Is gravity a force?

[@charmgezos]

So much respect for this man. The best explanations, sturdy, reliable, without long narrations or drama, but not boring either!

[@frankdimeglio8216]

WHAT IS E=MC2 IS SPACE AS what is gravity (ON/IN BALANCE). Consider TIME AND time dilation ON BALANCE. c squared CLEARLY AND NECESSARILY represents a dimension of SPACE ON BALANCE. In other words, WHAT IS E=MC2 IS SPACE AS what is gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE) !!!! Indeed, consider what is THE EARTH/ground ON BALANCE !! The stars AND PLANETS are POINTS in the night sky. The rotation of WHAT IS THE MOON matches the revolution, AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE) !!!! Indeed, consider WHAT IS THE EYE ON BALANCE. Now, consider, ON BALANCE, what is the fully illuminated (AND setting/WHITE) MOON !!! So, ON BALANCE, consider what is the orange (AND setting) Sun !!! ON BALANCE, it is the SAME SIZE as WHAT IS THE EYE !!! CLEARLY, gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites (ON BALANCE); as the stars AND PLANETS are POINTS in the night sky. Consider TIME AND time dilation ON BALANCE. Indeed, WHAT IS GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. Now, notice what is the TRANSLUCENT AND BLUE sky ON BALANCE; AS what is THE EARTH is ALSO BLUE. GREAT !!! So, consider, ON BALANCE, why and how it is that there is something instead of nothing. (BALANCE AND completeness go hand in hand.) It ALL does CLEARLY make perfect sense ON BALANCE !!!! A given PLANET (including WHAT IS THE EARTH) sweeps out equal area in equal TIME, AS ELECTROMAGNETISM/energy is CLEARLY (AND NECESSARILY) proven to be gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE !!!! GREAT !!! By Frank Martin DiMeglio Consider what is THE SUN. Consider what is THE EYE. The stars AND PLANETS are POINTS in the night sky. This CLEARLY explains and proves what is the fourth dimension. By Frank Martin DiMeglio

[@to-rome]

What if a random dude, with great imagination and the ability to understand and visualize how mechanisms work knows what is gravity? What if his answer is agreed by math, observations, theory and the reality and has implications on everything, from transport to energy production and matter manipulation? I'm that guy & if I get 10k likes to my account, I will make a video explaining what gravity is in such a way that even 7 years old's will understand. ps to anybody wondering why I want followers first: I've spent too much time and energy on this question to give the answer away for free.

[@mattblack6736]

@@to-rome You kinda sound like an a$$hole tbh

[@mb-3faze]

"I'm partly right, some of the time" would make a great t-shirt slogan.

[@martinstubs6203]

Talking like he does in this video, he is not a scientist.

[@johnBSadro]

I am a retired physicist pushing 80 years old. Whenever I see and hear this guy I am delighted to be here!

[@bing43]

​@Noelle Leger gravity is just the effect caused by energy(mass) . The smaller space energy is kept in the higher the pit hole created by mass.(Einstein theory ) ___________Light,all particles are waves . ___________imagine a straight rope 🪢. U put energy and make it go up and down quickly and a particle with hight equal to the energy you put in is created and travells in the Rope 🪢 in the speed of light 🕯️.lol

[@frankdimeglio8216]

The ultimate mathematical unification (AND UNDERSTANDING) of physics/physical experience combines, BALANCES, AND includes opposites. The BALANCE of what is gravity WITH what is inertia/INERTIAL RESISTANCE requires and involves TIME AND time dilation ON/IN BALANCE, AS gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites (ON BALANCE); AS this CLEARLY explains the fourth dimension; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. INSTANTaneity is fundamental to what are TIME AND time dilation ON/IN BALANCE. Accordingly, ON BALANCE, INSTANTaneity is fundamental to what is the FULL and proper understanding of physics/physical experience; AS the extension of what is SPACE is CLEARLY (AND NECESSARILY) electromagnetic/gravitational ON/IN BALANCE. What is GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. What is E=MC is taken directly from F=ma, AS the rotation of WHAT IS THE MOON matches the revolution; AS the stars AND PLANETS are POINTS in the night sky. Great. INDEED, c squared CLEARLY AND NECESSARILY represents a dimension of SPACE ON BALANCE. ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE), AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. “Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent WITH/AS what is BALANCED electromagnetic/gravitational force/ENERGY, AS gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE (ON BALANCE). A given PLANET (including what is THE EARTH) sweeps out equal area in equal TIME. Great. What is E=MC is taken directly from F=ma. Consider TIME AND time dilation ON/IN BALANCE. INDEED, consider what is THE EYE ON BALANCE !!! Notice WHAT IS the fully illuminated AND setting/WHITE MOON ON BALANCE !!! NOW, consider what is the TRANSLUCENT AND BLUE sky ON BALANCE !!! So, consider what is the orange AND setting Sun ON BALANCE. ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE), AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. Inertia/INERTIAL RESISTANCE is proportional to (or BALANCED with/as) what is GRAVITATIONAL force/ENERGY, AS the extension of what is SPACE is CLEARLY (AND NECESSARILY) electromagnetic/gravitational ON/IN BALANCE. Consider TIME AND time dilation ON/IN BALANCE, AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. Gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites (ON BALANCE). GREAT !!!! BALANCE AND completeness go hand in hand. Carefully consider, ON BALANCE, why and how it is that there is something instead of nothing !!!! By Frank Martin DiMeglio

[@antog9770]

​​@@bing43 the satellites are the prove of the opposite: if there isn't a force, there isn't an acceleration, which means that a still body will continue to be still whenever the effect of the gravity is removed; instead the observations suggest that a still body will have a velocity different from 0 after a limited exposure to a gravitational field. The gravity can only be a force, coherently with the classical definition of force. Returning to satellites, if the gravitational force was apparent, we wouldn't observe the typical motion of the satellites around the planets, we would have circular trajectories which would be parallel and at the same time incident with the "right lines" of the near space, which doesn't make sense... The coherence is a principle of reality, the description of the gravitation must be coherent with all the rest...

[@kevino.7348]

Are you pushing 80, or is 80 pulling you?

[@kevino.7348]

@Noelle Leger Uhhh, what?

[@TimSnodgrass-x2v]

I am extremely interested in physics but as I get deeper into the field the math and concepts start to elude me. I am grateful that there are folks like Don Lincoln that can help explain the subject!

[@LiquidAudio]

Great explanation, as an ex science teacher I really appreciate your answer. People so often shoot from the hip without realising how little they really know!

[@pikiwiki]

Very accurate claim

[@gregturpin8931]

I only discovered Dr. Lincoln about six months ago. Still working my way through his amazing library. Please keep up the great work, sir! You are greatly appreciated!

[@richard84738]

When he overviews several theories and the result is "we just don't know" somehow it feels so satisfying. It's like he is the only person out there who really gets it, and gives it to us straight. "It's complicated" lol

[@dansandstrom9109]

"Theory" comes after Experimentation validating the Cause of an Effect observed in Nature/Physical Reality.

[@JamieDelour]

@Noelle Leger As a layman watching a few of these videos , my understanding was its earth moving towards the free falling object at 9.8m/s, but how do you make sense of that when considering all the directions of a sphere?

[@ChinnuWoW]

There are lots of other space youtubers who admit we don't know.

