theory” formulated by American scientists Walter Alvarez and Luis Alvarez. This theory states that a bolide (meteorite or comet) impact may have triggered the extinction event by ejecting a huge quantity of rock debris into the atmosphere , enshrouding Earth in darkness for several months or longer.
What was the idea of the Alvarez hypothesis?
The Alvarez hypothesis posits that the mass extinction of the non-avian dinosaurs and many other living things during the Cretaceous–Paleogene extinction event was caused by the impact of a large asteroid on the Earth .
What was Dr Luis W Alvarez famous theory about dinosaurs?
Alvarez has been best known for his theory that some large extraterrestrial object hit the Earth 65 million years ago , throwing up a dust cloud that blocked sunlight, halting plant photosynthesis and starving many species of land animals, including all the dinosaurs.
What did Luis Alvarez discover?
Luis Walter Alvarez invented a radio distance and direction indicator . During World War II, he designed a landing system for aircraft and a radar system for locating planes. Later, he helped develop the hydrogen bubble chamber, used to detect subatomic particles.
Why did Alvarez story of the extinction of the dinosaurs not sit well with many geologists in 1980?
Why did Walter Alvarez's story of the extinction of the dinosaurs not sit well with many geologists in 1980? ... Walter and Luis Alvarez found abnormally high levels of iridium in the clay layer between the Cretaceous and Tertiary rocks . What did this suggest? Iridium is extremely rare but common in meteorites.
How big was the asteroid that killed the dinosaurs?
The asteroid is thought to have been between 10 and 15 kilometres wide , but the velocity of its collision caused the creation of a much larger crater, 150 kilometres in diameter – the second-largest crater on the planet.
What is the evidence for the volcanic eruptions theory?
Massive beds of ancient lava found around the world depict an Earth 65 to 70 million years ago where volcanic eruptions were commonplace. According to the volcanism hypothesis, this global-scale volcanic activity spewed so much gas, ash, and dust into the atmosphere that it kept sunlight from reaching Earth's surface .
How many extinctions have occurred over Earth's history?
There have been five mass extinction events in Earth's history. In the worst one, 250 million years ago, 96 percent of marine species and 70 percent of land species died off. It took millions of years to recover. Nowadays, many scientists are predicting that we're on track for a sixth mass extinction.
Who discovered the asteroid that killed the dinosaurs?
The crater was discovered by Antonio Camargo and Glen Penfield , geophysicists who had been looking for petroleum in the Yucatán Peninsula during the late 1970s.
What was Luis Alvarez contribution to science?
Alvarez is responsible for the design and construction of the Berkeley 40-foot proton linear accelerator , which was completed in 1947. In 1951 he published the first suggestion for charge exchange acceleration that quickly led to the development of the “Tandem Van de Graaf accelerator”.
What is the most interesting fact about Luis Walter Alvarez?
Luis Alvarez was a Nobel Prize winning physicist, probably most famous for the discovery of the iridium layer and his theory that the mass extinction of dinosaurs was caused by an asteroid or comet colliding with Earth.
What country was Luis Alvarez born in?
Alvarez, (born June 13, 1911, San Francisco, California, U.S. —died September 1, 1988, Berkeley, California), American experimental physicist who was awarded the Nobel Prize for Physics in 1968 for work that included the discovery of many resonance particles (subatomic particles having extremely short lifetimes and ...
What was the longest dinosaur?
The longest dinosaur was Argentinosaurus , which measured over 40 metres, as long as four fire engines. It was part of the titanosaur group of dinosaurs. Its remains have been found in Argentina, South America.
What is the possible cause of dinosaur extinction?
A big meteorite crashed into Earth , changing the climatic conditions so dramatically that dinosaurs could not survive. Ash and gas spewing from volcanoes suffocated many of the dinosaurs. Diseases wiped out entire populations of dinosaurs. Food chain imbalances lead to the starvation of the dinosaurs.
What caused the dinosaur extinction?
As originally proposed in 1980 by a team of scientists led by Luis Alvarez and his son Walter, it is now generally thought that the K–Pg extinction was caused by the impact of a massive comet or asteroid 10 to 15 km (6 to 9 mi) wide, 66 million years ago , which devastated the global environment, mainly through a ...
