Astrophysics and Cosmology - Discuss the Universe here

[Tarbaby]

I can't put my finger on it but there's something about Tyson that creeps me out. Not sure if it's his voice or demeanor. Or both. But I have to endure it just so I can get the great information.

[area51drone]

It's because the asshat moved pluto to midget status.

[zeebo]

It's because the asshat moved pluto to midget status.

Hahaha please someone put this in the top right corner, thanks '51 for making me crack up again.

[area51drone]

I just watched the latest Cosmos.  Jesus H Christ.. enough about lead already.  Way too much of the show was dedicated to lead poisoning.

[Tarbaby]

I just watched the latest Cosmos.  Jesus H Christ.. enough about lead already.  Way too much of the show was dedicated to lead poisoning.

Agreed. Yet once I begin following it I did get interested. And it's amazing how big a deal it is and most people don't realize how serious the issue is and has been. Scientists four years told everyone how deadly lead is in the environment and people not only turned a blind eye but the greedy moronns ran ads trying to convince citizens that lead was actually good for you. So, I think the damage that led has done is far more far-reaching than anyone realizes, and even to this day in the genetic code. Brain damage, learning disabilities, psychopath ologies, autism, etc.

[area51drone]

I think they were looking to answer the old nuclear war bit that Sagan did on the original Cosmos.  But shit, spend 10 minutes on it, not an entire episode.

[Tarbaby]

Yep. And if they keep making such departures they might lose me as a viewer. I'm already mildly irritated with Tyson as I said earlier. But that's just me. I understand that everyone else seems to just worship him, which is fine.

[zeebo]

Yep. And if they keep making such departures they might lose me as a viewer. I'm already mildly irritated with Tyson as I said earlier. But that's just me. I understand that everyone else seems to just worship him, which is fine.

They've already lost me, which is sad as I watch all kinds of science/astronomy shows.  I'm sure there's good stuff in there but I'll wait till I can get it commercial-free and where I can fast-forward past the lame parts. 

As for Tyson I liked him when he did the Nova Science Now show.  He seems better in that shorter magazine-style format rather than an epic series (for which Sagan was great).  Btw, that guy that replaced Tyson on NSN is absolutely dreadful, with all his little wacky wisecracks etc.  I can't watch it anymore.

[onan]

They've already lost me, which is sad as I watch all kinds of science/astronomy shows.  I'm sure there's good stuff in there but I'll wait till I can get it commercial-free and where I can fast-forward past the lame parts. 

As for Tyson I liked him when he did the Nova Science Now show.  He seems better in that shorter magazine-style format rather than an epic series (for which Sagan was great).  Btw, that guy that replaced Tyson on NSN is absolutely dreadful, with all his little wacky wisecracks etc.  I can't watch it anymore.

I download Cosmos the next day. No commercials. I can't quite put my finger on what bothers me about Tyson... but it isn't so bothersome that I don't watch Cosmos. I thought the lead poison story was interesting. I think there was some presentation to suggest that isn't the only time big money has attempted to quiet research that didn't help the bottom line.

[area51drone]

I hear what you're saying Onan, but it's common knowledge, not really about science.  It just so happens that a scientific guy looking at meteors figured it out.   They also didn't really explain what the deal was when both he and the other guy were interpreting the same data in the same way, yet with two different conclusions.  I thought that was kind of leaving it open that perhaps lead isn't as dangerous as they say it is.   They say "since then, it has been proven that even trace amounts aren't good for you" or something to that effect.  Hmm, really?  No actual study references, just a comment about it.   I bet we have all handled plenty of lead in our lives, and we're still here.   Why not go after cell phone signals giving people brain cancer?  Because even if it did, at this point no one would give up their phones.     Don't even get me started about the cartoon dude walking around seeing everyone with lesions all over.  Ugh..  It was just kind of a political mish-mash of shit for a show, IMO.  I liked all the other ones a lot better.