[@JamieDelour]

@Noelle Leger I'm thinking of the rocket example used in Veritasium's "gravity is not a force" video. i.e When standing on earth, we are being pushed up. To rephrase my question a little, how can the earth be accelerating in all directions at once? or I have misunderstood the theory. Thanks

[@frankdimeglio8216]

​@Noelle Leger The ultimate mathematical unification (AND UNDERSTANDING) of physics/physical experience combines, BALANCES, AND includes opposites. The BALANCE of what is gravity WITH what is inertia/INERTIAL RESISTANCE requires and involves TIME AND time dilation ON/IN BALANCE, AS gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites (ON BALANCE); AS this CLEARLY explains the fourth dimension; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. INSTANTaneity is fundamental to what are TIME AND time dilation ON/IN BALANCE. Accordingly, ON BALANCE, INSTANTaneity is fundamental to what is the FULL and proper understanding of physics/physical experience; AS the extension of what is SPACE is CLEARLY (AND NECESSARILY) electromagnetic/gravitational ON/IN BALANCE. What is GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. What is E=MC is taken directly from F=ma, AS the rotation of WHAT IS THE MOON matches the revolution; AS the stars AND PLANETS are POINTS in the night sky. Great. INDEED, c squared CLEARLY AND NECESSARILY represents a dimension of SPACE ON BALANCE. ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE), AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. “Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent WITH/AS what is BALANCED electromagnetic/gravitational force/ENERGY, AS gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE (ON BALANCE). A given PLANET (including what is THE EARTH) sweeps out equal area in equal TIME. Great. What is E=MC is taken directly from F=ma. Consider TIME AND time dilation ON/IN BALANCE. INDEED, consider what is THE EYE ON BALANCE !!! Notice WHAT IS the fully illuminated AND setting/WHITE MOON ON BALANCE !!! NOW, consider what is the TRANSLUCENT AND BLUE sky ON BALANCE !!! So, consider what is the orange AND setting Sun ON BALANCE. ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE), AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. Inertia/INERTIAL RESISTANCE is proportional to (or BALANCED with/as) what is GRAVITATIONAL force/ENERGY, AS the extension of what is SPACE is CLEARLY (AND NECESSARILY) electromagnetic/gravitational ON/IN BALANCE. Consider TIME AND time dilation ON/IN BALANCE, AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. Gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites (ON BALANCE). GREAT !!!! BALANCE AND completeness go hand in hand. Carefully consider, ON BALANCE, why and how it is that there is something instead of nothing !!!! By Frank Martin DiMeglio

[@daves2520]

I appreciate his effort to be impartial and objective in his explanations.

[@garyc1384]

Thank you Don, for the time , effort and dedication to the topic you provide us all with in these vids.

[@paullukens7154]

I am a retired Biology Teacher. Believe it or not, I have watched DOZENS of KZbin physics videos... just trying to understand one tiny little bit of what 'gravity' is. Dr. Don... after watching your video I GET IT NOW!!! Woohoo. Great explanation. It only took me 42 YEARS (!) of trying, to finally understand. A million thanks!!! (I hope you don't let rude viewers change your teaching style. It is OH SO EASY to criticize using this 'Comments' format. Some people watch, just looking to cause grief.)

[@voges1001]

So what is it?

[@ub2bn]

Yes, what is Gravity, other than whatever one imagines it to be?

[@deandownsouth]

Really??

[@alexcadle1369]

😂A Biology Teacher and it only took you 42 years eh? I guess, I have a very long journey ahead, maybe not.

[@horse._]

I am in my sophomore year of highschool and Im thinking i want to be an astrophysicist. Even for me, someone with little physics know-how, this was extremely understandable. I applaud you for your ability to explain so well in such a simple manner.

[@stephenburrow9946]

Another outstanding video. Great presentation of why this issue is more complicated than it may seem at first.

[@kx4532]

Excellent, showing us stuff we wouldn't even know to look for!

[@faisafarrah9043]

​@@kx4532 I doubt physics exists.

[@kx4532]

@@faisafarrah9043 wut

[@kx4532]

kzbin.info/www/bejne/jGrbhoSNpJmphJI She types on a smartphone with its silicon field effect transistors with their gates constantly forcing the energy bands in the PN junctions to reduce to the point where electrons tunnel through the gap allowing current to flow and then the reverse of this in multiple billions on instances. All calculated out ahead from the results of labs all over the world.

[@kx4532]

kzbin.info/www/bejne/nGrdZ2p6pM1_n9U The horizontal axis is the distance from the gate oxide. It vertical axis on the graph is energy in Volts V or more often Electron Volts eV

[@chadbailey3623]

I love how you describe scientific debates. You are an A+ educator!!!

[@frankdimeglio8216]

@Noelle Leger WHAT IS E=MC2 IS SPACE AS what is gravity (ON/IN BALANCE). Consider TIME AND time dilation ON BALANCE. c squared CLEARLY AND NECESSARILY represents a dimension of SPACE ON BALANCE. In other words, WHAT IS E=MC2 IS SPACE AS what is gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE) !!!! Indeed, consider what is THE EARTH/ground ON BALANCE !! The stars AND PLANETS are POINTS in the night sky. The rotation of WHAT IS THE MOON matches the revolution, AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE) !!!! Indeed, consider WHAT IS THE EYE ON BALANCE. Now, consider, ON BALANCE, what is the fully illuminated (AND setting/WHITE) MOON !!! So, ON BALANCE, consider what is the orange (AND setting) Sun !!! ON BALANCE, it is the SAME SIZE as WHAT IS THE EYE !!! CLEARLY, gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites (ON BALANCE); as the stars AND PLANETS are POINTS in the night sky. Consider TIME AND time dilation ON BALANCE. Indeed, WHAT IS GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. Now, notice what is the TRANSLUCENT AND BLUE sky ON BALANCE; AS what is THE EARTH is ALSO BLUE. GREAT !!! So, consider, ON BALANCE, why and how it is that there is something instead of nothing. (BALANCE AND completeness go hand in hand.) It ALL does CLEARLY make perfect sense ON BALANCE !!!! A given PLANET (including WHAT IS THE EARTH) sweeps out equal area in equal TIME, AS ELECTROMAGNETISM/energy is CLEARLY (AND NECESSARILY) proven to be gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE !!!! GREAT !!! By Frank Martin DiMeglio Consider what is THE SUN. Consider what is THE EYE. The stars AND PLANETS are POINTS in the night sky. This CLEARLY explains and proves what is the fourth dimension. By Frank Martin DiMeglio

[@frankmalenfant2828]

I had that question in mind for a few months now. Thank you for that enlightening explanation.

[@pcbacklash_3261]

This website is quite useful to a layman like me. I've read a handful of books on subjects like cosmology and quantum physics, but it's difficult to find time to keep up to date on all the crazy theories out there! These videos may not make me an expert, but they at least make the topics comprehensible! Good job, Dr. Lincoln!

[@VardaMusic]

It’s wonderful how much we have yet to understand- and the way you highlighted that here helps the creative thoughts flow so that we can reach those higher levels of understanding with less road blocks caused by closing our minds to even what we can’t conceive of yet. So many things in astrophysics in particular hinge on theories, not definite fact, and it seems to me some videos I’ve watched forget to remind the watcher of that. Thank you for the thought you put into this!

[@anthonyhargis6855]

Always educational and hard to turn away from. Outstanding Professor!

[@faisafarrah9043]

Do should stop making people doubt physics

[@marioluna2957]

Santa Lincoln rocks👍

[@anthonyhargis6855]

@Noelle Leger You hit the wrong reply button.

