Neil deGrasse Tyson Explains Gravity Trains

What would happen if you fell through the center of the earth? On this explainer, Neil deGrasse Tyson and comic co-host Chuck Nice take another look at transportation and explore the concept of gravity trains: trains that are purely propelled by gravity.

Ever been digging a hole, minding your own business, and heard someone say you’re digging a hole in China? Find out why, if you dug through the earth, you would probably not end up in China. What would happen if you jumped into that hole and fell through the earth? Neil walks us through the physics of what would happen. Would you get vaporized? Stuck? Ejected from Earth? What about if the hole wasn’t through the center of the earth? We discuss swiss-cheese Earth and what would happen if there was an underground train through the earth that went directly between New York and California. All that and more, on another StarTalk explainer!

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Science meets pop culture on StarTalk! Astrophysicist & Hayden Planetarium director Neil deGrasse Tyson, his comic co-hosts, guest celebrities & scientists discuss astronomy, physics, and everything else about life in the universe. Keep Looking Up!

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0:00 - Introduction
0:26 - Digging Through the Earth
3:05 - Jumping Through the Hole
8:49 - Gravity Trains
11:36 - Closing Notes

[dylanrogers]

“Chuck you ever get tired of these explainer videos? Because I could do this forever”


Everyone: please do this forever

[TheDwightMamba]

Chuck is becoming the smartest comic of all time through casual conversations.

[fizyknaut]

Niel: "You tired of these explainers? I have unlimited."
Chuck: "I'm gonna take you up on that."
Everyone watching the video: "What he said."

[ponybot]

Chuck and Neil just compliment each other so well

[bullettube]

When I was in 8th grade I asked my teacher if I dug a hole straight down would I create a volcano. She said yes you would, now fill in the name of all 48 states on this map.

[sheiladikshit]

nooOoOooOo! Don‘t stop the explainer videos! Neil and Chuck are pure gold, the 15 or so minute format‘s perfect!

[tristanrocha]

Please never stop doing these. It hurts my soul to think about this star talk series stopping

[Josh-jjqt]

I'm really glad Neil cleared up the whole thing about gravity decreasing as you get closer to the centre as when I was younger, my teacher told me it would increase.

[davidmurphy]

Oh, I misread and thought they were explaining gravy trains. I've been looking for one of those for years....

[tuboid]

I'm pretty sure this form of travel is in the remake of Total Recall. They don't bother with Mars, they just travel through the earth from one part to another.

[hecate]

Neil and Chuck! You brighten my day and my mind! 💕

[nehalpal]

please make one playlist just for the explainer videos! That would be a blessing!

[retromillenium]

That's what made Man of Steel so cool. The Kryptonian World Engine was split between two points on the Earth diametrically opposite of one another. One was on the North East Coast of the continental U.S., Metropolis, and the other part was located in the Indian Ocean.

[booperduper]

I love these explainers because they're short and i always learn something i never thought i wanted to know

[julianb]

I always thought about this as a kid, that it would be an endless ride to jump down the hole and then have gravity "inverse" on you once past the center. Cool to have NDT explain it!

[ThoughtPhoenix]

One little skipped detail (ignoring the pressure and temperature at the center of the earth) is that once u reach the center u can no longer dig so for this to work u need to dig two holes on the exact opposite spots (antipodal points) and meet at the center.

[pranabdas]

Chuk & Neil the best duo on the internet. I can watch this forever ❤️👍

[chibiSakura]

Great idea~ reminded me of the movie "The Core" when digging through the earth was mentioned.

Would love to see more startalk in my lifetime~ cheers!

[davidmurphy]

Unless you do it from pole to pole, you'll smack into the side because you'd retain the angular momentum from the spin of the earth. Maybe grease the sides.

[juniorlara]

Noooo we don't get bored of these explainers😭😭please go on forever neil😤anyone agree?z