James Butler Yes, and it was dark, too. But I got a bit confused, when they said, that it´s actually transparent, because in my eyes it sure still looked brown & delicious:) All the best, Forrest Gump:)
Astronomers have thought of that, but even if you add up all black holes, cold gas, brown dwarfs, etc, it just doesn't give you enough mass to account for dark matter.
Umang Bhat We'll know only the day we get to understand it. Heck, it might even be not a single thing, but rather several other "realms" as incapable of interacting among them other than through gravity as we are towards them.
It depends on if it interacts with the strong force. If it doesn't, then the particles can't bind to each other to form more complex structures. But even if it does, it shouldn't influence the properties of the composite particles much, since what decides the properties of the element is the outermost electron layer, which they would not have, since they don't interact with the electromagnetic force and can't have a charge. Actually, if they don't have a charge, does that mean that there would be no factor that prevents from more and more dark matter to clump together? Since there's no positive charge to push protons apart...
I love all of these guys, and they're all incredibly humble and intelligent people, but let's all take a minute to appreciate Brady Haran - not only for making these videos in the first place, but because though he remains behind the camera and out of the spotlight he proves himself to be as smart as any of the rest of them because he fearlessly and consistently asks the right questions. Thank you Brady, and all of the rest of you at Sixty Symbols/Numberphile. Keep up the wonderful work!!
i was just talking with a young lady teenager and she asked me what i was watching i showed here the screen grab of dr gray(i think thats her name?) i told her she was a cosmologist ,and she said ohhh she works with makeup.....priceless
***** I swear this really happened i almost lost it , the schools are ok here but there are a lot of hill people who are not real big on education. I was lucky both my parents instilled a will to learn on us.
In one version Membrane theory, dark matter is just gravity wells from normal matter in a nearby universe. I equate it to having each universe on a sheet of paper and drawing on them with a ball-point pen. The drawing in the paper is matter, and the indentations are the gravity wells. When you lay one "universe" page on top of the other and then draw "matter" onto the top one, you can see the "gravity well" indentation on the bottom page(our own universe). It makes sense to me.
I'm not an astronomer, astronomy is for me just a hobby, but it makes me think of all these posibilities, and these videos help me understand all sort of things, and the real scientists that do the explainig part, they do it in a way that is easy for everyone to understand it all. So, thank you, Sixty Simbols :)
If it is gravitationally interacting with itself as well as normal matter, why isn't dark matter "lumpier" than is apparently observed? Normal matter is very lumpy. And as it apparently has mass, and there's about six times more of it than normal matter, why hasn't dark matter formed "dark black holes"? Or has it?
From what I understand, it's because the dark matter doesn't interact with itself or regular matter through electromagnetic forces. If you look at what happens in something like an accretion disk, the matter ends up colliding, which causes it to tend toward the center. With dark matter, it's more of an oscillation. You can see this effect easily if you look at the bullet cluster. The regular matter slows down from EM forces as well as gravity, while the dark matter just slows from gravity.
I clerly see the error in computer simulation shown after 9:42. It assumes that matter lumps only at certain regions, but not inertia of the already formed smaller lumps running into bigger lumps of matter. So, there is no rotation, and it doesn't looks like real galaxies or something similar. Each smaller lumps of matter may interact each other, forming 'twisted' looking structures, which is common in nature if you look how clouds are formed (although different forces, including Coriolis forces acting upon molecules of air and water vapor). Also, during lumping and 'running' of the smaller lumps toward bigger center of mass, matter experiencing something resembling air drag, because matter in front of moving lumps of matter is not yet 'swept', so every next lump has greater velocity - because previous lump of matter sweeping this area (creating less resistance). If so, then there may be explanation why galaxies' arms moving faster than expected, also why doppler shift between galaxies looks like universe expands, or like dark energy pushes them appart. On this animation, look carefuly - it appear that 'new space' emerges in between lumps of matter, while whole picture looks stationary - nothing expands.
Brady or someone from the Sixty Symbols team: I love your videos! I'm a high school science teacher in an American international school in China and you guys do a great job of making things visual and accessible for my students! Some of my students had really good questions about dark matter (very proud of them), and I was stumped! Does dark matter interact with black holes? Black holes collect mass around them because of their tremendously strong gravitational fields, so shouldn't we also see black holes becoming more massive several times faster than we can account for by monitoring their intake of "normal" matter?
My guess is it probably does, but it has to interact with something we can detect in order for us to detect it. Think about 2 invisible people. If they silently shakes hands, we wouldn't be able to tell if they are in the room or not. But if one of them picks up an object (interacts with something that we can see/detect) we will know that the invisible person is there. Hope that's helpful/the kind of answer you were looking for.
From what I understand, some/most Data Centers use a hybrid water-A/C cooling unit for their servers (basically a refrigeration unit cooling the water that's used to cool the air...i believe). But supercomputers are so advanced and different in such ways, I wouldn't have a clue to what would be best...like hot water?
Brady, I would love to see a video on the interaction between dark matter and black holes. It's tricky to find good information on Google because to so many people they're just interchangeable "mysterious stuff I don't understand" so hearing the scientists' perspectives would be really awesome!
lol chea its what ya gotta do to put da bread in ya bois hand. - of course im refering to street molecular science. these streets are hard for a young physicist.
To answer the car collision question (assuming gravity is negligible) nothing would happen because dark matter has no charge, thus no electrons repelling each other and stopping one material from passing through another, which we perceive as a "collision"
Great video! I must admit the moniker "dark" matter made me think of something like soot, but you make it clear that it difficult to detect - "elusive"! "They seek it here, they seek it there..." Pimpernelium?