[@frankdimeglio8216]

@@anthonyhargis6855 WHAT IS E=MC2 IS SPACE AS what is gravity (ON/IN BALANCE). Consider TIME AND time dilation ON BALANCE. c squared CLEARLY AND NECESSARILY represents a dimension of SPACE ON BALANCE. In other words, WHAT IS E=MC2 IS SPACE AS what is gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE) !!!! Indeed, consider what is THE EARTH/ground ON BALANCE !! The stars AND PLANETS are POINTS in the night sky. The rotation of WHAT IS THE MOON matches the revolution, AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE) !!!! Indeed, consider WHAT IS THE EYE ON BALANCE. Now, consider, ON BALANCE, what is the fully illuminated (AND setting/WHITE) MOON !!! So, ON BALANCE, consider what is the orange (AND setting) Sun !!! ON BALANCE, it is the SAME SIZE as WHAT IS THE EYE !!! CLEARLY, gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites (ON BALANCE); as the stars AND PLANETS are POINTS in the night sky. Consider TIME AND time dilation ON BALANCE. Indeed, WHAT IS GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. Now, notice what is the TRANSLUCENT AND BLUE sky ON BALANCE; AS what is THE EARTH is ALSO BLUE. GREAT !!! So, consider, ON BALANCE, why and how it is that there is something instead of nothing. (BALANCE AND completeness go hand in hand.) It ALL does CLEARLY make perfect sense ON BALANCE !!!! A given PLANET (including WHAT IS THE EARTH) sweeps out equal area in equal TIME, AS ELECTROMAGNETISM/energy is CLEARLY (AND NECESSARILY) proven to be gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE !!!! GREAT !!! By Frank Martin DiMeglio Consider what is THE SUN. Consider what is THE EYE. The stars AND PLANETS are POINTS in the night sky. This CLEARLY explains and proves what is the fourth dimension. By Frank Martin DiMeglio

[@frankdimeglio8216]

​@@marioluna2957 WHAT IS GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. WHAT IS E=MC2 IS dimensionally consistent, AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE) !!! BALANCE AND completeness go hand in hand. GREAT !!! WHAT IS GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. (WHAT IS E=MC2 IS dimensionally consistent.) Consider what is the man (AND THE EYE ON BALANCE) who IS standing on WHAT IS THE EARTH/ground, AS touch AND feeling BLEND; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE !!! BALANCE AND completeness go hand in hand. WHAT IS GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. WHAT IS E=MC2 IS dimensionally consistent, AS “mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent WITH/AS what is BALANCED electromagnetic/gravitational force/ENERGY; AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE (ON BALANCE). INDEED, GRAVITATIONAL force/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE !!! The stars AND PLANETS are POINTS in the night sky. WHAT IS E=MC2 IS dimensionally consistent !!! Accordingly, ON BALANCE, THE PLANETS (including what is THE EARTH) sweep out equal areas in equal times. Consider TIME (AND time dilation) ON BALANCE. WHAT IS E=MC2 is taken directly from F=ma, AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE). WHAT IS GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. WHAT IS E=MC2 IS dimensionally consistent !!! CLEARLY, gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites (ON BALANCE); as the stars AND PLANETS are POINTS in the night sky. Consider TIME (AND time dilation) ON BALANCE. INDEED, TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE) !!! GREAT !!! ACCORDINGLY, ON BALANCE, the rotation of WHAT IS THE MOON matches the revolution. GREAT !!! WHAT IS E=MC2 IS dimensionally consistent. GREAT !!! It is a very great truth that the SELF represents, FORMS, and experiences a COMPREHENSIVE approximation of experience in general by combining conscious and unconscious experience. INDEED, the INTEGRATED EXTENSIVENESS of THOUGHT AND description is improved in the truly superior mind. BALANCE AND completeness go hand in hand. By Frank Martin DiMeglio

[@RichardWilkin]

Just today I was thinking about the subjectivity of information. For example, if I was in an audience listening to someone speaking Cantonese, to me it would be data (I’m getting audible signals, but they don’t mean much to me), but to someone else who speaks it, it would be information. That could be another example of how the conceptual framework used affects the communication requirements.

[@AconservativeThought]

Wow how intriguing! Almost sounds like a 4 dimensional concept? Could you give an example of this outside of your example of hearing sounds without understanding what the sounds mean as with your language example?

[@Raziel_SSJ]

Thanks for this video. Being careful when asserting something and not beeing too sure of us is often overlooked.

[@toughenupfluffy7294]

3:37. Of all the videos and textbooks I've ever seen, this is the first to portray the bending of spacetime in 3 dimensions. Well done!

[@hanszlh6522]

as a lay person , but bloody old - 80+ ,,, i strut on wondering vhot my fellow countryman Albert E. had in mind for WHAT would CAUSE the "Space-Thyme" distortions - Other than stating "Mass" .... .. in my book a Cause might very reasonably 'synonymizised' as a Force .... - In short : " No Force -No Cause " ( Just my simplistic but 'quite human' logic ) And as to my understanding , there ain't not all that much around ( us .. ) that we wouldn't believe to 'depend' on NO-CAUSE - other than 'our' ( and Einstein's -? ) idea of "God" , and his - or Stephen H.'s "singularity ( .. ies ) - ? So , i don't see how Mass - most bloody 'obviously' bends Space-Time evver so 'effor(ce)tly' ... ??? enlighten-me, por favor , please , bitte !!!

[@VonJay]

But spacetime curvature equation was made with the use of intrinsic curvature and not extrinsic, so the 3D diagram is wrong.

[@S.L.S-407]

I just find it interesting that with all the brains we have here on earth, no one has an undisputed definition of what gravity is. Thanks for the video.

[@thomasherrin6798]

Of all the brains on Earth to date only three people mentioned in this video have majorly contributed to our understanding of it, in the 1700's and 1900's and, dare I add, without computers or AI!?!

[@S.L.S-407]

@@thomasherrin6798 - That's the problem. They have "contributed" to our understanding but no one can actually nail it down. I find that amazing.

[@Soupy_loopy]

This guy really knows how to address internet trolls. Maybe one of the best.

[@voltydequa845]

«This guy really knows how to address internet trolls. Maybe one of the best.» ---- Smart and wise gentleman. But here he is addressing parrots - that trolls are yet another phenomena that no other than ban can address.

[@Shadow_B4nned]

Just made a gravity bong for science. There's definitely some mysterious force in action. Will report back after I have isolated source.

[@NondescriptMammal]

"This view is made possible for us by the teaching of experience as to the existence of a field of force, namely, the gravitational field, which possesses the remarkable property of imparting the same acceleration to all bodies." "Thus, according to the general theory of relativity, gravitation occupies an exceptional position with regard to other forces, ..." -- Albert Einstein, The Foundation of the General Theory of Relativity, 1916

[@JoeDeglman]

General relativity is a failed model, by experiment.

[@davemmar]

It’s complicated but your answer is clear and concise. With it I feel like I don’t need to answer the question “Is gravity a force?”. But rather use our knowledge of gravity to explain the processes. I am a docent at DMNS.

[@mathsinmarathibyanillimaye3083]

I am a small time school teacher, this great GURU made me interested in life again. Thanks.

[@TheRealLughnatic]

The sight of those KZbin comments trying to tell a literal physicist what gravity is...good lord. Edit: This wasn't supposed to blow up...

[@MrNicePotato]

I can imagine these know-it-all nerds who watches a lot of popular science videos only remembering catchy lines about gravity, without actually having gone through the ins and outs of relativity. But on the other hand, I also appreciate the willingness to challenge and argue, not blindly believing someone just because he is a trusty looking scientist, as long as its healthy and constructive of course.

[@AverageAlien]

Appeal to authority

[@AverageAlien]

Anyone can tell anyone anything, funnily enough

[@0-by-1_Publishing_LLC]

*"The sight of those KZbin comments trying to tell a literal physicist what gravity is...good lord."* ... We have already entered the age where the collective input from a broad range of humans will produce more answers than the intellectually gifted individuals operating in their specialized fields. A famous artist can paint wonderful works of art in his or her particular style, but an A.I. can create new art styles by pulling imagery from every known work of art that's available. You will soon start seeing "random people" answering hard questions that have stumped the most popular and highly regarded scientists, physicists, philosophers, and mathematicians of their times.

[@Narokkurai]

@@AverageAlien Appealing to authority is only a fallacy when that authority isn't relevant to the topic at hand.

[@Condor512]

Dr. Don, Thanks for another enlightening video.😁

[@yeeyourlasthaw2803]

I'm not calling myself a scientist until I get a degree in a science field. For now, I am an admirer of scientists and I appreciate the knowledge all of them bring.

