The Royal Institution
Why ‘invent’ dark matter rather than just adjust our understanding of the laws of gravity? Are there dark matter particles in orbit?
Following his lecture, Andrew Pontzen hosts a Q&A on the fantastically weird Universe.
The Universe seems to be governed by rules that we can, with some effort, understand. Andrew Pontzen introduces the stranger side of the cosmos – dark matter and dark energy – but then argues that these things are not so weird or unexpected after all. The strangest thing is that our rule-laden cosmos should be so predictable.
Andrew Pontzen is a lecturer and Royal Society University Research Fellow at University College London, as well as a musician and science communicator. His work focuses on galaxy formation and computational cosmology, as well as some early-Universe physics. Previously, he has held fellowships at Oxford Astrophysics and at the Kavli Institute for Cosmology in Cambridge. And now, he finds the time to go around the country presenting shows at science festivals.
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I haven't finished it, so I don't know whether it's been answered, but what if dark matter is nothing more than us being lighter on the galaxy side and most galaxies being made out of heavier elements?
is it possible that dark matter does not exist within our dimension physically but influences and is influenced by our own dimension and if so would it even be possible to get a physical reaction from an extra-dimensional source?
Have they considered that dark matter may have antigravity as a quality to it. If it was present from the big bang, It would spread out evenly between the stars except for the dark matter that would be accelerated out of the universe as the universe expanded, which would be moving faster than normal matter, initially it would have carried along a shell of normal matter. Since it wouldn't be found in the center of stars, it would consist primarily of hydrogen. The antigravity (-gluon) would accelerate the normal matter out of the universe since it would be denser the closer you got to the big bang since it would be confined by the shell of matter around it, and then dark matter in front of the matter in the universe would be less dense than the dark in front of it, causing the universe to expand? There's no reason it couldn't form normal covalent bonds, but it would, by definition, be excluded in the area where normal gravity is the strongest. it could also be output from black holes. if it formed in free space. this would eliminate the need to explain dark energy, and explain the difference in quantity of dark matter to normal matter.
There's also the possibility that dark matter is composed, not only of an anti-gluon, but also antimatter. the Earth would be protected from it by the massive gravitational field of the sun,
I meant anti-graviton not anti-gluon.
That would also explain why interstellar travel is so difficult!
I posted gere before can not ser my comments…but anyhow…If someone proposes a different speed for gravity And nothing changes it wouldn't be wrong…but If It is wrong what would change?
Darkmatter isn't negative mass ?
Like só massless that is negative like the graviton?scarse down here abundant elsewhere?
Couldnt darkmatter bem the imaginary counter part of matter?
Could dark matter be virtual particles?
dark energy is not energy because energy and mass are eual and mass gravitates. dark energy is antigravitational so it is not energy.
Neutron stars are a good example of a lot of stuff taking up small amount of space.
Could dark energy be like a reverse gravity? Like a bump in space-time instead of a well.
What is the source of Dark Energy and Dark Matter?
Does Anti-Dark Energy exist?
Does Anti-Dark Matter exist?
If dark matter is moving at a great speed and is unaffected by matter in their path. What force generates thrust of the dark matter?
The more I listen to this guy . Why doesn't he just say we don't know. Stop making stuff up and end the lecture.
What is the relationship between dark matter and (normal) energy?
If dark dark matter interacts with black holes in the same way as regular matter, doesn't that mean black holes are actively converting dark matter into (normal) energy through hawking radiation?
That feels like it'd have serious consequences for the evolution of the universe over long periods of time.
If mass is not a property of matter, why are we speaking of the mass of dark matter ?
Could dark energy be created from the stretching of space, like a vacuum transforms into dark matter, much like matter is transformed into energy ?
This could be an avalanche effect, with the newly created dark energy increasing the expansion of space ?
Second viewing – this is interesting.
When you say that "light curves through space" do you mean the space is curved and the light follows that curve or the space is unchanged and light actually curves?
So why can't the effects of accumulated gravity bend space outwards and cause objects to fall away from each other?
