The TWP Astronomy Thread

[Bhang Bhang Duc]

I've been carrying the signature containing the advice that I'm TWP's official astronomer for quite some time now.  Thought I should do something about it.

 

Anyway I've created this thread for discussions of astronomical topics, astronautics as well.  I'll attempt to answer any questions put to me, keep order and generally jump on anyone who mentions UFOs (more on that later).

 

I'm not a professional astronomer, just an amateur who has been studying this subject and doing it for close to 50 years.  My main interest is the Sun, the aurora and variable stars, though I'm relatively knowledgeable about most aspects of the subject.

 

Couple of guidelines.  Confusing astronomy with astrology will earn you a large raspberry.  Posting stuff about UFOs, crop circles, faces on Mars, the imminent arrival of Planet X and other crackpot things will earn you heaps of derisive laughter, though I will be happy to explain to you why these things are crackpot.

 

Let's see how this goes.  Have fun.

 

BBD

[Yy4u]

I wish to know what the latest news is on new planetary system discoveries and if dark matter has been proven and does it indeed account for the missing mass?

[Intelligent Holograms]

I can jump in on those, I believe. Planetary systems are being discovered at an ever increasing rate due to the activities of the Kepler Satellite and the legion of volunteers that donate time to seeking patterns (namely dips in luminosity in the spectra from distant stars. The list of discovered planets and the planets that they orbit is listed here: http://kepler.nasa.gov/Mission/discoveries/

 

The pursuit of Dark Matter has yet to progress past the theoretical stage - by virtue of the fact that it is theorised to not interact with light, there is little that we can do to actively research it experimentally. When it turns back on later this year, CMS in CERN has a primary goal of looking for the particles that may constitute what we call Dark Matter. So far, though, all experiments that have set out to look for evidence of Dark Matter have failed - Physicists continue to look for Dark Matter, though, as it is the most probable answer to some of the most challenging unanswered questions in physics, like why the Universe is expanding rather than contracting and why galaxies spin at faster rates than what they should given the amount of mass we see them having. Theoretically, yes, Dark Matter does account for the missing mass in the Universe, it's just proving to be extraordinarily difficult to pin down. More information here: http://www.wired.com/wiredscience/2013/10/lux-dark-matter/

[Consular]

I can jump in on those, I believe. Planetary systems are being discovered at an ever increasing rate due to the activities of the Kepler Satellite and the legion of volunteers that donate time to seeking patterns (namely dips in luminosity in the spectra from distant stars. The list of discovered planets and the planets that they orbit is listed here: http://kepler.nasa.gov/Mission/discoveries/

 

 

Basically, planets do not emit light, thus unlike a star there is no way to directly "see" them in the darkness of space. One way to see them is if they reflect starlight, which is how we can see the inner planets of our solar system in the night sky, because the sun illuminates them. 

 

What IH refers to here is an alternate method used for finding extrasolar planets, that is, planets not in orbit around "Sol", our local star, aka the sun. (On a tangent, that's why our system is called the solar system - it's the system ob planets around the star Sol.) What we do is keep watch using advanced telescopes and such over far away stars and look out for a dip in luminosity, or brightness, that would occur if something passed in front of the star. If this dip occurs in a regular pattern over an extended period of time we can assume that it is a planet passing in front of the star while on orbit around it.

[Westwind]

 if dark matter has been proven

 

 

Yes, this is a point that bothers me.  The most recent programs and articles I have read all presume Dark Matter to be a fact, when it's barely theoretical AFAIK.  A whole lot of "this is like that because of Dark Matter!", when you can't prove it exists, and so many theories are being hung upon the hook of dark matter.  I was watching a show with my daughter last week that told how Dark Matter explains the fate of the universe (as if it was fact) and I had to explain and teach her otherwise.  These were popular astrophysicists making this out to be fact, and they should know better.

 

We even have Steven Hawking changing his mind about the nature of Black Holes now to bridge the gap between physics and quantum mechanics.

 

All that being said, what if Dark Matter is merely a form of Anti-Matter that collessed into it's own anti-material form within the Universe rather than completing the process of annihilation between matter and anti-matter in the early Universe ?

 

BUT....this is suppose to be Astronomy more than astrophysics and quantum mechanics

 

The last solar cycle and this one were generally expected to have the strongest maximum we've seen, yet the last cycle lingered at minimum beyond expectation and the current cycle has had a pathetic maximum.  As the Sun is close to completing it's pole reversal and head toward minimum, do you expect this comming minimum will be extended like the prior cycle, or that we'll see a more normal pattern resume ?  Or is there enough data to make any kind of educated guess on that, given the recent failures of expectations ?