[@nickjanke227]

🎉

[@videoinformer]

The "tautology" part is in reference to the fact whether gravity is a "force" depends on the definition of "force" that is being used (among other things). The definition of "force" that requires particle mediation and also presumes gravity isn't mediated by particles, doesn't really explain what gravity is because it doesn't explain what "space-time" even is, i.e., the thing that is "curved" and is thus perceived as "gravity". But, a an alternate definition of "force" that doesn't require particle mediation would include gravity as a "force". Thus, the tautology, opposite tautologies, depending on the definition of "force".

[@masonduarte8001]

This is a wonderful video. The way you express these ideas in a simple way is amazing.

[@tomschmidt381]

Great explanation of whether or not gravity is a force. I'm confident once the physics is understood it will turn out to be very counterintuitive, which is why it has taken so long to figure out.

[@everythingisalllies2141]

Its "counter intuitive because they are flat out wrong and their theories are nonsensical gibberish. Curved fabric of Spacetime" is 100% a mathematical construct, its abstract, so nothing in Physical reality is going to "follow a spacetime curvature". Gravity is a force, like magnetism. Simple as that and Einstein is full of crap. So is quantum nonsense.

[@shannontaylor1849]

I was expecting to be mildly disappointed. After several viewings, I am mildly disappointed in my expectations. Excellent explanation of difficult concepts. Thank you for giving the effort required to share such information about the nature of our reality.

[@VonJay]

I mean he got it wrong. If Newton was right then both the earth's acceleration upward and the gravitational force downward would cancel each other out at the earth's surface. But Einstein's field equations posit that gravity isn't a force, and it is the earth that is accelerating. The very thing that proves this is the use of an accelerometer on the earth's surface. It has a positive or non-zero read out of acceleration. When if Newton was right, it would be 0. So gravity isn't a force.

[@ericlani2622]

Nice nuanced take! One of my grad school professors said it’s even incorrect to describe the 4 forces of nature as forces. Opting rather to describe them as “interactions”

[@kylelochlann5053]

He is correct. A fundamental interaction is an irreducible phenomenon that may or not produce a physical acceleration.

[@ar4203]

​@@kylelochlann5053 see this is what i really dont get- the idea of a fundamental force makes sense as a force which is not reducable, but it doesnt make any sense to me to say that an "interaction" is irreducable - an interaction implies 2(or more things) which are interacting to produce an effect, like gravity or etc, & if thats the case calling it irreducable seems incoherent to me. Can anyone explain what im not getting here because this really bothers me.

[@kylelochlann5053]

@@ar4203 Sure. Let's start with a reducible interaction, say the interaction between two surfaces sliding past each other (a.k.a. the force of kinetic friction). Is this friction force reducible to a more general interaction? Yes, friction is a function of the normal component of the contact force, f=μN. We can then ask if contact forces, the interaction between two surface more generally, is reducible to more general interactions. Yes, contact forces are dependent on the electromagnetic interaction. Here's where it becomes irreducible - we cannot express the interaction between charged particles in anything more general, or any other type of interaction. Basically that's the idea and we 4 types of interactions that cannot be explained in terms of anything else.

[@eran3851]

I've seen another video trying to explain why gravity is not a force, and I could not understand it enough to remember. I understood Your explanation instantly. Thank You sir.

[@VonJay]

I don't see how he made it any clearer lol

[@noctisarcanus7894]

What a beautiful field of study. I'd love to study Physics and work in a place like you do, but that's impossible for me. In my country there's little to no investment in science so there's barely work for a Physicist rather than teaching and also, I'm too old for that... Thank you for letting me, at least, get a grasp of this wonderful knowledge. Your channel is, by far, the best in KZbin and I've seen thousands of science videos in the last 10 years.

[@AconservativeThought]

Wow because of this picture (3:38) and animation coupled with the explanation in the background, I can finally understand what the 2 dimensional space time fabric looks like in our 3 dimensional reality. I was never able “see” or comprehend how space time could be 2d in our 3d reality that we live and see things in. Now I can see how 2d space time fabric can exist within our 3d reality. I was never able to picture any of this with the classic flat picture of space time with the earth and sun sitting on top of what looks like a blanket with 2 balls (earth and sun) sinking into the flat surface represented as the space time 2 dimensional fabric that it indeed is. To put it another way, lol I never understood how a 2 dimensional plain could coexist and interact with the 3 dimensional reality we live in. NOW I need to try and see and understand what 4 dimensional looks like in our 3 dimensional reality and what it looks like interacting with 3d reality. Right now I can not picture how or what it looks like for 4d to exist within our 3d reality because right now it seems just as ghost like as how 2d existed in our 3d reality. Is it possible to even be able to see and picture it within 3d reality?

[@sapelesteve]

All that I can say is "May The Force Be With You Dr. Don"! 🤔🤔👍👍

[@timjohnson979]

Or, may the curvature of the space you're in always be in your favor.😃

[@drdon5205]

We definitely should have released this video on May 4th.

[@thomasherrin6798]

That doesn't hold gravity!?!

[@anthonystevens6705]

Thank you, Dr. Don! Wonderful video

[@frankdimeglio8216]

​@Noelle Leger WHAT IS E=MC2 is CLEARLY consistent with the fourth dimension in/of/AS SPACE, AS the stars AND PLANETS are POINTS in the night sky; AS the rotation of WHAT IS THE MOON matches the revolution; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity ON/IN BALANCE; AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE !! INDEED, consider WHAT IS THE EYE ON BALANCE; AS c squared CLEARLY (AND NECESSARILY) represents a dimension of SPACE ON BALANCE !! Consider TIME AND time dilation ON BALANCE !!!! Gravity AND ELECTROMAGNETISM energy are linked AND BALANCED opposites (ON BALANCE), AS the stars AND PLANETS are POINTS in the night sky. TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. I have CLEARLY proven and explained what is the fourth dimension. Magnificent. By Frank Martin DiMeglio

[@edwardlee2794]

Is science absolute ? I thought so, like so many people. With Dr Don s enlightenment, science is the ever perfecting process to get to the true picture of the fact. Before then, scientific observation maybe the observation in the theory of the beholder. Thanks Dr Don and keep up the good work.

[@jamestoupin4221]

Serious question: given the curvature of light by mass and that photons have zero rest mass and not affected by gravity, doesn't that lend more credence to Relativity's curves spacetime explanation?

[@dwaynezilla]

Oo yes, a deep dive into entropic gravity would be fabulous. The brutal weirdness of it makes it seem promising!

[@terryjwood]

Thanks for clarifying this! I've wondered about this question for some time.

[@edwardofgreene]

Actually he didn't clarify it, and that was the point. He explained that we can't definitively clarify it at this time. And it might never have a clarification from all points of view even when we do understand it better. (Sort of like the long standing debate over whether light is a particle or a wave. In the end we definitively decided.... both? Depends how you look at it. It definitely has properties of both!)

[@terryjwood]

@@edwardofgreene He clarified why sometimes we say gravity is a force and sometimes we don't. It all depends upon which method, Newton's or Einstein's, we're using.

[@kylelochlann5053]

@@terryjwood but he's wrong - physics isn't about our feelings, it's about measurement. All measurements indicate and require that gravity cannot be a force.

[@terryjwood]

@@kylelochlann5053 Have you told him that?

[@kylelochlann5053]

@@terryjwood Every single time.

[@ChinnuWoW]

I think it definitely must be a force because space can’t distort itself. Distorting space(or anything) requires work. The gravitational effect is not the force itself but it is indirectly caused by it.

[@kylelochlann5053]

Yes, spacetime distorts itself, a non-linear aspect of the theory. In quantum parlance, the gravitational field couples to itself.

[@thomasherrin6798]

Newton is majorly right and Einstein and his Professor have taken us up a bit of a cul-de-sac, there is universal time, there is also specific object time!?!

