A light year is the distance traveled by light in one year. Multiply light years by 9,460,730,472,580,800 (approximately 9.5 trillion or 9.46 x 10**12) to get kilometers. Other values sometimes seen are the result of rounding errors in the speed of light, or in how to define a "year". Scientists tend to use "parsecs" rather than light-years; light years are used more in popular science publications.
280 mph = 450.6 kph
Dinosaurs became extinct around 65 million years ago during the Cretaceous-Paleogene extinction event. It is believed that a combination of climate change, asteroid impact, and volcanic activity contributed to their extinction.
Over the last 150 years, CO2 concentrations have increased from around 300 ppm to around 400 ppm - mostly in the last 70 years or so. Current scientific thinking is that anything over 350 ppm is likely to have unwanted consequences.
On earth carbon dioxide levels varied from 250 parts per million to 280 ppm over the past 800,000 years, per ice core samples. There is additional decent proxy evidence to indicate CO2 has not exceeded 280 ppm over the past 20 million years. Before the industrial revolution began in 1700, CO2 was at the 280 ppm maximum. We would expect without human activity CO2 would still be about 280 ppm, as the normal variation was roughly 5 parts per million over the course of a thousand years. Many scientists believe 350 parts per million might be earth's maximum sustainable level. We are now at 400 parts per million and at present rates will pass 500 parts per million before 2050, less than 40 years from now.
According to the 2012 Geologic Time Scale the Permian Period of the Paleozoic Era lasted from about 298.9 million to 252.2 million years ago. It is the last (latest) period of the Paleozoic.
7.5 percent of 280 million is 21 million.
Yes they are real. They were first on earth 280 million years ago and then went extinct 225 million years ago.
The first vertebrate was Pikaia, which lived 510 million years ago, 280 million years BEFORE dinosaurs.
The late Permian, around 280 to 250 million years ago
280 million can also be written as 2.8*108 or 2.8E8.
280 mph = 450.6 kph
It is 280 million%
280,000,000,000 or 280 billion
Trilobites lived for 280 million years before they became extinct, from the Cambrian to the Permian.
0.0280 grams?
56 million
280 × 10^8