[Tweedy]

...... if dark matter has been proven....?

I have some dark matter at the end of my life line on my left palm; is this serious?

[Intelligent Holograms]

what if Dark Matter is merely a form of Anti-Matter that collessed into it's own anti-material form

Under the current train of thought, there wouldn't be enough antimatter to account for all of the Dark Matter in the universe. During the Big Bang, equal amounts of matter and antimatter came into existence, now the Universe is around 4% normal matter and over 20% Dark Matter - such an imbalance could not occur from the same amounts of both.

 

We even have Steven Hawking changing his mind about the nature of Black Holes now to bridge the gap between physics and quantum mechanics.

This was the most intriguing for me, essentially, Hawking has changed the definition of what a black hole is to battle the arguments around what happens around the Event Horizon, now he says that there is no such thing as the Event Horizon and things may escape from the area of space beyond what we would have called the Event Horizon so long as they wait long enough. This, to me, is not a Black Hole. Also, the bridge between classical

physics and quantum mechanics has been present in Black Hole Theory for a while now, Stephen Hawking postulated using quantum mechanics that black holes evaporate over time and that they give off Hawking Radiation in the process.

 

Sorry for derailing your thread, BBD. 

[Aestate]

So here we go: I read that CERN's Particle accelerators could create a black hole. Is this true? If yes, what are the odds?

[Intelligent Holograms]

So here we go: I read that CERN's Particle accelerators could create a black hole. Is this true? If yes, what are the odds?

It is not true. Astronomical black holes require the collapse of a mass much greater than the size of our own sun into a relatively small space under the force of gravity - there is nothing at the LHC that has anything close to the amount of mass required for this. Microscopic black holes will also not occur due to the fact than any particle capable of forming one decays at a rate that would render the formation of black hole impossible.

[Bhang Bhang Duc]

Wow good start folks, I'll do my best to keep up and thanks to those who are jumping in and providing answers.

 

Going backwards.

 

So here we go: I read that CERN's Particle accelerators could create a black hole. Is this true? If yes, what are the odds?

 

IH is completely correct - you need the collapse of a massive star in a supernova explosion to produce a stellar black hole (as opposed to the super-massive ones found at the centre of galaxies, including our own).  Quantum black holes i.e. very small ones were hypothesised as having formed during the Big Bang - however they would have evaporated (yes, evaporated) very quickly a long long time ago.  Quantum black holes have been used by a number of SF writers over the years, most notable Larry Niven in "The Borderland of Sol".

 

 

Yes, this is a point that bothers me.  The most recent programs and articles I have read all presume Dark Matter to be a fact, when it's barely theoretical AFAIK.  A whole lot of "this is like that because of Dark Matter!", when you can't prove it exists, and so many theories are being hung upon the hook of dark matter.  I was watching a show with my daughter last week that told how Dark Matter explains the fate of the universe (as if it was fact) and I had to explain and teach her otherwise.  These were popular astrophysicists making this out to be fact, and they should know better.

 

We even have Steven Hawking changing his mind about the nature of Black Holes now to bridge the gap between physics and quantum mechanics.

 

All that being said, what if Dark Matter is merely a form of Anti-Matter that collessed into it's own anti-material form within the Universe rather than completing the process of annihilation between matter and anti-matter in the early Universe ?

 

BUT....this is suppose to be Astronomy more than astrophysics and quantum mechanics

 

 

OK dark matter does exist we just don't know what it is.  We can see it's effects - the matter we can see in galaxies is not massive enough to account for the gravitational effects observed.  Rotational speed of galaxies also is too high for the observed mass (a lady astronomer named Vera Rubin did most  of the work on that).

 

So it exists, but what the heck it is nobody knows.  And then there is dark energy which will determine the fate of the Universe - but I'm not going there.

 

 

The last solar cycle and this one were generally expected to have the strongest maximum we've seen, yet the last cycle lingered at minimum beyond expectation and the current cycle has had a pathetic maximum.  As the Sun is close to completing it's pole reversal and head toward minimum, do you expect this comming minimum will be extended like the prior cycle, or that we'll see a more normal pattern resume ?  Or is there enough data to make any kind of educated guess on that, given the recent failures of expectations ?

 

Predicting the strenght of solar cycles is akin to witchcraft at the moment - a lot of solar astronomers have theories and methods but none of them work particularly well.

 

The problem is we have visual data for 400 years, but no real measurement of what's happening in the Sun and how it produces the sunspot cycle.  Well we have about 50 - 60 years of magnetic data, and 20 years of helioseismology data, but not enough theory to link this data and to be able to provide a decent prediction.

