Darkover
Archangel
- Jul 29, 2021
- 5,280
The worst part? Even if we left Earth today at the speed of light, we'd never catch up.
That's because the universe isn't just expanding — it's accelerating. Galaxies more than 18 billion light-years away are being pushed from us faster than light itself, not because they're moving through space, but because space itself is expanding between us and them. This phenomenon, known as metric expansion, is a consequence of Einstein's general relativity — and it means that distance in the universe isn't fixed. It stretches.
And here's the real kicker: this expansion is driven by dark energy, a mysterious force that permeates all of space and grows stronger as the universe grows larger. Unlike gravity or radiation, which weaken with distance, dark energy remains constant — or possibly increases — with volume. That means the farther galaxies are, the faster they recede. Beyond a certain threshold — around 14.5 billion light-years away — the rate of expansion exceeds the speed of light itself. These galaxies aren't just far away. They are permanently unreachable.
Of the ~2 trillion galaxies in the observable universe, roughly 94% have already crossed that cosmic horizon.
We can still see them, because the light they emitted billions of years ago is still arriving. But we'll never witness their present, never interact with them, and never send a signal that could reach them.
What's left behind is a kind of silent farewell — a visible past with no possible future. A universe full of light we can study, but a reality we can never visit.
1 meter = 1,000,000,000 nanometer
1 millimeter = 1,000,000 nanometer
the circumference of the earth is 40,075,000 meters or 40,075,000,000,000,000 nanometers
the radius of the earth in meters 6,371,000 meters or 6,371,000,000,000,000 nanometers
enclosed volume of a sphere V = 4/3 * 6,371,000,000,000,000^3 *pi
equals 1.08×10^48 or
1,080,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000
The number of atoms in the world is around 1.3 x 10^50.
300,000,000,000,000,000 nanometers the speed of light in nano meters per second
94 billion light years to meters
94,000,000,000
How many seconds are there in a year of 365 days? 31,536,000 seconds
300,000,000,000,000,000 the speed of light in nanometer times the number of second in a year
equals
9,460,800,000,000,000,000,000,000
How many meters are in a light-year?
9.461e+15
9,460,730,472,580,800 meters
9,460,730,472,580,800,000,000,000 nanometers travel in one year at the speed of light
9,460,730,472,580,800,000,000,000*94,000,000,000 94 billion light years
equals
889,308,664,422,595,200,000,000,000,000,000,000 how wide the universe is in nanometers
889,308,664,423,000,064,616,544,040,104,848,432 how wide the universe is in nanometers
it would take this many seconds to travel from end of the universe to the another or 34 trillion days at the speed of light
2,964,362,214,743,333,548 seconds
/86400 convert from second to days
equals
34,309,747,855,825 days
That's because the universe isn't just expanding — it's accelerating. Galaxies more than 18 billion light-years away are being pushed from us faster than light itself, not because they're moving through space, but because space itself is expanding between us and them. This phenomenon, known as metric expansion, is a consequence of Einstein's general relativity — and it means that distance in the universe isn't fixed. It stretches.
And here's the real kicker: this expansion is driven by dark energy, a mysterious force that permeates all of space and grows stronger as the universe grows larger. Unlike gravity or radiation, which weaken with distance, dark energy remains constant — or possibly increases — with volume. That means the farther galaxies are, the faster they recede. Beyond a certain threshold — around 14.5 billion light-years away — the rate of expansion exceeds the speed of light itself. These galaxies aren't just far away. They are permanently unreachable.
Of the ~2 trillion galaxies in the observable universe, roughly 94% have already crossed that cosmic horizon.
We can still see them, because the light they emitted billions of years ago is still arriving. But we'll never witness their present, never interact with them, and never send a signal that could reach them.
What's left behind is a kind of silent farewell — a visible past with no possible future. A universe full of light we can study, but a reality we can never visit.
1 meter = 1,000,000,000 nanometer
1 millimeter = 1,000,000 nanometer
the circumference of the earth is 40,075,000 meters or 40,075,000,000,000,000 nanometers
the radius of the earth in meters 6,371,000 meters or 6,371,000,000,000,000 nanometers
enclosed volume of a sphere V = 4/3 * 6,371,000,000,000,000^3 *pi
equals 1.08×10^48 or
1,080,000,000,000,000,000,000,000,000,000,000,000,000,000,000,000
The number of atoms in the world is around 1.3 x 10^50.
300,000,000,000,000,000 nanometers the speed of light in nano meters per second
94 billion light years to meters
94,000,000,000
How many seconds are there in a year of 365 days? 31,536,000 seconds
300,000,000,000,000,000 the speed of light in nanometer times the number of second in a year
equals
9,460,800,000,000,000,000,000,000
How many meters are in a light-year?
9.461e+15
9,460,730,472,580,800 meters
9,460,730,472,580,800,000,000,000 nanometers travel in one year at the speed of light
9,460,730,472,580,800,000,000,000*94,000,000,000 94 billion light years
equals
889,308,664,422,595,200,000,000,000,000,000,000 how wide the universe is in nanometers
889,308,664,423,000,064,616,544,040,104,848,432 how wide the universe is in nanometers
it would take this many seconds to travel from end of the universe to the another or 34 trillion days at the speed of light
2,964,362,214,743,333,548 seconds
/86400 convert from second to days
equals
34,309,747,855,825 days
