Physics Concepts as Observable Phenomena Governed by Mathematical Frameworks

Key Quotes

"What's the deal with the strong nuclear force? Neil deGrasse Tyson answers the burning questions Chuck Nice, Gary O’Reilly, and the StarTalk Team have been saving all year about gravity as a force, emergence, and how physicists decide which equations to apply."

This quote introduces the core topics of the podcast episode, highlighting Neil deGrasse Tyson's role in answering complex scientific questions posed by the hosts and team. It sets the stage for discussions on fundamental forces, emergent properties, and the practical application of physics.

"So when you said the time axis has been what you mean by that is the amount of mass represented by earth and its surface gravity has a certain slope of that line correct that you would move at at an angle so to speak right on that timeline and that would be either faster or slower than the time that passes for someone on a more massive object or less massive object correct"

Neil deGrasse Tyson explains the concept of spacetime curvature in relation to gravity. He clarifies that the mass of an object, like Earth, influences the "slope" of the time axis, affecting the passage of time for observers at different gravitational potentials. This illustrates how mass warps spacetime.

"So einstein said if i'm in a rocket and the rocket is accelerating at one g okay that's a pretty fast acceleration it is okay so one g in in american units is 32 feet per second for every second you're subjected to the force per second per second right so after one second you're going how fast 32 feet per second for every second after two seconds you're going how fast 64 feet per second right after three seconds 96 feet see i'm already confused 96 add another 32 okay so that's the recipe to get your speed after three seconds right because and it will just continue like that the farther the longer you fall it just keeps continuing and you just gets faster and faster okay okay so now so that's earth's acceleration of gravity okay all right so in fact what you're standing here and you that's your weight if i dropped you from an elevator shaft or put you in an elevator and cut the cable you will fall to earth at 32 feet per second for every second"

Neil deGrasse Tyson uses the analogy of a rocket accelerating at one g to explain the equivalence principle. He details how acceleration in space can mimic the effects of gravity on Earth, illustrating that the experience of falling at a constant acceleration is indistinguishable from being in a gravitational field.

"So you asked if gravity is a force you can think of it as a force when you're sitting here on earth right but when you're just rocketing through space is it a force no it's just the leftover speed the ball had over here that gives the illusion that something pulled it down but in a sealed rocket you cannot tell the difference okay and so to say is gravity a force or is it just the curvature of space and time i'm saying that distinction is immaterial it's immaterial it doesn't really make a difference you want to make you want to make you want it to be because that is our natural intuitive thought process experimentally identical exactly so and since one of them involves no planet at all right all we can say is it's convenient to think of that as this thing called gravity here on earth right it's a convenience in space it's not gravity but it's doing exactly the same thing"

Neil deGrasse Tyson addresses the debate on whether gravity is a force or a curvature of spacetime. He argues that from an experimental standpoint, the distinction is immaterial because the observable effects are identical, whether one considers it a force or a consequence of spacetime geometry.

"The electromagnetic force weakens as the distance separates correct correct right gravity weakens as distance separates correct the strong force gets stronger as the distance separates right because why didn't you ask because on the other one it didn't come into my head because those other forces are we operate they're in your everyday life in ways that the strong nuclear force isn't so you can ask is there anything in your life where if you increase the distance they are attracted together more strongly the answer is yes a rubber band a rubber band oh yeah a spring a spring yes in fact in physics but not a slinky because when you stretch it it just gives up yeah a slinky is a weak ass spring a weak ass he stretches it out and it's like okay yeah slinkies are not help me help me i'm a slinky and they stretched me i'm no good"

Neil deGrasse Tyson explains a key characteristic of the strong nuclear force: it intensifies with increased distance, unlike electromagnetism and gravity which weaken. He uses the analogy of a rubber band or a spring to illustrate this behavior, contrasting it with the behavior of a slinky.

"So every week there were typically six physics problems each testing different for homework each testing a different physical principle you'd have to apply a new formula you learned that week in order to solve it and when i say formula that cheapens it you'd have to apply a new understanding of the behavior of nature that you learned that week and here's the equation of that new understanding so there you that's your toolbox toolbox yeah that's it toolbox so you look around and you say wait a minute there's matter becoming energy here what's going on marie curie one of the first to show radioactivity is a source of energy coming out of nowhere right there's no machine or engine going in what's going on there was no way to understand that without an equation that has energy on one side and mass on the other there was no way it was you can just describe it but there's no way to calculate with it until einstein and in 1905 e equals mc squared oh my gosh a little bit of mass times speed of light which is a big number squared you would get a lot of energy out of that by doing so"

Neil deGrasse Tyson describes how physics problems function as a "toolbox" for understanding nature. He emphasizes that solving these problems requires applying new understandings of physical principles, exemplified by Einstein's E=mc², which provided the equation to quantify the relationship between mass and energy.