13 Subatomic Stories: Why general relativity is definitely right
Vložit
- čas přidán 19. 06. 2024
- Of the known fundamental forces, gravity stands out. Rather than being caused by force-carrying particles jumping between matter particles, gravity can be explained as the bending of space and time. In episode 13 of Subatomic Stories, Fermilab’s Dr. Don Lincoln briefly sketches Einstein’s theory of general relativity (our current theory of gravity) and mentions some tests that prove that it’s right.
Can leptogenesis explain why there’s something instead of nothing?
• Can leptogenesis expla...
Relativity: How people get time dilation wrong.
• Relativity: how people...
Length contraction: The real explanation
• Length contraction: th...
Fermilab physics 101:
www.fnal.gov/pub/science/part...
Fermilab home page:
fnal.gov
Andromeda image: Adam Evans
Galileo constellation image: ESA - J. Huart - Věda a technologie
Watching these is like a blackhole. Time just disappears. Pop out the other side of a 15min video and feels like no time has passed. ANOTHER!
I would argue, the reason that time "disappears" when you encounter a black hole, is because space and time exist infinitely in perfect symmetry. Because light has an observed speed limit (i.e. finite experience of spacetime) in our reality, we cannot observe time and space existing infinitely in perfect balance, because our observations of reality are dependant upon light having a finite experience of space in terms of finite passage of time. So when spacetime is warped such that the escape velocity of a gravitational body exceeds the speed of light (300,00o km/sec), true spacetime reveals itself in the form of infinite symmetrical spacetime characterized by finite properties of observation. The boundary of the event horizon, represents a barrier against viewing a reality not beholden to our finite observational sense of time.
@@ericfarina9609 I've thought about what if a blackhole is not actually a thing that consumes a volume of space in space-time, but literally space-time itself. So we cannot think of what is "inside" of it because it literally does not have an inside. And it's not so much that it has a "surface" as viewing the space-time from different directions gives a different perspective of the same space-time.
@@BenjaminCronce it does have an "inside" but we can only contextualize what lies inside by our own finite properties of observation. I.e. finite rules of external observation characterize an infinity of relative states of infinity
@@BenjaminCronce Hey! I gave this a re-read and realized I only focused on the one part I didn't like. Most of what you said is 100% accurate from my perspective
Pizza was made to hold pineapple!!!
I just love it when Don uploads
Me too, he’s wicked cool!
Same same. I also love how he connects with his audience with the question round at the end every episode
Very down to Earth and humble guy.
I never miss a vid.
yeah, he makes me happy
Doc seems a little under the weather, hope he's ok, he' one of the good guys.
How so? He looks fine in the video
Dr Don Lincoln, I have a question out of the topic:
Let's assume we send a radio-wave of very long wavelength pointing at a small Black Hole.
What's the problem?
The wavelength of a radio-wave can be anywhere from shorter than a grain of rice to longer than the diameter of the Earth. At 30 Hz the corresponding wavelength is as big as 10,000 km.
On the other hand: average Stellar Black Hole (10x mass of the Sun) has a radius of ~30 km. That's three orders of magnitude smaller than the wavelength of our radio signal.
And here is an important info: if I make a hole in my microwave the size of my thumb, I can safely look threw it when it is working, and no damage to my eye would take place - the microwaves used in the oven have a wavelenght of ~14 cm, and my 2 cm hole is so small, microwaves don't even register the hole.
So...even though, light cannot escape a Black Holes, would also our sent radio signal (that is many times bigger then the Black Hole), pass threw the Black Hole as if it were not there?
On forums people say the radio-wave would be somehow split in half...
I would think the energy is simply absorbed like anything else. But it makes me wonder if black holes will really evaporate from Hawking Radiation when the incident radiation of the visible Universe could overwhelm any loss from Hawking Radiation. Everything in the Universe would have to go cold before a net loss is achieved.
The 'size of the black hole' that you mention refers to the size of its event horizon. But the path of the light will be affected well outside the event horizon, since the spacetime is still curved there. The event horizon is just a point of no return. The size of the black hole that the radio wave 'sees' is determined by how much and how far the spacetime is curved outside the event horizon. A hole on a microwave oven however, doesn't curve the spacetime around it. Therefore the size of the aperture is just the visible size of the hole.
