Astrophysics and Cosmology - Discuss the Universe here

[zeebo]

Reminds me of Clarke's Rendezvous with Rama. Still surprised that has not been made into a movie yet especially considering how bankrupt Hollywood is on imagination these days

Funny, I was thinking the same thing, as I read that for the first time recently as I work through one of those sci-fi book lists.  One thing he was able to get across somehow was the enormity of the ship, which I thought was impressive.  It's so huge that just climbing down to the floor is a major hike, and then there's the part with the guy flying around in that little ultra-lite craft which gave a sense of the scale. 

You're right, it would make a cool movie.  Some time ago I saw a film student's experimental attempt at the part where they first enter the ship and it was pretty good actually:

http://www.openfilm.com/videos/rendezvous-with-rama-vfs/

Another book btw I can't understand why they don't make into a movie when it's such a great story and nowadays would be relatively easy to do is Frederick Pohl's Gateway. 

[Agent : Orange]

Funny, I was thinking the same thing, as I read that for the first time recently as I work through one of those sci-fi book lists.  One thing he was able to get across somehow was the enormity of the ship, which I thought was impressive.  It's so huge that just climbing down to the floor is a major hike, and then there's the part with the guy flying around in that little ultra-lite craft which gave a sense of the scale. 

You're right, it would make a cool movie.  Some time ago I saw a film student's experimental attempt at the part where they first enter the ship and it was pretty good actually:

http://www.openfilm.com/videos/rendezvous-with-rama-vfs/

Another book btw I can't understand why they don't make into a movie when it's such a great story and nowadays would be relatively easy to do is Frederick Pohl's Gateway.

That was an awesome link!
Also loved Gateway as well. The whole Heechee series was pretty interesting.

[zeebo]

That was an awesome link!
Also loved Gateway as well. The whole Heechee series was pretty interesting.

Oh little Heechee, where'd you go? ..... Ok sorry, veering off into sci-fi ... back to the hard stuff:

http://en.wikipedia.org/wiki/Observable_universe

[Agent : Orange]

back to the hard stuff:

Mysterious X-ray Signal Intrigues Astronomers

For Release: June 24, 2014

http://chandra.harvard.edu/press/14_releases/press_062414.html

[Agent : Orange]

*gush*

http://youtu.be/NjSFR40SY58

[maureen]

Gosh!!

[zeebo]

Pretty amazing pic of our garden-variety sun

http://www.avertedimagination.com/img_pages/sundisk072912.html

[Agent : Orange]

Pretty amazing pic of our garden-variety sun

http://www.avertedimagination.com/img_pages/sundisk072912.html

I can't stop staring at this. The detail in this picture is amazing. This is the chromosphere in H-alpha light I think. Looks like long grass all over the surface.
http://www.universetoday.com/40631/parts-of-the-sun/

[wr250]

our universe is astounding. everywhere we look we find questions. when we figure out the answer to 1 question 2 more pop up to take its place it seems.

[Agent : Orange]

The first precessing magnetar has been found. Neat for me because I know one of the guys that worked on this personally.

This compact star with a superstrong magnetic field is precessing like a top as it spins. The first time this has been seen with a magnetar. Tells details of the magnetic field inside the star and also about it's shape and what it's made out of.

http://phys.org/news/2014-07-satellite-x-ray-reveal-neutron-star.html

[zeebo]

The first precessing magnetar has been found...

The findings suggest that the magnetar is deformed from a perfect sphere due to an extremely strong, tightly wound toroidal magnetic field buried deep in the star's core.

I don't know what "toroidal" means, but it sound pretty hardcore!   

[wr250]

The findings suggest that the magnetar is deformed from a perfect sphere due to an extremely strong, tightly wound toroidal magnetic field buried deep in the star's core.

I don't know what "toroidal" means, but it sound pretty hardcore!   

well its not RCH's torsion field detector.
http://en.wikipedia.org/wiki/Toroid
http://en.wikipedia.org/wiki/Toroidal

[zeebo]

well its not RCH's torsion field detector. ...

Yes but I suspect there are some toroidal formations somewhere in his hair.

[zeebo]

Ok I admit I have a bit of a bias towards the Alcubierre Drive, since it's just ... cool.   But there are some issues, like the colossal amounts of energy required and also I read somewhere that the massive gravitational forces at work would create temperatures higher than the surface of the sun - so bring your Coppertone, it's gonna get a bit toasty. 

Anyway here's a pretty good article from a year ago which includes a NASA video worth checking out, if you're interested.

[Agent : Orange]

Ok I admit I have a bit of a bias towards the Alcubierre Drive, since it's just ... cool.   But there are some issues, like the colossal amounts of energy required and also I read somewhere that the massive gravitational forces at work would create temperatures higher than the surface of the sun - so bring your Coppertone, it's gonna get a bit toasty. 

Anyway here's a pretty good article from a year ago which includes a NASA video worth checking out, if you're interested.

That's a really interesting article. There are still many issues with the Alcubierre drive, and I'm not sure if White's modifications will be enough. Still, fascinating that such things are being considered at all, let alone directly tested.

