Kate the Chemist Challenges Neil deGrasse Tyson to a Chemistry Experiment

[youtubersdigest]

See this is why I love scientists. When they disagree it doesn’t matter how you feel. One is wrong and the other is right. AND THEY CAN PROVE IT! Nobody leaves mad because you leaned something new

[GamerbyDesign]

You can tell she answered with no hesitation and followed it up with an exact number. When you know your s*** you know your s***.

[andrewjuby]

To quote a friend of mine, "I like being right so much that, when I'm proven wrong, I change my mind."

[bloodink]

For those who mistake Niel's enthusiasm for arrogance. Scientists love to be proven wrong, but they will require proof. That's the part that people mistake for arogance. The fact they don't just take your word for it and that they can back their word with study and experiment.

[frogpaste]

When Neil feels he knows something, he stands by it. But when he's shown to be wrong he's always humble and asks questions to learn more. Great character!

[thec]

that "FALSE!" sounded like Sheldon tbh

[Emone]

I just imagine Niel going home and doing it and then going “well I’ll be…”

[mikel]

Hold on... Freezing point depression means that the liquid-to-solid phase change occurs at a lower temperature for saltwater than for pure water. When making ice cream, you need salted water AND ice. With ice equilibrated to a temperature well below freezing (e.g., 0F), the salted water cool and then hold at a lower temperature due to freezing point depression.

This is a different phenomenon than an endothermic process leading to a temperature change upon mixing. For example, water will cool appreciably when urea is dissolved into it. That has nothing to do with freezing point depression.

I've never seen Neil concede so quickly but, unless there's more to this conversation, I think hhe was correct that the phenomena behind "instant" cold packs and making ice cream are not the same thing.

[usuariocelular]

2 scientists enter
1 scientist leaves..

[mikeruland]

Okay we need to see a video of Neil doing the experiment. I'm going to follow this with baited breath.

[rhetta]

I believe her argument is fallacious: she mentions freezing point depression, which is distinct from the equilibrium temperature of the just-combined salt and water mix in room temperature conditions.

[ACU_misfit]

Hope NDT has some calamine lotion for that burn.

[ItchyNavel]

Things kind of got mixed up there, pardon the pun, salt lowers the freezing point of a solution but does not cause the solution to get cold. Cold packs get cold because the mixing process of the ionic compound and water is endothermic, sucking heat out of the surroundings. I don't recall if table salt mixing in water is endothermic, but if it is, it is very minimally endothermic, not nearly enough to freeze ice cream. The ice you use to freeze the ice cream is much colder than zero Celsius, but the salt allows the liquid/ice solution to get colder than zero when the solution would normally be limited to zero.

[philippeperron]

Incorrect. She explained why water cools down when you add some salts (some have the opposite effect) in water by accurately describing the cryoscopic constant of water. The phenomena that explains the change of temperature when you add different salts in water is called enthalpy of dissolution. These two phenomena are unrelated.

[xyz]

Yay! I knew this, it's in my high school chemistry book! Probably the only time I'm gonna know something that Neil doesn't!

[akashaabeysundara]

Basically, when you dissolve salt like NaCl, it dissociates into Na⁺ and Cl⁻ ions, and this process requires energy which is absorbed from the surroundings.

[charlesmaunder]

Freezing point depression just means that the water has a lower freezing temperature. That doesn't lower the temperature of the water.

[shaned]

Freezing point depression isn't the same as lower the temperature. More confused after this than before lol

[guardiandemon]

God this is refreshing discourse that ends in a goal to test a new hypothesis right or wrong this is what ideological debates should yield not screaming or popularity contests

[a.m.]

if it goes DOWN by -1.86°C, doesn't that mean that delta t is +1.86°C? Language is so easily misunderstood, I love it.