Does Dark Matter Even Exist? Neil deGrasse Tyson on Dark Matter & MOND

Does Dark Matter Even Exist? Neil deGrasse Tyson on Dark Matter & MOND

Journey with us as Neil deGrasse Tyson plunges into the depths of one of the universe's most tantalizing questions: Does dark matter truly exist?

This enigma, constituting nearly 85% of the universe's matter, remains unseen, influencing galaxies from the shadows.

As scientists race to unravel its mysteries through groundbreaking experiments, theories like Modified Newtonian Dynamics (MOND) challenge the conventional wisdom. What revelations might arise from the external field effect observed across 150 galaxies?

Could we be on the precipice of shattering longstanding beliefs about gravity and our universe's structure? Join us, as we dive deep into the interplay of particles, forces, and the very essence of existence, seeking answers to questions that have perplexed scientists for decades. And ponder, if dark matter is unmasked one day, how might it redefine our cosmic understanding?

#neildegrassetyson #darkmatter #universe

[nathanbutler]

I think dark matter should be called dark gravity.

[Khyranleander]

Multiversal ideas always appealed to me. Aside from scifi, always felt like it explained dark matter & dark energy: if neighbor universes have matter, its gravity affects us. If a neighbor universe deflates, it pulls us to expand until we & other neighbors fill the deflator's former volume. Wrongheaded, I know, but cherished notion.

[RobertHopkinsArt]

Given our understanding that black holes exist and they prevent the escape of light and information, could it be possible that there are more black holes in existence than we previously believed, contributing to a greater cumulative mass over time? Might this be a straightforward explanation for what constitutes Dark Matter? The absence of direct observation does not negate the potential presence of their mass. In the vast expanse of space, black holes, existing in darkness, may play a crucial role.

[pjopie]

6:50 Then why does my tv remote control work when there is glass inbetween?

[colleenforrest]

Wouldn't it be funny if dark matter turned out to be water vapor and water was literally everywhere in space?

[roberttsou]

My own theory of VOID, Relativity and Dark Matter
1. Empty space/vacuum/void is not really empty.
a. The universe first started the two basic elements: matter and void. Humans belong to the world of matter and its equipment is also made from matter. This limits mankind’s ability to successfully measure the parameters of the VOID as of today. Could not measure it does not mean the void itself is really empty. It is like electrons and protons. The “Matters” and the “VOID” are the opposite of one another, and they interact with each other.
b. The relativity theory helps us understand matter causes the space to curve. Another way to say this is it is an interaction in between the matter and the void. The relativity couldn’t say why matter causes that space to curve, but it was proven by observations that there is interaction in between space and matter. If VOID is not really void and interacts with matter then it makes sense why gravity can affect something millions miles away. It seems to me rather saying it is a curvature of space I would rather say it is an interaction in between the void and the matter.
c. I think when Matter and Void are close to each other then it weakens the space/VOID. This is because they are opposite entities. For example, the earth and the sun, when you put two large matters in that space it weakens the space in between. The space starts to shrink in between. This is similar to the interaction you have with electrons and protons. When you have more electrons than protons it weakens the overall positive charge. You put sun and earth there then it weakens the space in between and it starts to shrink. I have doubts about calling it as a curvature. It is more like a space shrinking effect.
2. Dark Matter and Dark Energy are also can be explained by VOID. Void itself is the actual Dark Matter and Energy. We swim inside it every day without knowing it.
a. Maybe we have thought about the Dark Matter/Energy in a wrong direction. They do exist but they are maybe not the matters and energies we known of. We are in a matter world ourselves and we think like a person in a matter world. All our equipment is also made from matters and that makes things even more complicated and make detection of Dark Matter almost impossible because it has something to do with the VOID.
b. The galaxy spins faster in the outer layer. Scientists could not figure out why it against the newton’s gravity theory. The Dark matter theory then created to explain that, and it was able to explain the phenomenon perfectly, but the problem is no one can detect those things in the real world. At least so far have not been able to. This makes me think we are looking at the wrong places.
c. We may be looked at the wrong direction. The Dark Matter is not hidden inside the Galaxy but it is majorly outside the galaxy and push the galaxy from outside inward. The galaxy is floating in a mass of emptiness/VOID and all that emptiness has a very strong force coming from the void and they push the galaxy inward. Because there was so much emptier space/VOID in between galaxies compare to inside galaxies then it makes sense the outer galaxy stars have to move faster to compensate the force coming from the outside of the galaxy. So maybe we are looking at the Dark Matter in a wrong way. It is coming from the huge void in between all the galaxies, not inside the galaxy, and it is the opposite force of the Dark Matter we known of that actually generated all those extra gravity from outside the galaxy. It is the VOID that does all the job.
3. Universe expansion now makes sense.
a. We know the universe is expanding but we all scratch our heads about what actually causes the expansion and why it is expanding. If you believe what I said in no.1 and no.2 have some meaning, then it is very easy to explain why the universe is expanding. Because the VOID is pushing everything around it to every direction no matter where you are.
b. My puzzle now is the VOID and the matter should be equal at the beginning of the universe due to the opposite properties but now it seems the VOID is winning due to the universe expanding. The more it expands then there is less chance the “matters” can catch up with the space expansion to reverse the cycle. The universe should be VOID and matter balanced so this is what I still couldn’t figure out why.
4. Singularity now makes sense.
a. Black holes now make sense. The black hole is full of matters and very small VOID there. There is not enough VOID inside to push it to expand so it will reach singularity.
b. The whole universe will eventually become huge empty spaces/VOID and lots of singularities in few places if the universe expansion continues. I do not know if all those singularities will explode toward the end or not but I do not think they will combine into a single super-size singularity due to the universe’s expansion property. I also think the universe’s expansion will not stop because the more it expands the VOID gains more upper hand there and “matter” world will lose.

