The Cosmic Hiss : Remnants of origin of universe
In 1965, two radio astronomers, Arno Penzias and Robert Wilson, were using a large communication antenna in New Jersey to conduct experiments. They aimed to find a quiet spot in the radio spectrum, but kept encountering a persistent hiss of static noise, no matter where they pointed the antenna.
Determined to eliminate this mysterious interference, Penzias and Wilson tried everything. They rebuilt their instruments, retested their systems, and even cleaned bird droppings off the antenna. Despite their efforts, the hiss remained.
Frustrated, they sought help from Robert Dicke, an astrophysicist at Princeton. When Dicke heard their story, he immediately knew what was causing the noise. It was cosmic background radiation, the afterglow of the Big Bang. By accident, Penzias and Wilson had stumbled upon the first concrete evidence of the Big Bang – the moment our universe was born.
So, what exactly did Penzias and Wilson discover? The intense energy released during the Big Bang eventually cooled and transformed into microwaves. These microwaves are what Penzias and Wilson picked up as a hiss with their antenna.
You don’t need a huge communication antenna to witness this evidence of the Big Bang. If you detune your TV and listen to the static between stations, about 1% of that static is the leftover radiation from the Big Bang, a relic from the earliest moments of our universe.
Understanding the Big Bang
The Big Bang theory suggests that the universe started from an incredibly dense and tiny point, called a singularity. This point had no dimensions and contained all the building blocks of the universe. Suddenly, this singularity exploded, and all the future contents of the universe were flung into the void at an unimaginable speed.
To grasp the scale and speed of this explosion, scientists estimate that immediately after the Big Bang, the universe doubled in size every 10-34 seconds. In just three minutes, it expanded from a minuscule speck to over 100 billion light-years in diameter. During this brief period, 98% of all matter and the fundamental forces governing the universe were created.
What Happened During the Big Bang?
The Big Bang Theory suggests the universe began as a tiny, extremely dense point called a singularity. Suddenly, this point exploded, and the universe began to expand rapidly. Scientists believe that right after the Big Bang, the universe doubled in size every tiny fraction of a second. In just three minutes, it grew from almost nothing to over 100 billion light-years across.
Are We Alone in the Universe?
The universe is vast, making it likely that other beings exist, though we haven’t found them yet. There are around 140 billion galaxies, each potentially filled with billions of stars and planets. According to the Drake Equation, which calculates the number of civilizations, there could be millions of advanced civilizations in our galaxy alone. However, due to the vast distances, we may never meet them.
The Drake Equation: Estimating Alien Civilizations
Drake’s calculation starts with a large number: the number of stars in a chosen part of the universe.
- Stars with Planetary Systems: First, he considered how many of these stars are likely to have planets around them. This number is smaller than the total number of stars.
- Habitable Planets: Next, from the stars with planets, he estimated how many planetary systems could potentially support life. This number is smaller still.
- Intelligent Life: Finally, he focused on the planets where life could evolve to become intelligent. This final number is much smaller than the previous one.
Despite these reductions, Drake concluded there could be a multitude of civilizations out there. He estimated there may be millions of advanced civilizations in our galaxy alone!
The Vastness of Space
However, we need to keep in mind how vast the universe is. Even if there are millions of civilizations, the average distance between any two of them is likely at least 200 light-years.
To put it into perspective:
- One light-year is about 5.8 trillion miles.
- 200 light-years is incredibly vast.
So, even if alien civilizations do exist, they are so far away that we are never going to see them.
Isaac Newton and His Discoveries
Isaac Newton was dedicated to understanding how the universe and Earth move. His most influential work, “Philosophiæ Naturalis Principia Mathematica,” introduced groundbreaking ideas like the universal law of gravitation. This law states that every object exerts a pull on every other object, with the force depending on their masses.
Newton’s “Principia” helped us learn a lot about Earth’s weight and shape
- Estimating Earth’s Weight: Thanks to Newton’s laws, we know the Earth weighs about 5.9725 billion trillion metric tons.
- Understanding Earth’s Shape: Newton’s work revealed that Earth isn’t a perfect sphere. Because of its spin, the Earth is slightly flattened at the poles and bulges at the equator, making it an oblate spheroid.
The Age of the Earth: Rocks, Fossils, and Radioactivity
Discovering Earth’s Age Through Rocks and Radioactivity
In the nineteenth century, geologists learned a lot from studying Earth’s rocks. By examining rock layers, they realized that Earth had many geological periods. Older rocks were found at the bottom layers, while newer ones were at the top. It became clear that it took millions of years for each layer to form, though the exact time remained uncertain.
The Breakthrough with Radioactivity
The true age of Earth remained unknown until the twentieth century, thanks to the discovery of radioactivity. In 1896, Marie and Pierre Curie discovered that certain rocks release energy without changing in size or shape, naming this phenomenon radioactivity. This caught the interest of physicist Ernest Rutherford, who found that radioactive elements decay into other elements at a constant rate, a process known as half-life. For example, Uranium-235 decays into Lead-207, always at the same speed.