[West of the Rockies]

I download Cosmos the next day. No commercials. I can't quite put my finger on what bothers me about Tyson... but it isn't so bothersome that I don't watch Cosmos. I thought the lead poison story was interesting. I think there was some presentation to suggest that isn't the only time big money has attempted to quiet research that didn't help the bottom line.

I always got a sense of humility with Carl Sagan that I do not really get with DeGrasse-Tyson; that's a very subjective observation, but there it is.  I DO greatly respect Tyson though.

[Agent : Orange]

Hey guys, just wanted to poke my head back in and say hi to everyone. Work has been drowning me lately and I haven't had time for much else. Anyway I saw this during a break in an all-nighter and knew I had to post it here.

http://phys.org/news/2014-04-cosmic-illusion-revealed-gravitational-lens.html

Brief summary: Observers found a type-Ia supernovae which was brighter than expected and guessed gravitational lensing effects were magnifying the flux, but could not see a lens galaxy. When they went back after the supernovae had quieted down sure enough they were able to find a faint galaxy that all previous surveys missed. This is a delicious example of a prediction coming true and rings all the bells folks here would probably like to hear about.
Also when I get a bit of time will try to address some of your questions too Tarbaby.

[Tarbaby]

Agent orange, thanks! Looking forward to it!

[zeebo]

...Observers found a type-Ia supernovae which was brighter than expected and guessed gravitational lensing effects were magnifying the flux, but could not see a lens galaxy. When they went back after the supernovae had quieted down sure enough they were able to find a faint galaxy that all previous surveys missed. ..

Pretty cool find.  I was amazed it got magnified 30x!  Also interesting that supernovae have relatively standard luminosity patterns which can be used as standard candles to study the expanding universe, and these gravitationally-lensed rascals can really stretch the limits.

[Agent : Orange]

Hey guys

Trying to keep my head above water here and not doing so well fighting off a mountain of work in front of me. I have three projects on the go right now and all are within striking distance, so I have to keep the pressure on for the next while. I really miss posting here and have completely fallen out of touch with what's been going on with all of my online haunts. Days are blurring into nights. I made a point of keeping my Monday night free and hoped to listen to a gabCast, but since they're not live tonight I'm going back to some of the older shows I've missed.

Anyway, I recall something about this:

There is another model that could explain the spiral effect. The same principles that cause water to spiral as it goes down the drain.

This is more along the way of thinking about it but you can imagine two magnets moving about or two planets pulling on one another - as long as you remember to include the effect of motion. Whenever objects are moving with respect to one another, there is angular momentum at play. Just like linear momentum, this is a conserved quantity. So with gravity/electromagnetism/whatever other attractive force you might be interested in thrown in the mix, mergers and interactions of moving bodies will always always involve rotation. There's nothing really mysterious about this if you think about it, so it's not really a surprise that pretty much all of the cosmological scale structures in the universe are rotating in some way. All of the processes in forming these these things rely on forces acting between objects in motion, and hence rotation is important. This is exactly analagous to water going down a drain or the motion of a cyclone for example.

Next: how do we resolve the following two sentences, one, "matter and energy can be neither created nor destroyed", two, "matter and energy were  formed at the time of the Big Bang".

A very interesting and profound question.
In quantum mechanics, there is an uncertainty relation which says that in order for us to know a particle's location in space exactly, we have to measure it's position, which typically involves bouncing a photon off of it and seeing where we can detect the scattered photon. But this means we've basically just given the particle a little kick, so now we can't be sure of it's position anymore. The more accurately I want to know the position of an object, the more energy I have to throw at it and the more violently it will react. There is a lot of detailed factors that can be included, but this is the jist of it. The uncertainty relationship is a fact that has been verified in the lab in many different settings and leads into a more detailed description of nature through wave functions and et cetera.