 

A further problem exists in the Sunspot Number itself.  The orthodoxy is that we had a Grand Maximum of solar activity in the middle of the last century and that the cycle that peaked in 1957/1958 was the biggest on record.  Unfortunately it looks like the Zurich observatory between 1946 and 1980 introduced a deliberate observational bias into the sunspot number.  Once you remove this then the evidence for a Grand Maximum disappears.  Not a popular viewpoint with climate change sceptics who believe that solar forcing during the Grand Maximum is a major part of temperature rises.  Remove a Grand Maximum and you remove solar forcing.

 

However, I digress.  It becomes difficult to make predictions if you can't trust the veracity and accuracy of the data you are using.

 

From a personal point of view this current cycle is interesting - it was a long minimum and the maximums (two of them, the Sun's northern hemisphere peaked first in Feb 2012 and we're nearing the peak for the southern hemisphere now) have been unspectacular, though the last couple of months have produced a number of large groups.  However, we're no worse now than we were a century ago - the cycle that peaked in 1908 was of a similar magnitude to this one.

 

As for the next cycle I have no idea and neither do the professionals.

 

I wish to know what the latest news is on new planetary system discoveries and if dark matter has been proven and does it indeed account for the missing mass?

 

The number of exoplanets discovered stands at over 1,000.  Two methods have been used - the occulatation method that IH and Arch described.  The other was gravitational wobble; stars could be seen to be wobbling.  The amount of movement was extremely small and could only be detected in the spectrum of the star, but it was enough to detect very massive planets orbiting very close to the parent star - "hot Jupiters".  So many of these were discovered that some astronomers were starting to worry that our solar system was a freak.  However, it was the method of detection that biased the results.  We're discovering more and more "normal" solar systems.

 

If you think I've made a mistake or I haven't been clear enough please let me know.

[Vulcan Prime]

My question is probably unanswerable but you probably have some insight I haven't thought of. If the universe is infinite, does that not mean that there is a 100% chance that somewhere in the stars is a duplicate Earth? If it is infinite, does that not mean there are infinite duplicate Earths? Space is always one for extremes but this has been hard to wrap my brain around.

[Consular]

 

 

IH is completely correct - you need the collapse of a massive star in a supernova explosion to produce a stellar black hole (as opposed to the super-massive ones found at the centre of galaxies, including our own).  Quantum black holes i.e. very small ones were hypothesised as having formed during the Big Bang - however they would have evaporated (yes, evaporated) very quickly a long long time ago.  Quantum black holes have been used by a number of SF writers over the years, most notable Larry Niven in "The Borderland of Sol".

 

Carrying from this, small stars do not cause black holes when they die, because they do not have sufficient mass to go supernova. They simply fizzle out over time. As IH mentioned, there is nothing at Cern with enough mass to collapse in such a way.

 

All the scares over the LHC are nonsense really.

 

My question is probably unanswerable but you probably have some insight I haven't thought of. If the universe is infinite, does that not mean that there is a 100% chance that somewhere in the stars is a duplicate Earth? If it is infinite, does that not mean there are infinite duplicate Earths? Space is always one for extremes but this has been hard to wrap my brain around.

 

 

Well, there's never really an 100% chance of anything. But statistically speaking, given the amount of stars and planets in the universe, it is statistically probable that there is another planet out there highly similar to Earth. Earth sits in what we call the "goldilocks" zone, which sounds ridiculous, but that's the name for it. It's a narrow band of space the exact right distance from a star where it is neither too hot nor too cold, allowing water to potentially exist in a liquid state on the surface of a planet. Obviously, if the planet is too close to the sun then it is too hot and the water evaporates (which has the potential to form a runaway greenhouse effect like on Venus). If the planet is too far away, it is too cold and water freezes, or alternatively can only exist underground (For example on the moon of Europa, where gravational stresses from Jupiter may have heated the core of the planet enough for underground oceans to exist). So it is fairly likely that somewhere another planet exists at a similar distance (relative to the size and heat of its star) as Earth.

 

Unless you meant more astrophysics related stuff, like how the universe is expanding?

 

 

 

This was the most intriguing for me, essentially, Hawking has changed the definition of what a black hole is to battle the arguments around what happens around the Event Horizon, now he says that there is no such thing as the Event Horizon and things may escape from the area of space beyond what we would have called the Event Horizon so long as they wait long enough.

 

I admit I'm not sure I understand his newer theories around this. Frankly, if not even light can escape a black hole beyond the event horizon, then nothing could, as there is nothing at all that is faster than light.

[Vulcan Prime]

Unless you meant more astrophysics related stuff, like how the universe is expanding?

