Brady, if you ever read this, I find your questions absolutely brilliant and asked the right way so we can understand (and i'm a french-speaker). Ed Copeland was absolutely right when he said around 11:00 "Brady, you should be here!", you truly have the curiosity and the sharpness (is it the right word?) of a brilliant scientist. Thank you for your amazing work.
Ed sums up Brady's greatest gift to us all at 22:09 "Wow exactly you know how to say things scientifically correct" - I love these concepts, explained by incredible professors, through your unique questioning. Thanks Brady - never stop
Wow. Binge watching old Brady videos pays off big time. Also, the amount of understanding Brady displays in them shows he would have had the potential to be like any of his interview partners.
What shapes the spatial frequency distribution of the pre-inflation field? Why can't low-frequency information be present, creating large density variations? In my experience 1/f noise is very fundamental in our universe, why is the universe apparently isotropic at any scale?
I think the model of posting edited and condensed videos on the topic channels, and largely uncut footage on a secondary channel like this is a great idea. Then the people who just want the condensed version can get it, and those who want more can get this. I don't think posting largely uncut foodage like this requires much work, and if it gets 20% (or more) of the views of the main video for 10% added work (or less?) i'd say that's good value for time spent.
It is said that the universe is 13.8 billion light years across at some point here. But I was under the impression it was something in the order of 90 billion? The observable universe that is. And that's because of inflation stretching spacetime out at speeds faster than light thus allowing the universe to stretch out more than it could if space couldn't move faster than light. Basically it's 90 not 14 right?
I just started studying Geosciences and know i know: Every time when i am feeling stressed or ask myself if all the effort is worth it i just have to watch these videos. It really is awesome to see how excited these scientists are about their work, the universe and science in general. That is the kind of scientist i want to be. tl;dr: these videos motivate me do study even more to become a better scientist.
I have a question about homogeneity: When you get to the scale when you would start to expect it, you would span quite a large part of the AGE of the universe, and since the universe is evolving, it may appear less homogeneous than it actually is.
From what I understand, even the observable universe is over 90 billion lightyears across due to the expansion of spacetime occuring faster than light travel. So just because the universe is 14 billion years old, doesn't mean the universe is 14 billion light years across...that seems a very silly mistake in this video...
Exactly. On top of that, the universe is about 90 billion lightyears across from every standpoint (assuming that the universe is homogeneous on large scales, which I still believe).
EebstertheGreat Redshift of z~1.3 (the mean redshift, the real values are 1.2 < z < 1.8) means we are looking at the universe when it was around 4 billion years old, around 9 billion years to the past. I can't be arsed to check if the 1/3 of the size of the universe holds for that redshift.
I just tried a numerical calculation and z=1.3 corresponds to a time when the universe was about 26 billion light years in diameter, so he probably just meant 13 Gly in radius.
It's a good point you make. I went to look up the estimated size of the nucleus - theory suggests a diameter of only a few light days. So at 30 light years, a quasar would have an angular size around 0.1 degrees.
The brightest quasar can be about 4 trillion times as bright as our Sun. If a quasar was about 30 light years from Earth, it would look as bright as the Sun... imagine the havoc that would play with the seasons!
Also, when people talk about the universe expanding, they mean a dilation round a point in (n+1) dimensions, like blowing up a balloon, so that everywhere on the surface gets farther from everywhere else. Because of homogeneity and isotropy, again, it can't be a simple stretch along a particular line or from a particular pole in the universe
Except that from us to the edge of the observable universe there's a distance of about 46 billion light years. (about 93 billion light years from one side to the other).
02:30: "... bearing in mind that the entire universe is only about 13 billion light-years across..." Isn't that just the radius? Shouldn't that be doubled to get the diameter? Or does not doubling it have something to do with how every point on the universe appears to be the center, as inferred by the CMB radiation? So, what is it really?
a troll is a person who says things to incite anger. it doesnt matter if they admit it later. technically i was being a poe. but u seem to be suggesting trolls are not childish
Brady, how about letting them write the equations. Then edit up your normal video as you would normally, just cutting out the equations. Then... for those who are interested, just put up the raw footage. I love your normal videos, don't get me wrong, but I feel like they're trying to talk with one hand tied behind their metaphorical back.
