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#161
Quote by darkwolf291
Me too man.
We're here for less than a blink of an eye in the universe.
100 years is like a second.
No matter what we do, it will never make a lasting effect on the universe.
We work our 9 to 5 jobs hoping what we do will make an impact on something.
In the end, nothing anyone does matters.
On the other hand, it's kind of a good thing as well.
No matter how much we **** up, it will never effect the universe.
Earth is gonna go away, and once it does, nothing anyone ever did on it will matter.
The Holocaust, Hiroshima, Chernobyl, none of it will matter anymore.
For me, it's a strangely inspirational thought.

Why should the universal scale be the only one that matters? Your life is real, and the people surrounding you are also stuck in real experiences. However brief they may be in the Whole Sort of General Mish-Mash, I refuse to believe that's nothing. There's 6 billion people. If we live to just an average age of 30, that's still 180 billion human-years that everyone currently alive is responsible for. Is it really so little?

[IN PHIL WE TRUST]


Quote by Trowzaa
I only play bots. Bots never abandon me. (´・ω・`)

#163
Odd that it keeps you going. It crushes me like the Perspective Device on Frogstar B.

[IN PHIL WE TRUST]


Quote by Trowzaa
I only play bots. Bots never abandon me. (´・ω・`)

#165
I've read a lot of pop-sci stuff on string theory. I've fallen into the "good idea, shit execution" camp I think. It's not the first theory of unification to imagine higher dimensions, and since that's not well known it should give you an idea of the fate of the earlier attempts (failure). It claims to unify gravity with quantum physics, but it depends on a stable background, while gravity, as governed by general relativity, requires there to be no such background--matter and energy aren't IN space, they ARE space. It seems to be a good piece of the puzzle but not a final answer by any means. Even if it were the final answer, as of now, there's no experiments saying so. Everything at the Large Hardon that was supposed to support string theory has fallen on the "lol nah" side.

Plus, it's a common misconception (encouraged by some string theorists, unfortunately) that M-theory is a real thing. Witten proposed that the 5 leading string theories at that time, because of certain dualities between them, were really 5 ways of looking at one underlying theory, which he called M-theory. That's all we know about it. We don't know what it is or whether it exists.

It's a really gorgeous theory. I love it. But that doesn't make it real.

[IN PHIL WE TRUST]


Quote by Trowzaa
I only play bots. Bots never abandon me. (´・ω・`)

#167
M-theory assumes supersymmetry, which only works in the low-entropy conditions of 10 spatial dimensions and time. So yeah. 11. Up-down, Left-right, Forward-back, Before-after, and a six-dimensional thingy called a Calabi-Yau space curled up about the size of the Planck length (that's wayyyy tiny). And an eleventh that I still don't even sort of get. Funny thing is, there's hundreds of possible Calabi-Yau spaces they could be referring to.

This convo would be better had in the Physics thread, by the way, but it's, erm...... dead and decaying.

[IN PHIL WE TRUST]


Quote by Trowzaa
I only play bots. Bots never abandon me. (´・ω・`)

Last edited by SteveHouse at Jul 2, 2011,
#168
Quote by darkwolf291
I realize that Steve.
Sometimes though, I just can't help but to think on a Universal scale.
Keeps me going when I'm down.


No offence, but I think you're being depressive for the sake of it
#169
It relates to astonomy and the universe, so I think it applies here as well.

I don't know why, but the idea of unobservable dimensions has always intrigued me.
I've been meaning to catch Through the Wormhole on the discovery science channel, but I can never remember to watch it.
Last edited by darkwolf291 at Jul 2, 2011,
#170
Quote by darkwolf291
It relates to astonomy and the universe, so I think it applies here as well.

I don't know why, but the idea of unobservable dimensions has always intrigued me.
I've been meaning to catch Through the Wormhole on the discovery science channel, but I can never remember to watch it.