[@beders]

​@@thomasherrin6798 Einstein's predictions have been verified over and over and over again. Your GPS wouldn't work if Einstein was wrong. Note that Dr. Lincoln said: Einstein's theory is incomplete. That doesn't mean you can't make real-world calculations

[@amanvalodia3669]

This question was troubling me for a long time. this video helped me a lot. Thank you so much Dr.Lincoln

[@VonJay]

except that based on Newton's equations, the downward force of gravity and the upward acceleration of the earth would cause both forces to cancel out. In Einstein's field equations, gravity isn't a force and only the earth is accelerating upward, and the acceleration is 9.8 m/s^2. The thing that proves Einstein's posit that gravity isn't a force is the use of an accelerometer on earth's surface. It reads out that the earth is accelerating. But if Newton were right then the accelerometer wouldn't read out anything. It would be zero. So gravity isn't a force.

[@JarjanFisher]

Best statement ever: "You'll only be partly right, some of the time." I think the world would be a better place if everyone took that to heart!

[@northerngannetproject3147]

Better but boring 😁

[@Mr.Not_Sure]

I like it when real physicists aren't so zealous as physics geeks.

[@easternhills1329]

Dunning-Kruger effect doing its thing.

[@Mr.Not_Sure]

@Noelle Leger Are you idiot or just pretend?

[@voltydequa845]

@@easternhills1329 «Dunning-Kruger effect doing its thing.» ---- There's not such an effect. It was dismantled, soon after announced, by other researchers, as artefact (bias in premises, measure, repeatability, etc). Btw I knew that it was a bluff, before having read that they already demolished it, since the measure cannot be but subjective. Anyway, from what I remember, officially there were two problems - 1) absence of repeating 2) totally random answers gave the same results as obtained from their tests.

[@betaneptune]

@noelleleger232 Einstein said not to take the geometric interpretation too literally. So he thought it was a force. Besides, how do you conserve energy if it's not a force?

[@betaneptune]

@noelleleger232 I've seen the video. I'm not convinced. And why is it popular now to have rockets accelerate the elevator car? The rocket will reduce the mass of the car by hurling propellant away. Why not just use the traditional rope pulling the thing? I have also seen posts from a reliable person about how Einstein himself said not to take the geometrical view too seriously. This same person explained that you could view electromagnetism geometrically, except that you have different geometry based on different charges. With gravity, everything is affected, so you can have a single geometry describe everything. Also, how would you conserve energy that way, e.g.? And sorry, I'm not interested in any conspiracy theories about 9/11. I suppose you're next going to claim we didn't go to the moon. Or that JFK Jr. is coming back as a Republican.

[@DMBHomes]

Love these videos, really gets you thinking. It’s pretty uplifting. Reminds me of when I was a kid walking out of a science class feeling like the world has changed a little because of my new knowledge. Such a cool feeling. Thank you

[@idontwantahandlethough]

love that feeling; feeling like the world is somehow slightly more vast and wonderful than it was the hour before :)

[@Earwaxfire909]

Very well done. I'd like to learn more about entropic models of gravity when you have the space-time.

[@nuckyducky]

I am in love with entropic gravity. I can't wait to learn more about the topic. Thank you for this overview!

[@cosmicdebris2223]

1:54 "but the floor pushes me up". This is a standard explanation and sort of makes sense, but has always troubled me since I would argue that the floor (in that example) offers resistance rather than an active force in the other direction. Otherwise the floor would be moving up, but it doesn't. It stays there and offers resistance. Would love to be corrected on that one or guided as to how I am viewing this incorrectly.

[@JorgenHenningsen]

Hi Don. As I understand it there are a few theoretical scientist working on thoughts about the link between entanglement and gravity. I think it will eventually lead to testable predictions. Have you got some thoughts in that direction?

[@ExecutiveChefLance]

Its not Testable. So a Wolfgang Pauli "Not Even Wrong" theory. The idea is that the Entanglement of Particles at beginning of the Universe has collected among Black Holes and this has some effect. Look up Leonard Susskind 2022 Oppenheimer Lecture on "Quantum Gravity". IMO this is the BEST theory out there. And Susskind straight up says his Math on Quantum Decoherence, the Momentum of Information spread within the Quantum Hologram equals Marco Gravity. Reality is a Hologram created by Quantum Particles and Waves that we cannot see or cohere. Therefore similar to a Technological Hologram the Quantum World creates the Reality we perceive similar to that. This happens because we cannot perceive the True Nature of Quantum Waves and what we call Wave Function Collapse occurs. When this occurs something starts it. Imagine poking a Hologram the Information of your Poke spreads throughout the Hologram. This is what happens in Reality. That information spread of Macro Things interacting with Quantum World. The momentum of that Interaction equals the Math of Newtonian Gravity. He has another lecture I have not watched yet. Funny enough its called Debunking Quantum Gravity. Which is interesting because its all the stuff I just said here. Guess he doesn't consider that "Quantum" but simply what Gravity is? I need to watch it for real. He even says it will be testable in Low Energy Labs soon. Guy is Next Level. We are Giants swatting a Dense Clot of Quantum Gnats swarming around us. With every Movement and Action rippling through these Swarms. You follow this Logic a Black Hole is simply when Energy gets to a Point when Waves cannot Exist any longer. So No Reality can Cohere.

[@orthoplex64]

@/O/ Isn't everything constantly getting entangled with its immediate surroundings? There's no special thing required to make it happen.

[@abelincoln8885]

Newtonian physics is .... Universal Functions This means everything is a Function ... with purpose, form, properties, processes & design ... and can only be made by an intelligence. Universal Functions ... is the hypothesis for Sir Issac Newton's Watchmaker Analogy (Observation) over 300 years ago ... and ... an Machine Analogy used by Theists to explain "Intelligent Design." And the Function, Intelligence, Mind Categories ... as well as the origin of any THERMODYNAMIC System .... proves the Universe & Life ... are Functions, composed entirely of Functions and were made by an UNNATURAL Intelligence in a UNNATURAL surrounding System that is timeless & infinite. Quantum particles, fields & forces ... atoms, elements, compounds, molecules, ... chemical & nuclear reactions ... space, time, Laws of Nature, matter & energy ... are all Functions .... with purpose, form, properties, processes & design. There is ZERO evidence ... that nature natural processes can make the simplest physical function .... 13.7 or 4 billion years ago ... or ... today. We know for a fact ... that nature & natural processes ... can never make & operate the simplest physical function made by Man ( Intelligence) ... like the lever, wedge, spring, nut, bolt, nail, hammer, axe, shovel, wheel, .... cup, plate, knife & fork. Newtonian physics ... is Universal Functions. Science is a method (function) ... created by Man( function) ... to explain natural Phenomena(functions) ... rely completely of fixed Laws of nature, space, time, matter & energy which are all Functions. What the hell up and stop believing the fairy tales from religious zealots with PhDs about their Almighty Mother Nature & the Holy Natural Processes. A religion ... is simply a man made BELIEF system .... in someone or something ... responsible for the Universe, Life & existence/reality. Theists ... have a firm belief in someone (the gods of UNNATURAL intelligence). Atheists ... have a firm belief in something (Natural processes). And again ... Science is simply a method to EXPLAIN natural processes ( functions) based on fixed Laws of Nature(functions). Gravity .. if s function ... composed entirely of interacting functions ... that include at least mass, velocity & radius ... at the Cosmic or Macro level as Newton only 17th Century knowledge of the space, time, Laws of Nature, matter & energy of the Universe. And Newton did not realize everything, including Life, is a function composed entirely of INTERACTION functions.

[@vast634]

At very small distances, gravity might not act as "directed" (attraction vector) as we know it, and might act more randomly. That would be prediction.