@@ohanneskamerkoseyan3157 's answer inspires me. In ordinary situations, Ciekawostki o poranku would be right; a long wavelength wiggles around a small obstacle.
But consider the bending of light around a mass, such as the 1919 verification of Enstein by observing a star at a position offset by the mass of the sun. The mass of a black hole is so large that it bends nearby light beams so they point right into the black hole, thus no "sneaking by unnoticed"
@@ohanneskamerkoseyan3157 also, won't there be blue shifting of the radio wave on approaching the black hole due to infinite bending of space time
I love the ratio between the length of the explanation and Q&A portions of the video.
Hi Don,
I am a consultant by profession but what keeps me going is physics really.. Love your videos and this series on subatomic stories is amazing..
Love from India!
The strangest and most interesting thing you said about light: that to its perspective it is does not experience time, its everywhere at once, and (to it) the universe has zero thickness... I've heard this before, but for some reason it really sunk in this time... it's mind blowing to ponder💥
It blew my mind as well the first time I realized it. But when I think of time in terms of causality it makes sense that at C one does not experience time anymore.
I agree. This one fact leads to all sorts of different ways of thinking. Humans are so locked to our mass based space time, it is difficult to break out of that position and think of other ways the universe is built, i.e. not from a Human perspective.
The thought that staggers me is that a photon from our Sun takes 8 minutes to reach 'my eyes', however that is TOTALLY based on my perspective - not the photon's. Weird for sure. Nice point.
Edit: What the heck is a proton?
I always though rotation and time were going together.
"It certainly appears that massless particles experience no time and no distance." What is actually happening, is massless particles experience infinite time and infinite space in perfect balance. Light is massless in our reality precisely because it is what sets the parameters of our finite existence, by interacting with our finite reality in a relative expression if its infinite form.
@@ericfarina9609 IMO,,,rotation is locked with time despite mass.
Hey Don, I'm really enjoying this series of videos. As an enthusiastic amateur I've learnt a lot about math and physics from CZcams. However one gets to a point where even new content just seems to repeat stuff already covered. In your video's, though, I'm learning new points and insights that the other channels just gloss over. Keep'em coming, they're pitched just right.
It's the questions that keep them fresh.
Hello Dr. Lincoln...always enjoy your videos, not necessarily because of the content itself but knowing that what you talk about is mostly a modern standpoint. The one point that I was glad to see from a modern (working) scientist was at around 4:30. You don't say that 'time' slows in a gravitational field but that 'clocks' do and that's an important difference. I have experienced many times that people identify a 'clock' with 'time' and will say that 'time' slows in a gravitational field. As you will know, nowadays 'time' is subject of much discussion, 'is it an illusion', 'is it real' etc etc. But whatever the arguments what we actually observe is the slowing of clocks and that is the evidence. To me it means 'the rate at which change occurs'.
Don, you cannot imagine how thankful I am for this series.
Hey Don ! Here's another question, not related to physics tho;
I always loved particle physics and find it interesting. I wanted to know how you got the inspiration to become a particle physicist ?
Those were some great answers, pls keep asking questions. I like this program....
Great content as always! Can you please tell something about the new particle they discovered LHC?
Don I love your book. Understanding the universe from quarks to cosmos
Your description of matter being a concentrated form of energy is probably making all of the physics post-docs who watch these videos roll their eyes in horror, but it definitely helped this humanities major better understand gravity's relationship to space-time. Thank you.
Physics postdocs know it's true.
czcams.com/video/x8grN3zP8cg/video.html
that was a short discussion on GR even though I have seen it numerous times in other channels, it is just amazing.
Hi Don! I was a bit late with the last episode, so if you don't mind, I'll put my question here about neutrinos.
They should've escaped far earlier than photons after the big bang right? So there should be a cosmic neutrino background too?
What would that look like, would we need a solarsystem-sized argontank to detect it?
Is it even feasible to detect them? and for bonus a stupid question: would it help? :)
Please never stop these videos!
Great explanation Dr. Lincoln - as always! Thank you for sharing your brilliant insight into and knowledge about things
I like where this is going and look forward to the IOU episodes :)
yea is time discreet or not LULZ.
Recently I watched an excellent video by Fermilab that shows how particles are accelerated, including some awesome 3D animations. Is it possible to tell use more about how things work? For example, how do those clocks in Boulder, Colorado work? Don't even need to show us fancy 3D animations, simple diagrams would be fine.