The biggest problem I have with the dark matter theory: Why doesn't the dark matter affect planetary systems? If there is dark matter permeating space all throughout a galaxy - enough to pull stars around at high velocities - why is it not affecting planetary orbits *at all*? Why can we completely explain the orbits of the planets with conventional theories? We only needed this idea of dark matter after observing the orbital motion of stars. Well after we had explained the orbits of the planets quite accurately. Why does dark matter seemingly only affect the orbits of stars? Perhaps this is explained within the theory, but I've never heard this question even asked.
Vinthis1 Yes, I am aware that its most visible on large scales. What I mean is, can we see its influence on planets at all? What do the equations say the influence on planetary orbits should be, and could we measure that? The effect, if dark matter is fundamentally affecting galaxy structure, is surely not going to be immeasurably small. It might not be overwhelming but we should surely still be able to see it. Personally, it feels more like we need to work on our theory of gravity. Obviously work on both theories is required, but I have a hunch that it is gravity behaving differently rather than dark matter.
***** This was actually proposed in the late eighties by A scientist named Milgrom. He proposed what he called Modified Newtonian Dynamics, which suggested that at low accelerations the force of gravitation begins go by 1/distance rather than 1/(distance)^2. This would work to explain the motions of stars in galaxies without the need for dark matter halos, but doesn't explain the heavy gravitational lensing of the galaxy clusters seen in the video (among other things). Dark matter is a much more complete theory which is why it's preferred.
Drainojunkie Yes, I am aware that Dark matter is a fuller theory, but my question is, can we see its effects on planetary orbits? If it is permeating all of space and dragging stars into large orbits, shouldn't we be able to measure its influence on planets as well? I am not saying that I think this ruins the theory, I am just wondering if and how the theory deals with this, as I have never heard anyone mention it.
From what I understand, as far as we are from the galactic edge, we wouldn't see any effects on the orbit of planets because we are far enough from the halo that the gravitation would likely be affecting the orbitals too uniformly to measure. However, I second your question. I would think that very close to the halo we should see that orbits elongate towards the edge of the galaxy as they rotate. I'm just not sure that we can measure that, or if the effects on out own solar system would be large enough to measure. Essentially, I just spent all that time to say "good point, I don't know".
lol...you're right. And I would say they are "technically" air cooled, since none of the water cooling parts are on the electronic components. I would assume the "more parts, the more likely a break", or leak in this case. So they wouldn't "water cool". Just my opinion.
I've a few suggestions what dark matter and dark energy are and i bet that people are already thinking about this: 1. broken gravity or free gravitons in spacetime. 2. particles too small to detect 3. psi phenomena emitted by nonliving and living things 4. spirit realm that exists in another dimension (i know people are smirking at this but options are still options)-ghosts sometimes interact with electromagnetism but are mostly not present in our universe.
As far your question of how i would explain how a galaxy separated from the dark matter, my best guess would be that a majority of the matter in the galaxy had already been absorbed into a central black hole and that black hole didn't have a large enough sphere of gravity to maintain a hold on the dark matter around it. Some of the dark matter stuck with it as it gained velocity during a stellar collision, but a majority did not. That's just a guess, but it's better than your guess.
Dark matter is assumed to exist because our theories brake down when trying to explain how galaxies stay together without it. Could it not be that our theories are just wrong?
ajuk1 Yes. This is a valid question. Modified Newtonian Dynamics is a theory that accounts for the galaxy rotation curves by modifying laws of physics at larger scales.
That is always an option. But because our theories give the right predictions in so many other areas it is more likely that there is a mysterious dark matter that we haven't accounted for, rather than that there is a completely alternative explanation for everything out there. But believe me, there's thousands of incredibly smart people trying to come up with alternative explanations!
We didn't know that light traveled at finite speeds until someone observed the eclipses of the moons of Jupiter very carefully and saw discrepancies with what Newton's theory of gravity predicted. Having confidence on theories that have repeatedly proven themselves true allow you to postulate the existence of otherwise unknown entities to explain anomalies in our observations.
I am not a physicist. When a gas cloud collapses, the atoms are spaced far enough apart to experience almost no friction. As they are drawn in to a common central area they are moved close enough to increase the probability of collision. These collisions transfer the kinetic energy from external (velocity) to internal (heat). If that didn't happen, then the particles would just rubber band backwards and forward. No collisions = no energy loss due to heat. 1/2
Anti-matter is essentially matter, but with opposite electrical charge. It thus fits in to the matter part of the pie. It probably isn't too far fetched to assume there exists anti-dark matter as well as well, but this would then fit into the dark matter part of the pie. The point of the pie is to show the total energy density of the universe, one can of course split the parts in to matter/antimatter, but it is essentially pointless, because they have the same traits.
What we identify as dark matter shares many characteristics with neutrinos. One considerable difference, though, is that dark matter particles is predicted to be quite massive, but neutrinos barely have any mass at all. (The standard model predicts neutrinos being massless, but experiments have shown them to have a tiny mass.) Thus the the neutralino is instead offered as an explanation for dark matter. The problem here is that supersymmetry is having trouble showing itself at the LHC.
If a dark matter unit is in line to come into contact with a conventional piece of matter, say an electron, something extraordinary happens. When it's within a plank length it disappears into a separate dimension or universe or what have you. It then reappears a planks length away on the other side. Since light behaves like a particle it does the same to photons. Hence its visual imperceptibility.