What most people don't know is that there is an analogous relationship between energy and time. In other words, energy can be "borrowed" from a quantum system for a certain amount of time. This can be compared with measuring the position of a particle. The more energy I want to use, the shorter the time I will have it before I have to return it to the vacuum. The smaller the amount of energy I take the longer I can use it for. This is the nature of the quantum vacuum, and how particles can spontaneously come into existence before annihilating themselves. There are a number of observable consequences of these effects as well (like the Cassimir effect for example http://en.wikipedia.org/wiki/Casimir_effect). The upshot of this is that low amounts of energy can be taken from the vacuum for increasingly long times.

Since we now understand that both general relativity and quantum mechanics should have played important roles in the earliest moments of the universe, these kinds of relationships should also hold in the early universe. Since our universe has existed so long (about 14 billion years) it should be that it actually contains a very low amount of energy, and in fact it has been argued that the universe is a zero-energy system, that the energy locked up in all the matter should be balanced by the negative attractive force of gravity. Hawking has argued that in this view the universe can be a stable vacuum fluctuation if it contains zero energy budget in the grand scheme of things. That's not so hard to imagine since on the largest scales the universe appears to be exactly flat when all the matter and dark energy is tallied.

We know now for a fact that the universe inflated at early times because of the BICEP2 observations that were made earlier this year. So that means it started off in a high energy density "false vacuum" state, like a pencil balanced on it's point. Then as the universe started to expand we can think of it as a low energy "true vacuum" state, and the big bang is something like the pencil tipping over. All of these processes involve quantum fields and so they are all wrapped up in what quantum mechanics is and what it really means for nature on it's smallest scales.

[maureen]

so very well explained, Agent!! I deeply appreciate the way you make the universe comprehensible. the Sagan of Bellgab!!

[zeebo]

so very well explained, Agent!! I deeply appreciate the way you make the universe comprehensible. the Sagan of Bellgab!!

That's Agent, doin' that science like a boss!

[attachimg=1]

[Tarbaby]

Agent orange, we really appreciate your visits here! I've been reading your post and thinking about it for the last four hours.

In  my previous post when I said how can these two statements be resolved I was referring to the fact that they were direct  contradictions of each other.

I still don't understand the nature of that gravity that you talk about in that zero energy model, four example. What is the locus of that gravity? I mean, if it's analogist to a solar system or a Galaxy then… where is the gravitational center of the universe? That all that extra energy is fighting against.

[Agent : Orange]

Agent orange, we really appreciate your visits here! I've been reading your post and thinking about it for the last four hours.

I wish I had more time lately to hang out here, I really miss regular bellgab posting

In  my previous post when I said how can these two statements be resolved I was referring to the fact that they were direct  contradictions of each other.

They are direct contradictions of each other  the way you stated them and rigidly that is true from a classical perspective. In my response I tried to make the argument that it isn't necessarily so, that what appears to be a classical contradiction may not be so from the point of view of a more fundamental picture (quantum, mechanics). A lot of the predictions of modern physics seem to contradict what we expect (ie, the double slit experiment and wave-particle duality http://en.wikipedia.org/wiki/Double-slit_experiment) from our common sense. This really just means our common sense is wrong and nature is not like that at all, that if we were able to live on the scale of quantum mechanical phenomena then quantum mechanics would be our "common sense". But because we are on large classical scales the predictions of quantum mechanics don't really apply to us in everyday life - I don't have to think of the wave-nature of a car, for example, because it's so miniscule on our scale - so some of the predictions of our theories of the very small seem alien and strange to us on large scales. Similarly with relativity, it seems odd that time should run slowly for observers moving close to the speed of light, but if we lived our lives at those speeds it would be completely natural to think in terms of those effects. It's because we live in a low gravity world at speeds slow with respect to light that makes relativity seem weird to our every day reasoning.

I still don't understand the nature of that gravity that you talk about in that zero energy model, four example. What is the locus of that gravity? I mean, if it's analogist to a solar system or a Galaxy then… where is the gravitational center of the universe? That all that extra energy is fighting against.

