Probably the best series on youtube right now. The fact that we can ask a noted physicist any question we want for free doesn't get nealy enough appreciation.

"High energy means small sizes" This is best demonstrated after Thanksgiving dinner, where your mass has increased but your energy is near zero

Thanks for the lesson Dr. Don ❤

Someday show us your t-shirt collection. It is always the first thing I look for.

These episodes are so wonderful to watch.

The Mr. Multiverse shirt gave me a chuckle. 😄

How refreshing that a scientist can humbly and honestly discuss intelligent design without bias or prejudice. He presents the theory, shows how it would fit/solve the observed data, but then provides the caveat that it's inherently unverifiable with science and so the truly "scientific" thing is not to dismiss it, ridicule it, or reject it, but simply to move on and focus on applying the science where we can. Science is an incredible and powerful tool but is impotent and useless in the face of moral, philosophical, or religious questions. It's like praising the success of you axe, which truthfully has helped you to achieve a great deal, to the point where you insist on using it to drink water with. It's just an entirely different form of thinking/reasoning.

“This is rather as if you imagine a puddle waking up one morning and thinking, 'This is an interesting world I find myself in - an interesting hole I find myself in - fits me rather neatly, doesn't it? In fact it fits me staggeringly well, must have been made to have me in it!'

Thanks Doctor Lincoln, informative funny and a cool t shirt. What more can one ask for? Keep up the good work.

Another great tutorial! Keep up the good work!

Dr. Don, during the Q&A section of your videos, would you pick one book from the shelf behind you and give us a 30 second review? Great videos, keep up the great work!!

I would very much wish for you to continue this format after the covid situation. 🙂 Of course I still look forward to more normal editions also. 👍

Very good and informative, look forward to more videos..

It's going pretty good, thanks for asking!

Thanks for another great video Brian.

Hi Don, great video as always. You often say that physics is everything. Do you think that one day we will be able to explain the origins of consciousness and subjective experiences using particle physics?

Brilliant explanation.

Thanks again, very nice video as always

Currently watching these backwards, so to speak. Fantastic series. I love speculative science because it frees the mind to imagine pretty much any situation. For a sci-fi writer, if only for a small group, this is fantastic 'fodder'. Having said that, I only write it if I think I can use any scenario within acceptable parameters. I really appreciate your clear explanations, as much as any speculation can be clear!

Love this series, and love this episode on the multiverse. I noticed that you didn't mention anything about the Many-Worlds Interpretation of Quantum Physics. Is that a deliberate omission, because they're very different ideas? Are there ways that MW and the multiverse are related to one another?

Hi, thanks for your great channel. I was under the impression that the idea of a multiverse was first proposed by Eugene Wigner as a possible interpretation of the wave function collapsing and the measurement problem in QM.

I never took a physics class so most of your videos are over my head, but the curiosity is still there. Are there any web sites your might recommend to get a more basic understanding of physics, more specifically, particle physics?

I noticed you have a copy of Parker's "The Roman Legions" on your shelf. It's one of my favorites! In Hawking et. al.'s paper "A Smooth Exit from Eternal Inflation," Hawking mentions that the early inflationary period might have been part of a cluster of similar expansions of several other universes, and that we could detect evidence of this in the CMB. If so, what sort of evidence would we look for? Something like the Cold Spot, or another feature that's more subtle?

I think the multiverse is probably real. I can't say for sure of course but the fact that particles behave like a wave and the fact that our universe was once smaller than a particle, it should be that the universe is smeared so to speak and exist in multiple locations simultaneously.

Hi Don, thanks for the video! If travelling time was not a problem - which place in the universe you'd want to visit? Or which event to observe?

Thanks for your detailed explanation of where we’ve been and where we’re headed...all on a time scale which is beyond us mere mortals!

I am SO sold on the Anthropic Principle... if things weren't the way they are, we wouldn't be here to ask why they are the way they are.

Hey, a new one... and a cool topic too!

In the multiverse hypothesis, does the multiples universes share the same big bang ? _ By the way, I discovered this channel recently and I love it. Thanks for your work and your attention to random questions people like me ask every time.

If there TRULY was symmetry in the universe, there'd be a Don Fermi doing KZfaq videos for Lincoln Labs!

Where does gravity fit on the 'Increasing Strength' v Log(Energy) graph?

I like getting more technical so to put more technical Q&A at the end seems a fair deal to not loose the majority at the beginning of the videos.

Wait, what about branes? And what do you think about the Arecibo news? Thanks for doing this series.

Hi Don, String and superstring theory are very interesting ideas you have mentioned. What are the strings made of though? Spacetime, energy, math? Is there an allegory of string theory using mathematical knots and braids to model the particle zoo?

