What Do You Mean Mass is Energy?

the most ubiquitous equation in all pop science energy is mass and mass is energy nuclear bombs Stars Fusion conceptually it doesn't quite make sense how something ethereal like electricity or heat can be the same as something tangible like a dumbbell or a Crunchwrap but give me a shot to change that [Music] if you've ever tried researching how mass and energy are one in the same you probably come across statements like only one percent of your mass is the actual mass of the particles the rest is the binding and kinetic energy of those particles or the Higgs mechanism is only responsible for this one percent of mass now this is confusing how is kinetic energy Mass what is the Higgs mechanism and what does that mean to give Mass it's such a conceptually confusing idea well let's start over we start with the broad picture particles particles are excitations in Quantum Fields the intensity of excitation is what we refer to as energy since particles are also waves when they are moving around they possess more energy if we want to compare two particles it doesn't make sense to compare their energy if they are moving around so we either stop them or catch up and enter the same frame of reference so they appear Motionless now we can see how much energy they have in fact that's what the masses of particles are the up Quark has a mass of two Mega electron volts which is 3.2 times 10 to the minus 13th joules its energy for particles mass is the amount of energy that particle possesses at rest or in the same frame of reference as the Observer or mass is motionless energy when we move to a bigger scale from particles we have to slightly modify that phrase and definition otherwise it doesn't make sense how kinetic energy can contribute to mass when we say mass is the energy of particles at rest for larger Realms we say mass is energy confined to an arbitrary system what does that mean let's imagine a simple proton conceptually we see a particle a sphere and so of course it has mass particles or spheres have mass now we look inside the proton and we see three more particles or quarks this is a little uncomfortable I like Mass to have boundaries but I see three new particles and of course particles or spheres have mass so it makes sense that the proton that they make up has mass we then take out these three new particles and put them on a scale opposite another proton now we see the proton weighs almost a hundred times more than these three particles I don't like that that's not the mass I know when we look back at the quarks on a proton suddenly now they are waves this is even more uncomfortable but the longer I look I see they more or less still fit in this imaginary boundary we've defined as a proton so I guess yeah it's easy to imagine they still have mass but why does this weigh less than a proton what we are missing is the other energy not on display here the quarks in the proton are held together by the gluon field or rather they create a gluon vacuum or flux tube in between them that sucks them together now we say vacuum but really it's just an absence of glue on field fluctuations the universe wants there to be Quantum fluctuations here so this vacuum is preventing that from happening which is energy it takes energy to stop Quantum fluctuations Ergo this vacuum represents a localization of energy in the gluon field I'll connect the quarks with little springy so it's more evident there's glue on energy here now the internal composition of protons is still contested evidence suggests there could be a fourth quark and multiple quarks do continuously form and disappear one interpretation of a proton looks like this but that's not the point the point is all of these constituents quarks gluons and the kinetic energy from their motion are stable and trapped in this volume they won't leave or intrinsically power any other process mass is energy confined to an arbitrary system nothing here is conceptually anything but waves or excitations of energy the only difference is that their presence and interactions keep them contained in this little volume unable to leave and do anything else I can now Define our arbitrary system as this volume and suddenly it's Motionless now I just measure how much energy is here which appears to be 938 Mega electron volts I can now say the mass of a proton is 938 Mega electron volts if we think of a photon or light this is pure energy it has no Mass because it is never Motionless but if we had two imaginary boxes that were white bodies theoretical matter that would absorb at zero light and we trapped a photon inside one and closed it then that Photon would bounce around Forever on the inside if we were to somehow measure the masses of these two boxes with the Precision of a photon we'd find that the box with the photon had greater mass now you may be thinking well that kind of doesn't make sense and you're not wrong it's not intuitive how can a photon bouncing around inside add mass or cause the box to weigh more well that's that darn Einstein again you see although light doesn't have mass it has momentum oh didn't see there so if it smacks into something it will exert a tiny amount of radiative impulse this impulse increases the shinier or more reflective a surface is this is how solar sails work when we weigh this box or anything else we are measuring how strongly it interacts with a gravitational field the bottom of the box is further down the gravity well or closer to the source of gravity than the top you may not know this but gravity gets stronger the closer you get to the source and you also might not know this but light becomes more energetic as it moves down a gravity well or its momentum increases now we are talking absolutely infinitesimally small amounts that no real experiment would ever be able to detect but believe it or not the photon hits the bottom of the box with slightly more momentum than when it hits the top of the box so if you were to add those forces together you'd see by golly the box is experiencing a tiny tiny tiny downward force from the photon in fact the trapped photons in the sun contribute to its mass but this is an incredibly tiny amount if we assume photons take on average half a million years to escape the sun then they contribute only about one percent the mass of the Earth or 34 billionths the mass of the Sun to the overall Mass you may be thinking oh yes of course Mass's energy confined to a system or volume I get it now but let me ask you an electron and a photon are both fundamental particles yet the electron has mass but the photon does not why is that this confusion arises because the idea of what is mass is incomplete without the discussion of inertia inertia is an intrinsic property of mass and it describes a masses unwillingness to change frames of reference or in simple terms it's difficult to accelerate masses why is that earlier we saw that the quarks inside our proton are actually complex wave functions waves and wave functions however are very dependent on the frame of reference in which they are observed if we look at these two waves the top one clearly has a higher frequency than the bottom one therefore the top wave has more energy but if I zoom out we see they are the exact same wave I'm just moving the top one to the left if we return to our proton this little volume of energy is stable in this frame of reference as soon as I try to move it I start changing the wave functions of all of its constituents that flux tube in the gluon field stretches and compresses which increases or decreases the resistance between the connecting quarks the wave function of the quarks themselves now appear to vibrate faster and interact more with the Higgs field relative to the old frame of reference these faster vibrating wave functions have more energy than before it takes energy to change this energy that is inertia I mentioned Higgs there and this is where our electron and Photon differ every particle that has mass interacts with the Higgs field this interaction is what people talk about when they say the Higgs field gives things Mass but how the Higgs field serves as a way of giving or maintaining the frame of reference for our particles I like to imagine the Higgs field like a lazy oscillator let's pretend our massive fundamental particle is this standing wave the Higgs field vibrates right along sleeping on top of the wave function suddenly the particle is accelerated and its wave function now has more energy the Higgs field is jostled awake and goes anytime a massive particle is accelerated the Higgs field tries to resist further acceleration so it can go back to sleep the Higgs field doesn't interact with photons photons have been cursed by a deeper evil and thus must go through life without a frame of reference this also means the original question was misleading as the idea of a stationary Photon cannot exist since it does not interact with the Higgs field photons have no frame of reference and since we needed a frame of reference to measure the masses of our particles at the beginning we say that photons have no mass since they have no frame of reference so there you have it mass is energy confined to an arbitrary system particles have mass because although they are just energetic excitations in a Quantum field the Higgs field is like okay but keep it to this frame of reference hadrons are just a bunch of quark and gluon energies that are unable to leave the confines of some arbitrary volume and putting more energy into some arbitrary system gives it more inertia and mass as any attempt to move it now has to change the way functions of the energy that has been stored inside hopefully this gives you a fairly intuitive idea of what mass is in the next video we'll see what it means to convert mass into energy [Music] thank you foreign [Music]

Channel: But Why?

Views: 333,030

Keywords: e=mc2, mass, energy, einstein, higgs, higgs mechanism, how is mass energy, mass is energy, inertia

Id: NbBtfBduVJc

Length: 11min 37sec (697 seconds)

Published: Tue Feb 07 2023