Thinking of time and space
28/04/25 01:56
The bees are active now. The fruit trees are blooming, and there are plenty of bulb flowers to provide nectar. The bees head out from the hive and return with pollen and nectar. The entrances of the hives are hubs of activity with bees coming and going, and during the day, there is a continual cluster of bees around the hive. At first glance, it seems chaotic. Some bees are leaving the hive, others are heading toward the hive. There is so much activity at the hive that one might expect midair collisions between bees. However, they are graceful flyers and don’t run into each other. At the entrance to the hive, they are close enough to be touching as they go in and out. The bees returning have pollen attached to their legs, so they can easily be distinguished from those departing.
Once away from the hive, a bee generally flies straight to a particular tree or flower, often returning repeatedly to the same destination. The bees communicate information about pollen and nectar sources by performing waggle dances. The direction the bee moves in relation to the hive indicates the direction to a tree, flower patch, or water source. The vertical motion of the bee indicates distance. The bees use the sun as a standard to orient their navigation, so they only forage during the day.
Humans have used the sun and other celestial bodies for navigation. Ancients learned to use the sun and the stars for navigation across seas and oceans, which resulted in successful trade with others and was a factor in human migration. Phoenicians, Polynesians, and Early Vikings mastered the ability to journey at sea and return to the point of origin, and became able to travel long distances successfully.
European explorers developed systems of navigation that enabled them to know their location on the Earth's surface through a system of imaginary lines of latitude and longitude. Latitude, the area north and south, can be determined by measuring the angle between the horizon, a plumb bob, and the sun. At noon, the sun is directly overhead at the equator, in line with a plumb bob or at a right angle with the horizon. Using a protractor to measure the angle allows a traveler to determine the distance from the equator. A similar process can be used at night by measuring the angle of the North Star.
Measuring longitude, or east or west location, is a more complex challenge. The Earth makes one complete turn each day. The system navigators use has 360 degrees of longitude, so the Earth rotates 360 degrees in 24 hours. That works out to one degree every four minutes. If you know the time at a fixed point, and compare it to when the sun is highest at your location, you can determine how many degrees of longitude separate you from the fixed point. Navigators have used Greenwich, England, as the fixed point for naval navigation. This system was developed in Europe in the 16th century.
Knowing the time at the fixed point required accurate, portable clocks. Such devices began to appear in the 17th century, and with the development of that technology, long-distance navigation and exploration expanded greatly.
People accepted that time was measured in relation to the motion of the Earth relative to the Sun. Noon was when the sun was at its highest point in the sky, so the noon time was unique to each location. As clocks became more sophisticated and accurate, each town or village had an official clock set to noon at that location. Each location had its own time. However, the advent of railroads meant that timepieces had to be continually reset as the trains moved east or west. This proved impractical, so in 1847, Britain established Greenwich Mean Time and had all clocks in that nation set to the same time. This concept was applied to the globe, resulting in the creation of time zones.
I have been particularly aware of time zones, as I spent most of my career in a different time zone from my conference office. Therefore, I had to account for the change in time zones when planning travel to meetings. Our church's national offices are four time zones away, so when I participate in discussions over Zoom, I have to adjust my schedule. For example, a 9 a.m. meeting in Cleveland starts at 6 a.m., where I live.
When we think of the Earth, we have become comfortable with the relationship between time and space. However, when cosmologists observe the more expansive universe, the challenges of time and space are much more complex. Observations of distant bodies in the universe challenge our understanding of time and distance. Albert Einstein proposed a general theory of relativity that gave a mathematical description of the relationship between time and space. He observed that the rate at which time passes differs depending on relative motion.
In the 1990s, using ever greater telescopes and more accurate measurements, scientists observed distant supernovae that allowed them to calculate their distance from Earth. Their observations didn’t quite match predictions based on the theory of a big bang, resulting in an expanding universe that would gradually slow down as gravity took over. Direct observations showed that this slowing was not occurring in objects at extreme distances. Scientists began to incorporate “dark energy” into their theories. This energy is a force that pushes against gravity to expand the universe at an ever-increasing rate.
A few decades later, scientists began to question the explanation of dark energy. The irregular distribution of distant objects in the universe leads some to conclude that the universe is not uniform but rather has greater and lesser density areas. Their mathematical predictions don’t quite match their observations. Some cosmologists have begun to develop timescape models that describe the universe as having giant cosmic structures with areas of void between them. According to this theory, the universe's age depends on where it is measured. While we estimate the age of the universe to be around 14.2 billion years, in the middle of a giant void, the universe might be observed to be 21 billion years old.