I believe I did. Also I was under the impression that the universe is infinite. If it is finite then I suppose my question's answer is no.

[Intelligent Holograms]

This problem is fascinating for a number of reasons and I'll admit that I can't answer your question as it deals with some very complicated topics surrounding the nature of infinity and what this means when applied to something like the Universe. In Mathematics, infinity is an elementary component of some calculations - even in normal graph work, we say that parabolic curves tend towards infinity when the function of the graph depicts it as never actually touching a point; take the graph 'y=1/x', in this graph the 'line' will never touch either the x or y-axis, no matter how low or high the value of x you assign, thus the graph tends towards infinity with decreasing and increasing values of x.

 

_{Graph of y=1/x}

 

 

So in Pure Mathematics (Mathematics that don't necessarily apply to the real world), infinity is a concept that is often used. When we move to apply infinity to the real world, though, we run into problems, so much so that Philosophers claim that an actual infinity (one that can be applied to the real world) is impossible. To prove this, we must look to some examples; there are some excellent examples out there on the topic of infinity, like Zeno's paradox and William Lane Craig's (a philosopher/theologian) Infinite Coin Problem. Zeno's Paradox about the arrow moving through the air is described (I'm going to immensely paraphrase this) as that if you divide the arrow into and infinite number of 'instances' where a bouts the arrow is stationary, the arrow does not move at all and is in its totality motionless. Naturally, this is impossible in the real world, when was the last time anybody fired an arrow only for it to not move at all due to the infinite number of 'instances' between the archer and the target? In William Lane Craig's (WLC) Coin Problem, WLC makes the point that if he had an infinite number of coins and he subtracted an infinite number of coins from the original pile, he would have still have an infinity - infact, if he took any fraction of the coins away from the infinite pile, he would not only still have an infinite pile, he would also have an infinite in the pile that he had just taken away. Using these logic problems (entirely in the mind), we can state that an actual infinite is impossible.

 

This conclusion raises interesting questions when applied to the universe as we've apparently rendered infinity impossible, so where does the Universe end? Some would argue that the Universe doesn't end by virtue of it being all that is, to argue that there is an ending to all that is/was/ever will be is ludicrous to these people as there can be nothing where not even 'nothing' exists (poorly worded but I can't think of anything better). Then we encounter the multiverse, being that 'outside' of our universe there is a universe of universes, then if this is also finite, what's beyond it?

 

The more I try and follow this train of thought, the more confusing it becomes to myself and probably to whoever's reading this due to the fact that we cannot answer this question. Then if we look on the other side of the coin, if we call the universe infinite, we live in the knowledge that there is an infinite number of you doing exactly the same as what you are doing now, with everything else exactly the same. Both of these positions are untenable to me, probably because I cannot get my head around either of them.

 

Personally, I find the idea of the Universe being actually infinite (so that there are is an infinite number of IH's) unpalatable.

[Vulcan Prime]

I say to skip my question for now. I don't think it is possible to prove the universe's finity.

[Westwind]

Some of my reading for today:

 

Could sterile neutrinos solve the cosmological mass conundrum?

http://physicsworld.com/cws/article/news/2014/feb/18/could-sterile-neutrinos-solve-the-cosmological-mass-conundrum

 

What Is Dark Energy?

http://www.slate.com/articles/health_and_science/mysteries_of_the_universe/2014/02/what_is_dark_energy_vacuum_energy_braneworlds_string_theory_gravity_quantum.html

 

Researchers discover association of gas-rich galaxies near the infancy of cosmic time

http://phys.org/news/2014-02-association-gas-rich-galaxies-infancy-cosmic.html

 

Einstein's conversion from a static to an expanding universe

http://phys.org/news/2014-02-einstein-conversion-static-universe.html

[Bhang Bhang Duc]

I say to skip my question for now. I don't think it is possible to prove the universe's finity.

 

Quick answer - yes the Universe is finite.  It was formed approximately 13.8 billion years ago and has been expanding ever since.  So we can see about 13.8 billion light years away (and back in time), but the diameter of the Universe is estimated at about 90 billion light years - and growing.  And this number depends on the topology of the Universe as well - flat, positively curved or negatively curved.  We're getting into heavy cosmology here though.

 

I admit I'm not sure I understand his newer theories around this. Frankly, if not even light can escape a black hole beyond the event horizon, then nothing could, as there is nothing at all that is faster than light.

 

Basically paired virtual particles can form at the event horizon.  One of the pair will escape the other will not, but overall the black hole loses some mass.  This is the evaporation I mentioned earlier with quantum black holes.

