Things You Thought You Knew with Neil deGrasse Tyson

Mass? Weight? Density? There are some things you thought you knew and on this episode of StarTalk Radio, Neil deGrasse Tyson and comic co-host Chuck Nice are here to investigate what we know and what we thought we knew.

We start with mass, weight, and density. If you’re trying to get in shape you need to lose weight, right? Neil deGrasse Tyson says wrong. Neil tells us why when you want to get in shape, you need to lose mass. You’ll learn why a weight-loss book written by a physicist would just be one sentence. We explore the difference between mass and weight and why weight is all about forces. Find out why heavy cream is lighter than skim milk. We explore how the hull of a ship keeps the ship buoyant. All that, plus, Neil explains why, if you want to lose weight quickly, just head to the Moon and hop on a scale.

Then, we move on to another seemingly simple question: Why does ice float? Neil explains why peculiar things happen to water when it changes state. We explore what happens when water freezes. Chuck gives a demonstration of why you usually see 10% of ice above water. You’ll learn why the arctic ice sheets float on the water. And, why the ice we need to worry about is the ice on land and the “runoff.” We discuss the power of freezing ice (which leads to bursting pipes). Find out more about the density of water. What if bodies of water froze from the bottom up? Neil tells us how a certain property of water protects aquatic life over the winter.

Lastly, we turn our attention to space. How much do you weigh in space? Neil tells us why we should be thinking about how much mass something contains instead of how much something weighs. You’ll learn why your weight in water is basically zero. Why are astronauts weightless in space? Neil explains how Sir Isaac Newton discovered orbits. Find out why most energy from a rocket launch is not used to get the rocket into space. All that, plus, we explore the science of Ad Astra, The Expanse, and 2001: A Space Odyssey.

Thanks to our Patrons Christopher Sukhanenya, Dmitry Pugachevich, Eugenio Barrera, Dakota Clifford, Nick Mancusi, Nicholas Musial, Sebastian Roser, Bryan J. Jacop, Robert Frasco, and Obumneme Ozoh for supporting us this week.

NOTE: StarTalk+ Patrons can watch or listen to this entire episode commercial-free.

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About StarTalk:
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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[bryanstrange]

Can we just appreciate the fact that we have the honor of being alive in the same life time as this man?

[sparrowthesissy]

Neil is literally never going to forgive that one barista who forgot his whipped cream that one time. That anonymous lad will be immortalized in physics lectures for the rest of human history.

[nikhilsomvanshi]

When you've been a Tyson fan for long, you know you've heard so many of his stories over and over and over again. PS: Not complaining <3

[williamwalbridge]

I love how excited Chuck gets when he suddenly understands the concepts Neil is teaching him. The thrill of discovery and understanding.

[lotushead_music]

I listen to Neil when I can't sleep which is often. I never get bored of hearing him explain how life works

[undrcoverlouky]

GO SEE NEIL DEGRASSE TYSON GIVE A LIVE LECTURE!!!! I saw him two weeks ago and it was amazing. He asked the audience a question. I yelled out an answer. He looked right at me and said No. My heart fluttered a bit. He spoke to ME! I was so excited, that I forgot the question he asked in the first place. HE SPOKE TO ME!

[truesimplicity]

Awesome team... Chucks genuine appreciation and enthusiasm for the pearls if wisdom imparted by Neill are priceless.

Thanks Guys

[thenullhypothesis]

I love Chuck's bubbly persona. He helps me feel more excited about what is admittedly, probably very dry and boring subject matter.

[ArtDigitalMediaTV]

Sitting down to a conversation with these two would be so fun! And I'm glad they brought up the topic of water and ice. Yes, life is only possible because of this 'feature' of water. And maybe they don't want to get too technical, but, it would have been nice to explain why ice expands when it freezes. It's the hydrogen bonding between molecules that makes it form a lattice. And, as an example, a lattice of metal pipes is less dense than a pile of metal pipes, it's the same concept. The shape of the water molecule + hydrogen bonding forces it into a lattice since the molecules interact more strongly at lower temperatures. And maybe the concept of hydrogen bonds is too complicated for a short segment, but, it's a topic that always fascinated me. It's not a full bond. Far from the strongest bond. And yet, it essentially makes life possible. The life-sustaining properties of water, and also our very own proteins and DNA are stabilized by hydrogen bonds.

[EnigmaticPsych]

I would suspect that the reason floating soap was a selling point is because people use to take baths, rather than showers and if you dropped the soap, it was easier to recover in the bath if it were floating. Otherwise, you'ld be fishing for it.

[russell_szabados]

Fun fact: the planet Saturn is less dense than water. If there were a body of water large enough, Saturn would float & bob on top of the water. Because of Saturn’s low density, its gravity is close to that of Earth, despite its immense size.

[owenpichot]

It's been a few years since i started following neil on youtube and his various books, I could'nt possibly count the number of times i heard that coffee story with the cream 😂 Keep bringing science to everyday people you rule 😉

[germansanchez]

I had a rough day. When Chuck looks serious and says "Tell me about it." y almost exploded in loughter. They do me good while I learn something new. These dudes rule, they match each other like toast and butter.

[nasiruddin]

Neil is great teacher of our time. He is genetically unique and distinct. Planet earth needs more intelligent minds like him to prepare generation z to graduate ours to an advanced civilization in stage two. My deepest regards to Neil to make me understand complex dynamics of a broad range of scientific issues to a lucid one. Long live dear professor Neil.
Nasir Uddin from Bangladesh

[fstimellom]

Now thats what i call a great comunicator of science. Even i understood that

[GarageWoodworks]

17:10 Would have been the perfect opportunity to discuss why ice takes up more volume than the liquid state: crystal packing/hydrogen bonding etc. The question "why does ice float?" answered with "ice is less dense than water - takes up more volume" only begs the question : "why is ice less dense than water - take up more volume?" A perfect opportunity to discuss hydrogen bonding, crystal packing and maybe even a great place to discuss entropy.

[donsayers]

You gentlemen are alot of fun to learn from even at my advanced age of 62. Please Keep it up we /I always enjoy it. Thanks guys.

[calabrais]

I love Dr. Tyson, but I adore Chuck. This is a perfect 50/50 partnership. Thanks for the great content!!

[rowenaredd]

I feel like you weigh less on the top of Everest because of all the calories you burned getting up there.

[tadonplane]

Learning can be so much fun! Thanks Neil and Chuck!