Astrophysics and Cosmology - Discuss the Universe here

[zeebo]

I just finished up the Great Courses' Experiencing Hubble lecture series, and I have to say it was pretty awesome.  I wasn't expecting much, but if this course was an indicator of the others, I'm really looking forward to the ones I have on the way - Sean Carroll's Dark Matter series, Particle Physics for the non Physicist and the behemoth Understanding the Universe in 96 lectures by The Universe's Alexei Filippenko...   But this Hubble one was awesome, and for $13 shipped on ebay, it was a steal of a deal.  I would have gladly paid the $40 they ask on Great Courses for it.  There was plenty I already knew, but I still learned quite a bit over the 6 hours of lecture, and I will actually watch it again to go back over some of the material.   He even covers a bit about dark matter, dark energy and zeebo, you'd love the last lecture - he talks a lot about exoplanet detection.

Sounds very cool.  I've watched pretty much everything astronomy-related on the Science, Discovery, and History channels over the years, but maybe it's time for me to dig a little deeper.  I'm intrigued by the Filippenko series, wow 96 lectures, sounds pretty hardcore, but I like him alot, he always pops up on various shows.  Let us know how it is if you manage to get through that one.

[area51drone]

I'm curious if anyone is familiar with the following experiment I was reading about online...

Lately a few scientists---such as Laurent Freidel, Joao Magueijo,...---have been considering the possibility that Special Rel is slightly (ever so slightly) wrong and needs to be corrected.

A test has been proposed using a satellite scheduled for launch next year (2007)

In the modified theory not all light travels the same speed in vacuum. Very energetic gammaray photons are predicted to go just a wee bit faster.

(think of the slight differences in speed as a "quantum correction" that could be just barely measurable using the GLAST satellite: "gammaray large array space telescope")

the idea is to examine very powerful brief GRB "gammary bursts" that have been traveling on the order of a billion years, and look at brief millisecond spikes containing some photons that are very much more energetic than the rest.

If the more energetic photons have crept out in front, during the billion years of flight, so they arrive just a fraction of a second earlier than the rest, this will be evidence suggesting a slight difference in speed. Too small to detect in ordinary earth circumstances (where the time of flight is not long enough for a small difference in speed to take effect)

Daniel's explanation is correct----the theory of a clearcut max is based on the POSTULATES of Special Rel. there is no ultimate certainty that Special Rel is absolutely correct and will never be improved on by some small adjustment like this.

The satellite he's referring to is the Fermi Gamma Ray space telescope.  It's been up since 2008.   Curious about the results of this study, but finding nothing so far.

[area51drone]

So I'm watching Carroll's lecture series on Dark Matter and Dark Energy, and he just said something very interesting - in that in regards to DE, you can think of space not expanding, but that particles are shrinking.   He dismisses this and says its more convenient to think about space as expanding and us staying the same, but that put me on a thought...

Since everything, including particles, are just energies in a field, what if dark energy is actually just regular energy below the visible point (not strong enough to create detectable particles) that is propagating out into "space", and the reason that matter is not expanding with space is that the energy we're made of is being held together by other forces - EM for example - but we're still propagating out, just in clumps.   Anyone have any thoughts on this?

[zeebo]

So I'm watching Carroll's lecture series on Dark Matter and Dark Energy, and he just said something very interesting - in that in regards to DE, you can think of space not expanding, but that particles are shrinking.   He dismisses this and says its more convenient to think about space as expanding and us staying the same, but that put me on a thought...

Since everything, including particles, are just energies in a field, what if dark energy is actually just regular energy below the visible point (not strong enough to create detectable particles) that is propagating out into "space", and the reason that matter is not expanding with space is that the energy we're made of is being held together by other forces - EM for example - but we're still propagating out, just in clumps.   Anyone have any thoughts on this?

Just dropping out of lurk mode to say I basically have zero useful thoughts on any of this serious science stuff, but I do find it fascinating to follow along with, much like a toddler with a toy phone tries to suss out what the adults are doing on their real phones.   Anyway thanks for some cool posts and now back to lurk mode.   

[area51drone]

Just dropping out of lurk mode to say I basically have zero useful thoughts on any of this serious science stuff, but I do find it fascinating to follow along with, much like a toddler with a toy phone tries to suss out what the adults are doing on their real phones.   Anyway thanks for some cool posts and now back to lurk mode.   

Oh I'm just pissing in the wind, hoping it doesn't come back to hit me in the face.   I got the Alex Fillipenko set in yesterday..  I'll post a review after I get started with it, but it might be a while.

