Working on a little collaboration with the space store and George and one of the ideas I had recently that George has been doing a little 3D animation of was the Cosmic web turning in to to the human brain and the synapses


But it turned out lots of other people have been thinking about this idea was an exhibition last year in San Francisco called as above as below with this connection between the universe and the human mind and recently a paper was on to the archive that looks at some of these similarities but I thought what a great space word of the week cosmic web


So what is the cosmic web exactly?

Incredible when you look up at the night sky and you see all the star up there and you think they're all randomly and evenly spread out, there are little lumps there, but that’s what you'd expect from a kind of random distribution. What's more extraordinary is the stars that we see in the night sky are really all very close to us, we can virtually see no other galaxies, except maybe Andromeda if you've got very dark skies, very good eyesight and you can just about see that as a smudge, that and a couple of other galaxies. They are the most distant objects you can see. Most of the stars in our own galaxy we don't see we just see the local stars around us so discovering the Cosmic web is indeed one of the most incredible achievements of humankind.

If you have something as powerful as Hubble, again really the galaxies are a bit like our local stars, they all seem pretty evenly spread out. But astronomers have looked closer and found this isn't really the case at all.

There is a scale at which you look at the universe and clearly see a structural pattern the Cosmic Web. The galaxies and Galaxy clusters and gases in filament stretch out across the universe like a web with large voids in between.

In the early universe near the big bang, everything was very very smooth, but probably due to quantum variations, there was a tiny tiny uniformness.

Overtime this tiny tiny non-uniform slightly denser areas are made denser by the attractive force of gravity, but it will take millions of years for them to collect enough matter and increase their density before the first stars are formed. As we heard a few weeks ago from Emma Chapman, these first stars are still a bit of a mystery and are the next hot topic of discovery.

How did the voids get there

Baryonic Acoustic Oscillations

Fossilised into the night sky by way of the distribution of galaxies.

Since the Big Bang, 13.7 billion years ago, the universe has passed through many different phases, it arguably saw more activity and change during the first second than in all the billions of years since. The observable universe was approximately 10 light-years in radius after a second

After the first 1 millionth of a second and for the first 379,000 years the universe was a plasma of electrons, protons, neutrons and other Baryonic matter, dark matter and Photons, Why a plasma?, it was just WAY too hot for any atoms to form.

In this intense glowing opaque soup, the photons couldn’t escape as light, as they would bump into electrons and basically just couldn’t go in a straight line, there essentially was no light.


But as this bubble of plasma, ie the universe expanded it was also cooling of course and at 379,000 years in we have an event called recombination, as the plasma reaches 3000K the electrons are captured by the protons and neutrons and we have the first Atoms in the universe, Hydrogen. At this point we have photons able to travel in straight lines and Light is born!!! Observable Universe had a radius of approximately 42 million light-years at the time of recombination.


This event is just a miracle as it gives us a window into all that happened before. There is a spherical shell ever-expanding away from us from this period and is called the surface of last scattering, where the recombination happened and light first entered the universe. As the universe has expanded the light waves have been stretched (redshifted) to the microwave spectrum. The map of this surface is the famous CMB, Cosmic Microwave background and is a Mollweide map to show the equal area as that is the important factor astronomers wished to preserve. The spectrum is so precisely that of black body radiation, the observed and theoretical curve are impossible to tell apart. The universe has expanded so far now that the temperature has dropped to 2.72 K.

So what about these acoustic oscillations, well these are vital in telling what was happening to this plasma before the recombination event, as we can’t see beyond this event, but we can see the fossils of these vibrations. In fact, we can actually see to a point when the Universe was subatomic in size, cosmologists believe that random quantum fluctuations in this tiny universe are expanded during inflation, which did a good job at smoothing out the universe, but still would have left density fluctuations.

