Search results
3 dni temu · A light-year is the distance light travels in one Earth year. One light-year is about 6 trillion miles (9 trillion km). That is a 6 with 12 zeros behind it!
1 dzień temu · At the end of this epoch, the spherical volume of space which will become the observable universe is about 300 light-years in radius, baryonic matter density is on the order of 4 grams per m 3 (about 0.3% of sea level air density)—however, most energy at this time is in electromagnetic radiation.
2 dni temu · A 4.4 billion-year-old zircon. Until recently, many discounted the idea that life could have existed on Earth before 3.8 billion years ago because it was thought that heavy pummelling from ...
2 dni temu · Today the universe has expanded into an age and size that is physically only in parts observable as the observable universe, which is approximately 93 billion light-years in diameter at the present day, while the spatial size, if any, of the entire universe is unknown. [ 3]
3 dni temu · This is a timeline of space exploration which includes notable achievements, first accomplishments and milestones in humanity's exploration of outer space. This timeline generally does not distinguish achievements by a specific country or private company, as it considers humanity as a whole.
2 dni temu · Astronomers define stellar brightness in terms of magnitudes: the apparent magnitude (the perceived and measured brightness of a star) and the absolute magnitude of the brightness of the star, which is the brightness of a star seen from a standard distance of 32.6 light-years, or 10 parsecs.
2 dni temu · The Short Answer: The big bang is how astronomers explain the way the universe began. It is the idea that the universe began as just a single point, then expanded and stretched to grow as large as it is right now—and it is still stretching! What's This Big Bang All About? In 1927, an astronomer named Georges Lemaître had a big idea.