As our last podcast episode, Connor and Nik interview each other. We summarize the highlight of the observatory program and our scientific works.

Why the Dark Age?

There is certainly plenty of light to go around but there is no new light being made. We won’t see any new light until the stars start to form. Hence the dark ages.
Where we left off, about 300,000 years after the big bang the universe is a balmy 3,500 degrees celsius. More or less the entire universe looks like the area just above the surface of the sun.
At this point something subtle begins to happen. During the early stages of the universe (inflation) tiny quantum fluctuations slowly grew until they were very large.
The regions of slight hot/cold we discussed in the previous episode which make up the cosmic microwave background now form regions of slightly high/low density. High density areas have slightly more gravity and pull more material towards them while the low density regions lose material.
This continued on for hundreds of millions of years. Slowly material piled together into the first galaxies and compressed further to become the first stars.
At this point the universe would be 200-400 million years old and about -200 degrees celsius. We’ve come a long way from the over a thousand trillion degrees we had early in the last episode!
The First Stars:

You may recall that at this point the universe is filled with hydrogen, helium, and a bit of lithium. This is the material which would make the first stars.
This has two major effects. First, it means the gas would cool slowly. For gas to form stars it needs to cool down and collapse to become very compact.
Second, the stars themselves would be very different. It’s quite possible that the first generation of stars with only hydrogen and helium to power their fusion would have grown to enormous sizes of around 1,000 times the mass of our sun.
The first stars would have been incredible candles in the darkness. They would shine incredibly brightly, each one thousands of times brighter than our sun.
So bright in fact that they would be able to split off electrons from hydrogen molecules.
The first population of stars would have been created in the first galaxies.
The First Galaxies:

The first galaxies would be quite different from the Milky Way Galaxy that we call home today. These galaxies would have been much smaller.
A galaxy is basically a region with above average dark matter and gas and some stars.
These galaxies would immediately begin merging with each other. The universe would be noticeably smaller and more cramped than it is today.
This means that galaxies would be constantly colliding with each other. Quickly, we end up with big galaxies that swallow up smaller ones in their path, astronomers call the process “Hierarchical Merging”.
The Universe Today:

So about 3 billion years after the big bang, star formation had really picked up. From this point, and for a couple billion more years, the universe would be in its most active star formation period.
During the next 10 billion years, the galaxies would settle to what we know today. Some ancient galaxies that look like giant balls of stars whizzing around in all directions, they dont really make new stars for themselves, they just absorb other galaxies.
The latest generation of stars also has the kinds of material around them to form rocky planets.
At this point we have essentially made it up to today as far as astronomy is concerned.

Special thanks to Colin Vendromin for the music, also thanks to Zac Kenny for the logo!

The Beginning of the Universe:

Age of the Universe: 13.8 billion year
It is just as easy to say “the universe was 1 second old” as it is to say “the universe was 10 billion degrees celsius”
It’s called the “Big Bang” for a reason, this would have been the most cataclysmic explosion ever.
The earliest moment: A Planck Epoch
At about a billion billion billion billionth of a second in, the three primary forces (electromagnetic, strong and weak nuclear force) of the standard model would be about to separate from one unified force.
After about a trillionth of a second, the universe starts to take on properties that are well represented by the standard model and has reached temperatures of about a thousand trillion degrees celsius which we can test in the lab.
However, at about a 10,000th of a second as the universe cooled to about 10 billion degrees, protons and neutrons could start to form. These are the building blocks that make up us, once they join together to make atoms, but that isn’t for a while yet.
After less than an hour from the big bang things get pretty boring. The universe has expanded enough that atoms don’t collide with each other enough to build up to bigger atoms, so mostly the universe is a big ball of very consistent plasma.
It’s important to emphasize how consistent the plasma is, fluctuations were on the scale of one in 100 thousand. So at this point the universe is about 10 million degrees and from one point to the next the temperatures are exactly the same except by about a hundred degrees. That’s very smooth!
As the universe cools to about 4000 kelvin, crossing just below the temperature of the surface of the sun, it is finally cold enough for electrons to match up with the hydrogen/helium to form neutral atoms. This happens after about 300,000 years.

Special thanks to Colin Vendromin for the music, also thanks to Zac Kenny for the logo!

Looking for Extraterrestrial life:

The Arecebo message:

The numbers one to ten
The atomic numbers of the elements hydrogen, carbon, nitrogen, oxygen, and phosphorus, which make up deoxyribonucleic acid (DNA)
The formulas for the chemical compounds that make up the nucleotides of DNA
The estimated number of DNA nucleotides in the human genome, and a graphic of the double helix structure of DNA
The dimension (physical height) of an average man, a graphic figure of a human being, and the human population of Earth
A graphic of the Solar System, indicating which of the planets the message is coming from
A graphic of the Arecibo radio telescope and the dimension (the physical diameter) of the transmitting antenna dish
Have there been any other attempts?

A second attempt at communication with aliens is the Voyager spacecrafts launched in 1977
The records contain sounds and images selected to portray the diversity of life and culture on Earth, and are intended for any intelligent extraterrestrial life form who may find them. The records are a sort of a time capsule.
Sagan and his associates assembled 115 images and a variety of natural sounds, such as those made by surf, wind, thunder and animals. To this they added audio content to represent humanity: spoken greetings in 55 ancient and modern languages and a greeting by Sagan’s six-year-old son, Nick; the inspirational message Per aspera ad astra in Morse code; and musical selections from different cultures and eras.
What are we doing to look for extraterrestrial life now?

