How Big is the Universe?

The quest to understand the size of the universe has fascinated scientists for decades. Over the years, hundreds of scientists have conducted thousands of experiments and observations to address this profound question. A common approach involves measuring cosmic background waves and determining the distance from Earth to the most distant observable objects.

But what are these cosmic background waves, and how do they help measure distances in the universe? The journey to answer this question began in 1964 when American scientists Arno Allan Penzias and Robert Woodrow Wilson discovered faint microwave radiation present throughout the universe. This radiation, known as the Cosmic Microwave Background (CMB), corresponds to a uniform temperature of approximately 2.7 Kelvin (-270.45 degrees Celsius) across the cosmos.

This radiation originated during the early stages of the universe’s formation, around the time when protons and electrons combined to form neutral atoms. Since then, the radiation has traveled at the speed of light, uniformly spreading across the universe. When scientists use highly sensitive antennas to capture this radiation, they detect minute fluctuations at the level of 10^-5. These fluctuations are directly related to the age of the radiation.

In 2013, the European Space Agency achieved a groundbreaking milestone by measuring these fluctuations with unprecedented accuracy. Their findings revealed the oldest detectable radiation, dating back 13.8 billion years. This indicates that the distance from Earth to the point in space where this radiation originated is 13.8 billion light-years. Assuming Earth is at the center of the observable universe, the universe’s radius would be 13.8 billion light-years, giving a diameter of 27.6 billion light-years.

However, this seemingly straightforward calculation is accompanied by significant assumptions. First, it presumes that the spot where the CMB was produced remains stationary in space, which contradicts our understanding of cosmic motion. Second, it assumes Earth is at the center of the universe, an unscientific notion. These assumptions prompt organizations like NASA to state that the universe's size cannot be conclusively measured and is likely far greater than what we perceive.

Does this mean the size of the universe will forever remain a mystery? Perhaps not. Ancient Indian knowledge provides fascinating insights into this topic. In the 12th century, Indian mathematician Bhaskaracharya wrote the “Siddhanta Shiromani,” which includes detailed information about the universe’s dimensions in its third volume, “Goladhyaya.” This text was later translated by the renowned astrologer Srila Bhaktisiddhanta Saraswati Thakur in the 19th century.

According to this work, the inner part of our universe has a circumference of 18,612,920 crore yojanas (a traditional Vedic unit of measurement), translating to a diameter of 5,956,200 crore yojanas. Converting this to modern units gives a diameter of 47,649,600 billion miles.

But this measurement only accounts for the inner portion of the universe, primarily composed of earthly elements. The Srimad Bhagavatam describes this inner universe as being enveloped by seven layers—water, fire, air, space, mind, intelligence, and ego. Each layer is ten times thicker than the previous one. Using this framework, the universe’s total diameter is calculated as:

47,649,600 billion miles × (1 + 10 + 100 + 1,000 + 10,000 + 100,000 + 1,000,000 + 10,000,000) = 5.29439994706 × 10^14 billion miles.

When converted to light-years, this gives a total diameter of approximately 90.06 billion light-years.

This ancient calculation aligns intriguingly with modern scientific explorations, offering a perspective that merges tradition and contemporary understanding. While science continues to refine its tools and techniques, Vedic knowledge reminds us that the universe’s vastness may hold secrets beyond our imagination.