Calculating Earth’s Age
By measuring the amounts of Uranium-235 and Lead-207 in rocks, scientists could estimate the rocks’ ages. This method led to a significant discovery in 1956, when Clair Cameron Patterson used ancient meteorites and the knowledge of radioactivity to calculate that Earth is about 4.55 billion years old. This breakthrough brought together decades of research and provided a precise age for our planet.
Einstein’s Theory of Relativity
Albert Einstein revolutionized our understanding of time and gravity. His special theory of relativity states that time is relative, not constant. This means time can pass at different speeds depending on circumstances. For instance, a fast-moving train would experience time slower than a stationary observer.
Einstein’s Special Theory of Relativity
In 1905, Albert Einstein introduced a surprising idea: time is not the same for everyone. It changes depending on certain conditions. This idea is called the special theory of relativity.
Time Feels Constant, But It’s Not
We usually think of time as constant. A second is always a second, and an hour is always an hour. It seems like time never speeds up or slows down. But Einstein showed that this isn’t true.
Time Depends on Speed and Position
Time can actually move at different speeds depending on how fast you’re going and where you are. Here’s a simple way to understand this, using an example from philosopher Bertrand Russell.
A Train Example
Imagine you’re standing on a train platform. A train is approaching at almost the speed of light. To you, the train looks strange, and the voices of people inside sound slow and distorted. If you see any clocks on the train, they seem to be ticking slower than the clock on the platform. However, for the people on the train, everything feels normal. Their voices sound regular, and their clocks tick at the usual speed. But if they look at you, they would see you as moving and speaking slowly.
Einstein’s General Theory of Relativity and Spacetime
In 1917, Albert Einstein introduced a groundbreaking idea called the general theory of relativity. This theory proposed the concept of spacetime, which combines the three dimensions of space with a fourth dimension: time. In simple terms, space and time are part of the same entity.
Understanding Spacetime
Spacetime can be tricky to imagine, but a helpful analogy is to think of it as a stretched rubber or cotton sheet. This sheet is flat but flexible – it can bend and warp.
Gravity as Curved Spacetime
Einstein’s idea of spacetime changed our understanding of gravity. Gravity is actually the bending of spacetime.
objects with heavy mass (like that of Sun) bend spacetime. Larger objects bend it more. When smaller objects move through spacetime, they follow these curves. This bending of spacetime is what we perceive as gravity.
The Rubber Sheet Analogy
Imagine our rubber sheet again. If you place a heavy object, like a bowling ball, in the middle of the sheet, it will stretch and sag. This represents how massive objects, like the sun, bend and curve spacetime.
Now, imagine you roll a ball across the sheet. The ball will try to move in a straight line, but as it gets closer to the bowling ball, it will start to follow the curve created by the heavier object. Eventually, the marble will circle around the curve, much like how planets orbit the sun.
Einstein’s general theory of relativity and the concept of spacetime provide a new way to understand gravity and the universe. It’s all about how objects with mass bend and curve the fabric of spacetime.
The Bizarre World of Atoms and Quantum Theory
Atoms are made up of a nucleus containing neutrons and positively charged protons, with negatively charged electrons spinning around this nucleus. Early scientists were puzzled by how these particles behaved. According to conventional physics, the spinning electrons should lose energy quickly and stop, while the protons in the nucleus should repel each other. In other words, by old rules, atoms shouldn’t exist.
The Need for Quantum Theory
To understand this strange atomic world, a new branch of science was needed, which became known as quantum theory. A key figure in developing quantum theory was Werner Heisenberg. In 1926, he introduced the concept of quantum mechanics.
Heisenberg’s Uncertainty Principle
At the core of Heisenberg’s work is the uncertainty principle. When scientists first measured electrons around an atom’s nucleus, they noticed something strange: electrons sometimes acted like waves and sometimes like particles. This dual behavior was confusing because it seemed they should be one or the other, not both.
Heisenberg’s uncertainty principle provided an explanation. Simply put, the principle states that an electron is a particle, but it can be described in wave terms. It also states that it’s impossible to know both the exact position and the exact path (or speed) of an electron at the same time. You can know one or the other, but not both. This means you can’t predict exactly where an electron will be; you can only estimate the probability of its location.
Two Incomplete Theories
Quantum theory is complex but it explains the behavior of very small particles well. However, it doesn’t work for larger phenomena, like gravity and time. On the other hand, the theory of relativity is excellent for understanding large-scale forces in the universe, but it fails to explain the subatomic world.
Four Unique Conditions for Life on Earth
Life on Earth exists because of four unique conditions:
- Right Distance from the Sun: If Earth were just 5% closer or 15% further from the Sun, life wouldn’t have developed.
- Protective Atmosphere: Earth’s molten core creates a magnetic field that shields us from harmful cosmic radiation.
- Perfectly Sized Moon: The Moon stabilizes Earth’s rotation, which helps maintain a stable climate.
- Timing: Events like the collision that formed the Moon happened at the right times to allow life to develop.
The Overlooked Oceans: A Brief History of Ocean Exploration
Ninety-seven percent of Earth’s water is in the oceans, yet humans have largely ignored them for most of history. The first major ocean exploration didn’t happen until 1872, when the British ship HMS Challenger set sail to study the seas. Over three and a half years, the Challenger collected marine organisms and took various measurements, resulting in a comprehensive 50-volume report and the birth of oceanography.