The upshot in the larger cosmological picture is that there is no center to the expansion, space-time itself is expanding, so we see other distant galaxies rushing away from us. But they are locally bound together. So the large scale cosmological motion overcomes the local force of gravity holding things together. Gravity holds together the individual stars which make up a galaxy but the distance between locally bound clumps of matter is always growing because the universe is expanding.

[Tarbaby]

Thanks Agent Orange. Well, I'm afraid I'm giving up for a while. Because even though I'm sure your two answers above  our spot on my understanding is getting murkier and murkier. Four instance on my two statements that are contradictory, which one would you say is true in the mundane sense? There is no one word answer without going into the wave/particle weaves? Both of those statements were presented in public forums as  scientific back. they  can't both be true.  matter and energy were created at least one time or they already existed. Or they are rather like illusions in the matrix. Or  energy nodules in the holograph.

And on that negative gravitational attraction, I thought I was getting it thinking about the energy and dark energy being the force expanding the universe but then you reiterate that there is no center of the universe so then how can there be a gravitational center that is attracting,

With all great respect and admiration I sometimes think you are just a program or algorithm that is putting  out ideas that sound exciting but are  doubletalk.;-) and I'm on all these quantum issues I have gone into the weeds many times and come out merely  mosquito bitten and confused. One minute the universe is a bubble and there is no center because we exist on the surface but the next minute there is a gravity source hoping all the outer reaches of the universe back towards the center. And losing, by the way.

Is the universe inside our bodies and inside this planet expanding at the same rate as the rest of the universe? Or just the vast empty regions of space?

[Tarbaby]

And, AO, don't think I've forgotten my question about the life phenomenon. I had asked what you thought of the relationship between the life phenomenon and dark matter. But I could've just as easily have asked  about the relationship between the life phenomenon and regular matter. How would you define it? Or how would you describe it? Can there be a perspective from the quantum level on the intra- workings of matter/energy?  IE, as it pertains to "life"?

Do you think the life process is merely the illusion of autonomy within otherwise inert matter? I mean, free will could be an illusion in a mechanistic universe but autonomy exists.  Certainly when a life form dies the matter does become inert So life must be a property or subset of matter/ENERGY. And it takes charge seamlessly of all the atoms and molecules of that body pursuing its own goals and values autonomously. I am describing an empirical given, something we see every day. What does the quantum scientist say about it?

Or is the quantum perspective silent. Is it analogous to the difference between high level computer languages like C++ compared to the lowest level of machine language which only knows about sectors, not programs or higher processes. Ergo, quantum understanding deals with metaphorical sectors of energy/matter not higher levels? Like how life is a specific function of energy, a sub-process spanning the highest and lowest levels of the energy field, embedded. The virtual deus ex machina

And when I say "lowest levels "I don't mean most unsophisticated levels I mean most fundamental levels. In other words, are the subatomic smallest units of reality simply conveying information or are they involved in and part of thatinformation? Similar to pixels on a TV screen. Apparently, no, the smallest units of reality Are not  just conveyers of information they are affected  by consciousness. His consciousness a form of energy that can affect the Speed or  location of the quantum electron?

[Agent : Orange]

Thanks Agent Orange. Well, I'm afraid I'm giving up for a while. Because even though I'm sure your two answers above  our spot on my understanding is getting murkier and murkier. Four instance on my two statements that are contradictory, which one would you say is true in the mundane sense? There is no one word answer without going into the wave/particle weaves? Both of those statements were presented in public forums as  scientific back. they  can't both be true.  matter and energy were created at least one time or they already existed. Or they are rather like illusions in the matrix. Or  energy nodules in the holograph.

I'm sorry that I seem to have confused the issue. I'm really trying to do my best with some difficult and profound questions and clearly not doing well! Unfortunately I just don't think I can answer with a single word. In order to get into how the universe can arise we need to be able to talk about how particles and particle pairs can be generated from a background vacuum in quantum mechanics, and how that process relates to the overall energy budget of the universe. Both matter and energy were liberated by the big bang, which depends on the initial state of the universe being a high energy density quantum field and this picture makes predictions which have now been observed by instruments. So it seems like it is a good description of the birthing process of the universe.