Except for watching the opening 6 minutes of Baby Driver every day, this is my favorite viewing on KZfaq. Thanks, and Happy Thanksgiving, Dr. Don🦃🦃.

Dr.Don what is your stance on QM and its interpretations?

Is something like the space between electron orbits and the nucleus of an atom also dark energy?

The word universe meaning "everything" is kind of analogous to how "atom" originally meant "uncuttable". As our understanding becomes more subtle, sometimes words take on new meanings that are in conflict with the old meanings.

In your Forces Graph when you added Supersymmetry, why did the lines get that little 'curve' at the start of the curve?

Hi Don, does Godel's incompleteness theorem suggest to you that the universe is computational (e.g. Wolfram cellular automata) or that human beings can think in ways that computers cannot (e.g. Penrose microtubules)?

Hello Dr. Don, you explained the our universe might just be the "one" of countless that happens to be finely tuned to support life, but is this the strong or weak anthropic principal? and what is the difference between the two?

Dr. Lincoln, two questions (sorry about that). In mentioning 'a fine tuning' or perhaps I should say a fine tuned universe among a multitude of universes (to stay off 'intelligent design') that is fined tuned enough for us to exist. Assuming our universe is fine tuned throughout wouldn't that rather imply that life should exist elsewhere in our universe too? You did say that you didn't believe in MU hypothesis does that include the idea of a 'parallel universe' too?

Yay, new vid!!

hey don @fermilab, what is your favorite book? any book, not just physics or science, what book has effected YOU the most?

I always had a problem with fine tuning, there is implied in there that the constant of the universe could be any other way. I mean, we don't have a second universe to test against ours, and check if the constants are the same, so even implying that changes in the constant would bring an another non-life permitting universe seems unscientific to me.

What are your views about Strange matter in cores of neutron stars?

Do quantum fields continue outside universe, such as before big bang and beyond particle horizon of universe?

A question: if before electoweak symmetry breaking all particles are massless, does that mean there are no neutrino oscillations in the unbroken phase, and no oscillations between left- and right-handedness? If so, how does the proposed leptogenesis work again, doesn't it depend on neutrinos changing handedness?

Very cool. One thing about "fine-tuning". There is a paper Adams, F. Stars in other universes: stellar structure with different fundamental constants. Journal of Cosmology and Astroparticle Physics 2008, (2008). that shows that the space for three constants is relatively large for stars (as we know them) to form. So, it may be likely that fine-tuning isn't quite as fine as some thing. The other point is that humans exist because our universe is the way it is. The universe isn't the way it is because we were destined to exist. This is simple evolution. Life evolves to best survive and reproduce in the environment it exists in, not the other way round.

Besides intelligent design or the multiverse, what other explanations can explain the fine tuning of the universe?

Hi Dr, hoping to find my question in the next section. Can you explain in an easy way, maybe with some maths, how scientists have deduced black holes or the expansion of the universe from GR?

What does it really mean for the laws of physics to change? If particles go over a sort of boundary, would they suddenly act differently? Or do different particles exist that always act the same no matter where they are in space? In that case, why would they exist somewhere else but not here?

Hi Dr. Lincoln, Do you mind to please explain why putting a high potential electric field across a cloud chamber produces more visible particle tracks than without the field? There are differing explanations floating around for this, but nothing very clear and certainly no consensus. Thanks.

Totally agree with Dr. Don about the supposed multiverse. I recently watched a video whereby two Astrophysicists were discussing a galaxy that apparently was devoid of dark matter. So, how is that possible when the existence of dark matter is still just a theory? Any thoughts on that? Thanks....

Hi, I am curious why speaking of multiverse ideas you seemingly avoid the topic of multiverse interpretation of QM. Was it intentional? Why?

Question: Could the "many worlds" theory solve the fine tunung problen or do these paramateres have to be fixed before we can us the "many worlds" theory?

Hi Don! Could you elaborate on why some physicists think that the existence of more universes makes the existence of ours with "life-supporting" fine tuning more plausible? Are those other universes necessarily expected to produce constants "all over the place" and so to get it just right once in a while? I am thinking about throwing dice here, expecting a "6-6" scenario. But underlying is the asssumption that that scenario can and will be achieved.

Do you consider the many worlds interpretation of quantum mechanics to be a multiverse theory and if so what are your thoughts. A whole video discussing the decoherance phenomenon would be awesome

I have a few questions.... 1..... Why would it take an intelligent designer to make fine tuning.... What if there was no fine tuning and no multiverse...... There was a one in a million lucky draw and we won!!! And can make video thinking it can't be pure chance??? 2.... What make scientists assume that the rate of change of physical law can be different in other pockets of universe??? 3..... why the physical law and/or constant will change just because it stem off from different point of different layers??? Can not the daughter universes have the same property of mother universe in inflation theory?? Thanks for the educational videos.... Huge fan....

