Not so long ago, not long after the September Equinox and my birthday, I was talking to a co-author on a somewhat related topic, amongst other things, about the poverty of software available that people could use (emphasis on use) to make scientifically valid astronomy measurements in the middle/high-school classroom for free with relatively little headaches. The free part is necessary as science teachers simply don’t have a budget and what budget they do have usually gets spend largely on chemistry consumables. The scientifically valid part is necessary because…. whats the point in making a dodgy measurement? You may as well just outside and make paper planes (which I would totally be up for and would be an institutional part of any science class I run). The usability part is necessary because if I can’t decipher how a software package works with years of experience in astronomy then it is unlikely that any high school student is going to unravel Egyptian hieroglyphics to do so.
And that was my initial opinion of Aperture Photometry Tool (APT). An image of which is above. This is from a more recent updated version and you can see it still is confusing to look at initially but, believe me, it has come a long way! So, as I said, I was talking to a co-author and she said “Why haven’t you included APT in your list?” to which I replied “I can’t see any possible way that this could be used in the classroom!” in a little more detail than that. Little did I know that she worked closely with the author at CalTech. It could have been a foot in mouth issue, but in reality it really turned into an intellectual honesty thing… perhaps if I had used more tact, I would have transmitted less information! So I said I’d outline the problem, which I did in a fairly lengthy 3 page email with all of the problems I saw, both scientific and user-interface related.
I’m at proud to say now that after 200 email interchanges and I think 15 different iterations of APT it is now finally at where I can confidently say that this software is the first totally scientifically valid, cross-platform, free to use piece of astronomy software. The playing field for high school or amateur astronomy has suddenly jumped infinitely from 0 pieces of software to 1 (in my honest, quite realistic, opinion). That is not to say that I don’t still have major issues with the interface for middle and lower ability students, but I have extensively tested it’s usability out with an advanced student and am pretty happy with what she strung out of it! And I am sure there are improvements to come in the future. Russ Laher has done an amazing job to bring it up to this standard, where the quality of photometry is very close to the PSF heavyweights of DaoPhot and DoPhot for non-crowded fields. The results of this are pending and I will post them when I am allowed to! But if you are into this sorta stuff, check it out!
This image was made by a group of high school students supervised by their teacher who use me and McKinnon‘s in-class materials. The students can ask us for images from the 2m Faulkes telescopes, we get them back to them and then they transform the rather dull grey separate images into a groovy RGB colour composite. Anyway thats enough explanation, I just wanted to post the image! It’s not as zoomy-inny as a Hubble Image, but I think this image has achieved a valid dark evil brooding exploding star cluster aesthetic all of it’s own! The Hubble image is all impressive with it’s diamondy bling, but the student’s image is much more dark and brooding! Kudos student-type people.
I got these questions below somewhat randomly emailed to me the other day. This was at a perfect time to take a break, and I haven’t had an opportunity to do a Q&A like this for a while, so I laid into them fairly hard! The answer is approximate but simplified for the person I was writing it for, so here tis!
- Can Solar Systems form without a galaxy?
- If Yes, How?
- If No, Can an entire Solar System get ejected out of the gravitational pull of a Galaxy, and remain outside the galaxy as a self-sustained system.
- And, does this ejection likely to cause disruptions in the orbits and positions of the planets within that solar system?
- And if so, can we even call it a self-sustained system at all?
All of these questions have related answers, so I’ll try to tie them all together. I simplify the universe into galaxies, stars, rocks and dust… and the categories are not really standard astronomy categories, but they are just definitions anyway so *shrug* I know some dust people will surely have heart attacks but I treat gas and dust as a single organisational unit.
The simplest way to think of how things form in the universe is that most of the ‘stuff’ (galaxies, stars, planets etc.) is due to big balls of ‘dust’ (gas and molecules.. something clumps of dust as thick as particles of cigarette smoke) collapsing… as they collapse they become denser. There are some sweet vids on this site to check out (http://www.ukaff.ac.uk/starcluster/) that shows a dust cloud collapsing to a ‘cluster’ of stars. Basically if you start with a big dust cloud under certain conditions it will collapse and form stars (the white dots in the animations)… but when the stars form (in the proto-star), there is still dust around the star which collapses to a spinning disk (called a proto-planetary disc). Proto in this context means …. ‘early form of’… so protostar is just before a star… it hasn’t ‘ignited’ into nuclear reactions yet, and the proto-planetary disc is the disc that exists before there are everyday planetary systems. What happens when the star ignites is that it pumps out heaps of light (radiation energy/pressure) and pushes out all of the fine dust leaving the chunky bits (small asteroids to large planets) alone… shown pretty awesomely by this video : (http://www.youtube.com/watch?v=E4yirtvUurA).