Though I can absolutely recommend the Corsair (and/or CoolIT) product lines. Running a i7 3700K@4500mhz workstation here & it's a dead quiet system running the H100. Very nice. :)
@Nyphur I understand you view in that you want proof. I however regard this as a public forum for thought and discussion. I did try to work on the geometry and if you search for "The Effects of an Index of Refraction for Dark Matter.xlsx" perhaps it will show up. You can take it or leave it.
a physics professor from my university once argued passionate that a much better explaination for the observations that lead to the assumption that there is dark matter would be a quantum theory for gravitation. i cant remember the exact argument but he talked about how the additional gravity from the dark matter only seems to exist in these huge galactic scales of thousands of lightyears, influencing galaxy formation but beeing negligible on the scale of our solar system for example.
1 theory is that although dark matter can create a gravitational effect for regular matter, it may not attract other dark matter particles the same ways. Regardless stars run on the fission of atomic nuclei which not something shared by most particles know today.
Sixty Symbols What if dark matter is a particle with absolute zero temperature? It does not react with other particles nor emit light because it cannot, but it still has gravity. You should measure dark matter at your laser cooler experiment. ^(Do I get a Nobels prize for this idea)
Nothing can be at absolute zero. If we had the exact opposite of a Nobel Prize, you might have earned it. Also, instead of getting a million dollars with the prize, you'd be fined a million dollars as a penalty for believing that you can pull ideas out of your rear end and win cash and valuable prizes.
Thank you for all those wonderfull video's. I'm a teacher on high school in the Netherlands, so this is far from my daily work. But I love how it trains my brain. I started to get interested in these kind of video's, when I say a documentary on the Fermat theorem a few years ago. Now I ended up here. Sorry for my poor English. It is not my native language.
ek_tha_KC I don't think you understand. We can measure a gravitational anomaly, and we have named it's cause "dark matter" as a placeholder. It exists. Whatever theory you are talking about, it should account for this measurement.
legisnuntius The gravitational effects are observed. The cause of the effects is inferred. If any theory is going to be accurate, it is going to include these effects, regardless of what explanation it has for them. The physicists in the video presented the effects of dark matter as fact, because they are. None of them provided an explanation for the effects as fact: 4:24 and again at 7:24.
Vinthis1 so you are saying effects are a fact right?? not the dark matter...dark matter is just a proposal and a possible reason for the effects. We still do not know whether there is really any thing like that.
My thought as always been, instead of dark matter to explain why galaxies are spinning strange, what if we delved deeper into gravity? What if there is more to the gravitational constant? What if it was not a constant at all, but a group of variables that we do not understand because in our solar system its the same variables, and its not until you go out further, that new variables are used? That's just what is floating in my head, but I hope it can get tested someday.
Nobody can see that dark matter, nor can detect, measure, prove, affect, etc. But at that the physicists know for sure and tell exactly how much space it occupies and gravity it has. How can one assert something about anything if one knows nothing about it at all? I wonder if the physicists ever were struck by the thought that their knowledge of the universe is near the absolute zero.
Because we don't "know nothing about it at all". We know it interacts gravitationally. We can see and measure this affect. We can calculate how much of it is needed to cause the effects we observe. And the answer is, a lot.
Having just watched 6 Dimensions, Extra Dimensions, and Dark Matter back-to-back, it seems an obvious suggestion that the anomalies we see in gravity distribution would be caused by something going on outside of our 4 observable time-space dimensions. Perhaps a video to explain how this compares to the hunt for exotic "dark matter" particles?
Love this girl....unlike emancipated american whores she does not need to shout or take an aggressive stance to prove a point and garner attention. She is just smart and cute.
A theory should explain the interactions you observe with as few assumptions as possible. My theory (plasma-electric-universe) makes only two assumptions: 1. Protons and Electrons are objects which represent the elementary charge. 2. The electromagnetic interaction is based on the elementary charge, it's only one force. Neutrons decay to an electron and a proton, it is a composite of these two elementary charge particles. The EMI-Theory explains everything, redshift, galaxies, solar system etc.
Well, people developed gravitational formulas based on visible matter. Now we used it to conclude that 5/6 of the matter is dark matter. Why not to conclude that all bodies weigh 5~6 times more than we thought before? Wouldn't be accurate that every person, object, planet or star should weigh more because everything have a dark matter shell?
I just found an article about the possibility of the confirmation of Dark Matter by the particle collider on the International Space Station. Hopefully Brady does a video about it.
Not really related to quantum gravity tmk, but that sounds kind of like the competitor theory to dark matter: Modified Newtownian Dynamics (MOND) which introduces slight changes to the equations that only have an effect on larger scales. Brady, it'd be awesome if you made a video about that. Maybe you can find someone who is not in the Dark Matter camp? (: (I vaguely remember Prof. Merrifield mentioning someone next door working on it...(?))
@Nyphur I agree with what you are saying and when Doppler red shift fails to explain NGC7603 I think you at least have to start to question it. I'm too lazy to give you mathematical proof and perhaps it's beyond my capabilities. Also with only 500 characters at my disposal it's hard to give a meaningful explanation. But there are several ways of testing this, but I don't have a telescope or a way to measure "red shift". Do you?
i dont understand why we automatically assume that dark matter is a type of matter, just because matter seems to been drawn by unknown forces. There are so many things we dont understand about space-time and our universe,i think that this extra gravitational pull could be caused by something other than a type of matter
I liked the unsophisticated thumbnail of the chocolate pie! The simplicity was in such contrast to the matter at hand... (any pun that could be derived from this was not intended).
I have one problem with the theory of dark matter existing while interacting with itself and with gravity. The problem is that it would, in the same way as with regular matter, converge in very small spaces and form dark matter back holes. Now if those existed we would be able to observe them in much the same way we observe black holes consisting of matter, and with the ratio of darkmatter to matter being so high you'd think they'd be more commonly observable, and also by conventional methods.