You are getting better and better at making videos, Keep it up
4:28 omg i was assuming you will talk about a clock in space vs here, 1 foot omg
So little time, so much to learn. I'm considering moving into an extreme gravitational field. Thank you Don!
Science dad jokes?
The difference between a total solar eclipse and a partial solar eclipse is like night and day.
That's high grade humor right there.
The difference between a total lunar eclipse and a total solar eclipse is like night and day. :D
Thank you sir, for clearing up my doubt on that, that was really kind of you. ☺
Hi Dr. Don:
Since GR modifies spacetime, is it useful to try to think about the laws of physics apart from the concept of "time"? Along these lines, is it proper to think of "mass" as "the ability and/or act of an object to change configuration"?
Thanks!
Hi Don! In case we find a way to discover them, can the axion and the graviton introduced by string theory actually be the same particle? and maybe also with the right-handed neutrino?
THANK YOU PROFESSOR LINCOLN...!!!
The question & answer part was a bit speedy !
Great series! Keep it up!
I love this series. So, riddle me this: does the universe have angular momentum?
*General Relativity presidcts:*
- Gravitational lensing, during an eclipse a beam of light from a distant star is deflected by the gravitational field of the sun. - Precise calculation of the precision in Mercury's orbit.
- Results of Hulse-Taylor binary pulsar experiment, the loss of energy found in two neutron stars orbiting each other, is in exact agreement with the predictions of general relativity.
- Detection of gravitational waves.
Yep, it's definietely right!
I mean, it seems pretty accuarate but the fact that we need dark matter and that it doesn't work in quantum scales should tells us that's not quite right. Also, I'm not entirely sure that if GR is a bit off and we found out what's really going on it wouldn't also explain dark energy
@Mike Doonsebury Failed to predict the existence of Mike Doonsebury. Obviously an incomplete theory.
@@impCaesarAvg Maybe _incomplete_ but not _incorrect_
Also don't forget the Event Horizon Telescopes image of the photon sphere of M87* or the measurments of stars close to Sag A* in our own Milky Way.
Also I have recently been looking into Wolfram's fundamental physics project and one of its computation based universe consequences is that the Feynman path integral behind Quantum Field Theory becomes equivalent to applying General relativity within a phase space of all possible outcomes referred to as Branchial space. In this context quantum weirdness is entirely dependent of Branchial reference frames and the curvature of Branchial space. Its too early to say whether it is right or not but if true General Relativity is more fundamental that Quantum mechanics though both do effectively become quantized in terms or relations between adjacent states.
Note the choice of wording are key as if I am interpreting the technical papers right it seems to be meaningless in this context to say states of "what" as they are simply information packets that can interact/exchange information with space being an emergent quantity based on their degree of interconnectedness and the time it takes to update. An implication of this is that time and space are separate after all which space being dependent on time relative to the connections in the system.
The point is if this hypothesis/model is true tit would imply GR was more right than Quantum mechanics in that the latter becomes the former acting within a phase space with a different causal interaction rate(analogous to a "speed of entanglement, which seems to be on the order of 5 solar masses per second). It is fascinating so far but it is clearly a work in progress making the validity hard to assess as there are areas of mathematics which haven't been developed yet needed to identifiable testable predictions. Apparently algebra extended to fractional dimensions doesn't exist yet but is needed for computations....
@Mike Doonsebury
- the Universe isn't perfectly homogenous and no one believes that.
- angular velocity depends on mass which is a free parameter in GR.
- see point 2.
- see point 2.
- see point 2.
Ditto.
Perhaps one more question. What determines the speed of propagation of gravitational waves?
Would love to get some of the t-shirts you wear. Are they available online?
Can you give us a tour of your bookshelf? Any recommendations?
Clear, informative, awesome.
This series is one of the best things coming out of this pandemic, love it. Also, on a side note, the new comment layout is mind bending
Hi Don. I'm loving this series and I've learned so much so far! I have a question about antimatter. As you mentioned in Episode 7: Antimatter, the only difference between say an electron and positron is that they have opposite charge, all other properties are equal, then why do they annihilate when they come into contact? What is the actual process of these two equal particles with opposite charge converting into energy when colliding?