[Agent : Orange]

Hey all just dropped in for a sec to post this
http://phys.org/news/2013-11-soho-images-comet-ison.html
and say keep an eye out for the stuff going on with comet ISON in the next few days, it will be interesting to see what happens to this object.

And for area51drone, this interesting blog post a friend sent to me just the other day.
http://www.science20.com/hammock_physicist/universe_expanding_or_are_we_shrinking-118673
Great timing

[zeebo]

Guys I just want to mention something.  I've always been interested in astronomy, sci-fi etc.  But it wasn't until a few years ago when I moved to a somewhat remote part of Oregon with low light pollution, and picked up a decent telescope, that I really got inspired.  Of all things, it was the Dumbell Nebula.  In my 'scope you can't even see the dumbell really, you just see the green smudge in the middle of it.  Still it blew my mind to just see this thing just hanging in the sky.  Charles Messier noticed this thing back in friggin 1764, and it's designated M27.

What's my point?  Well I'm rambling a bit but I'm just saying I feel priveliged to live in a time where 1) I have an amateur telescope where I can get good look at the thing, and 2) I live in a time of sufficient scientific advancement that we can actually understand what it is.  That's pretty cool. 

The other one that blew my mind was Bode's galaxies M81 & M82 which you can resolve in the same frame, one top-down and one edge-on, friggin amazing really, especiallly given all we've learned in the last hundred years about the origin and evolution of galaxies.  What were once little fuzzy blurs to Messier, are just average galactic instances in a vast universe expanding out past 13 billion light years.

Ok that's all I had to interject for now, just felt the need to express that.

[Agent : Orange]

Guys I just want to mention something.  I've always been interested in astronomy, sci-fi etc.  But it wasn't until a few years ago when I moved to a somewhat remote part of Oregon with low light pollution, and picked up a decent telescope, that I really got inspired.  Of all things, it was the Dumbell Nebula.  In my 'scope you can't even see the dumbell really, you just see the green smudge in the middle of it.  Still it blew my mind to just see this thing just hanging in the sky.  Charles Messier noticed this thing back in friggin 1764, and it's designated M27.

What's my point?  Well I'm rambling a bit but I'm just saying I feel priveliged to live in a time where 1) I have an amateur telescope where I can get good look at the thing, and 2) I live in a time of sufficient scientific advancement that we can actually understand what it is.  That's pretty cool. 

The other one that blew my mind was Bode's galaxies M81 & M82 which you can resolve in the same frame, one top-down and one edge-on, friggin amazing really, especiallly given all we've learned in the last hundred years about the origin and evolution of galaxies.

Ok that's all I had to interject for now, just felt the need to express that.

What kind of scope do you have?

[zeebo]

What kind of scope do you have?

Hi Agent it's the FS-135DX Galileo 135mm reflector, 1100mm focal length.  Nothing super fancy but opened up some pretty amazing stuff for a city kid like me.

[Agent : Orange]

Hi Agent it's the FS-135DX Galileo 135mm reflector, 1100mm focal length.  Nothing super fancy but opened up some pretty amazing stuff for a city kid like me.

Nice! Man I remember seeing the moons of Jupiter through a scope for the first time. That blew my mind. And the moon still gives an inspiring view for me to be honest. I don't have a telescope of my own so any chance I get is a bonus.

[Agent : Orange]

Thought I'd share this which I just ran across the other day. Small clips from a "theory of everything" movie.
http://www.youtube.com/user/thetoemovie/videos

[maureen]

Thanks, guys, for this thread on the Universe-- or multiverse, or parallelverse, or dimensionalverse-- and for the always entertaining theorizing!! When we don't KNOW, any theory is worthy of consideration.

[zeebo]

Nice! Man I remember seeing the moons of Jupiter through a scope for the first time. That blew my mind. And the moon still gives an inspiring view for me to be honest. I don't have a telescope of my own so any chance I get is a bonus.

Yeah the Jupiter moons are cool.  FYI here's a neat page with tips on viewing (you don't need a scope, you can use binoculars.)  At the bottom is a link to a great little tool that shows you the current location of the 4 main moons at any date/time (look for "Jupiter's Moons JavaScript utility" link at the bottom of the first page).

http://www.skyandtelescope.com/observing/objects/planets/3307071.html

[SciFiAuthor]

Something neat. This amateur astronomer managed to photograph the Beta Pictoris debris disk with a 10" Newtonian.

http://www.rolfolsenastrophotography.com/Astrophotography/Beta-Pictoris

Beta Pictoris has at least one exoplanet that has been directly imaged. If a guy with a 10" telescope can photograph a disc like that, it's only a matter of time before an amateur astronomer with a really big telescope will pick up a planet directly. I remember that Coulter Optical used to make a 29" Dobsonian back in the 80's, with today's imaging tech and remounting on an equatorial platform or similar, it might be doable.