Also assuming it is clumped and not evenly distributed or counteracted by other clumps. As she stated we are 4% of "normal" matter and dark matter compromises 23%.
The "Vacuum Energy" effect of stiffness or hysteresis has an equivalent in water, in that warm moving water is "softer" and more yielding than cool still water, and the same applies to the atmosphere, ..and thixotropic fluids of any type and scale are a property of synchronization, which blends in with mass, gravity, momentum and large "objects" astronomically (?), inertially-gravitationally bound or "congealed". (Like chocolate pudding)
There is much more observation and interpretation necessary. But to give you an example for EM interactions. The Coulomb-Force is 10^36-times stronger than gravity, so even an infinitesimal small amount of EM forces overwhelms gravity. You can't see electric or magnetic fields, what you see are currents build out of real matter in plasma state. Electrons orbit, if a magnetic field is present. At the same time, these electrons generate a magnetic field. That's called electromagnetic induction.
Dark matter is the darkness shield, like a curtain, the mechanical elves use to conceal themselves as they constantly work with their little space hammers to fine tune the universe and to tug on the strings connected to all the cosmic bodies.
I agree. Love Corsair. I'm testing an H80i on this i3 3225 atm for my Moms build and it keeps the temps under 55C, even oc'd to 3554MHz at 1.2v (from 3300MHz at 1.1v), without fans even! As long as the room temp stays under 35C at least, otherwise it'll get to 58-59C. But I'm talkin an i3 after all.
I feel that DM is leftover aftereffects of comprehensive dynamics placed on past conventional matter as humans understand it.The most difficult part in understanding it, is how DM's interreational status compares with standard matter as we know it.I feel that expressively this would be categorized as base weights measurements based in a comparative quantitative survey.
This just don't know what it is yet. Imagine your car is making a funny knocking sound in the engine. You know there's something wrong with your car, you just haven't figure it out yet. This is how science works. We discover something unusual, and then slowly gather evidence for what it is. Come back in 50 years and see how much progress has been made.
I thought black holes or dark holes were made of the super compressed remains of a star, with a gravitational force so huge that it actually pulls away light. Since no light is coming from it, it seems dark.
so, yes, in our solar system for example, neptune is orbiting very slowly compared to mercury. and will keep orbiting slower than mercury even if the sun was 2x massive. the only way to speed up neptune is to add so much mass to it, to let him interact stronger with the sun. the problem here is not the sun and its mass, but neptune. small and distant.
Thank you for your enlightening words. I have been working in physics for over a decade now without knowing that dark matter only interacts weakly. Really appreciate it.
I wish I were smart. So much of this stuff I can grasp at a conceptual level, but it eludes me. Especially the idea of general relativity. How time moves slower in other time frames, like a rocket speeding by is something I will never fully grasp. Like this dark matter thing. I just have to assume it to be true and move along with my life.
Very clever to have that pie on hand. Otherwise we would never have grasped this so-called "three-fourths" concept.
James Butler Yes, and it was dark, too.
But I got a bit confused, when they said, that it´s actually transparent, because in my eyes it sure still looked brown & delicious:)
All the best,
Forrest Gump:)
LOL
5:15
When it comes to chocolate pie, "The heart has its reasons of which reason knows nothing." 😂
Part of that pie represented itself o_O
Well played, Sir.
Winter Summers about an atom's worth
It's a recursive pie.
Right. Every set is a subset of itself.
@@leonhardeuler9839 ye
Astronomers have thought of that, but even if you add up all black holes, cold gas, brown dwarfs, etc, it just doesn't give you enough mass to account for dark matter.
I want that pie.
xXEliteTNCXx i just want a slice q_q
+xXEliteTNCXx The cake is a lie!
Klaus Von Liechtenstein Still waiting for the "Why not both"-Guy
xXEliteTNCXx ^^ im a compromise guy
Klaus Von Liechtenstein me too actually ^^
Does dark matter have a dark periodic table?
Umang Bhat We'll know only the day we get to understand it.
Heck, it might even be not a single thing, but rather several other "realms" as incapable of interacting among them other than through gravity as we are towards them.
Nice concept
Umang Bhat It could be. Dark Matter is not really the best name since that implies we know it is matter, when in reality we don’t know.
It depends on if it interacts with the strong force. If it doesn't, then the particles can't bind to each other to form more complex structures.
But even if it does, it shouldn't influence the properties of the composite particles much, since what decides the properties of the element is the outermost electron layer, which they would not have, since they don't interact with the electromagnetic force and can't have a charge.
Actually, if they don't have a charge, does that mean that there would be no factor that prevents from more and more dark matter to clump together? Since there's no positive charge to push protons apart...
Had a smoke before this and all I could think about was the pie
Paul McDonagh weird flex but ok
Id like to see an update of this video where we get to see the ten years of progress from then until now.
just eat that pie already
That Pie is very distracting.
Makes me...Hungry
even me
I love all of these guys, and they're all incredibly humble and intelligent people, but let's all take a minute to appreciate Brady Haran - not only for making these videos in the first place, but because though he remains behind the camera and out of the spotlight he proves himself to be as smart as any of the rest of them because he fearlessly and consistently asks the right questions. Thank you Brady, and all of the rest of you at Sixty Symbols/Numberphile. Keep up the wonderful work!!
so dark matter is made of dark chocolate, that explains everything.
She really does have an impeccable speaking voice. I love listening to her explain things.
Never thought a video of dark matter could make me hungry. Seriously the first three minutes i only heard pie, pie and pie.