You should google "Dirac Sea"
Hi Dr Don, have a basic question on relativity.can you please explain the below questions
1. If I drop something why does it fall in a straight line considering space-time is curved
2. Can you please explain why objects move between 2 points in a curved path .
Love your amazingly explained videos! Can you add me to the next vid?
What a fantastic episode! Thank you.
@Fermilab At 11:26 I suspect you mixed up linear density with volumetric density. I'm pretty sure neutron stars have a density that is at least 10^14 times as much as lead, or something like that. And wouldn't the scattering probability be proportional to the cross sectional area (area density), and not the linear density?
Thanks for providing us good information
Does gravity's distortion of space(time) enlarge it? I.e., If I take an empty lightyear cube, and a second one where I place a massive star or black hole into it, and compare them: does the second one have a larger volume?
Thank you for this great series. I have a question. Why does concentration of energy curves the space time? What is the property of energy which causes events to tick slower?
What is the property of spacetime that causes it to be bent by the presence of energy? Physics doesn't really answer "why?", it answers "how, and by how much, exactly?" We say "If space is like this, and energy is like that, then they should interact thus", why things are the way they are is a matter for philosophy or religion.
GR doesn't answer this, unfortunately. It only says "how much", but not "why" or "by what means". Maybe the answer will come from quantum mechanics when we get to a good theory of quantum gravity.
@@thedeemon "Why" is a bit of a tautology. "Why" do charged particles emit virtual photons? Basically, because charges and fields behave in such-and-such a manner, that can be quantified mathematically.
Why do they behave thus? Because.
If we are in loop hole space does we live or time again and again as space has been looped and so space and time is related?
Love your work
I'm curious about an idea.
Science considers mass to be the origin/cause of gravity (warped space)
My idea is that gravity causes the phenomena we refer to as mass.
That is, movement of fields of energy (relative to one another) create areas of space that are smaller and more "permanent".
So the fields are moving into that small, fast moving area, resulting in what appears to be mass.
The reason we "observe" particles is to do with our movement relative to the movement of the field.
That is, we can only observe that part of the field whose movement corresponds to ours.
As the velocity of the field increases, the energy reaches a point where the field shrinks even further, and the particle appears in a different valence shell.
This is the reason the "particles" appear quantized.
This idea, extrapolated, unifies the fundamental forces and explains dark matter/energy.
Put the idea into equations, make a quantified prediction, do an experiment, and then you are doing science. Until then, you are not.
(a belated dad joke) Heisenberg, Schroedinger and Ohm are in a car and they get pulled over. Heisenberg is driving and the cop asks him "Do you know how fast you were going?"
"No, but I know exactly where I am" Heisenberg replies.
The cop says "You were doing 55 in a 35."
Heisenberg throws up his hands and shouts "Great! Now I'm lost!"
The cop thinks this is suspicious and orders him to pop open the trunk. He checks it out and says "Do you know you have a dead cat back here?"
"We do now, you fool!" shouts Schroedinger.
The cop moves to arrest them.
Ohm resists.
(I heard Coulomb got charged for something similar)
Hi Don.. if energy is mass how come u can increase the energy (with an accelerator) lets say of a neutrino but it still keeps its (low) mass?
In a philosophy class I was asked to think of a response to Zeno's Dichotomy paradox. My response was that it was self-contradictory because it assumes space is quantized while time is not, and spacetime cannot be quantized and not quantized.
You briefly mentioned around 3:13 that not everyone believes in GR. Do they have compelling alternatives?
No
Hi Don, why does the time dimension have a direction (since you can't go back in time), while the other 3 (spatial) dimensions don't? Love your videos!
You should read Sean Carroll's book on the subject.
Dr Lincoln, been following you since the first series... My doubt being off topic, is about how our solar system, galaxies have nevertheless come to a single plane, though the primordial gas cloud had matter was swirling in different planes, and was chaotic.
Conservation of angular momentum. The gas cloud had some eddy in it. That eddy defined the rotation axis of the solar system. Gravity could pull the gas down into the rotational plane, but angular momentum resisted contraction within the plane.
@@drdon5205 Thank you sir. How would there just be a single axis of rotation? Also won't particles collide with each other internally, making it still more chaotic...