Question: if I understood it correctly the multiverse has been proposed to explain why our universe has certain settings (fine tuning), by hypothesizing that there’s a lot of universes all with different “settings” and we found ourselves in one of them. My problem is: based on what principle the other universes are different? In our universe we postulate that the laws of physics are the same everywhere, why should they be different in the other universes? If I have a bubble bath that produces bubbles, they may differ in size but for the rest they are the same.

So does the multiverse that you described in today's episode have a relationship to the many-worlds interpretation of quantum mechanics?

Question: What would the impact be on our current model of physics be if dark matter/energy violate parity symmetry as recent research from Minami-san & Komatsu-san, regarding β not being zero due to a polarisation in the CMB, might suggest? (only "suggest" as not yet considered "evidence", apparently)

*Is there any is for many worlds interpretation in future?*

Is there a higher energy of gravity and if so, does it also appear to unify with the other forces?

If a particle of mass rebounds back in the opposite direction, it has to come to a complete stop before going back in the opposite direction. For that moment it is stopped, is it experiencing the maximum amount of time any mass can experience in the universe? For that matter, can a photon be reflected back in the same way in which it would have to come to an absolute stop before reversing direction and would this give it a momentary rest frame?

Is the speed of light constant only in the current size of universe and faster in an expanded universe ? Or is it an absolute constant ?

I have a question that I can't seem to get a clear answer from. If you are traveling at the speed of light, in a ship for instance, and shine a light ahead of you, does the light from your flashlight travel twice the speed of light? for instance, if a particle is traveling at the speed of light and splits (or I should say the halves repel each other) where one half goes forward and the other goes backwards, wouldn't the forward piece travel faster than the speed of light?

I'd be interested in hearing a talk about microwave energy. In particular, can light energy become microwave energy if the distance traveled is multiple times the distance of the observable universe?

Do gravitational waves propagate with the constant c speed no matter the medium, or do they behave as electromagnetic waves exhibiting different speeds in different media? If the 2nd case is what describes the reality, is it a gravitational shock wave possible to happen and how would it affect the matter nearby?

I'm still not clear what's meant by "at higher energies" when referring to the universe (or space) rather than individual particles. I know that individual particles can have higher or lower kinetic (or relativistic) energies. But what does it mean when you say that in the past, the universe (or space) itself had a much higher energy? Are you still referring to the energy of the particles, that is, good old thermal energy? Or something different? Can space itself have different levels of energy at different times, even after excluding dark energy and any (real) particles within it?

Hi Don.. does this multiverse idea has somehow to do with quantum mechanics (wave function) many worlds interpretation?

Do gravity waves interfere with the Dune or the particle accelerator experiments?

When we say quant field already existed and fluctuation in started Big Bang... it is still hard to perceive “what is the source of these field “ what started it ?

Let's assume that there is a pair particle-artiparticle created. Is it possible for the detector to be located inside light cone of one but not the other one? Would that mean the detector will be able to register more and more particles or antiparticles (depending on type of the detector) but not the other one when they are showing up from nowhere?

How do you define “small change in parameters “? Regardless, you could divide any amount of change an infinite number of times , so you can have many values that would still make this universe work. That’s assuming of course we have it right in the first place.

Which video is about how the universe is 125M times bigger than the visible part? Can you link that too please? It's mentioned at 4:00

AFAIU, multiverse is a shape of universe in which bubbles are expanding along space axis, but what about a multiverse in which bubble are along time axis? What would it mean? I'd guess either having physical constants changing across time, but far slower than "our universe" lifetime if we're not able to bring it out; another guess would be that multiverse could be identical to "bouncing universe", in which universe would bounce and we are located in a rebound which is suitable for life, which is consistent with anthropic principle?

Could a multiverse / megaverse and fine tuned constants of nature come from quantum and inflation fields? Probability distributions of inflation / quantum fields develop variations of the constants of nature which grow into multiverse or megaverse?

What is the tensional strength of space? How much 'give' is there before it pulls on the next consecutive location when space is warped? With the space between 2 close blackholes, does something about space stretch or is new space created between the blackholes to keep the amount of space there to maintain distance and then spacetime curves towards each blackhole to their curvatures saturation point? Why would space be smooth when everything else in the universe is quantized?