My astrophysics professor always said that dark matter: "is a real bitch" lol
i was just talking with a young lady teenager and she asked me what i was watching i showed here the screen grab of dr gray(i think thats her name?) i told her she was a cosmologist ,and she said ohhh she works with makeup.....priceless
.......wow
gotama420 congrats. great education you got there
MsHoaxx how do you mean?
***** danke schon
***** I swear this really happened i almost lost it ,
the schools are ok here but there are a lot of hill people who are not real big on education. I was lucky both my parents instilled a will to learn on us.
wow this completely blows my mind, please keep us posted on this subject and also bring us up to speed with dark energy story, Thanks, David.
This video made me hungry. I'll tell you what. Since you're not using the dark energy, why don't I...dispose of it for you.
In one version Membrane theory, dark matter is just gravity wells from normal matter in a nearby universe. I equate it to having each universe on a sheet of paper and drawing on them with a ball-point pen. The drawing in the paper is matter, and the indentations are the gravity wells. When you lay one "universe" page on top of the other and then draw "matter" onto the top one, you can see the "gravity well" indentation on the bottom page(our own universe). It makes sense to me.
I love the quote from time stamp 10:11 to 10:23.
I'm not an astronomer, astronomy is for me just a hobby, but it makes me think of all these posibilities, and these videos help me understand all sort of things, and the real scientists that do the explainig part, they do it in a way that is easy for everyone to understand it all. So, thank you, Sixty Simbols :)
Dr, Gray is absolutely endearing!
I will continue to believe that dark matter smells like chocolate.
If it is gravitationally interacting with itself as well as normal matter, why isn't dark matter "lumpier" than is apparently observed? Normal matter is very lumpy. And as it apparently has mass, and there's about six times more of it than normal matter, why hasn't dark matter formed "dark black holes"? Or has it?
8 years later and I still think about that pie.
Where is it? Its dark you can't see it.... lol
...sounds so Monty Python the way he said it XD
From what I understand, it's because the dark matter doesn't interact with itself or regular matter through electromagnetic forces. If you look at what happens in something like an accretion disk, the matter ends up colliding, which causes it to tend toward the center. With dark matter, it's more of an oscillation. You can see this effect easily if you look at the bullet cluster. The regular matter slows down from EM forces as well as gravity, while the dark matter just slows from gravity.
I love all of the Brady channels....absolutely fascinating.
"What would happen if I drove my car into a big clump of dark matter?"
This is what makes your videos relatable!
I thought the first slice was a third of the pie, but what do I know?
I clerly see the error in computer simulation shown after 9:42. It assumes that matter lumps only at certain regions, but not inertia of the already formed smaller lumps running into bigger lumps of matter. So, there is no rotation, and it doesn't looks like real galaxies or something similar.
Each smaller lumps of matter may interact each other, forming 'twisted' looking structures, which is common in nature if you look how clouds are formed (although different forces, including Coriolis forces acting upon molecules of air and water vapor).
Also, during lumping and 'running' of the smaller lumps toward bigger center of mass, matter experiencing something resembling air drag, because matter in front of moving lumps of matter is not yet 'swept', so every next lump has greater velocity - because previous lump of matter sweeping this area (creating less resistance).
If so, then there may be explanation why galaxies' arms moving faster than expected, also why doppler shift between galaxies looks like universe expands, or like dark energy pushes them appart.
On this animation, look carefuly - it appear that 'new space' emerges in between lumps of matter, while whole picture looks stationary - nothing expands.
Brady or someone from the Sixty Symbols team: I love your videos! I'm a high school science teacher in an American international school in China and you guys do a great job of making things visual and accessible for my students!
Some of my students had really good questions about dark matter (very proud of them), and I was stumped!
Does dark matter interact with black holes? Black holes collect mass around them because of their tremendously strong gravitational fields, so shouldn't we also see black holes becoming more massive several times faster than we can account for by monitoring their intake of "normal" matter?
My guess is it probably does, but it has to interact with something we can detect in order for us to detect it. Think about 2 invisible people. If they silently shakes hands, we wouldn't be able to tell if they are in the room or not. But if one of them picks up an object (interacts with something that we can see/detect) we will know that the invisible person is there.
Hope that's helpful/the kind of answer you were looking for.
Where can I find the recipe for dark matter chocolate pie? Or there is no way of knowing it? :)
From what I understand, some/most Data Centers use a hybrid water-A/C cooling unit for their servers (basically a refrigeration unit cooling the water that's used to cool the air...i believe). But supercomputers are so advanced and different in such ways, I wouldn't have a clue to what would be best...like hot water?
So, basically, we're still stuck with an aether.
Brady, I would love to see a video on the interaction between dark matter and black holes. It's tricky to find good information on Google because to so many people they're just interchangeable "mysterious stuff I don't understand" so hearing the scientists' perspectives would be really awesome!
Are your sure the dark matter isn't a combination of quarks that is neutral like 2 strange and 1 charm?
This lady is super nice and an excellent speaker as well.
I see the Crips have started to diversify their activities.
lol chea its what ya gotta do to put da bread in ya bois hand. - of course im refering to street molecular science. these streets are hard for a young physicist.
Bilb Ono My favorite rapper is Young Phyzy. Well either him or Higgz Tha Boson
To answer the car collision question (assuming gravity is negligible) nothing would happen because dark matter has no charge, thus no electrons repelling each other and stopping one material from passing through another, which we perceive as a "collision"
Umm...that piece of dark matter looks delicious...
Great video! I must admit the moniker "dark" matter made me think of something like soot, but you make it clear that it difficult to detect - "elusive"!
"They seek it here, they seek it there..." Pimpernelium?