It's disappointing to hear a professional physicist who can not use the word *exponentially* correctly. The is no such thing as "exponentially quickly". What he is referring to is a period when expansion was exponential. He could also say that the rate of expansion was increasing exponentially. There is no place the for the "quickly". This word has become ever more misused as though it is some kind of superlative, like it means really, really quickly.
"Entire Universe is only about 13bn light years across". Interesting quote at 2:30 I read that physicists thought the universe may be bigger or infinite, that the expansion doesn't match the speed of light and is much quicker because over millions of years we will slowly see less and less of the universe because it's expanding beyond the universe in LY to age.
Just before inflation, let's say the universe was a centimeter sphere, wouldn't the Centre of the sphere have a very small difference of density and be ever so slightly more dense and when inflation happens and the expansion of the universe to a grapefruit takes place maybe the fluctuations or ripples it the Higgs part causes the slightly higher distribution of density that we see in the clusters of large matter in the paper?
Brady you do more for science than anyone around nowadays. I wish I had these videos when I was at school (back in the 90s). However I think there needs to be some regulation of truth on the internet. There are so many snake-oil peddlers giving misinformation and pseudoscience, and people lap that stuff up. Any ideas?
Now, yes. But keep in mind that they're looking "back in time" - and the universe was probably a lot smaller back then. (I might be really far off here, but that's how I understood it. I have no actual knowledge to back me up here.)
Whats the big deal if gravity is not distributed evenly throughout the universe? It wouldn't seem to change its function. Maybe there is no "dark matter" but just areas where gravity is denser?
The Universe is 90+ billion light years across, not 13+ billion light years across. Sorry, Professor M. So, a very large structure at 4 billion light years across is not 30% of the Universe, but 4% of the Universe.
Keith Robben That would make total sense; because even at the speed of light, we can only observe part of the immense, both figurativly and literally, universe*; it may well have been that, as you rightly say, when all the quasars where at their brightest, we are only seeing them now at the time of their greatest luminosity, and thus when the observable universe was only 13 Ly in diameter; apparently another paper came out after this was filmed describing a even bigger structure (will find a link for that if/when I find it) ... We now know that the observable universe is ~ 93 - 95 billion Ly across ... but that took a great deal of science from various land- and space- based observatories/telescopes etc ... The other explanation for the, possible, gaff, is, as some brilliant minds are wont to do, his mind was working faster than he was articulating, and thus miss-spoke ... personally, I give him the benefit of the doubt ... *= heck, even after 20-something years of being an amateur astronomer, I still can't grasp the enormity of just 1Ly ... let alone 1 billion Ly ...
If your mate Dave arranged those quasars or not talks about nature of Dave... Not of his existence. It is indeed very convenient that we would accept proof of intelligence and will of Dave as proof of his existence, jet it being convenient does not make it less true. And difficult fact is that it does not work other way around. As long as there is intelligent life whatsoever anywhere, you can claim that there must be Dave somewhere and in search when you fail, change scope, and look elsewhere.
I think that it would be really good for Brady to do a video on the statistical evidence that the writers of the paper had that implies the improbability of randomness in this structure. Not that I necessarily doubt them (I'm not honestly sure what to believe, and I'm certainly not qualified to make a definitive statement on it), but I'm personally very curious as to what it is about the structure that makes them think it's unlikely that it's the spawn of random happenstance.
Stars and galaxies certainly wouldn't form. I'm no cosmologist but I'd imagine that hydrogen and some helium would still form after the big bang but, if gravity were repulsive, every atom or molecule would be pushed away from each other and you'd have a very thin (basically vacuum) covering of hydrogen across the universe. Maybe clouds of hydrogen would still form (my chemistry is pretty rusty!) but they wouldn't collapse to form stars and would be repelled from each other.
What if gravity worked in reverse, instead of gravity causing masses to attract each other it caused them to repel each other. The more massive an object is the stronger its repulsion and the force of the repulsion is inversely proportional to the distance between the masses. How would this effect other aspects of physics, would celestial bodies still be able to form, could anything form into a structure, if you magically dropped a human into that universe what would happen, etc?
