Posts Tagged ‘Dinosaur’

by Morgan McFall-Johnsen

The NASA scientist Jessie Christiansen made a video that traces our solar system’s movement through the Milky Way as dinosaurs emerged, went extinct, and were replaced by mammals on Earth.

Our sun orbits the galaxy’s center, so many dinosaurs roamed the Earth while the planet was on the other side of the Milky Way.

Our solar system’s orbit keeps us just the right distance from the galaxy’s chaotic center for life to exist.

When dinosaurs ruled the Earth, the planet was on a completely different side of the galaxy.

A new animation by the NASA scientist Jessie Christiansen shows just how long the dinosaurs’ reign lasted — and how short the era of humans has been in comparison — by tracing our solar system’s movement through the Milky Way.

Our sun orbits the galaxy’s center, completing its rotation every 250 million years or so. So Christiansen’s animation shows that the last time our solar system was at its current point in the galaxy, the Triassic period was in full swing and dinosaurs were just emerging. Many of the most iconic dinosaurs roamed the Earth when the planet was in a very different part of the Milky Way.

Christiansen got the idea to illustrate this history when she was leading a stargazing party at the California Institute of Technology in Pasadena. Attendees were astonished when she mentioned that our solar system was across the galaxy when dinosaurs roamed.

“That was the first time I realized that those time scales — archaeological, fossil-record time scales and astronomical time scales — actually kind of match along together,” Christiansen told Business Insider. “Then I had this idea that I could map out dinosaur evolution through the galaxy’s rotation.”

Christiansen said it took her about four hours to make the film using timed animations in PowerPoint. She also noted a couple of minor corrections to the text in her video: Plesiosaurs are not dinosaurs, and we complete a galactic orbit every 250 million years, not 200 million years.

‘A spiral through space’

But galactic movement is more complicated than the video shows. The other stars and planetary systems in the galaxy are also moving, at different speeds and in different orbits. The inner portions spin faster than the outer regions.

What’s more, the galaxy itself is moving through space, slowly approaching the nearby Andromeda galaxy.

“The animation kind of makes it seem like we’ve come back to the same spot, but in reality the whole galaxy has moved a very long way,” Christiansen said. “It’s more like we’re doing a spiral through space. As the whole galaxy’s moving and we’re rotating around the center, it kind of creates this spiral.”

So in the solar system’s rotation around the galactic center, we’re not returning to a fixed point. The neighborhood is different from the last time we were here.

Earth, however, is not drastically different; it still supports complex life. That’s partially thanks to the path of our sun’s galactic orbit.

“Our solar system doesn’t travel to the center of the galaxy and then back again,” Christiansen said. “We always stay about this distance away.”

In other words, even as our solar system travels through the Milky Way, it doesn’t approach the inhospitable center, where life probably wouldn’t survive.

“There’s a lot of stars, it’s dynamically unstable, there’s a lot of radiation,” Christiansen said. “Our solar system certainly doesn’t pass through that.”

That’s a huge part of why dinosaurs, mammals, or any other form of life can exist on Earth.

https://www.businessinsider.com/video-nasa-scientist-dinosaurs-milky-way-2019-10

by Ed Mazza

The new Ark Encounter tourist attraction in Kentucky wants you to think that dinosaurs were practically pets just a few thousand years ago.

While scientists agree that dinosaurs died out some 65 million years ago during the K-T mass extinction, Ark Encounter creator Ken Ham believes the planet is only around 6,000 years old. Thus, man and dinosaurs lived together… maybe like in the Flintstones.

The Noah’s Ark he built in Williamstown features exhibits showing dinosaurs peacefully living in cages aboard the ship.

Ham, a “young Earth” creationist, explained in a 2000 blog post exactly how massive dinosaurs could fit on the ship:

“Although there are about 668 names of dinosaurs, there are perhaps only 55 different ‘kinds’ of dinosaurs. Furthermore, not all dinosaurs were huge like the brachiosaurus, and even those dinosaurs on the Ark were probably ‘teenagers’ or young adults.”

Ham said the ark had 8,000 “animal genera” or about 16,000 in total, including some that are now extinct, like those dinosaurs.

“Without getting into all the math, the 16,000-plus animals would have occupied much less than half the space in the Ark (even allowing them some moving-around space),” he wrote.

Along with dinosaurs, NPR reported that there were other eyebrow-raising “animals” on display, including unicorns.

The fact that the displays were completely at odds with science hasn’t kept guests from enjoying them.

Rachael Cross, who visited with her five children, told CBS News that the Ark shows actual history.

“The truth. The absolute truth,” Cross told the network. “God’s word is the Bible and it’s the absolute truth. I totally believe that.”

Critics said the Ark was a threat to kids.

“Basically, this boat is a church raising scientifically illiterate children and lying to them about science,” local resident Jim Helton told The Associated Press.

The massive attraction has been the subject of controversy, not only because it stands as a giant monument to creationism, but also for its hiring practices and tax breaks.

Ark Encounter employees are required to sign a statement saying they are Christians and that Jesus Christ is their savior, the Christian Post reported. In addition, the site has been given $18 million in state tax incentives, something critics said shouldn’t have been allowed, given its religious nature.

Ark Encounter formally opens today.

http://www.huffingtonpost.com/entry/noahs-ark-dinosaurs_us_577d9ff8e4b0344d514dea93?