Is ozone layer is also rotate and revolve along with earth
Hi Don, I was looking Higgs field, Higgs boson. A question came to my mind if interaction with Higgs field is the reason particle have mass, so where does quantum excited of Higgs field i.e. Higgs boson gets its mass?
p.s. I am in 12 grade and I was thinking of a career as a physicist because of you ,Dr. Sheldon Cooper and of course Richard Feynman
Dr. Lincoln I have a question about neutrinos. The fact that each type is a mix (superposition?) of masses and vice versa is the same phenomenon as a qubit measured in the computational base (|0>,|1>) being in a superposition in the diagonal base (|+>,|->) and vice versa?
While I understand the four fundamental forces are similar in that they affect matter, why do we think gravity is "a force like the others"? Why would we expect a gravity particle, or that it can be unified with the known quantum forces?
Yes it moves at c like the other forces, but it appears to have such a vastly different manifestation - bending spacetime vs moving/interacting with particles - that I can't figure out why it's always spoken about in the same way as the other three.
i was building a universe in my head (for fun) and imagined a void of energy with a collapsing 0 vaccum into a 2d space, the 2d void creating G and T and t (twister field) in the collapse. the rest of the void energy rushing inward begins to form the rest of the fields of space and the rebound in our universe arises.
bit of a mind game probably nonsense, but looking at it like that G and T are more fundamental than the forces that would follow.
could be bs BUT since G and T and S are fundamental in ways the other forces and fields are not.
lovin' this stuff, good sir. thanks.
thank you for a well presented, relatable channel that allows me think that even though i cannot spell phd, i could probably get one.
and i agree, the worserer the joke the better.
and pineapple pizza people prove the many-worlds hypothesis, cuz they're all from some other universe where good taste disappeared early on in their universe like the anti-matter did in ours. so these pizza-pineapple people must be made of pure anti-matter and puons(the sub-atomic particle that accounts for 100% of their pizza on pineapple problem)
The identity of massive don't change over distance. Before the breaking of electroweak symmetry could it be possible that those oscillates as well?
Dear Don Lincoln, could the 2nd or 3rd generations quarks and leptons form new pattern of "exotic atoms", and consequenly, new patterns of "exotic periodic tables" in regions of high gravity, such as Black holes or neutron/quark stars?
You have your own books behind you! I didn't know you were an author, I mean of books for the general populace. Nice.
Yep. Several.
You never answer the question proposed, but these videos are always educational somehow.
Why do the clocks become slower with increasing gravity independent of their internal clocking mechanism? For example, a simple wall clock has mechanical movement producing the clockwork, while the atomic clocks that you mentioned in the lecture located at Colorado probably work on the basis of some spontaneous transition of electron from one quantum state to another, right.
Does light undergo spegatification when heading towards black hole? And we can observe? And dose it still within theory of relativit
@4:32 you said the one clock that was raised a single foot moved faster but you did not say by how much. I calculated 3.326e-17 seconds faster per second than the clock that was a foot lower. But I didn't use relativity to do that calculation.
Then what did you use??
i am confused with watch example at 4:30 timeline... Does watch represent time? or its mechanical movements were equivalent to time? if so what slows the time or its mechanical movements?.. sir i am not contradicting you or try to be disrespectful... can you please explain?
On electrovolts and mass: shouldn't you use an equation with m^2c^4 and p^2 instead of the one with mc^2? A charged particle as you've shown it will be moving, right?
@roblox hedgehog p^2 will be very small, unless the accelerated particle is moving at relativistic speeds. Also, it should be (pc)^2
Hi Don. Love this series. Just one question : if mass is just concentrated energy (E=mc^2). Is energy-impulsion just concentrated space-time ? (G_{\mu,
u}=8 \pi T_{\mu,
u})
And the word of the day is "geometrodynamical exciton."
Sir ....one question...
I understand that in CERN LHC the best vacuum ever possible is achieved but as it is not Absolute vacuum there are still about 2million atoms are present...so does the high spped proton collide with them before reaching set target?
Presumably, such collisions do occur, but there are lots and lots of protons in the beam.
What Michael Sommers said. Some protons do collide.
Dr Don you're the man. When you have the time could you please explain the Dirac equation as I'm attempting to extract sunlight out of cucumbers and it may just help !! Your vidios give me a reason to live. Yiiiipppppeeeeee 😁
Is there any relation between the wave function of a photon and the interpretation of that photon as an electromagnetic wave?