SETI started with a NASA program but has since grown into it’s own institute. They run a lot of outreach and education. Their main goal is to detect intelligent life in the universe.
The Perseverance rover on mars is another one. Listen to the Perseverance rover episode here.
The Kepler telescope has completed its primary mission and has detected thousands of other worlds in our galaxy.
Along with JWST which would look at atmosphere of planets to study complex compounds – watch our podcast here.

Special thanks to Colin Vendromin for the music, also thanks to Zac Kenny for the logo!

We interview Mike Smith, a PhD student, at University of Hertfordshire, in the United Kingdom.

Hertfordshire in the UK
He has also spent time in Kingston at Queen’s University, working with our group.
He is also associated with the Alan Turing Institute in the UK as well.

Special thanks to Colin Vendromin for the music, also thanks to Zac Kenny for the logo!

Introduction:

Plan today is to try and solve the paradox from Living Universe E1. If life should be everywhere and we don’t see it, then what happened?
The Fermi paradox: Why don’t we see life everywhere?
Simple Solutions:

The “Rare Earth” solution just means that in some way, Earth-like planets are very rare. Maybe there is some mechanism that stops rocky planets from forming in the habitable zone.
The “Rare Chemistry” solution means that maybe Earth got lucky in having just the right mix of chemicals to support life.
The “Rare Intelligence” solution means that there is some factor which limits the development of intelligent life.
Finally, the “Rare Technology” solution means that intelligent life develops but rarely in a way that develops tools/technology.
Other Mechanism for restricting life:

“Shielded Earth” Hypothesis in which our Earth is protected by our special solar system. We know that Jupiter has absorbed many asteroids/comets that could have instead hit us and wiped out life on the planet.
“Early self-limiting life” where an early stage of life does something that inhibits growth or kills life all together.
Another possible limit on life is “late annihilation” where a civilization becomes technologically advanced but destroys itself with nuclear weapons.
Fermi paradox with life:

First, there is the “Firstborn” hypothesis. The idea is that life is as common as we think it is, we are just the first.
Another possibility is the “zoo world” hypothesis. Where Earth is an experiment by aliens to observe how life evolves.
A similar possibility is the “prime directive” hypothesis. This is popularized in star trek, where there is a collaboration of advanced civilizations that hide themselves from new civilizations until they reach a certain technology level.
A more sinister version is the “Dark forest” hypothesis. This is the idea that there are indeed many civilizations that are technologically advanced, but they are all hiding from each other.
A less sinister version is the “Secluded world” hypothesis. Where a civilization just isn’t interested in exploring, they develop really good virtual reality technology and end up just playing games and simulations instead of exploring.
Finally, the least sinister is the “Transcension hypothesis”. Where some technology vastly beyond our understanding allows a civilization to leave our universe altogether and venture into some different plane of existence.

Special thanks to Colin Vendromin for the music, also thanks to Zac Kenny for the logo!

We interview Dr. Charles Joseph Woodford, a knowledge translation specialist at Arthur B. McDonald Institute at Queen’s University.

Recently moved to Kingston to work at Queen’s University with the McDonald Institute.
From Newfoundland; Bachelor in Physics and Applied Mathematics. With also a minor in Russian studies from Memorial University of Newfoundland
PhD. in Theoretical and Numerical Astrophysics from University of Toronto.
Binary Black holes:

Black holes are essentially dead stars. There can be three kinds of BH; stellar black holes, intermediate-mass black holes, and supermassive black holes. You go up the mass axis via eating other stars or merging with other black holes.
Laser Interferometry Gravitational-wave Observatory (LIGO) first saw a black hole collision/merger in September 2015. LIGO also won the Nobel Prize in Physics in the year 2017.

Special thanks to Colin Vendromin for the music, also thanks to Zac Kenny for the logo!

Introduction:

What is life?

Life is considered a characteristic of something that preserves, furthers or reinforces its existence in the given environment This characteristic exhibits all or most of the following traits: Homeostasis, Organization, Metabolism, Growth, Adaptation, Response to Stimuli, Reproduction.
It is important as well to specify what kind of life we are looking for. One may search for intelligent life by looking for radio signals, but bacteria may just change the chemistry of a planet’s atmosphere.
Life outside Earth:

First, life exists on Earth, so we know it’s possible for complex life to evolve.
Second, the scale of the Universe. As they said in the movie Contact “The Universe is a pretty big place. If it’s just us, seems like an awful waste of space”
The Paradox: Why don’t we see life everywhere?

The simple answer is that we just haven’t been looking long enough. If you consider the radio signals we send out into space, our communications have only reached a few hundred or thousand stars, and they are too faint to really register.
But this does miss one key point. If a civilization slightly more advanced than us could make spacecraft that went 10% the speed of light (200 times faster than Voyager probes, 20 times faster than our fastest probe ever), which is quite reasonable with some effort, then it would be possible to visit most stars in the galaxy in a few million years. Since the galaxy is billions of years old, this really should have happened already if life is as common as the Drake equation implies.
What does it take for there to be life?

Liquid water
Complex chemistry
Stability
Energy
Gradients

Special thanks to Colin Vendromin for the music, also thanks to Zac Kenny for the logo!