[Heather Wade]

Any of you guys check out Stellarium?

Though I do not post often here, I am lurkening.  It's so much fun to check in and see where you guys are taking the conversation.  Contemplating space is strangely calming.

I'm excited, because my new new pad has a great spot for a telescope, and not much light pollution.  One of those little things I've always wanted, for so long.

Can't wait to see what I can see of our solar system with my own eyes, and not on tv.

Thanks for all the interesting thoughts, please keep 'em coming.

[zeebo]

Any of you guys check out Stellarium?

Though I do not post often here, I am lurkening.  It's so much fun to check in and see where you guys are taking the conversation.  Contemplating space is strangely calming.

I'm excited, because my new new pad has a great spot for a telescope, and not much light pollution.  One of those little things I've always wanted, for so long.

Can't wait to see what I can see of our solar system with my own eyes, and not on tv.

Thanks for all the interesting thoughts, please keep 'em coming.

Sounds cool Red ... you're gonna love it.  I've just started checking out Stellarium, looks pretty good.  Some kind of planetarium 'ware is definitely helpful to orient oneself.  And you're right, seeing some of these things with your own eyes, while maybe not as visually spectacular as photos etc., is so compelling because it's "live action", and you really get a sense of how real it all is. 

Btw I have a book reco, if you happen to come across it used or maybe in the library, check this one out:  Secrets of the Night Sky by Bob Berman.  It's a fun and interesting intro to things you can see even just with the naked eye.  It's written for the layman like me, and along with some mild scientific stuff and viewing tips he covers some neat cultural and historical points as well. 

[Heather Wade]

A guidebook is most welcome.  Thank you.  It is incredible all the things Stellarium can do.  Also, how bright and alive the Earth looks, compared to all the other heavenly bodies, makes me appreciate our little planet that much more.

It is quite an astonishing thing to me that we hurtle in our orbit around the sun at 66,000 mph (or some such that I have heard on some show) everyday.  Out here in the cold of space we have this one warm, beautiful place. 

But, still I wonder, is a black hole creating a Big Bang on the other side of itself?  In another universe?  If black holes are constantly pulling in matter & energy... where is it, ultimately, all going? 

Been hooked on space ever since a teacher explained the Big & Little Dippers.  There is so much we do not know... and hours of entertainment to figure out what we do know...   

[SciFiAuthor]

Any of you guys check out Stellarium?

Though I do not post often here, I am lurkening.  It's so much fun to check in and see where you guys are taking the conversation.  Contemplating space is strangely calming.

I'm excited, because my new new pad has a great spot for a telescope, and not much light pollution.  One of those little things I've always wanted, for so long.

Can't wait to see what I can see of our solar system with my own eyes, and not on tv.

Thanks for all the interesting thoughts, please keep 'em coming.

Saturn will really get ya. The rings can be seen in any telescope. It looks the most like it's pictures out of anything.

[Heather Wade]

Saturn will really get ya. The rings can be seen in any telescope. It looks the most like it's pictures out of anything.

OOOooo, that's the stuff.  That will be... some visceral high strangeness, and I can't wait. 

[zeebo]

...Been hooked on space ever since a teacher explained the Big & Little Dippers. 

You may already know this but if you check out the star Mizar in the Big Dipper you'll see that it's actually a binary star system - the second fainter star revolving around it is called Alcor.  If you have great eyesight you can resolve it with the naked eye, but for sure in binocs or scope you can see it.  (An even neater binary star is Albireo in the constellation Cygnus - one's yellow and one's blue.)

[Agent : Orange]

You may already know this but if you check out the star Mizar in the Big Dipper you'll see that it's actually a binary star system - the second fainter star revolving around it is called Alcor.  If you have great eyesight you can resolve it with the naked eye, but for sure in binocs or scope you can see it.  (An even neater binary star is Albireo in the constellation Cygnus - one's yellow and one's blue.)

Both easy to find and very neat binaries!

I have not used Stellarium but I've heard good things about it. I have a copy and a lot of background with Starry Night which really does the same thing. Right now my new favorite is an app I got on my tablet that uses GPS positioning to figure out what the stars should look like from your position. A very useful tool.

[area51drone]

Just a quick post - this time of year I don't have a lot of time to write big long posts..  No need for even a telescope!   You can see Saturn's rings, Jupiter's moons and even Mar's ice cap through a good pair of binoculars.     When Mars was close by earth back in 2002 (2003?) I even took a picture of Mars with its ice cap with my cellphone.   And cellphone cameras sucked back then.  My telescope is a Celestron Nexstar 114GT (4.5" newtonian) with computer control.   I have taken pictures through it with a digital camera and stacked them with some decent results too.  I'd love to get a CCD attachment for it, that would be the ultimate.   Oh, and if you REALLY want to be impressed, get yourself a gen3 night vision monocular and prepared to be blown away.. I can see a couple galaxies no problem a 1x through my ATN NVM-14.