I believe they're pretty much the same thing, or if not one is the square of the other. (Caveat: I'm not a physicist, I'm just decent at math and watch a lot of Fermilab, PBS Space Time, and Kurzgesagt.)
think if anyone can sort this duality and test it then you would be famous.
there any number of theories out there though.
Yes. The higher the energy, the shorter the wavelength. Photon wave packets of a given momentum do not fall apart and spread out like those of things with mass.
Al device's that measure time are based on movement. Whether it is movement bij a spring and pendulum, vibration of a crystal or atoms.
How do we know we really measure time, when all we do is measure movement?
We assume that progressing of time equals the movement.
But is this true ? And how do we know this ?
A question, when we say space is flat, so how many flat layers are there one above the other or is it only one ?
No others that we know of. Just one
'Flat' in this context means zero curvature, not two-dimensional.
What is the basic differences between Majarona and Wyel in terms of Neutrino
Thank Dr Lincoln
The massless particle question left me wondering how the good doctor sees some of Penrose's more outlandish ideas like CCC
Conformal Cyclic Cosmology. Yeah, its a weird one. Food for though, but I doubt its "true". Penrose is a bit of an oddball, but he does push the envelope.
@@ozzymandius666 it was specifically the wording related to "light not experiencing time" that reminded me of some very similar wording by Penrose in one of his videos trying to explain it . I'm certainly no judge of truthiness, but I have found trying to at least get my head around that envelope pushing interesting.
I wondered if the Don saw any merits or even had any negative view of it / Penrose's approach!
@@williamprior7831 More than one "truth" has been discovered as a result of a "mathematical oddity", like antimatter and quarks.
What did the clock do while it was rising during its acceleration and deceleration to a stop?
What are the units of G(μν). When the equation is solved what is might G look like - is it simply 1,0, or -1?
Who are you?
Physics student: I'm a bunch of atoms and some other things.
Chemistry student: I'm a complex of carbohydrates, proteins, enzymes, fats, lipids, etc.
Biology student (Me): I'm a Sapiens sapiens homo hominini homininae hominidae simiiformes haplorhini primate mammalian amniotic tetrapodal sarcopterygiian osteichthyen gnathostomal vertebrate cranial chordate animal. That's it!
(Would like to hear from Dr. Don for a more appropriate answer from a Physics perspective :))
By Carlo Rovelli's perspective space and time are both quantized. The volume of the space derivates from loops, nodes (and spin nets) in the gravitational Faraday's lines of force. Space-time itself would be designated as a spin foam. Do you subscribe this perspective?
At 12:00 you show a chart that shows cross section vs. neutrino energy. Could you elaborate on this chart more? Why are Big Bang neutrinos so low energy, expansion? I imagine it's part of your research but why are galactic and extra galactic neutrinos so high energy, even higher than accelerator ones, or at least what are some current theories?
Big Bang neutrinos arose early on with a range of energies, but many of them were from the nuclear realm. Then the universe expanded and their wavelengths lengthened and energy dropped. The high energy cosmic neutrinos arise from shooting protons in crazy-strong magnetic fields outside black holes and whatnot. Those protons interact with matter and can make neutrinos.
@@drdon5205 Oh wow, a reply from the man himself! Thank you! I guess I was right assuming expansion was responsible for the low energy of the big bang neutrinos. And if the extragalactic ones are still such high energy even after traveling all that distance the magnetic environments around black holes and I would also guess neutron stars/magnetars must be truly spectacular!
Dr Lincoln I love you
Is there any correlation between:
- Light, which is pure energy, has no mass but can produce pairs with mass, experiences no time, and by its own viewpoint exists at all points in its path simulaneously and...
- The big bang, which all known mass springs forth from, marks the beginning of time as we know it, and encompassed all points of the universe?
It seems like there's some overlap in the relationship between space, mass, and time in these two concepts.
Question: what is the connection between inertial mass and gravity mass? Is there a scientific explanation of why they're the same?
Yes, that is the exact thing that general relativity (GR) explains. The main point of GR is that gravity is a virtual force. There is no force real between two massive objects - they just follow their inertial path. It's just that, the inertial paths lead through spacetime that isn't flat, due to the presence of energy.
Wouldn't a right hand neutrino going backwards in time appear (as seen by a time-forward observer) as a left handed neutrino? Is that what we're *really* seeing? Also explains why it's so hard to interact. Maybe, Neutrinos interact with time, rather than the weak force....