These tiny density fluctuations would have pulled the dark matter towards them gravitationally, but as a result trapped photons would start exerting a radiation pressure outwards carrying the baryonic matter with it and started a true sound wave, a pressure fluctuation propagating through the plasma at the speed of sound, which in the plasma medium is a whopping ½ the speed of light. The Plasma is ringing like a bell, These massive sound bubbles expanded for the duration of Epoque before recombination, but at the point of recombination, they were essentially frozen, as the speed of propagation dropped from ½ the speed of light to a few 100m per second. The radius of the shell of this acoustic bubble became fixed with the expansion of the universe, and is called the sound horizon and was about 500,000 light-years.



Due to the expansion of the Universe, these acoustic bubbles will now be 500 million light-years across. But can we see them? ...hell yes!!! If you tally up the distances between all the galaxies from one another you get a lovely smooth graph except there is a bump at this magical 500 million light-years, the distance from the centre of the acoustic oscillation where all the dark matter gathered, and therefore where loads of galaxies formed and the out edge of the sound horizon where a density area would also form galaxies.

Spotted in 2005 by the Sloan digital sky survey in the north and the 2df in the southern sky, and is exactly the number expected and is a stunning experimental proof of dark energy

By looking at the patterns in the cosmic background radiation, we know how big the rings were when they formed and how big they are now, and this gives us the expansion rate of the universe and it agrees with the standard candle measurement, at least in that the universe expansion is accelerating, a stunning proof of dark energy and how it follows Einstein’s cosmological constant.

Hey but that’s not ALL, thinking about the Acoustic oscillations in more detail, and the fluctuations in the heat (anisotropy) we can see in the CMB from satellites like ESA’s Planck (see episode 70), WMAP and COBE we can go even further, The power spectrum of these heat differences can be mapped out as a smooth graph that has several peaks, the first peak tell us about the curvature of the universe (it appears flat), the second peak tells us about the density of the baryonic matter, the third peak the dark matter density. The fossil of the Acoustic vibrations of the early universe is revealing the nature of the Cosmos in just unbelievable details ..we live in amazing times.


So

After 10s of millions of years the firsts stars formed, as gravity propagated through the universe, then 100s of millions of years the first galaxies were formed, then billions of years the galaxy Clusters and then superclusters and the vast filaments of gas joining all these structures up, and this is a huge clue to how the Universe formed, as it plays out in Computer simulations.

Gravity is essentially building the Cosmic web over time from the smallest structures and as it moves through the vastness of the expanding universe it pulls together bigger and bigger structures in this cosmic web. You go from smooth to stringy

But there is a limit to this structure and its permanency. Yes Gravity has been propagating through and pulling all these large structures together, but it’s been playing a catchup game with Darke Energy and it seems it’s now starting to lose, the huge structures that our local group of galaxies are in, are actually not going to collapse further. Take Laniakea, Hawaiian for immense heaven, the galaxy supercluster that is home to the Milky Way and approximately 100,000 other nearby galaxies, this structure unlike the structures contained within is doomed to fall apart.

The Universe is maybe at peak structure right now, part of the cosmic web will continue to collapse and get denser, while larger structures are torn apart by dark energy which eventually will encroach on everything and pull it all apart, until the heat death of the universe.


There have been a few papers recently remarking on the similarity between the structure of the Universe and that of the Human Brain, and it is indeed remarkable how similar these structures look. Yet clearly Gravity is the big cause of one and biology the big cause of the other, but there are certain principles that are at play that create these patterns at the vast and tiny scales, and that is profoundly interesting.

The brain is a billion billion billion times smaller yet has around 69 billion neurons; the cosmic web contains over 100 billion galaxies. neurons in the brain, galaxies in the Universe are connected via filaments, The brain is around 77 per cent water. The Universe is around 72 per cent dark energy. The analysis showed that the distribution of the fluctuation within the cerebellum neuronal network follows the same progression of the distribution of matter in the cosmic web but on a completely different scale of course. They have roughly 4 connections per node. Interesting that a human experience could be encoded theoretically in the structure of the Universe.

So what is more remarkable the structure of the Universe or the Brain in that case?

The Quantitative Comparison Between the Neuronal Network and the Cosmic Web F. Vazza A. Feletti



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