[@frankdimeglio8216]

​@/O/ The ultimate mathematical unification (AND UNDERSTANDING) of physics/physical experience combines, BALANCES, AND includes opposites. The BALANCE of what is gravity WITH what is inertia/INERTIAL RESISTANCE requires and involves TIME AND time dilation ON/IN BALANCE, AS gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites (ON BALANCE); AS this CLEARLY explains the fourth dimension; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. INSTANTaneity is fundamental to what are TIME AND time dilation ON/IN BALANCE. Accordingly, ON BALANCE, INSTANTaneity is fundamental to what is the FULL and proper understanding of physics/physical experience; AS the extension of what is SPACE is CLEARLY (AND NECESSARILY) electromagnetic/gravitational ON/IN BALANCE. What is GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. What is E=MC is taken directly from F=ma, AS the rotation of WHAT IS THE MOON matches the revolution; AS the stars AND PLANETS are POINTS in the night sky. Great. INDEED, c squared CLEARLY AND NECESSARILY represents a dimension of SPACE ON BALANCE. ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE), AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. “Mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent WITH/AS what is BALANCED electromagnetic/gravitational force/ENERGY, AS gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE (ON BALANCE). A given PLANET (including what is THE EARTH) sweeps out equal area in equal TIME. Great. What is E=MC is taken directly from F=ma. Consider TIME AND time dilation ON/IN BALANCE. INDEED, consider what is THE EYE ON BALANCE !!! Notice WHAT IS the fully illuminated AND setting/WHITE MOON ON BALANCE !!! NOW, consider what is the TRANSLUCENT AND BLUE sky ON BALANCE !!! So, consider what is the orange AND setting Sun ON BALANCE. ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE), AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. Inertia/INERTIAL RESISTANCE is proportional to (or BALANCED with/as) what is GRAVITATIONAL force/ENERGY, AS the extension of what is SPACE is CLEARLY (AND NECESSARILY) electromagnetic/gravitational ON/IN BALANCE. Consider TIME AND time dilation ON/IN BALANCE, AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE. Gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites (ON BALANCE). GREAT !!!! BALANCE AND completeness go hand in hand. Carefully consider, ON BALANCE, why and how it is that there is something instead of nothing !!!! By Frank Martin DiMeglio

[@Nightscape_]

I want to hear more about entropic gravity. I don't think I have ever heard that brought up before, or at least don't remember any videos about it.

[@grayaj23]

It's way over my head, but I think Erik Verlinde did a lecture about it recently that's available on youtube. Erik Verlinde "Emergence of Gravity from Quantum Information: a Progress Report"

[@quandaledingle2107]

@@grayaj23 thx

[@lasagnahog7695]

Samesies. It's cool to see I wasn't the only one who had their ears perked up by that.

[@abelincoln8885]

Why? Gravity is simply a Function ... as is space, time, Laws of Nature, matter & energy. All Systems are Functions ... with purpose, form, properties, processes & design ... which are INFORMATION that every function possesses to exist & to function. And information ... is an abstract construct .. that can only come from the Mind of an Intelligence. There is zero evidence that nature & natural processes can make & operate the simplest physical function .... 13.7 or 4 billion years ago .... or today. We know for a fact that Nature ... can not make & operate the simplest physical Function made by Man (Intelligence) ... like a lever, wedge, spring, nut & bolt, hammer & nail, ... cup, plate, knife & fork. A quantum particle, field & force ... are the currently known ... simplest Functions in the Universe ... with purpose, form, processes, properties & design. The Universe is the only known ISOLATED Thermodynamic System(function). All thermodynamic Systems .... originate from the surrounding System ... which must provide the space, time, Laws, matter, energy and INTELLIGENCE ... to exist & to function. And the Surrounding System ... of the Universe with time & NATURAL laws ... must be UNNATURAL, timeless & infinite ... otherwise it will be a Natural System(function) that originates from a surrounding System with an Intelligence that made it. You want to learn more about entropic gravity ... to be in awe of God's brilliant Creation right? lol.

[@chrimony]

Now you're going to get a bunch of comments saying it's the bending of spacetime, and not just space. Clever content farming, Don!

[@drdon5205]

You know our viewership so well...

[@private_citizen]

I will do you one better. Spacetime isn't real. Time isn't real. And space doesn't bend, move, or warp.

[@voltydequa845]

From Shakespeare's "What's in a name? That which we call a rose/ By any other name would smell as sweet", to Lincoln's "What's in a concept? That which we call gravity / By any other name would attract as well". Then from Duck Test "If it looks like a duck, swims like a duck, and quacks like a duck, then it probably is a duck.", to common sense's "If it looks like a forces, attracts like a force, weights like a force, then we can't but see it as a force". I like these videos. Please continue to teach that it (all) depends on the relative model / concept. Then hopefully applying the principle of simplest choice. I read, few minutes ago, "In curved space time you have to accelerate just to remain stationary" explanation of relativistic gravity explanation. So it is about changing the meaning of "acceleration". But this way one can generate point-of-view models at free will, and their acceptance will depend upon the administration of conformism. So we are about self-referential models / concepts that to satisfy their logic change, at free will, the meanings of the words / sub-concepts. Dear Lincoln, yes "Physics is all!", but only under the condition it is free. The smell that I feel is that it was hijacked long ago, and that partial liberation is underway nowadays. So "Physics is all when freedom is all!". Based on shared premises (especially meanings), and free of rhetorical decoration.

[@no_one_160]

Amazing articulation. As a teacher, I find your lecture extremely lucid, and try to replicate in class. Thanks!!

[@ulisesrivas6983]

Thank you Dr Don as always excellent content.

[@frankdimeglio8216]

​@Noelle Leger WHAT IS GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. WHAT IS E=MC2 IS dimensionally consistent, AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE) !!! BALANCE AND completeness go hand in hand. GREAT !!! WHAT IS GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. (WHAT IS E=MC2 IS dimensionally consistent.) Consider what is the man (AND THE EYE ON BALANCE) who IS standing on WHAT IS THE EARTH/ground, AS touch AND feeling BLEND; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE !!! BALANCE AND completeness go hand in hand. WHAT IS GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. WHAT IS E=MC2 IS dimensionally consistent, AS “mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent WITH/AS what is BALANCED electromagnetic/gravitational force/ENERGY; AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE (ON BALANCE). INDEED, GRAVITATIONAL force/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE !!! The stars AND PLANETS are POINTS in the night sky. WHAT IS E=MC2 IS dimensionally consistent !!! Accordingly, ON BALANCE, THE PLANETS (including what is THE EARTH) sweep out equal areas in equal times. Consider TIME (AND time dilation) ON BALANCE. WHAT IS E=MC2 is taken directly from F=ma, AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE). WHAT IS GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. WHAT IS E=MC2 IS dimensionally consistent !!! CLEARLY, gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites (ON BALANCE); as the stars AND PLANETS are POINTS in the night sky. Consider TIME (AND time dilation) ON BALANCE. INDEED, TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE) !!! GREAT !!! ACCORDINGLY, ON BALANCE, the rotation of WHAT IS THE MOON matches the revolution. GREAT !!! WHAT IS E=MC2 IS dimensionally consistent. GREAT !!! It is a very great truth that the SELF represents, FORMS, and experiences a COMPREHENSIVE approximation of experience in general by combining conscious and unconscious experience. INDEED, the INTEGRATED EXTENSIVENESS of THOUGHT AND description is improved in the truly superior mind. BALANCE AND completeness go hand in hand. By Frank Martin DiMeglio

[@Eliphas_Leary]

That deep dive into gravity (pun intended, Doc?) sounds like jumping into a rabbit hole that leads into a labyrinth wrapped in an iceberg. Looking foreward to it...

[@misterschifano]

Gravity is a force in GR... It forces you to learn math! 😁

[@theoccidilian4896]

“Be careful when you make a claim about what’s going on…”: thank you! Too many people do this, and it leads to misunderstanding. (Honestly, I’m only talking physics.)