I have to pull Mike up on a point at about 2:30. While the universe is a bit older than 13 billion years that does not mean its 13 billion light years across. Simple reason gives you 13 point whatever billion light years in opposite directions so that is 27 billion light years across but even that does not account for co-moving distances. When they are taken into account its something over 90 billion light years across... and even that is just the observable universe, not the whole shebang.
you are making a positive claim about the burden of proof. can you prove your claim? its self evident that Dave did it. if not him, then who? it is more absurd to believe Dave didnt do it, than, he did. can you provide evidence that your not being convinced that Dave did it is correct and true? you need to have faith that Dave did it before your mind can understand the evidence. are you just denying that Dave did it so you can be immoral (Dave says its wrong to have your Bed facing east)
John 1:-3 (KJV) 1 In the beginning was the Word, and the Word was with God, and the Word was God. 2 The same was in the beginning with God. 3 All things were made by him; and without him was not any thing made that was made. But, I'm glad you admit that the jesus character "also was God". Since you say Xtianity theology is not jewish theology, which god was this jesus supposedly? Zeus perhaps?
The thing which you didn't mention here, Brady, and which is crucial to understanding the homogeneity principle, is that the universe is either flat and infinite, or curved in some way, such as into a torus or sphere. It is NOT a sheet of paper, with edges, for example; if it were homogeneity obviously wouldn't be true because I could measure my distance from the edge
I second this notion. I know it might be a bit more work for Brady and the Doctors/Professors, but if they would do just a short bit and give us the name of the equation/s and a direction what to study I would be ecstatic. This and other reasons is why I don't watch the science channel anymore... well, that is if I still had cable.
Does the Theory of Homogeneity take into account the distance that we are peering into the universe? As several comments have noted, wouldn't you expect to find large objects such as this the further out that you look? In other words, isn't everything still homogeneous at a given distance from earth, or does this structure violate that theory as well?
I think what he's asking is if the structure is actually a structure, or just us linking things together that aren't actually related in any way. In other words, is there a real reason for the "structure" to look the way it is, or is it purely a random scattering of particles that formed into these quasars in a way that we perceive as a pattern.
Oh, oh, the "pick the quotation out of context" game! I have my favourite gem myself: 1 Cor 13:11 "When I was a child, I spake as a child, I understood as a child, I thought as a child: but when I became a man, I put away childish things." So sorry but I won't be talking about bronze age mythology, especially one that is considered "the only truth there is"
How do we know it's no homogenous? The ones that are nearby are all disappearing (currently gone), but the ones that are far away are still there visibly (could be gone for all we know, right?). Maybe it just looks like it's heterogenous, but it is homogenous. It's hard to tell for sure since the light needs time to travel to update us on the goings on. Hm... :/
since the box filled with particles is expanding at an extrem rate, the way you understand "homogeneity" must scale with the expansion at the time it happens. the randomly created seeds or ripples for all structures carry throw this expansion. Does the mentioned paper try to date the forming of structures by reverting the timeline of there forming?
I have thought about this before: When you look around you might see detailed, 3d trees and buildings. Look at the horizon, you might see trees, but they are more flat/less detailed. When you look at a mountain from Earth, it is tall and jagged. When you look at it, far in space, Earth, and the mountains are flat (well, circular on the Earth) - and Earth is smooth.
Question about relativity : When we say that we're looking back through time when looking afar, is it... literal? At this point in time, do those quasars exist, or do they probably have died out and I'm just percieving them because the information simply hasn't got the time to reach me yet? Is the universe perpetually being born further and further away?
reverse gravity would prevent anything to get too close to another forming quite a boring universe the human would repell all the matter around him im not sure if the human would stay in one piece but gravity is really not a strong force so he would probably be okay and most probably dead
I see, so you're saying that by examining the only two posts I made on this thread that you can conclude that I know nothing of Xtian theoglogy, even though the questions I asked are scriptual (Exo 11-12; ISA 45:7). And then claim I"m the one "feeling superior"? LMAO!
The current estimated diameter of the Observable Universe is about 93 billion light-years. However, the estimated age of the Universe is about 13.7 billion years. I think what we have here is just them trying to put the size of this cluster into a scale we can (sort of) understand.
Would this discovery give any insight to the mystery of the predicted mass of the universe? I'm aware they speak of dark matter and energy being the most prominent source of mass. But a structure 1/3 the size of the universe in a single area must throw that off a bit right?