The biggest problem I have with the dark matter theory:
Why doesn't the dark matter affect planetary systems? If there is dark matter permeating space all throughout a galaxy - enough to pull stars around at high velocities - why is it not affecting planetary orbits *at all*?
Why can we completely explain the orbits of the planets with conventional theories? We only needed this idea of dark matter after observing the orbital motion of stars. Well after we had explained the orbits of the planets quite accurately. Why does dark matter seemingly only affect the orbits of stars?
Perhaps this is explained within the theory, but I've never heard this question even asked.
It does. Like people are gravitationally attracted to ants. It is bending the light of distant galaxy's. It is operating on a different scale.
Vinthis1 Yes, I am aware that its most visible on large scales. What I mean is, can we see its influence on planets at all? What do the equations say the influence on planetary orbits should be, and could we measure that?
The effect, if dark matter is fundamentally affecting galaxy structure, is surely not going to be immeasurably small. It might not be overwhelming but we should surely still be able to see it.
Personally, it feels more like we need to work on our theory of gravity. Obviously work on both theories is required, but I have a hunch that it is gravity behaving differently rather than dark matter.
***** This was actually proposed in the late eighties by A scientist named Milgrom. He proposed what he called Modified Newtonian Dynamics, which suggested that at low accelerations the force of gravitation begins go by 1/distance rather than 1/(distance)^2.
This would work to explain the motions of stars in galaxies without the need for dark matter halos, but doesn't explain the heavy gravitational lensing of the galaxy clusters seen in the video (among other things). Dark matter is a much more complete theory which is why it's preferred.
Drainojunkie Yes, I am aware that Dark matter is a fuller theory, but my question is, can we see its effects on planetary orbits?
If it is permeating all of space and dragging stars into large orbits, shouldn't we be able to measure its influence on planets as well?
I am not saying that I think this ruins the theory, I am just wondering if and how the theory deals with this, as I have never heard anyone mention it.
From what I understand, as far as we are from the galactic edge, we wouldn't see any effects on the orbit of planets because we are far enough from the halo that the gravitation would likely be affecting the orbitals too uniformly to measure.
However, I second your question. I would think that very close to the halo we should see that orbits elongate towards the edge of the galaxy as they rotate. I'm just not sure that we can measure that, or if the effects on out own solar system would be large enough to measure.
Essentially, I just spent all that time to say "good point, I don't know".
lol...you're right. And I would say they are "technically" air cooled, since none of the water cooling parts are on the electronic components. I would assume the "more parts, the more likely a break", or leak in this case. So they wouldn't "water cool". Just my opinion.
the Kripps have a computing centre to simulate full universes of dark matter? wat..
I've a few suggestions what dark matter and dark energy are and i bet that people are already thinking about this: 1. broken gravity or free gravitons in spacetime. 2. particles too small to detect 3. psi phenomena emitted by nonliving and living things 4. spirit realm that exists in another dimension (i know people are smirking at this but options are still options)-ghosts sometimes interact with electromagnetism but are mostly not present in our universe.
What was the rest of the pie?
John Kerley Dark energy.
John Kerley Deez Nuts
Joshua Lemire hahahthat's funny xddd
As far your question of how i would explain how a galaxy separated from the dark matter, my best guess would be that a majority of the matter in the galaxy had already been absorbed into a central black hole and that black hole didn't have a large enough sphere of gravity to maintain a hold on the dark matter around it. Some of the dark matter stuck with it as it gained velocity during a stellar collision, but a majority did not. That's just a guess, but it's better than your guess.
Dark matter is assumed to exist because our theories brake down when trying to explain how galaxies stay together without it. Could it not be that our theories are just wrong?
ajuk1 There is no theory on why galaxies behave the way they do. The math changes for every hypotheses.
ajuk1 Yes. This is a valid question.
Modified Newtonian Dynamics is a theory that accounts for the galaxy rotation curves by modifying laws of physics at larger scales.
+xokocodo Modified Newtonian Dynamics also requires dark matter to work. ;)
That is always an option. But because our theories give the right predictions in so many other areas it is more likely that there is a mysterious dark matter that we haven't accounted for, rather than that there is a completely alternative explanation for everything out there.
But believe me, there's thousands of incredibly smart people trying to come up with alternative explanations!
We didn't know that light traveled at finite speeds until someone observed the eclipses of the moons of Jupiter very carefully and saw discrepancies with what Newton's theory of gravity predicted. Having confidence on theories that have repeatedly proven themselves true allow you to postulate the existence of otherwise unknown entities to explain anomalies in our observations.
I am not a physicist.
When a gas cloud collapses, the atoms are spaced far enough apart to experience almost no friction. As they are drawn in to a common central area they are moved close enough to increase the probability of collision. These collisions transfer the kinetic energy from external (velocity) to internal (heat).
If that didn't happen, then the particles would just rubber band backwards and forward. No collisions = no energy loss due to heat.
1/2
Am I the only one who thinks that woman is breath takingly gorgeous?
Nope. Not the only one.
She's super sexy. Love me some science girls.
She's clever. She's beautiful. She's perfect.
Nope
Andrew Trigueros she's attractive
Anti-matter is essentially matter, but with opposite electrical charge. It thus fits in to the matter part of the pie. It probably isn't too far fetched to assume there exists anti-dark matter as well as well, but this would then fit into the dark matter part of the pie.
The point of the pie is to show the total energy density of the universe, one can of course split the parts in to matter/antimatter, but it is essentially pointless, because they have the same traits.
That pie.