[marklewin]

Dark matter is the matter and mass of a parallel universe that is out of our reach and has different laws of physics

[daveandrews]

It’s simple, there is no dark matter. All our observations have not been corrected for gravitational time dilation. The stars appear to be moving too slow in the middle of the galaxy because there is a tremendous amount of gravity causing time dilation effects. Time dilation effects also cause the other perceived dark matter occurrences we observe.

[AlphaGatorDCS]

PLEASE do a review of Quantized Inertia by Dr. Mike McCulloch. It solves for galaxy rotation and wide binaries and MANY other things that break GR very elegantly. It's similar to MOND, but does not have adjustable parameters.

[michaelkahn]

4-D Hypershere model of Universe can easily explain Dark Matter, Dark Energy, Void and even the reason why the measurement values of Expansion Rate are around 70 km/sec-Mpc

Dark Matter, Dark Energy, Gravity, Void and Antigravity, ... all these are same phenomena. They just look different.
The problem of modern physics is they're trying to explain everything with particle physics and the physics is being cornered more and more to the dead end. To escape the dead end, they invent or design another imaginary particle in vain instead of trying to revise their way to approach to the problem.
I agree to the idea that the interaction between mass and space must be explained with quantum mechanics.
But that doesn't mean gravity is the QM phenomena. That's because gravity is not a force.
Dark Matter, Dark Energy, Gravity, Antigravity, Void... all these are just joint effects of the expansion of the Universe and the curvature of spacetime.
Details are given below.

Einstein’s theory of General Relativity states that spacetime is curved by the presence of mass.
This curvature influences the motion other objects with mass and gives rise to gravitation.
Thus, gravity is a result of geometric features in spacetime.
However, we also observe gravitational effects – curvature of spacetime – in areas without any detectable mass.
This has given rise to the concept of dark matter, which is matter that does not interact in any detectable way with normal matter, except through gravity.
So, there is some large quantity of dark matter scattered throughout the universe, which curves spacetime and causes gravitational effects just like normal matter, but we cannot see or detect it with any known method.

An alternative theory to the identity of dark matter is proposed – it is not matter at all, but rather an intrinsic curvature of spacetime.
In other words, spacetime is not naturally flat. Even in the absence of matter, we observe some inherent curvature of spacetime.

So, the question is now – why is spacetime naturally curved? Why is it not flat in the absence of mass?
The universe is 4-dimensional, with 3 spatial dimensions and one dimension in time.
Rather than consider time as a linear dimension, we can consider it as a radial one.

Therefore, rather than describing the universe with a Cartesian coordinate system, we describe it with a 4-dimensional spherical coordinate system – 3 angular coordinates, φ1, φ2, φ3, and one radial coordinate in time, t.
We live on the 3-dimensional surface of a 4-dimensional bubble which is expanding radially in time.
Thus, the Big Bang represents t=0, the beginning of time.