Oh, and here's another free online planetarium..

http://www.skyviewcafe.com/skyview.php

[zeebo]

Just a quick post - this time of year I don't have a lot of time to write big long posts..  No need for even a telescope!   You can see Saturn's rings, Jupiter's moons and even Mar's ice cap through a good pair of binoculars.     When Mars was close by earth back in 2002 (2003?) I even took a picture of Mars with its ice cap with my cellphone.   And cellphone cameras sucked back then.  My telescope is a Celestron Nexstar 114GT (4.5" newtonian) with computer control.  ...

Hey 51, dumb question, does computerized mean you can 1) point it from a computer and/or 2) that it tracks the rotation of the sky?  My scope is currently on long-term loan to my brother so I'm day-dreaming (night-dreaming?) about upgrading at some point. 

In the meantime I've got some good binocs and you're right Jupiter right now is like a beacon so I'll have to check it out.

[area51drone]

Hey 51, dumb question, does computerized mean you can 1) point it from a computer and/or 2) that it tracks the rotation of the sky?  My scope is currently on long-term loan to my brother so I'm day-dreaming (night-dreaming?) about upgrading at some point. 

In the meantime I've got some good binocs and you're right Jupiter right now is like a beacon so I'll have to check it out.

Right now in my area Neptune shows up the first thing in the evening, it is the brightest thing out there.

Yes, it has a little hand held computer controller ( I can't remember, but I don't think it can hook up to the PC, but maybe it can), and a motor that moves the scope with the rotation of the earth.   You align it by pointing it at some objects in the sky (it guides you through it) and then just pick from a list of stuff that's currently visible from your location and it will slew to the object and start tracking.   Its been a while since I pulled my scope out though.   I remember I used to take my laptop with Starry Night Pro out and  I kind of recall hooking it up through a serial connection for PC control but I can't be certain.   But you don't need a PC anyway.   Makes it a much more enjoyable experience having auto slew.  Adding a CCD would make it so that I could stack images automatically and come up with some halfway decent pictures of the planets anyway.   I think the galaxies would still just be little fuzzies.  But I would like to try.   Celestron has a 5MP camera out now that is supposedly pretty good.   I'm considering it or just using an attachment and my wife's Nikon D80, which would be a lot cheaper and higher quality but more of a pain than a CCD insert.

[area51drone]

Woops, I meant Venus  is ultra bright right at dusk.... not sure what I was thinking...

[zeebo]

Woops, I meant Venus  is ultra bright right at dusk.... not sure what I was thinking...

Haha yeah I was like wow 51's got eagle eyes to pick up Neptune ... anyway thanks for the scope info, I will definitely invest in one with the tracking motor as the sky movement thing becomes a huge issue when looking at things with high magnification.  There was one very clear night I super-zoomed in on Titan and it was great, for about like 2 seconds.

[Caruthers612]

    It's big. Really, really big. No, honestly. Rosie O'Donnell's head is a mere turnip by comparison. Hilary Clinton's ass? Not even close. Madonna's vagina? Nope, not even that well-trod ground is as cavernous. We're talking BIG. Big like a white girl's anus after Blackzilla is done with her. Big like a head cheerleader's mouth after giving the whole football team, uh, well, you know. Sizable. Capacious. Ponderous. Prodigious. Roomy. Copious. Burly. Think John Holmes and go from there.

[Agent : Orange]

    It's big. Really, really big. No, honestly. Rosie O'Donnell's head is a mere turnip by comparison. Hilary Clinton's ass? Not even close. Madonna's vagina? Nope, not even that well-trod ground is as cavernous. We're talking BIG. Big like a white girl's anus after Blackzilla is done with her. Big like a head cheerleader's mouth after giving the whole football team, uh, well, you know. Sizable. Capacious. Ponderous. Prodigious. Roomy. Copious. Burly. Think John Holmes and go from there.

Big.

[onan]

Big.

Big +1

[valdez]

      So I was watching some videos on the possible shapes that our universe may have, and I came across the concept that since light from a star beams out in all directions a star close to us, say five light years, would be seen in the sky as it was five years ago, but the light from that same star would be zooming out towards the other end of the universe taking a zillion light years to hit us from the other side of sky and so we would see two stars in the sky that are actually the same star at different times in its history.  As if life ain't mean enough.

or something to that effect