What we identify as dark matter shares many characteristics with neutrinos. One considerable difference, though, is that dark matter particles is predicted to be quite massive, but neutrinos barely have any mass at all. (The standard model predicts neutrinos being massless, but experiments have shown them to have a tiny mass.) Thus the the neutralino is instead offered as an explanation for dark matter. The problem here is that supersymmetry is having trouble showing itself at the LHC.
I NEED THAT PIE! It looks.... NECESSARY!
If a dark matter unit is in line to come into contact with a conventional piece of matter, say an electron, something extraordinary happens. When it's within a plank length it disappears into a separate dimension or universe or what have you. It then reappears a planks length away on the other side. Since light behaves like a particle it does the same to photons. Hence its visual imperceptibility.
Mmmmm... dark choc.. ehum.. matter :-)
Though I can absolutely recommend the Corsair (and/or CoolIT) product lines. Running a i7 3700K@4500mhz workstation here & it's a dead quiet system running the H100. Very nice. :)
Blood's better step it up. The Crips already got super computers.
CanadianBoardCrew came to the comments immediately to see if someone else got that, lol well played
Jocelyn Robyn no one here about that life
@Nyphur I understand you view in that you want proof. I however regard this as a public forum for thought and discussion. I did try to work on the geometry and if you search for "The Effects of an Index of Refraction for Dark Matter.xlsx" perhaps it will show up. You can take it or leave it.
I found some dark matter in my toilet earlier... xD
you should see a doctor
You didn't get the joke, pal.
a physics professor from my university once argued passionate that a much better explaination for the observations that lead to the assumption that there is dark matter would be a quantum theory for gravitation. i cant remember the exact argument but he talked about how the additional gravity from the dark matter only seems to exist in these huge galactic scales of thousands of lightyears, influencing galaxy formation but beeing negligible on the scale of our solar system for example.
Physicists: The is no aether!
Years later...
Um, there is dark matter and dark energy, and...
1 theory is that although dark matter can create a gravitational effect for regular matter, it may not attract other dark matter particles the same ways. Regardless stars run on the fission of atomic nuclei which not something shared by most particles know today.
Sixty Symbols What if dark matter is a particle with absolute zero temperature? It does not react with other particles nor emit light because it cannot, but it still has gravity. You should measure dark matter at your laser cooler experiment.
^(Do I get a Nobels prize for this idea)
You might if someone does the experiment and mentions your idea,else no
Nothing can be at absolute zero. If we had the exact opposite of a Nobel Prize, you might have earned it. Also, instead of getting a million dollars with the prize, you'd be fined a million dollars as a penalty for believing that you can pull ideas out of your rear end and win cash and valuable prizes.
thank you brady and thank you the professors, this is fascinating :-)
We don't know if dark matter really exist, we only know that galaxies are rotating much faster than their mass should allow.
There are many other clues that Dark Matter must exist.
The CMB power spectrum, galaxy cluster masses, galaxy cluster interactions etc. etc.
Thøger Emil Rivera-Thorsen ...Gravitational Lensing
Thank you for all those wonderfull video's. I'm a teacher on high school in the Netherlands, so this is far from my daily work. But I love how it trains my brain.
I started to get interested in these kind of video's, when I say a documentary on the Fermat theorem a few years ago. Now I ended up here.
Sorry for my poor English. It is not my native language.
why are they presenting this as a 'fact'?
Because it is an observable, measurable fact.
ek_tha_KC I don't think you understand. We can measure a gravitational anomaly, and we have named it's cause "dark matter" as a placeholder. It exists. Whatever theory you are talking about, it should account for this measurement.
Vinthis1 By its very definition, you can't observe dark matter. It's inferred, not observed. I don't think you understand it very well.
legisnuntius The gravitational effects are observed. The cause of the effects is inferred. If any theory is going to be accurate, it is going to include these effects, regardless of what explanation it has for them. The physicists in the video presented the effects of dark matter as fact, because they are. None of them provided an explanation for the effects as fact: 4:24 and again at 7:24.
Vinthis1 so you are saying effects are a fact right?? not the dark matter...dark matter is just a proposal and a possible reason for the effects. We still do not know whether there is really any thing like that.
My thought as always been, instead of dark matter to explain why galaxies are spinning strange, what if we delved deeper into gravity?
What if there is more to the gravitational constant? What if it was not a constant at all, but a group of variables that we do not understand because in our solar system its the same variables, and its not until you go out further, that new variables are used?
That's just what is floating in my head, but I hope it can get tested someday.
Smart attractive female physicist/astronomer with chocolate pie talking about... er... I got a bit distracted 😥
+Silence is Golden Duct Tape is Silver That's a smutty interpretation. BTW Duct tape comes in black and silver 😜
Same
2:14
If we're fairly certain there's dark matter going through that room, we can say for sure that whatever it is, it's not gonna kill ya!
Nobody can see that dark matter, nor can detect, measure, prove, affect, etc. But at that the physicists know for sure and tell exactly how much space it occupies and gravity it has. How can one assert something about anything if one knows nothing about it at all? I wonder if the physicists ever were struck by the thought that their knowledge of the universe is near the absolute zero.
They have proved it through equations
Because we don't "know nothing about it at all". We know it interacts gravitationally. We can see and measure this affect. We can calculate how much of it is needed to cause the effects we observe. And the answer is, a lot.
Having just watched 6 Dimensions, Extra Dimensions, and Dark Matter back-to-back, it seems an obvious suggestion that the anomalies we see in gravity distribution would be caused by something going on outside of our 4 observable time-space dimensions. Perhaps a video to explain how this compares to the hunt for exotic "dark matter" particles?
Love this girl....unlike emancipated american whores she does not need to shout or take an aggressive stance to prove a point and garner attention. She is just smart and cute.