[Mind Flayer Monk]

Have either of you seen articles comparing/contrasting heat production from gravity (friction?compression?) vs heat production from breaking covalent bonds/reactions?

[Agent : Orange]

Have either of you seen articles comparing/contrasting heat production from gravity (friction?compression?) vs heat production from breaking covalent bonds/reactions?

The calculations for the lifespan of the Sun based on the energy from chemical reactions and the lifespan of the Sun based on energy liberated from gravitational collapse were done by Newton and later on Lord Kelvin who treated the subject a bit more rigorously. It was found that the chemical assumption gives a much shorter lifespan, which was rejected. However, we now know that the Sun's energy comes from neither of these sources, and the Sun is really powered from the nuclear reactions that occur inside that are it's power source, the fusion of Hydrogen into heavier elements.

So you might be after something like this

http://www.phy.duke.edu/~hsg/134/lectures/ages-of-earth-sun.pdf

[Mind Flayer Monk]

So you might be after something like this

http://www.phy.duke.edu/~hsg/134/lectures/ages-of-earth-sun.pdf

Thanks A:O, that is what I was looking for. I was reading some of the sun links/images above.

[Camazotz Automat]

I do love this thread.

It's like coming home again - and that your home was where your parents lived in an astronomical observatory and it was in a small town with near zero light pollution and there wasn't an asshole in the whole town except for maybe the auto mechanic, "Goose", and even he knew to turn off his external lights at 10:00 PM.

[attachimg=1]

[Mind Flayer Monk]

I do love this thread.

It's like coming home again -

Have you seen the "Things That Annoy You Thread"?

[Camazotz Automat]

Have you seen the "Things That Annoy You Thread"?

Yes, I have. I witnessed a blinking honking Goose just recently, throwing his weight around.

[Agent : Orange]

The GabCast returns LIVE on Monday 7/7 at 8pm EST/5pm PST.

We have a very special guest joining us for a discussion on all things sciencey. Joining us will be BellGabs own Agent : Orange. We will ask him why he has a space on either side of the colon in his username as well as why he has a predilection for avatars with superheroes in mundane everyday poses. We may also ask him a question or two about science.

Join us and listen and chat LIVE at http://ufoship.com

Contact us by email: thegabcastemail@gmail.com

You can follow us on Facebook: https://www.facebook.com/thegabcast or on Twitter: @TheGabCast

Hope you will all listen and call in!

[SciFiAuthor]

Ok I admit I have a bit of a bias towards the Alcubierre Drive, since it's just ... cool.   But there are some issues, like the colossal amounts of energy required and also I read somewhere that the massive gravitational forces at work would create temperatures higher than the surface of the sun - so bring your Coppertone, it's gonna get a bit toasty. 

Anyway here's a pretty good article from a year ago which includes a NASA video worth checking out, if you're interested.

Harold White, for some reason that I've yet to uncover, believes that the energy necessary to create the Alcubierre warp field is much less than the usually cited titanic amounts. He keeps saying it in the various articles that have been coming out in conjunction with that concept ship he had an artist render but he hasn't said why. Does anyone know anything about that?

[wr250]

Tractor Beam Created Using Water Waves
Physicists have known for over a century that photons have momentum which they can impart to anything they hit. That means light can be a form of propulsion. Indeed, rocket scientists have tested laser propulsion in the hope of one day using it to accelerate spacecraft to the far reaches of the solar system and beyond.

But a couple of years ago, researchers in China showed that as well as pushing objects, laser beams can also pull them. The trick is to ensure that instead of hitting the object head-on, the light merely glances off it. At the same time, it must interact with the object to generate a backward pulling force. The result is a tractor beam capable of pulling objects towards it.

https://medium.com/the-physics-arxiv-blog/tractor-beam-created-using-water-waves-8d9271134c50

paper at cornell university: http://arxiv.org/abs/1407.0745

[Agent : Orange]

Harold White, for some reason that I've yet to uncover, believes that the energy necessary to create the Alcubierre warp field is much less than the usually cited titanic amounts. He keeps saying it in the various articles that have been coming out in conjunction with that concept ship he had an artist render but he hasn't said why. Does anyone know anything about that?

It's actually interesting and quite a good idea. In Alcubierre's original paper the bubble is taken to be spherical by definition. White found that changing the geometry of the bubble and it's time dependence also changes the energy requirements needed to set it up. White presented cases presumably found by numerically minimizing the initial energy condition that can produce a warp. The results are still huge but more reasonable than previously and have reduced the negative energy requirements substantially (but not eliminated them altogether iirc). I think the total initial energy is now something like the mass of jupiter converted directly to energy, which makes even White's modifications a non-starter. But it also means small scale tests can be done, which is what NASA is now interested in.

Ok I admit I have a bit of a bias towards the Alcubierre Drive, since it's just ... cool.   But there are some issues, like the colossal amounts of energy required and also I read somewhere that the massive gravitational forces at work would create temperatures higher than the surface of the sun - so bring your Coppertone, it's gonna get a bit toasty. 