Hello, I was wondering something...is the speed of a photon limited by the 'speed' of Gravity Waves? Or are Gravity Waves the 'carrier' mechanism of photons? I hope my questions naked sense.😊

I just realized that the lighting in all your videos is identical. All this time I imagine that there was a window to your left.

If the constants are zero, then the equation would give a Higgs mass of zero as well; supersymmetry disproved again?

there are few other explanations. Intelligent design is testable. Look for the creator signatures of the structures and processes that s/he controls to make the universe fine tuned. Or perhaps there are other explanation that some new science can come up with. Stay tuned.

Maybe there was the last big bang where the most of particles grained to the smallest equal size. The rest of particles varying in size...Infinity is possibility in between and is possible or impossible speed (unreal space) I don't know but phisic is awesome

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What aspect of communicating science to the general public do you find most challenging?

so if the wave function that shrodinger talks about is unique to our universe, could the constants, and other universal traits be 'fine-tuned' to a different wave function, making a different conceivable universe? or, more importantly, is our universe the one that 'materializes' upon conscience will and/or observation? so the other ones can be there and not be there simultaneously, up until consious being or some other way of collapsing the wave function finally comes about? im sure none of that makes sense, thats why im asking. i apologize for my ignorance

Hello! So glad to ask my first question here. Here it goes: At some point' right after the big bang shouldn't the density of the matter released be so great that it had to instantly form a black hole? Like when the universe was the size of a grapefruit shouldn't it be enaught to become a black hole? I know that the forces were all united and that gravity split first. Maybe that is the cause?

Can we detect other dimensions by measuring the time a beam of light takes to pass through some space. Example: If a beam of light takes 1 sec to travel from x1y1z0 to x2y2z0, it would take longer if we manipulate it in such a way that it also takes some time traveling in the Z dimension, and then returning to z0. (hard to explain without diagram) So if we make light beam travel in extra dimensions before returning, and it takes longer travel time, that could prove it had been roaming around.

2nd question: Does dark energy demonstrate any push on actual matter from one space to another, or does it only effect space itself? Alternately asked: is or isnt dark matter a "force" in the qm standard model sense of the word?

In the previous episode, you talked about the speed of light and of gravity. Light is related to electromagnetism. Its speed is related to the electric and the magnetic constants. Why the speed of gravity is the same? Does it mean that gravity is also related to electromagnetism?

Another possibility is the fundamental constants are not free to vary for reasons we don't yet understand. Listening to these science programs on I'm in awe brains that evolved to keep the owner from being eaten by lions are able to understand such complex and abstract topics. One has to wonder what effect slightly different DNA would have on our brains.

Is there any relativistic explanation for gyroscopic effect?

Multiverse - not to be confused with Everetts many-worlds idea to sidestep the measurement problem in QM. The term multiverse is being (mis-?)used for the latter, too.

One possible multiverse model is one where each universe is contained within a black hole of a parent universe. Is there potentially some way to 'stitch' universes together like in Penrose's CCC but at the other end of the energy spectrum, within a black hole's supposed singularity? Or perhaps holographically projected onto an ER bridge expanding from the Kerr ring (just spitballing here :P). How does one even go about this, have there been any notable attempts?

Brilliant video which I think I mostly understood. My view: It is fascinating to see a Super Sys graph showing the E & M, Weak and Strong forces merging as energy increases. I need ponder if Gravity would join them too as the energy increased to the singularity. I assume it would, this is fascinating because it explains how the four known forces split apart as the energy density in the early universe lowered from the singularity beginning. Regarding the multiverse, I did not realise it is a hypothesised theory to explain the seemingly intelligent design of this universe. This theory allows for those that don't believe in a creator (or whatever is the correct word for it, I don't like the word God) to understand how this universe is just right for matter to coalesce into all we can see in this uncomprehendingly gigantic universe. I don't believe in the multiverse after this video, I believe there is one universe. I believe in intelligent design of this universe. I would love to know more of the testing of higher dimensions. I have a feeling our universe is layered and lower dimensions cannot see the higher dimensions. I believe there are clues from the study of 'out of body' patient experiences, coma patients. Spirituality, has some interesting concepts of higher dimensions but I have not fully embraced the concept.

What are some current things you are personally working on? Or what have you just been working on?

Is there anything we know of where there is exactly 1 of it? I don’t mean the last of something, but only one ever made. Before watching, that was a reason a multiverse was plausible to me

How do we know a particle doesn't encounter a minute quantity of loss in energy in its trajectory through space? Assuming it's not light in an event horizon or a collision with mass as normally defined, but with space itself. Any known equations covering particles say tachyons encountering some negating effect through space itself? Same question 3 times :)

Could you please speak about white holes?