Not necessarily. Remember that quasars are the centers of whole galaxies. They appear point-like to us because they are so far away. If one was 30 light-years away, the brightness would be distributed over a huge area. That's not to say that it wouldn't still be a spectacular sight!
I think few cosmology professors could explain this as well as is done above. Videos like this should be required watching for astronomy students. Thank you.
1) 1stly we know arrangement requires an intelligent agency. - Unproven. 2) 2ndly if Dave did'nt who did? - Illogical. 3) if you dont accept my proof then it is up to you to prove Dave didnt create this structure! - Unproven that is is up to me
How far away is this object? if we are looking "back in time" as we look farther out would you not expect to find larger objects? I find it hard to think the universe had even distribution of matter from the vary start. just a random thought
yeah i just commented that assuming the universe was at one point homogeneous like proposed in the big bang theory, then the larger the structures found in space, the longer the timescales involved... its got to be way over the 13.7 billion years.
As someone pointed out on the other shorter video, the reference of the universe as being 13 billion light years across is off, as it's more like 93 billion light years, and that's only what the observable part of the universe is estimated to be
my mate Dave arranged the Quazars into this structure. i can prove it. 1stly we know arrangement requires an intelligent agency. 2ndly if Dave did'nt who did? if you dont accept my proof then it is up to you to prove Dave didnt create this structure!
2.27 I was under the impression that the radius of the observable universe is around 46 billion light years, and that means its like 92 billion light years across. Check the wikipedia article on the observable universe, under the section "misconceptions".
It can be if space expands faster than the speed of light. At points where the universe expands faster than light information cannot interact with that which it speeds away from, so it is essentially non-existant from our point of view
I agree, that's a great quote. But the word 'mythology' has a specific meaning to historian, that is, story about a particular deity. The Hebrew scriptures don't contain mythology. Lots of myths, but no mythology.
I would love if there was a channel which contained all the raw(ish) interview footage from all of your videos (across all of your channels). There is some awesome information that does not make it through editing.
We should see if Dave weighs the same as a duck. If so, he must be a witch and it is likely that he may have arranged this cosmological body. If not... he may go free and we won't have to burn him
How close do these quasars need to be to each other to be considered a "structure"? Would the structure look completely different to someone viewing it from 90 degrees away from us in the universe?
If the scale of homogeneity is larger than was expected does that not just imply the universe is much larger than the observable universe or has that already been factored in to the calculation?
This is why we love your channels: Brady: "A big blown up projection of just a funny little wobble in a field." Expert: "Wow! Exactly! You know how to say things scientifically technically correct haha."
Thanks for these vids and the time professor's allot for our viewing pleasure. if I had money...I would send it your way. The internet could use Moreno this kind of material.
So basically what you are saying is that i can proof something like this: To my knowledge stones cannot fly, and to my knowledge Dave cannot fly, therefore Dave is at stone. How do we know an arrangement requires an intelligent agency? The wind can arrange things, does that make it sentient? To prove my claim, i cannot, it is an arrangement that humankind have because it works!
Dave said he loves you and is really upset that you keep rejecting him. you must really hate Dave. you need to open your heart to Daves love in order to see the evidence clearly
How did you get that out of my comment I will never know. I do believe in God. Perhaps not classical view of omnipotent bearded man, but in God nonetheless and in love above all.
the universe is not 13 billion light years across and that is the end of discussion, and cosmologists should review their math again with some more challenging assumptions. I think
I'm subscribed to both channels. It doesn't fill up my subscription feed at all. Then again, I'm subscribed to all of Brady's major channels, so I'm interested in extra footage in general.
Correct me if I'm wrong. But isn't the observable universe 28 billion light years across rather than 14 billion? Because it's 14 billion light years in all directions.
followed a bit of the thread and determined that you like to feel superior based on your lack of knowledge of basic Christian theology? i guess there are trolls of all types.
Several years ago I read, about colliding branes being the cause of the "big bang", with this information I am thinking about the posibilities that the branes did not cease to exist with it.
Dave is more powerful, it says so in some book somewhere and the book says everything in the book is true (including that statement) therefor it must be true