Anyway here's a pretty good article from a year ago which includes a NASA video worth checking out, if you're interested.

Thanks for the link!

You've highlighted one of the big problems with this kind of technology, there's a massive blue shift of all infalling radiation so anything on the inside of the wall is going to be cooked. It was also shown that material particles can become stuck in the wall itself, and released when the drive is turned off (which is a problem all on it's own), turning into a giant effective accelerator. So you don't want to be in the path of this thing when it stops unless you have your sunblock on either! http://www.universetoday.com/93882/warp-drives-may-come-with-a-killer-downside/

How to deactivate the drive itself is a big problem, because the inside of the bubble and the outside are disconnected which means no signal can pass from inside to the outer universe at large, which makes problems in just turning the drive off. Alcubierre stated this as a major problem for the idea, not sure how this condition is modified in White's view.

There has also been some speculation whether this kind of drive will work at all. Basically the argument is like this, since space is flat (Minkowski) on the inside and outside, you can treat the bubble itself as a locally perturbed region of the universe, and the details of the bubble or whatever is inside don't really matter. Then since the external space is flat this perturbed region is subject to special relativity which restricts super-luminal travel. So it may be that the bubble wall has these strange effects on space-time around it but as a whole the velocity of the bubble is limited and so any ship based on this kind of warp drive is limited to sublight speeds. If this argument is true the whole situation is a non-starter.

[SciFiAuthor]

It's actually interesting and quite a good idea. In Alcubierre's original paper the bubble is taken to be spherical by definition. White found that changing the geometry of the bubble and it's time dependence also changes the energy requirements needed to set it up. White presented cases presumably found by numerically minimizing the initial energy condition that can produce a warp. The results are still huge but more reasonable than previously and have reduced the negative energy requirements substantially (but not eliminated them altogether iirc). I think the total initial energy is now something like the mass of jupiter converted directly to energy, which makes even White's modifications a non-starter. But it also means small scale tests can be done, which is what NASA is now interested in.

Oh sweet jesus thank god. Here I thought the earth was doomed in 5 billion years when the sun becomes a red giant, but all we merely have to do is convert Jupiter into energy and we can warp the earth to a new star system. And here I was all worried.

I see, so altering the geometry of the bubble was key. I couldn't find what White kept talking about and it was driving me nuts. I rather like the idea myself, and if it turns out to be viable it changes everything. While sending a spacecraft may be energy prohibitive, I wonder if sending a nanotechnological probe to another star system might be more realistic. 

[Agent : Orange]

Oh sweet jesus thank god. Here I thought the earth was doomed in 5 billion years when the sun becomes a red giant, but all we merely have to do is convert Jupiter into energy and we can warp the earth to a new star system. And here I was all worried.

haha, right?

I see, so altering the geometry of the bubble was key. I couldn't find what White kept talking about and it was driving me nuts. I rather like the idea myself, and if it turns out to be viable it changes everything. While sending a spacecraft may be energy prohibitive, I wonder if sending a nanotechnological probe to another star system might be more realistic.

It's a complete game changer. The smaller they can make the probe they want to send, the better. And there's no telling what other tech and theory may still contribute to this. It's a very ambitious plan, even if it turns out to be nothing I think everyone's still rooting for it

[SciFiAuthor]

It's a complete game changer. The smaller they can make the probe they want to send, the better. And there's no telling what other tech and theory may still contribute to this. It's a very ambitious plan, even if it turns out to be nothing I think everyone's still rooting for it

Hmm, so my brain is still cranking away. Another application would be that the warp bubble should be able to convey information faster than light. In which case individual subatomic particles could be sent out as a sort of Morse code; proton, neutron, proton, neutron, proton, proton or something. Thusly, faster than light communications might be a possible use for it, but dealing with even smaller objects than a nanoprobe or the Enterprise. In other words, if White's work pans out, SETI should be looking for tiny warp bubbles carrying particles travelling through space for evidence of E.T. if such a thing would be detectable (I have no clue if it would be). You probably couldn't figure out their message, but if you see a warp bubble you'd know it's artificial (or would it be? Natural warp bubbles?)

So what do you think the energy requirement for sending a proton in a warp field would be? Is that getting down into manageable energy requirements enough for it to be feasible?

[zeebo]

Hmm, so my brain is still cranking away. Another application would be that the warp bubble should be able to convey information faster than light. In which case individual subatomic particles could be sent out as a sort of Morse code; proton, neutron, proton, neutron, proton, proton or something. Thusly, faster than light communications might be a possible use  ...

Cool thing about this is perhaps you could send ahead a welcome message to greet yourself upon arrival.  "Hi Bob, welcome to the Rigel system.  What took you so long!"

[SciFiAuthor]

Cool thing about this is perhaps you could send ahead a welcome message to greet yourself upon arrival.  "Hi Bob, welcome to the Rigel system.  What took you so long!"

"Thatsch amazing Bob, tell me, is Rigel further away from Earth than Detroit and Hawaii are?"