The problem is that we don't have a full theory of quantum gravity so we can't go much beyond that. You may object because I've said we require the universe to start expanding by a transition from a high to low density state. Other than this starting point I can't do much better (though colleagues in string theory may object to that).

And on that negative gravitational attraction, I thought I was getting it thinking about the energy and dark energy being the force expanding the universe but then you reiterate that there is no center of the universe so then how can there be a gravitational center that is attracting,

There's no center. Gravity attracts each bit of matter to one another, not to some universal center. This tends to slow the universe's expansion. Over large distances (cosmological scales, much larger than the distances between individual galaxies) the universe is accelerating so very far away things seem to be moving away from us at ever increasing rates. The units for the expansion are km/s/[cosmic distance unit] so the more cosmic distance units between two things the faster they seem to be moving away from us. This relationship is the same if we were to look at distant objects from anywhere in the universe and is not unique to one perspective.

I used the analogy of a balloon's surface before. If you want a good example of how to think of it, draw small black dots on a balloon and measure the distance between each by stretching a string (or measuring tape) between two of the dots over the balloons surface. Then blow it up a bit and measure again. Each of the dots (galaxies) will have seemed to move away from one another by a proportional amount. In fact if you inflate the balloon at a constant speed then you can derive a "Hubble law for the balloon" which is analogous to the actual Hubble law in the real universe (http://en.wikipedia.org/wiki/Hubble%27s_law). In this picture, gravity would have to act over the surface of the balloon between each galaxy that would behave like a net resistive force to your inflating the balloon anymore. 

With all great respect and admiration I sometimes think you are just a program or algorithm that is putting  out ideas that sound exciting but are  doubletalk.;-) and I'm

Rather than human, I do consider myself a cleverly written script.

on all these quantum issues I have gone into the weeds many times and come out merely  mosquito bitten and confused. One minute the universe is a bubble and there is no center because we exist on the surface but the next minute there is a gravity source hoping all the outer reaches of the universe back towards the center. And losing, by the way.

In the balloon analogy only the surface of the balloon is important. Gravity has to act over the surface of the balloon. Forget about the center of the balloon and ignore it all together. This is generally a useful picture and can help visualize the expansion of the universe, just like the way the surface of a trampoline can help to illustrate the role of gravity around a star. Thought I do have to stress that it is not exact and there are limitations to this picture. Hope that helps. 

Is the universe inside our bodies and inside this planet expanding at the same rate as the rest of the universe? Or just the vast empty regions of space?

Sure, but think about what that means. Our bodies are extremely small things in the grand scheme of things. The expansion of the universe on small scales is negligible so much that it can be overcome by gravity (ie our attraction to the planet, the planet's attraction to the Sun, the Sun's attraction to the other stars in the galaxy, etc) and electromagnetic forces like magnetic and electric fields. The speed given from the expansion at small scales is negligible and completely overcome by local effects. We only see the expansion significantly affecting things very far from us. In terms of the expansion constant I mentioned before - speed per cosmic distance unit, we are extremely small fractions of a given cosmic distance unit so the speed we should experience from the expansion is negligible even between us and our nearest neighbor galaxies. It's only on the largest scales we notice the effect.

[Agent : Orange]

And, AO, don't think I've forgotten my question about the life phenomenon. I had asked what you thought of the relationship between the life phenomenon and dark matter. But I could've just as easily have asked  about the relationship between the life phenomenon and regular matter. How would you define it? Or how would you describe it? Can there be a perspective from the quantum level on the intra- workings of matter/energy?  IE, as it pertains to "life"?

I see a world made out of material building blocks (atoms) along with a few other ingredients we don't really understand yet (ie, dark matter and dark energy). There doesn't seem to be anything special about the stuff I'm made out of.