[@NickCalapa]

Dr. Lincoln, Whether gravity is a tug between masses, a distortion of space by a massive object or an exchange of gravitons wouldn't all of these require a constant expenditure of energy by the massive object? Where does the energy come from? Wouldn't the mass eventually have to evaporate as it was converted to energy?

[@jonwebb2417]

Great video. One question - does the "force" act on space itself to cause the curvature? i.e. against a tension (so that space "snaps back" to straight line cartesian space once the mass is removed?). Trying to understand if gravity is a force, but acting on space itself rather than directly on the bodies/masses involved...?

[@AconservativeThought]

I think it’s obvious that once the object disappears from the place it resided in the 2 dimensional space time fabric that it is no longer pulling that fabric. This is simply what happens as the sun, earth, est. est. move through space. The place were the object is no longer occupying causes the space fabric to go back to its original state ie: no more object in that spot to manipulate the space time fabric. If gravity kept effecting the space the object no longer resides means there would be gravity in a place were no object is placed and space time fabric would pull objects towards an empty spot in space and we already know that, that does not happen.

[@SpaceMan-f6d]

You're right Dr. Lincoln! "It's a force in geometry caused by buzzing of quantum particles". I would personally go for Strings and Gravitons, as Entropy seems to exotic to me. All best!

[@jacobblumin4260]

Another excellent video from Dr. Lincoln! It took me a few steps closer to understanding gravity.

[@OrpheusSonOfCalliope]

@Fermilab Dr. Lincoln, what has always troubled me is that when describing Einstein's relativistic framework, it is said that mass deforms space-time but no mechanism has been suggested (as far as I know, maybe I'm mistaken?). Is it possible that a force might be responsible for deforming space-time? How else can the deformity of space-time be explained? Asking for a friend ...

[@narfwhals7843]

Are you also troubled by the mechanism by which electric charge affects the electric field in classical electrmagnetism? It is the same. There is none. It is a fundamental relationship.

[@Sezstu]

I think the problem is language and our imperfect definitions. Gravity isn't a force like viruses aren't alive and like Pluto isn't a planet. What we call something doesn't affect what they are. It affects how we think of them.

[@ejikeawazie1469]

I ❤ the teacher who calmly teaches without yelling at his audience, like Neil... 😂😂😂

[@allenmorgan4309]

Gravity is both a force as when gravity coalesces gases to form stars and geometric as large objects curve space. Gravity is both depending on the context.

[@mikefochtman7164]

Great video, but I'm a bit confused @3:50. It shows how space is bent by a large mass (picture of earth) and how another body (green dot) travels along the bent line of space. The animation stops as the green dot (smaller mass) approaches earth, but it seems if it continued it would follow the same 'line' of bent space and curve away to the right as it passes by earth. But this isn't the direction a body would fly, it would curve around earth to the left!! So the large mass (earth in this case) doesn't 'bend' the lines in that particular way??

[@dritemolawzbks8574]

There's not enough information about the representative [ 🟢 ] @ [ 3:50 ] to predict its actual trajectory in 3D space, or its 4D spacetime worldline. It could simply be an apple 🍏 falling vertically toward the center of earth but the surface of the planet provides a normal force stopping its motion. The other options, could be a free-fall or gravitational orbit. The moon, satellites, or ISS remain weightless because there's not a force stopping them like we feel on the surface of the earth.

[@claudetremblay3892]

Quantum gravity can’t be proven, it is because it is impossible to prove something that doesn’t exist? It’s like proving that spirit exists . So if gravity is an effect and not a force, it can stay that way until proven otherwise. Usually in physics if it is simple to explain and proven, then it’s true, but if it is complicated it is most likely false. In quantum physics if it’s complicated to explain and proven it is true, but if it is simple it’s probably false. Ok it is a very simplistic explanation, but I think it is a fair representation of why we still don’t know much about where gravity comes from .

[@bryandraughn9830]

I love examples of gravitational lensing because they seem to support relativity in a very obvious way, but the idea that some mass could somehow "pull" on empty space still makes me wonder "how?". Great video!

[@mjhzen8313]

Two things seem certain about contemporary physics: 1) all definite questions have nebulous answers; and, 2) the probability of knowing anything is inversely proportional to the degree of enthusiasm you radiate for knowing something. :)

[@edd.]

I hope that you do a deep dive into those topics. I think we'd all love to see it.

[@dankmeme5214]

Hi, @fermilab , a recent video from the royal institution has the prof there saying time is more bent than space. That gravity bends space time. Which made me think differently about gravity. Isn't the bending of time sufficient that it affects how the way GPS satellites give us our position? Is time more bent than space by gravity?

[@narfwhals7843]

Time is not usually "bent more" than space. Around large lumps of matter, like earth or the sun, they are bent together and the same. But the bending of time is almost exclusively responsible for what we usually call "gravity", things like falling and orbits of objects moving significantly slower than the speed of light. Gravity does not bend spacetime. Gravity _is_ the bending of spacetime by the stuff in it. -All this applies in General Relativity.-

[@hulkthedane7542]

In ordinary people's everyday life, considering/treating gravity as a force makes the most sense. Great video 👍👍👍

[@northerngannetproject3147]

It's way more fun admitting that your weigh is only the centrifugal force of your body travelling in time on curved path... 😊

[@AurelienCarnoy]

Could gravity be an like an edge dislocation of virtual particles? I understand that virtual particles randomly pop in an out of existence, so it is bound to generate random patterns like shearing which is a gravitational wave. So could that be quantum gravity? (Like the white wave background) Thank you for your kindness.

[@kazimierzmarkiel5400]

1-In which direction this "space bending" is observed and meassured? On the graphs the physicists are shoving one distinguished direction (usually down). 2-All physical meassurements ,which created basis for the theory of quantum gravity were obtained via the devices, made of the atomic matter. So it could be giving the result, which is biased in the most subtle level - due to its atomic structure. Stary

[@cullanvanwyk4807]

i had to look up the meaning of "tautological." Anyway, if we have a 1kg mass suspended one meter from the surface of the earth and another 1kg mass suspended one meter from the surface of the moon, why do they drop at different rates? does the gravity change time or shorten the distance or is there a bigger force applied to the masses?

[@MrPoornakumar]

Merriam Webster is round-about in its definition of Force. Force is basic & fundamental. Its succinct definition is - Force is proportional (symbolised ∝) to the rate of change of momentum. This, of course, introduces a constant of proportionality between Force on one side as well as momentum & its change-rate on the right hand side - depending on a preferred units-system for use. The practical aspect is one worthy of a look. The proportionality constant can be reduced to equality (symbolised =) depending upon our choice of units used (length, mass & time), that was quite arbitrary till date. Yet, our defining that unit as 1 Newton, makes the proportionality constant as 1. It is this effort of rationalising or normalising, that is on now.

[@kristjanpeik7381]

Great video and channel! That guy really knows how to present information!

[@warriorsabe1792]

imo, whether gravity should be considered a force is in the same group as things like the centrifugal force: it depends on what you're doing. For complex orbital maneuvers it can be more helpful to think about gravity in terms of curved paths through spacetime, but when talking about how it affects people and mountains standing on a planet it's more useful to think about it as a force; much like how whether the centrifugal force should be considered to be one depends on whether you want to describe something released from a spinning wheel or someone sitting in a centrifuge

[@AconservativeThought]

So to put it simply, you are saying that gravity is both things at the same time?

[@Sun-Ra9]

Physics is soooooo delightful!! Thanks for the explanation. There is always a lot more to learn.

[@havehalkow]

So good you mentioned the Serway's physics book. After reading a few pages, it seems a very well put book.