However, oceanography didn’t gain much traction until the 1930s. Otis Barton and William Beebe aimed to explore the ocean’s deepest parts using a primitive iron submarine called a bathysphere. Though basic, this device allowed them to set new diving records: 183 meters in 1930 and over 900 meters by 1934. Despite their achievements, their lack of training and the poor visibility from the bathysphere led to their findings being largely ignored by the scientific community.
Today, ocean exploration has advanced, but there’s still a long way to go. Scientists have reached the bottom of the deepest oceans, yet we know more about Mars’ surface than our own seabeds. It’s estimated that we have explored only a tiny fraction of the ocean’s depths, highlighting the vast, uncharted mysteries that still lie beneath the waves.
Key Points:
- 97% of Earth’s Water: Found in oceans, largely ignored throughout history.
- HMS Challenger (1872): First organized ocean exploration, resulting in the creation of oceanography.
- Bathysphere Dives (1930s): Otis Barton and William Beebe set deep-sea diving records but had limited scientific impact due to lack of training and poor visibility.
- Modern Exploration: Despite reaching the ocean’s deepest parts, we’ve mapped more of Mars than our own ocean floors, having explored only a minuscule fraction of the ocean abyss.
Bacteria: The Most Abundant Life Forms
Bacteria are the most abundant life forms on Earth, crucial for our survival. They recycle waste, purify water, and help us process nutrients. While most bacteria are harmless or beneficial, a small percentage can cause diseases. However, our existence and the health of our planet depend heavily on these tiny organisms.
The Origins of Life: From Amino Acids to Complex Organisms
Proteins, formed when amino acids combine, are the building blocks of life. Their formation may seem random, but self-assembling processes are common in nature, seen in phenomena like the symmetry of snowflakes and Saturn’s rings. If such processes occur with inorganic materials like ice and rock, they can also happen with organic ingredients like carbon, hydrogen, oxygen, and nitrogen.
This suggests that spontaneous life is possible. However, it doesn’t explain how life specifically arose on Earth. Life began with a crucial genetic trick that occurred four billion years ago when a tiny bundle of chemicals managed to divide itself. This self-division allowed it to pass on its genetic code, marking the beginning of life on Earth, an event known as the Big Birth.
Initially, bacteria were the sole life forms on Earth for two billion years. These bacteria eventually learned to use water molecules through photosynthesis, producing oxygen. When oxygen levels reached current levels, more complex life forms emerged. These evolved into two main groups: plants, which expel oxygen, and animals, which consume it.
Life has continued to evolve since then, diversifying into the myriad forms we see today.
The Connection Between All Life on Earth
In 1859, Charles Darwin published On the Origin of Species, a groundbreaking work that demonstrated the interconnectedness of all living things. Darwin explained that different life forms evolve along various paths depending on their environment. Those that adapt well to their surroundings thrive and reproduce, while those that don’t perish. This process, known as natural selection, leads to the diversification of life.
However, if we trace back these evolutionary paths, we eventually find a common ancestor shared by every species on Earth.
Modern DNA research further highlights these connections. For instance:
- Human DNA Similarity: 99.9% of your DNA is identical to that of any other person.
- Cross-Species DNA Similarities:
- Approximately 50% of your DNA matches that of a banana.
- 60% of your genes are the same as those in a fruit fly.
- At least 90% of your genes correlate with those found in mice.
Interestingly, parts of our DNA are interchangeable between species. For example, human DNA can be inserted into certain cells of flies, and they will accept it as their own.
These findings clearly show that all life on Earth is far more closely connected than most of us would have imagined. The rich diversity of life we see today is nothing short of a miracle. However, this interconnected miracle also raises the question of whether it could abruptly end.
Earth’s In-House Dangers: Earthquakes and Volcanoes
While space holds its share of dangers, Earth has plenty of its own threats. Two of the most significant are earthquakes and volcanoes.
Earthquakes:
- Cause: Earthquakes occur when two tectonic plates clash. Pressure builds until one plate gives way, resulting in an earthquake.
- High-Risk Areas: Cities like Tokyo, which sits at the meeting point of three tectonic plates, are particularly vulnerable.
- Historical Example: In 1755, Lisbon, Portugal, was devastated by a series of powerful earthquakes and a subsequent tsunami, leading to the tragic loss of 60,000 lives.
Volcanoes:
- Modern Threat: Even with modern science, volcanoes remain unpredictable. In 1980, Mount St. Helens erupted in Washington State, USA, killing 57 people despite monitoring efforts.
- Supervolcano: The supervolcano beneath Yellowstone National Park is a major concern. It erupts approximately every 600,000 years, covering everything within 1,600 kilometers in a three-meter coat of ash. The last eruption was 630,000 years ago, making it overdue.
Despite these dangers, the history of everything shows how incredibly lucky we are to be here.
Well that’s all about the past and present, if you want to learn about the future do read Homo Deus by Yuval Noah Harari