Brilliant presentation. ?? Main feature and q & a
I propose our universe is collapsing back into the nearly infinite black hole from where all matter was ejected at the instant of the big bang. Furthermore, I propose the nearly infinite black hole has a nearly infinite flat horizon only detectable by the so called dark matter or in reality, universal gravity.
Consequently, the reason matter is accelerating away from us is because all matter in the universe is “sliding back” down into this nearly infinite black hole.
For roughly 9 billion years after the big bang, our universe expanded away from the nearly infinite black hole. However, due to the extreme mass of the nearly infinite black hole, gravity slowed and halted the expansion of our universe roughly 5 billion years ago. Currently our universe is collapsing at an ever increasing speed back towards the nearly infinite black hole. As the expansion stage took 9 billion years and we are now 5 billion years into the contraction stage, we have approximately 4 billion years before we are consumed by the nearly infinite horizon of the nearly infinite black hole.
The big bang gave birth to our universe 13.5 to 14 billion years ago. Thus our universe has an estimated life cycle of 17.5 to 18 billion years.
Love these smart, charismatic kids, they give me hope for our future!
As usual ;That's one less Thing" we have to figure out .Soon Another and another !
It's amazing how what makes the universe interesting is how some things don't respond to everything. Like if nothing obeyed gravity, we'd never be here. But if everything obeyed gravity, we wouldn't be here either. Like photons. Photons have no mass, so do not respond to gravity. They operate in space time, which can be manipulated by gravity, but not to gravity itself. If they did, light would have a finite distance. Our apparent horizon would be small, and the universe would only appear to be as old as the maximal distance covered by light emitted from the oldest star nearby. Dark matter, obeys gravity, but doesn't respond to electromagnetism. Spacetime compresses in the presence of gravity, but not the EM field, but expands exponentially in low gravitational regions. Like an inflating balloon with tape on it. The tape prevents certain regions from expanding, while the rest of the surface expands.
Is being super small a property of dark matter or can there be a large chunk? The logical answer seems to be no because if there were large chunks we'd surely walk into one by now (being on this planet for millions of years). If dark matter cannot clump then how can we be so certain it obeys gravity? If dark matter obeys gravity it should be able to clump together to create larger chunks of dark matter, especially considering there is 5 times as much mass, this clumping process should have been more common than our matter clumping yet it does not seem to be the case.
Could dark matter be perhaps made of phlogiston, and dark energy be composed of aether?
Could dark energy be the energy released from dark matter annihilating with its anti-matter self? ~21:00 made me ponder this idea
Who are these kids in the audience?
how does the continuous increase of dark energy – and empty space, square with the conservation of energy law ?
I haven't read up too much on the subject of dark matter, but it has been invented to explain the accelerating expansion of the universe. What if, outside our universe, there is an all encompassing attractive force, would that explain it?
Is the following true:
DE = DM x C2
Where
DE = dark energy
DM =. dark matter
C2 = speed of light squared
I love that he takes every question seriously even when from the young members of the audience. What a great guy
really worth looking this guy talk. Cleared all my questions. The audience were completely into it. I would absolutely love to hear more
Dark matter? First off, the Big Bang is still happening, as the universal dimensions of space/time continue to unfold at the edges, presumably at the speed of light. So, the universe gets continuously larger, but is finite at any given moment in time. ("beyond" these edges we have a nondimensional void.) I mean, what would have stopped the big bang from continuing, once it got going?? So, we also now know that matter is continuously forming and self-destructing virtual particles, and that by random chance some of these virtual particles become actual particles. And thus the volume of matter and the amount of gravity continue to increase in the universe. and if this is true, how can we know how much dark matter is needed??
Could dark matter, and separately but similarly dark energy, be a directional wave, instead of a particle (sphere)?
If dark matter is that tiny and has a lot of mass then, why doesn't they stick up together by their own gravitational pull and become black hole??
I would have asked, are black holes (that are theorized to be at the center of most galaxies) being taken into consideration into any of this math. And how does one count for the excretion that we don't understand, and where any of this matter is going as it circles down the drain?
Wonderfully patient and attentive Q&A from Dr Andrew Pontzen.. Brilliant sir.