If a neutrino is moving at the speed of light, it essentially is a function of infinite time manifesting in our finite contextual existence. If it is moving slightly slower than the speed of light, it will appear to be right-handed only if the observer is moving at the speed of light. That is my understanding. Neutrinos tend not to interact with our reality very much precisely because they move at or approaching the speed of light, and thus experience time very differently (if moving slightly slower than lightspeed) or experiences time and space infinitely in a perfectly symmetrical state (if moving at lightspeed). This is based on my own personal idea about the nature of space and time, which posits that the fundamental principle on which all modern physics rests is space and time existing infinitely in perfect symmetry, in an infinity of relative configurations contextualized by finite rules of observation.
Could the small-scale/large-scale difference with gravity be due to gravitons having a very long wavelength? Similar to the "quantum push" for plates that are placed extremely close together, where only the waves that can fit between them manage to get in - maybe particles need to be at least one graviton-wavelength apart to be effected by gravity?
Edit: Clarified wording.
Hi doctor Don! Thanks for the video! I guess I have a quite good intuition on how matter bend the space, but I cant seen to have an intuition on how it bend time... Can you please help me?
It is never space and time, but just spacetime. Assume(Imagine) 3 dimensions of space as 1 or 2 dimensions and time being another dimension running perpendicular to space.
Time bending just means at different points in space time ticks at different rates. Bending of space and time is encoded in the metric tensor, you need to learn how metric tensor works in order to grok the topic, all visual analogies are somewhat misleading.
@@Magma_Meteor thanks for the reply! It really helped a lot just imagining one dimension of space! =)
@@thedeemon thanks a lot for the reply! I'll look up about the tensors! Also, the insights about the clock ticking really helped!
Is there any chance that the speed of light is actually a speed slightly less than some higher limit on the speed of an object?
Thank you for scientifically confirming that pineapple does not belong on pizza
Except when balanced by an equal and opposite amount of anchovies.
Brett Romberg It is just a hypothesis.
There are no actual proof.
I've seen some build models with and without ananas. That's right ananas, not pineapple. Pineapple is an imperial unit, rest of the world use SI units.
Hi Don👋👋👋 I have a question. I have read that energy is the capability to do work. If this is true I would like to know what gives this capability physically speaking. Thank you!!! I really love this channel!!!
By nature of being energy, it has the potential to make some kind of a change to itself or its surroundings, so it can "work". The work could be anything that needs energy to function, for example: the heat energy from a fire could cook your meal, or, the electricity energy in your power grid could push your oscillating fan around, or, electrostatic energy in a collapsing galaxy could draw tiny bits of matter towards each other :D
Hope Krempa Thank you my friend for your reply!!! Thanks to it I have something to think about!!👍
11:30 I'm confused about the density of neutron stars. A density of 10^9 kg/m3 seems very low, and numbers I could find range between 3 and 6x10^17 kg/m3. With this density the mass of the sun would be compressed into a sphere with a diameter of some 20km, which sound reasonable.
@chi-wei shen I was looking for this comment. I noticed the same mistake.
@Dr Deuteron I thought he was mixing up linear density with volumetric density.
Hello, I have a question. Can entropy be defined as a measure of uniformity of energy rather than a measure of disorder?
Ask this question. Is energy more uniform now when u compare it to the big bang ?
@@mujdatdinc7265 but won't when maximum entropy is achieved in our universe, lead to a uniform distribution or energy?
@@jasveerdhillon5456 Universe is expanding and cooling down. Entropy is data of universe. It is increasing hence universe creating more data(microstates). This will end when universe reaches 0 kelvin. This not related with changing uniformness of energy. Entropy is keeping energy uniform not changing it. When you put all energy in single point its still uniform and becase of increasin entropy its always stay uniform space expands.
When we derive the equation for the potential energy of an electron in an electric field (integrating the field strength over distance and multiplying by the charge of the electron), we get that an electron can, and perhaps must always have negative electrostatic potential energy. My question is whether this counts as ‘negative energy’ in the relativistic sense, and by extension, if an electron in a strong enough field (I think it falls in the mega volt range) that it’s potential energy cancels out its mass energy, can we achieve negative energy density within a region , and by extension, negative space-time curvature?