The crucial point is that the expansion of the universe is not homogeneous in all directions.
The expansion rate at one point on the bubble’s surface may differ slightly from another point near it.
The universe is only roughly spherical in 4 dimensions, the same way that the Earth is only roughly spherical in 3 dimensions.
The same way we observe local mountains and valleys on the surface of Earth, we observe local “mountains” and “valleys” on the surface of the universe bubble.
The inhomogeneity of the expansion of the universe has given rise to natural curvature of spacetime. This natural curvature causes the phenomenon of “dark matter”. “Valleys” in spacetime pull matter in, similarly to the warping of spacetime of massive objects.
So “dark matter” is really “valleys” in spacetime that are expanding slower than the regions surrounding it.
These valleys tend to pull matter in and create planets, stars, and galaxies – regions of space with higher-than-average densities of mass.
Conversely, “mountains” in spacetime will repel matter away, an “anti-gravitational” effect, which gives rise to cosmic voids in space where we observe no matter.

Each point on the surface of the universe bubble traces out a time arrow in 4-dimensional space, perpendicular to the surface.
These time arrows are not parallel to each other since the universe is not flat.
This causes points to have nonzero relative velocity away from each other.

It is generally accepted that the universe is expanding faster than observable energy can explain, and this is expansion is believe to be still accelerating.
The “missing” energy required to explain these observations has given rise to the theory of dark energy.
The time dilation caused by non-parallel time arrows can be proposed as an explanation for dark energy.
Alternatively, dark energy is real energy coming from potential energy gradients caused by non-parallel time arrows.

As a sanity check, we can calculate the expansion rate of the universe based on the universe bubble model.
Since the radius of the universe bubble is expanding at the speed of light in the time direction, it increases at 1 light second per second.
Therefore, the “circumference” of the 3-dimensional surface increases by 2π light seconds per second, or about 1.88*10^6 km/s.
This expansion is distributed equally across the 3-dimensional surface, so the actual observed expansion rate is proportional to the distance from the observer.
At present, the age of the universe is estimated to be 13.8 billion years, so the radius of the universe bubble is 13.8 billion light years, or about 4233 megaparsecs (3.26 million light years to 1 Mpc).
Thus, we can calculate the expansion rate of the universe, per megaparsec from the observer, as:

Expansion rate =

The popularly accepted empirical expansion rate is 73.5 +/- 2.5 km/s/Mpc, so our calculated value is close.
There may be some additional source of expansion (or observed red shift) to make up for the discrepancy. For example, if two adjacent points have some gravitational gradient due to non-parallel time arrows, then light passing through these points will be red-shifted.

[nerd]

Undetectable dark-matter beings coexisting with us in the universe are wondering why the universe appears to contain 5% more matter than they can account for...

[Andrew-losc]

Made me think if space was an infinite object that was endless wouldn't it technically be a one dimensional object? It would only be a matter of time before any multidimension space degrades to its base physical state.

I imagine a one dimensional space would have a difficult time reacting with one like ours. That kind of space would have to mock a frequency to pair up with particles and do it on the move. Even if that space had more mass than ours it would only be allowed to react with ours in a particular fashion.

[beachmasterX]

For every action Newton has an answer.

[edwardlewis]

How much "dark matter" is there in our solar system?

[AmmentfB]

It was me Austin.
It was me all along.
Ha.

[Soulwrite]

So we are on a hunt for 'dark matter' which we evidence though distortions in space that do not accord with our formulation of gravity. Makes sense as we know mass causes gravity; missing gravity, add mass.

However while people are hunting dark matter, and other are trying to modify gravity to suit, is it possible that our assumption that space is uniform is not correct? After-all the initial feedback received is spacial distortions that do not accord with our understanding? We know that 'gravity waves' ripples in space move without mass maintaining the 'wave' shape. So distorted space can be decoupled from mass. Bear in mind that our understanding of the fabric of space we still relate to water (waves and surface tension), and any distortion is attributed to matter.

I am just saying that we are hunting for planet Vulcan assuming that our math derived from our singular vantage point, and terrestrial experience is complete; then one day someone comes along conjecturing about relativity. Optimistically if funding had gone towards more diverse solution exploration, relativity would have been discovered first, or at least the hunt for Vulcan given up. Pessimistically funding and efforts are mostly wasted, waiting for the luminary to emerge bringing fire from mount Olympus. I am no expert nor investor, though I am skeptical only two avenues are being pursued, one better funded than the other in the hunt for answers dark matter, and modified gravity.

[Salvation_Setshedi]

Dark matter is to us what water is to fish

[mkaberli]

Tyson doesn't believe in the scientific method. He stated that we should trust the popular consensus and NOT listen to alternative hypotheses.

[airsevens]

We are to dark matter what snow angels are to snow?

[dtarby]

This is insane- they believe they have calculated every particle in the universe? The math is flawed by arrogance - space is not a complete vacuum