The most recent information we can receive about the star would be from about 100 years ago, as it takes light around 100 years to travel a distance of 100 light years from the star to reach us on Earth.
No, they did not.
The total amount of water on Earth has remained relatively constant over the past 100 years. However, changes in the distribution of water due to activities like urbanization and climate change may have altered the availability of freshwater in some regions.
The Andromeda galaxy is about 2.4 million light years away, meaning that light from it takes 2.4 million light years to reach us, so the light we see from it now was emitted 2.4 million years ago.
Man did not invent light. Light has been around since the beginning of the universe. Man did; however, discover electricity, learn how to produce it, and invent the lightbulb over 150 years ago.
100 years ago
The most recent information we can receive about the star would be from about 100 years ago, as it takes light around 100 years to travel a distance of 100 light years from the star to reach us on Earth.
Radio waves travel at the speed of light, so radio waves broadcast 100 years ago that were strong enough to reach into space are 100 light-years away.
Depends on the distance from us. If it was 100 light years away, it would have occurred 100 years ago.
Homes 2000 years ago would have been lit by candles and oil burning lamps. They emit very little light in comparison to modern light bulbs and have a limited lifespan.
The expectation is that we sleep about 20% less then 100 years ago. This is due to the imitation light in houses that influences our melatonin levels. 100 years ago we did not have a light source such as a television that bombards the brain with signals and light. Research has shown that watching television before going to bed can influence the sleep hormone melatonin drasticly. See the related link.
No. This was well before electricity was discovered. Jesus lived 2,000 years ago. Lightbulbs have been around for less than 150 years.
There was no gas for automobiles 100 years ago
There are many places to find facts about life 100 years ago. You could find facts about life 100 years ago in a library.
I think there wasn't copying machine 100 years ago
Yes, kimchi was eaten 100 years ago.
No because it didn't exist 100 years ago, or 1913. It first opened in 1955