Like bees, humans have become proficient in navigation within our area. We can even successfully navigate and travel within the solar system. However, we still have a lot to learn before we can successfully navigate the distances of the cosmos.
Once away from the hive, a bee generally flies straight to a particular tree or flower, often returning repeatedly to the same destination. The bees communicate information about pollen and nectar sources by performing waggle dances. The direction the bee moves in relation to the hive indicates the direction to a tree, flower patch, or water source. The vertical motion of the bee indicates distance. The bees use the sun as a standard to orient their navigation, so they only forage during the day.
Humans have used the sun and other celestial bodies for navigation. Ancients learned to use the sun and the stars for navigation across seas and oceans, which resulted in successful trade with others and was a factor in human migration. Phoenicians, Polynesians, and Early Vikings mastered the ability to journey at sea and return to the point of origin, and became able to travel long distances successfully.
European explorers developed systems of navigation that enabled them to know their location on the Earth's surface through a system of imaginary lines of latitude and longitude. Latitude, the area north and south, can be determined by measuring the angle between the horizon, a plumb bob, and the sun. At noon, the sun is directly overhead at the equator, in line with a plumb bob or at a right angle with the horizon. Using a protractor to measure the angle allows a traveler to determine the distance from the equator. A similar process can be used at night by measuring the angle of the North Star.
Measuring longitude, or east or west location, is a more complex challenge. The Earth makes one complete turn each day. The system navigators use has 360 degrees of longitude, so the Earth rotates 360 degrees in 24 hours. That works out to one degree every four minutes. If you know the time at a fixed point, and compare it to when the sun is highest at your location, you can determine how many degrees of longitude separate you from the fixed point. Navigators have used Greenwich, England, as the fixed point for naval navigation. This system was developed in Europe in the 16th century.
Knowing the time at the fixed point required accurate, portable clocks. Such devices began to appear in the 17th century, and with the development of that technology, long-distance navigation and exploration expanded greatly.
People accepted that time was measured in relation to the motion of the Earth relative to the Sun. Noon was when the sun was at its highest point in the sky, so the noon time was unique to each location. As clocks became more sophisticated and accurate, each town or village had an official clock set to noon at that location. Each location had its own time. However, the advent of railroads meant that timepieces had to be continually reset as the trains moved east or west. This proved impractical, so in 1847, Britain established Greenwich Mean Time and had all clocks in that nation set to the same time. This concept was applied to the globe, resulting in the creation of time zones.
I have been particularly aware of time zones, as I spent most of my career in a different time zone from my conference office. Therefore, I had to account for the change in time zones when planning travel to meetings. Our church's national offices are four time zones away, so when I participate in discussions over Zoom, I have to adjust my schedule. For example, a 9 a.m. meeting in Cleveland starts at 6 a.m., where I live.
When we think of the Earth, we have become comfortable with the relationship between time and space. However, when cosmologists observe the more expansive universe, the challenges of time and space are much more complex. Observations of distant bodies in the universe challenge our understanding of time and distance. Albert Einstein proposed a general theory of relativity that gave a mathematical description of the relationship between time and space. He observed that the rate at which time passes differs depending on relative motion.
In the 1990s, using ever greater telescopes and more accurate measurements, scientists observed distant supernovae that allowed them to calculate their distance from Earth. Their observations didn’t quite match predictions based on the theory of a big bang, resulting in an expanding universe that would gradually slow down as gravity took over. Direct observations showed that this slowing was not occurring in objects at extreme distances. Scientists began to incorporate “dark energy” into their theories. This energy is a force that pushes against gravity to expand the universe at an ever-increasing rate.
A few decades later, scientists began to question the explanation of dark energy. The irregular distribution of distant objects in the universe leads some to conclude that the universe is not uniform but rather has greater and lesser density areas. Their mathematical predictions don’t quite match their observations. Some cosmologists have begun to develop timescape models that describe the universe as having giant cosmic structures with areas of void between them. According to this theory, the universe's age depends on where it is measured. While we estimate the age of the universe to be around 14.2 billion years, in the middle of a giant void, the universe might be observed to be 21 billion years old.
Like bees, humans have become proficient in navigation within our area. We can even successfully navigate and travel within the solar system. However, we still have a lot to learn before we can successfully navigate the distances of the cosmos.