I'm not a religious person but I'm curious about it. I don't think I really believe in a soul and I don't know what to make of consciousness at all. Certainly quantum mechanics won't give me an understanding of that. It was thought once that consciousness was important for quantum measurement to occur, but that is an old picture and out of date since it has been shown that quantum processes can occur without the need of consciousness.

Do you think the life process is merely the illusion of autonomy within otherwise inert matter? I mean, free will could be an illusion in a mechanistic universe but autonomy exists.  Certainly when a life form dies the matter does become inert So life must be a property or subset of matter/ENERGY. And it takes charge seamlessly of all the atoms and molecules of that body pursuing its own goals and values autonomously. I am describing an empirical given, something we see every day. What does the quantum scientist say about it?

I don't see much difference between the matter that makes up a dead corpse and a living body. The carbon, the electrons, the atoms, the material itself is the same from a quantum perspective. Processes in the organs have stopped which is the crucial difference. But that's not a quantum mechanics problem.

Or is the quantum perspective silent. Is it analogous to the difference between high level computer languages like C++ compared to the lowest level of machine language which only knows about sectors, not programs or higher processes. Ergo, quantum understanding deals with metaphorical sectors of energy/matter not higher levels? Like how life is a specific function of energy, a sub-process spanning the highest and lowest levels of the energy field, embedded. The virtual deus ex machina

I'd argue that life does not span the lowest levels of the universe. Cells are so much larger than quantum scales that surely what goes on in them at larger scales than the molecular level must be dictated by classical and not quantum mechanics. Our lives take place on much larger scales than quantum so we have no direct experience of such phenomena. We experience it only indirectly in our everyday lives.

And when I say "lowest levels "I don't mean most unsophisticated levels I mean most fundamental levels. In other words, are the subatomic smallest units of reality simply conveying information or are they involved in and part of thatinformation? Similar to pixels on a TV screen. Apparently, no, the smallest units of reality Are not  just conveyers of information they are affected  by consciousness.
His consciousness a form of energy that can affect the Speed or  location of the quantum electron?

No, that's not true. But an observer can choose to do an experiment in a certain way that affects the speed of an electron. But then you have two bits of material (an observer and an electron) that interact with one another. An observer can't affect electrons with his mind alone, he needs to interact with them through material processes. Those material processes are well defined in quantum mechanics. It can't be used to describe the state of someone's thoughts from first principles.

Again, hope I've explained myself clearly.

[Agent : Orange]

so very well explained, Agent!! I deeply appreciate the way you make the universe comprehensible. the Sagan of Bellgab!!

That's Agent, doin' that science like a boss!

And thanks guys for the encouraging words too!

[Tarbaby]

AO, thanks, you did answer my question about gravity in the universe in a way that had not been answered earlier. (Or else I didn't grok it.) This is a big puzzle piece that helps.

[zeebo]

Some pages ago I mentioned M87, and it's mind-boggling size. 

Oh really?

[attachimg=1]

Check out IC1101 by comparison.

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[area51drone]

Some pages ago I mentioned M87, and it's mind-boggling size. 

Don't worry, it's not really that big, it's being magnified by a bunch dark matter.   : LOL!   

[zeebo]

Don't worry, it's not really that big, it's being magnified by a bunch dark matter.   : LOL!

And don't get me started about dark energy.  Puh-lease....

[attachimg=1]

[zeebo]

Ever want to check out the International Space Station?  You can search on your city or zip here and find out when it'll pass overhead.

http://iss.astroviewer.net/observation.php

If you just want to see where it is right now, perhaps to rule it out as an explanation for the UFO you just saw, try this one.

http://iss.astroviewer.net/index.php

[Agent : Orange]

Mayan apocalypse narrowly averted: A huge coronal mass ejection just missed us in July 2012!
http://phys.org/news/2014-05-carrington-class-cme-narrowly-earth.html
The date is of course a coincidence, but the universe has a dark sense of humor it seems