[Aestate]

It is not true. Astronomical black holes require the collapse of a mass much greater than the size of our own sun into a relatively small space under the force of gravity - there is nothing at the LHC that has anything close to the amount of mass required for this. Microscopic black holes will also not occur due to the fact than any particle capable of forming one decays at a rate that would render the formation of black hole impossible.

 

IH is completely correct - you need the collapse of a massive star in a supernova explosion to produce a stellar black hole (as opposed to the super-massive ones found at the centre of galaxies, including our own).  Quantum black holes i.e. very small ones were hypothesised as having formed during the Big Bang - however they would have evaporated (yes, evaporated) very quickly a long long time ago.  Quantum black holes have been used by a number of SF writers over the years, most notable Larry Niven in "The Borderland of Sol".

 

Carrying from this, small stars do not cause black holes when they die, because they do not have sufficient mass to go supernova. They simply fizzle out over time. As IH mentioned, there is nothing at Cern with enough mass to collapse in such a way.

 

All the scares over the LHC are nonsense really.

 

 

Good! It’s quite logical. Another thing I've always wondered, also about black holes, is how to identify them 

 

And another question is about a theory that I read: That the sun would be a binary star, and the other would be a black star. Have you seen anything about that? It is a accepted theory?

[Charax]

Whatever happened to that New Earth place they found a few years back? It was supposed to be bigger than earth, with potentially breathable air, and water. It was a big deal, and then all of a sudden people just stopped caring.

[Bhang Bhang Duc]

Good! It’s quite logical. Another thing I've always wondered, also about black holes, is how to identify them 

 

And another question is about a theory that I read: That the sun would be a binary star, and the other would be a black star. Have you seen anything about that? It is a accepted theory?

 

A lot of stars are multiple systems, double, triple even quadruple (epsilon Lyrae is a lovely quad system, near to the bright star Vega in the summer sky, and the nearest star to us, alpha Centauri, is a triple).

 

No evidence at all that the Sun has any sort of companion.  It's gravitational effects would show up in the movement of the planets, comets etc.  No sign of that.

 

 

Whatever happened to that New Earth place they found a few years back? It was supposed to be bigger than earth, with potentially breathable air, and water. It was a big deal, and then all of a sudden people just stopped caring.

 

Not sure.  Currently there are about 20 exoplanets with masses from 1.1 to about 9 Earth masses.  Nothing at Earth's mass.  Of these 20 or so, 6 orbit in the Goldilocks zone.

 

Goldilocks zone - a zone around a star where water can exist as a liquid and the surface temperature is not too hot and not too cold.  Varies with the temperature of the star.  For a hot blue-white star Goldilocks will be further out, for a cool red dwarf it will be closer in.  The problem with this zone around red dwarfs is that you can get tidal locking, i.e. like the Moon with the Earth, one face always facing the star.

[Westwind]

Side note of the day:  My daughter's science class had the option of watching a presentation on Black Holes or Dark Matter yesterday.  My daughter was disappointed, she was the only one that wanted to see the one on Dark Matter.

[Vulcan Prime]

Clever girl.

[Westwind]

We had been watching the series 'How the Universe Works' on Netflix, which had already covered Black Holes for her   I'm looking forward to the new Cosmos series.

 

Spaceweather.com is saying that 'stormy space weather' could continue through the weekend.  High latitude folks might want to be on the lookout for Aurora.

[Bhang Bhang Duc]

Spaceweather.com is saying that 'stormy space weather' could continue through the weekend.  High latitude folks might want to be on the lookout for Aurora.

 

True, true.

[Bhang Bhang Duc]

Back to the discussion on the Sun.  The attached image is real data - mine.  30+ years with some gaps caused by moving jobs, country etc.  Activity on the Sun is measured by the Relative Sunspot Number (RSN).  It's calculated as follows:

 

R = k(10g +f)

 

• k = correction factor.  For the standard instrument used in determining R, k=1.  Everyone else has a number that can be less than or greater than 1, depending on a number of factors
• g = number of groups visible.  Susnspots naturally form as groups.  They can be individual spots separated by at least 10 degrees from their neghbour or they can be huge, maybe spanning 15 - 20 degrees of solar longitude
• f = number of individual sunspots observable.  Sunspot are made up of a dark umbra and a lighter penumbra - you count the umbra you can see

So in this graph you can see the raw, monthly RSN value, the corrected monthly RSN value (my k factor 1982 - 1996 was 1.1, now it's about 0.75 - bigger telescope, different observational method) and the smoothed RSN.

 

Looking at the smoothed value you can see the current cycle is very much lower than the last two.  And we're moving towards our second peak.

 

Edit - spelling