Setting the zero point of potential energy is entirely arbitrary, because the only thing that is physically significant is potential differences. For example, when dealing with gravitational potential energy near the surface of the Earth, you usually pick the ground as the zero point, but if you are dealing with planetary orbits, you pick infinity as the zero point. You could say that the potential at the Earth's surface was a zillion and thirty-seven, but in practice you pick the zero point to make the math easier.
Dr. Lincoln: I have a question about gravity and black holes. How can a black hole have a charge, when charge is associated with electric field lines that need to escape outside the event horizon of the black hole? How can these field lines (in a classical electromagnetic sense) be detected outside the black hole?
A black hole will have a charge if unequal amounts of positive and negative charge fall into it. If I am not mistaken, the charge will appear to be smeared out over the event horizon.
How do you explain the Biological changes in the body when the clocks slow down?
There are no such changes. In your own reference frame, your clocks always tick at the same rate.
Good evening sir,
I have a question,
We define wave as disturbance in medium...
And on the other hand we define electromagnetic wave as a wave which do not require a material medium...
I m confused plzz clear my confusion.
We define a wave as a continuous, smooth function that propagates and changes in space as a function of time, no medium required.
@@ARBB1 You are taking about all type waves or only about electromagnetic waves????
@@piyushkumar6609 All types of waves as defined in mathematics.
Could momentum and inertia be due to mass trying to fall back into its own gravity well before the gravity waves from its acceleration have had time to propogate?
(I would assume such a situation would resist acceleration)
Is the bending of the spacetime by mass similar to the bending of field lines by charges?
(in both cases, they tend to follow the curves that they, themselves, created)
is it possible to separate matter from mass? If mass is given by a field, then I would think it would be possible to. Also um so if you were traveling through the universe at just below the speed of light and the universe flattens at this point, what would that look like? And could that flat surface be considered a boundary into the bulk?
Hey doctor... what's the sphaleron process?
One thing I've always wondered about is the ways in which physicists attempt to rectify general relativity with quantum physics (or, at least, the way they communicate that to us lay people). If gravity is an effect of the warping of spacetime, rather than an actual force, then why should we expect gravity to have a gauge boson, given that those are particles which carry a force? Is it just because relativity doesn't work on quantum scales, so it's easier to think of it as a quantum field? Are gravitons theorized to carry force between matter particles and spacetime itself? (Corollary: Are there any hypotheses that spacetime itself is the gravitational quantum field? Does that idea even make any sense?) Should gravitons even be theoretically possible, or as carriers of the "gravitational force," shouldn't they technically be point black holes? Are physicists just still in the "throwing stuff at the wall to see what sticks" stage of figuring out a quantum theory of gravity? Maybe it's just because, as a lay person who can barely follow along with a differential equation, I don't have enough information to know where these hypotheses come from or tell the difference between a series of separate theories and one whole weird theory, but it feels like there's some contradiction going on here.
Ooh, I like the question about quantization of spacetime. I look forward to hearing your take on Zeno's paradox, the Planck length, and Planck time.
Sean Carroll did a video yesterday that covered that very question (along with a lot of other things). Basically, gravity can be treated as a gauge field theory, from which emerges the graviton. czcams.com/video/AuqKsBQnE2A/video.html
@@michaelsommers2356 But does the fact that it _can_ be treated as a gauge field theory mean that it's appropriate? I mean, I feel a little like that's the same as saying electron holes are real particles just because the math works if you act like they are. Of course gravitons should exist if gravity really is a gauge field (or so I'm led to believe, since the math goes a bit beyond me), but if we have solid evidence that gravity is an emergent property of spacetime rather than a quantum field embedded in spacetime (or maybe I'm just misunderstanding QFT and GFT?), then I'm having trouble understanding why anyone would follow the math that far. Basically, it seems like, if GR is true, treating gravity as a GFT is nothing more than a useful analogy; but expecting gravitons sounds more like expecting that gravity really _is_ a GFT.
But thanks for reminding me to catch up on Biggest Ideas in the Universe. I'm a few episodes behind. :D
@@tildessmoo Why follow the math that far? Because, historically it has often been the case that following the math that far has led to the "truth", even if that "truth" initially looked silly. As for GR versus field theory, I suspect that they will eventually be found to be equivalent, just as Heisenberg's matrix mechanics and Schroedinger's wave mechanics were show to be equivalent.
Please make a video on physics carrers in usa and canada and how to become theoretical physicist