[@andrewpaulhart]

Now skip to the end and see how it ends

[@frankdimeglio8216]

​@@andrewpaulhart WHAT IS GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. WHAT IS E=MC2 IS dimensionally consistent, AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE) !!! BALANCE AND completeness go hand in hand. GREAT !!! WHAT IS GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. (WHAT IS E=MC2 IS dimensionally consistent.) Consider what is the man (AND THE EYE ON BALANCE) who IS standing on WHAT IS THE EARTH/ground, AS touch AND feeling BLEND; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE !!! BALANCE AND completeness go hand in hand. WHAT IS GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. WHAT IS E=MC2 IS dimensionally consistent, AS “mass"/ENERGY involves BALANCED inertia/INERTIAL RESISTANCE consistent WITH/AS what is BALANCED electromagnetic/gravitational force/ENERGY; AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS gravity/acceleration involves BALANCED inertia/INERTIAL RESISTANCE (ON BALANCE). INDEED, GRAVITATIONAL force/ENERGY IS proportional to (or BALANCED with/as) inertia/INERTIAL RESISTANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE); AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE !!! The stars AND PLANETS are POINTS in the night sky. WHAT IS E=MC2 IS dimensionally consistent !!! Accordingly, ON BALANCE, THE PLANETS (including what is THE EARTH) sweep out equal areas in equal times. Consider TIME (AND time dilation) ON BALANCE. WHAT IS E=MC2 is taken directly from F=ma, AS TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE). WHAT IS GRAVITY IS, ON BALANCE, an INTERACTION that cannot be shielded or blocked. WHAT IS E=MC2 IS dimensionally consistent !!! CLEARLY, gravity AND ELECTROMAGNETISM/energy are linked AND BALANCED opposites (ON BALANCE); as the stars AND PLANETS are POINTS in the night sky. Consider TIME (AND time dilation) ON BALANCE. INDEED, TIME is NECESSARILY possible/potential AND actual ON/IN BALANCE; AS ELECTROMAGNETISM/energy is CLEARLY AND NECESSARILY proven to be gravity (ON/IN BALANCE) !!! GREAT !!! ACCORDINGLY, ON BALANCE, the rotation of WHAT IS THE MOON matches the revolution. GREAT !!! WHAT IS E=MC2 IS dimensionally consistent. GREAT !!! It is a very great truth that the SELF represents, FORMS, and experiences a COMPREHENSIVE approximation of experience in general by combining conscious and unconscious experience. INDEED, the INTEGRATED EXTENSIVENESS of THOUGHT AND description is improved in the truly superior mind. BALANCE AND completeness go hand in hand. By Frank Martin DiMeglio

[@waynelast1685]

How can we pursue gravity "particle-like" explanations when you need a space-time backdrop to describe it, but gravity itself IS the backdrop? That's like saying you are describing the backdrop operating on itself? Or it's like saying describing x-y-z coordinates influencing the behavior of x-y-z coordinates?

[@jasonsebring3983]

You have been a positive "force" for me in learning. Thank you!

[@WilliamParmley]

Another outstanding video! I love this: "...you're probably only partly right, and then only some of the time." That's on a par with Oliver Cromwell's "...think it possible that you may be mistaken." Or James Thurber's "Beware of half truths. You may have the wrong half." I had a physics professor (a high energy physicist, by the way) who used to joke that "the graviton is a spin 2 particle roughly the size of a basketball." 😁 My version of Betteridge's Law: "If the headline ends in a question mark, don't read the article."

[@mortezarazavi9307]

Thank you for your explanation I have a question is this possible travel through from earth to moon by using gravity force from one place to the other without using any source of fuel or energy just focus on gravity of different location we want to go

[@narfwhals7843]

To change gravity you have to move the energy equivalent of the mass that would cause that gravity. You can't do it without "and source of fuel".

[@theoriginaltroll4truth]

It is a consequence/result/by-product of aether flow! All matter/compressed aether, creates a negative pressure zone in uncompressed aether/space and a pressure gradient is formed. The pressure is top-down as is the flow. The larger the mass of matter, the greater the pressure gradient.

[@dinnoel3147]

It appears it is an axiom gravitational affect we observe on matter is of the same nature (whether force or not) as gravitational affect on massless objects. Could there be multiple mechanisms?

[@johnofepsom]

Great videos Don. This puzzles me: the 'force' of gravity depends on the distance between the centres of the two masses, squared. But when those two masses are touching, like a person on the Earth, it does not make sense to me. Because the distance is squared, the nearest part of the Earth must have a much greater effect than the furthest part of the Earth. Consequently, the 'centre' of the gravitational effect must be closer than the centre of the Earth. What am I missing?

[@festeradams3972]

A question I've often posed, is does a object generating a Gravity Well "pulling" or is the surrounding spacetime "pushing"? Probably doesn't matter much practically, as a sudden stop usually hurts anyway....

[@narfwhals7843]

Neither. Because there is no force is a curved spacetime. No pushing or pulling. Objects are just following the straightest line they can in accordance with newton's first law.

[@festeradams3972]

@@narfwhals7843 Perhaps, but nobody is sure.

[@narfwhals7843]

@@festeradams3972 We may not be sure that gravity is spacetime curvature. (we're pretty sure). But we are sure that gravity wells add together. More mass=more gravity. Not less.

[@visualedtech]

I lean more to the theory that gravity is an attractive accelerating force rather than a distortion of space. Newton's gravitational laws did not explain the elliptical paths of orbiting bodies. However, in 1915, they did not know that the sun was orbiting the center of our galaxy. Secondly, in 1915, electromagnetic waves were thought to have no known mass and should not be affected by gravity. However, some articles claim that they do have a mass. If so, they would be affected by a strong gravitational force, no called "lensing". One last claim that I've heard in many presentations: "Mass slows time". Gravity is an accelerating attractive force that is active on all mass. Gravity would slow down any measurement of time from a simple watch to an atomic clock. Great Presentation! Thanks.

[@narfwhals7843]

Einstein _predicted_ in 1915 that light should be affected by a strong gravitational field exactly because in his model gravity is not about mass but about motion in curved spacetime. Everything follows that curvature, mass or not. That was actually the first test they did. The "Eddington experiment" confirmed light bending around the sun as predicted by Einstein. We have tested for the mass of light extensively and all results are consistent with zero.

[@jarodrosenthal6994]

Just found this channel. Thank you for making these videos!

[@Biskawow]

Entropic gravity would be an interesting video. It seems these are all connected - entropy, time, mass and gravity. Time flows towards higher entropy, mass wants to occupy lowest rate of time flow like lowest energy levels, and it manifests as gravity (like how time flows slower on Earth than on a space station).

[@marcelvdzalm7380]

My kind of brainwork 👌 definitly not a force acting on it s own...this gravity.

[@kenmapp4891]

What i don't get about curved space is why an object would move in the 1st place. Like it a we just set a mass at 10 ft above the ground, with no motion relative to the earth, why would it fall to the ground? All the explanations of curved space (that I've seen) illustrate it with a moving body.

[@davidszmyd1506]

I've wondered that too. OK, so a moving object follows the direct path of curved space. But to get it moving, or change its velocity, a FORCE is needed. F = ma after all. I wish this point were addressed in the video.

[@herval]

Excellent presentation, 🙏 thank u

[@ilovetech8341]

The F=ma is an incomplete equation. Just because we discount the mass of a tiny object in relation to say the earth and chop it off the equation doesn't explain the whole system. Then that's why we also say things like a mass traveling through space is not accelerating unless another force acts on it.

[@bernardkisby4490]

I love that line near the end, "You'll probably be only partly right and then only some of the time",

[@willem1642]

So how fast do gravitons move? What happens if they have mass, do they interact with aech other?

[@therealebolaboy]

Thank you very much for making these videos!

[@LeoH3L1]

If gravity is caused by the curvature of spacetime, then something must be applying a force to spacetime to force it to be distorted, it's just a different kind of force to the others we know of. There must be some kind of influence between mass and space-time involved, and that influence could easily be called a "force".