A theory should explain the interactions you observe with as few assumptions as possible. My theory (plasma-electric-universe) makes only two assumptions:
1. Protons and Electrons are objects which represent the elementary charge.
2. The electromagnetic interaction is based on the elementary charge, it's only one force.
Neutrons decay to an electron and a proton, it is a composite of these two elementary charge particles. The EMI-Theory explains everything, redshift, galaxies, solar system etc.
Well, people developed gravitational formulas based on visible matter. Now we used it to conclude that 5/6 of the matter is dark matter.
Why not to conclude that all bodies weigh 5~6 times more than we thought before?
Wouldn't be accurate that every person, object, planet or star should weigh more because everything have a dark matter shell?
8 years later I am still looking at the pie.
14 years later and i still think about the pie
I just found an article about the possibility of the confirmation of Dark Matter by the particle collider on the International Space Station. Hopefully Brady does a video about it.
Not really related to quantum gravity tmk, but that sounds kind of like the competitor theory to dark matter: Modified Newtownian Dynamics (MOND) which introduces slight changes to the equations that only have an effect on larger scales. Brady, it'd be awesome if you made a video about that. Maybe you can find someone who is not in the Dark Matter camp? (: (I vaguely remember Prof. Merrifield mentioning someone next door working on it...(?))
I'd like to have that supercomputer for a graphics card... I think that I might get around, say, 7.5 billion FPS maybe...
@Nyphur I agree with what you are saying and when Doppler red shift fails to explain NGC7603 I think you at least have to start to question it. I'm too lazy to give you mathematical proof and perhaps it's beyond my capabilities. Also with only 500 characters at my disposal it's hard to give a meaningful explanation. But there are several ways of testing this, but I don't have a telescope or a way to measure "red shift". Do you?
i dont understand why we automatically assume that dark matter is a type of matter, just because matter seems to been drawn by unknown forces. There are so many things we dont understand about space-time and our universe,i think that this extra gravitational pull could be caused by something other than a type of matter
I liked the unsophisticated thumbnail of the chocolate pie!
The simplicity was in such contrast to the matter at hand... (any pun that could be derived from this was not intended).
I have one problem with the theory of dark matter existing while interacting with itself and with gravity. The problem is that it would, in the same way as with regular matter, converge in very small spaces and form dark matter back holes. Now if those existed we would be able to observe them in much the same way we observe black holes consisting of matter, and with the ratio of darkmatter to matter being so high you'd think they'd be more commonly observable, and also by conventional methods.
Also assuming it is clumped and not evenly distributed or counteracted by other clumps. As she stated we are 4% of "normal" matter and dark matter compromises 23%.
The "Vacuum Energy" effect of stiffness or hysteresis has an equivalent in water, in that warm moving water is "softer" and more yielding than cool still water, and the same applies to the atmosphere, ..and thixotropic fluids of any type and scale are a property of synchronization, which blends in with mass, gravity, momentum and large "objects" astronomically (?), inertially-gravitationally bound or "congealed". (Like chocolate pudding)
There is much more observation and interpretation necessary. But to give you an example for EM interactions. The Coulomb-Force is 10^36-times stronger than gravity, so even an infinitesimal small amount of EM forces overwhelms gravity. You can't see electric or magnetic fields, what you see are currents build out of real matter in plasma state. Electrons orbit, if a magnetic field is present. At the same time, these electrons generate a magnetic field. That's called electromagnetic induction.
Dark matter is the darkness shield, like a curtain, the mechanical elves use to conceal themselves as they constantly work with their little space hammers to fine tune the universe and to tug on the strings connected to all the cosmic bodies.
I agree. Love Corsair. I'm testing an H80i on this i3 3225 atm for my Moms build and it keeps the temps under 55C, even oc'd to 3554MHz at 1.2v (from 3300MHz at 1.1v), without fans even! As long as the room temp stays under 35C at least, otherwise it'll get to 58-59C. But I'm talkin an i3 after all.
The name of the lecture that explains why the sky is blue during the day and red at sunset is called For the Love of Physics - given at MIT.
Did you use what you learned doing the vuvuzela video with Prof. Moriarty to enhance Megan's voice in this clip?
I feel that DM is leftover aftereffects of comprehensive dynamics placed on past conventional matter as humans understand it.The most difficult part in understanding it, is how DM's interreational status compares with standard matter as we know it.I feel that expressively this would be categorized as base weights measurements based in a comparative quantitative survey.
This just don't know what it is yet. Imagine your car is making a funny knocking sound in the engine. You know there's something wrong with your car, you just haven't figure it out yet. This is how science works. We discover something unusual, and then slowly gather evidence for what it is. Come back in 50 years and see how much progress has been made.
@sschhuu the other GUY with the glasses did that too when explaining a quark
I thought black holes or dark holes were made of the super compressed remains of a star, with a gravitational force so huge that it actually pulls away light. Since no light is coming from it, it seems dark.
so, yes, in our solar system for example, neptune is orbiting very slowly compared to mercury. and will keep orbiting slower than mercury even if the sun was 2x massive. the only way to speed up neptune is to add so much mass to it, to let him interact stronger with the sun. the problem here is not the sun and its mass, but neptune. small and distant.
Thank you for your explanation
Thank you for your enlightening words. I have been working in physics for over a decade now without knowing that dark matter only interacts weakly. Really appreciate it.
I wish I were smart. So much of this stuff I can grasp at a conceptual level, but it eludes me. Especially the idea of general relativity. How time moves slower in other time frames, like a rocket speeding by is something I will never fully grasp. Like this dark matter thing. I just have to assume it to be true and move along with my life.