So ….. the answer to 1) is… solar systems can really form anywhere this is enough dust. But the qualifier is that…… in the universe, galaxies are where we see the most stars and planets because that’s where most of the dust is! The universe is make up of ‘filaments’ (long trails of ‘stuff’) and ‘voids’ (big balls of nothing).. this video (http://www.galaxydynamics.org/cosmic_cruise.html) and this simulation (http://www.mpa-garching.mpg.de/galform/millennium/) show this fairly well. Where you can see stuff… that’s basically all galaxies made out of stars (and dark matter… but lets not get started on that! We’ll just leave it at ‘stuff’ and pretend we never heard about ‘dark energy’ either). So inside galaxies there are likely to be bucketloads of planets (and dust), near galaxies there are likely to be some planets (and dust), but you are insanely unlikely to find them in one of the voids (no dust, so nothing at all really)…. as far as I know.
‘Dust collapsing’ is the answer to 2) and really a very basic fundamental step in the making of everything. As Carl Sagan said – “To bake an apple pie from scratch, you first must create the universe”… in analogy – “If you see a planet or a star or a galaxy, there must first have been a big pile of dust hanging out somewhere”
As for being spat out of the galaxy, sure, this happens ALL THE TIME. Stars and Galaxies are formed from dust… sure… but modern galaxies are actually made up of many lesser galaxies that have been cannibalized by other galaxies! (http://www.youtube.com/watch?v=uDsWD9QmwJ8) So getting ejected is not unlikely at all in the turbulent mess of galactic consumption! (Answering 3)) We are actually colliding with the Andromeda Galaxy and where I work at MQ there are people watching stars in the process of being digested by our galaxy as we speak. (A field called Galactic Archaeology). So yeah, a solar system (Star+Planets) can easily be ejected from the galaxy and still survive. A star has a pretty extreme hold on its very closeby and small planets so it is unlikely, although not impossible if there were to be a very close pass by another star, for the planets to be ejected, but if I was going to bet on any one solar system surviving, I’d totally reckon 95%+ would hold on to their planets (but this is just me guessing really… I could ask someone much more knowledge, but currently they would probably be guessing also as we don’t have enough data yet! ) So that answers 4)… unlikely because the space between the stars compared to the size of a solar system is HUGE. In proportion to their size, galaxies are much closer together than stars ever are. Also a sidenote … a picture of a galaxy is just stars (and dust)…. that’s basically it… so if you see light coming from the galaxy it is generally stars and sometimes dust. As for 5) Well…. yeah, nothing is ever a completely closed system, but for the solar system you can assume everything inside a certain distance is ‘Solar dominated’ (http://en.wikipedia.org/wiki/Heliosphere) although this is a somewhat arbitrary limit as fundamentally the gravitational force exerted by a star spreads out for infinity but realistically becomes ridiculously small fairly quickly. So yeah… basically there is either A) systems that are relatively left alone and pretend to be closed systems and B) those that aren’t. Case A can turn into Case B at a moment’s notice though and Case A is just a special case I guess!
The abstract below is from my paper published today in “Research in Science Education” and contains the basic summary. If you want to get the full thing, just send me an email (firstname.lastname@example.org). If this was astronomy I could link the full paper for free.. but academic publishing being what it is, I can’t link straight to the paper itself. Anyhows, this forms a fairly solid part of the PhD introduction trio of papers… 2 down, one to go for the introduction and the other one is coming down the tubes fast! Watch out!
So what’s changed? Not much.. some promising signs except the doozy is that between 2001 and 2010 we found that students who said they copied notes ALMOST EVERY CLASS jumped from 61% to 76%. I think there is a good reason for this as copying notes is a form of crowd control and teachers need to revert to this when they are stressed and underprepared… which is essentially the world a teacher lives in these days…. there will be more about that in future papers. But, apart from the actual findings themselves (which you can read in teh abstract below so I’m not repeating them in this paragraph… important though they may be…), is the seeming fact that it doesn’t matter how much money you throw at a problem (A relatively large amount in certain aspects in Australia over the last 10 years), it won’t be solved unless you spend the money on plausible solutions. What’s a plausible solution? Watch this space!