It's intrigued people since the idea was first proposed. Which I think dates to Riemann, but don't quote me on that one. He ended up using a fourth spatial dimension to mathematically-proof Euclidean geometry, if I remember right... that story's in Hyperspace by Michio Kaku, which is a pretty good tale of the history of higher-dimensional theory. Plus it contains the following mind-melting explanation of a hypercube (a cube in 4 dimensions) (and I'm paraphrasing badly):

Imagine a line, which exists in only one dimension. If you lay four of them out just so, and fold them up into right angles in a second dimension, you get a square. Much the same way, if you fold up six squares properly into a third dimension, you get a cube. Imagine a box if that doesn't make sense to you. When you unfold all the sides of a box, you get a flat piece made of six squares--fold the squares up, and you get a cube. Continuing that train of thought, we can lay out eight cubes just so, and fold them up the right way into a fourth dimension: that's a hypercube.


I read that and spent the next five minutes looking at the ceiling fan, going "whoa."

[IN PHIL WE TRUST]


Quote by Trowzaa
I only play bots. Bots never abandon me. (´・ω・`)

Last edited by SteveHouse at Jul 2, 2011,
#171
Quote by SteveHouse


Imagine a line, which exists in only one dimension. If you lay four of them out just so, and fold them up into right angles in a second dimension, you get a square. Much the same way, if you fold up six squares properly into a third dimension, you get a cube. Imagine a box if that doesn't make sense to you. When you unfold all the sides of a box, you get a flat piece made of six squares--fold the squares up, and you get a cube. Continuing that train of thought, we can lay out eight cubes just so, and fold them up the right way into a fourth dimension: that's a hypercube.

I read that and spent the next five minutes looking at the ceiling fan, going "whoa."


Does anyone else have a way of explaining extra dimensions? I tried picturing the 'Hypercube' thing but when it came to putting the 8 cubes together i can only picture a larger cube of double the length, width, breadth (hence 8 times the volume, composed of the 8 cubes)

When i did Astronomy at uni to explain universe 'curvature' the lecturer said to imagine all matter in the universe to exist on the surface of a balloon. As the universe/balloon expands, the distances 'from A to B' in the universe expands as the balloon does. Nothing exists in the space within the balloon but if we could somehow travel through this 'nothing' we could get from 'A to B' along a shorter straight line distance, a 'wormhole'.

Did i just answer my own question? Im not sure. Don't know if this is directly related to string-theory etc. either.

I still have the a problem with the balloon analogy though in picturing the 3 known dimensions on the 2 dimensional surface of the balloon.

Hmmmmm.......
#172
Quote by LukeyEL
Does anyone else have a way of explaining extra dimensions? I tried picturing the 'Hypercube' thing but when it came to putting the 8 cubes together i can only picture a larger cube of double the length, width, breadth (hence 8 times the volume, composed of the 8 cubes)

Carl Sagan explains

It blew my mind the first time I watched it.
#173
Just finished Carl Sagan's books Cosmos and Pale Blue Dot. Really enjoyed them, anyone got any suggestions for next books to read? Don't have to be by Carl Sagan.
#174
Quote by T.s.e
Carl Sagan explains

It blew my mind the first time I watched it.


I love that video. Really blows up the picture in your Mind's Eye so that you can get your head around the concept.
My signature lacks content. It is, however, blue.
#175
Quote by conor-figgy
So, is a UG space programme too premature?

Well maybe if we bought that missile silo a while back...

please tell me someone here remembers that
#176
Floods_Solo, you should check out John Gribbin if you haven't already, especially In Search of Schrödinger's Cat.
#177
Quote by T.s.e
Carl Sagan explains

It blew my mind the first time I watched it.


Thanks for that, i really need to buy Carl Sagan's books. I'm not much of a reader but that sort of thing i WILL read.

His 'flatland' reminded me of Sheldon's (from the Big Bang Theory) flatland
#178
Quote by Ninja Vampirate
No offence, but I think you're being depressive for the sake of it



I disagree. If you think on the scale of the universe , then no mistakes you've made in your life really matter. Just some chemical reactions in the brains of some organisms on a piece of dust into the cosmos.

I can see how thats a freeing thought.
Quote by Zaphod_Beeblebr
Theory is descriptive, not prescriptive.


Quote by MiKe Hendryckz
theory states 1+1=2 sometimes in music 1+1=3.
#179
Quote by LukeyEL
Does anyone else have a way of explaining extra dimensions? I tried picturing the 'Hypercube' thing but when it came to putting the 8 cubes together i can only picture a larger cube of double the length, width, breadth (hence 8 times the volume, composed of the 8 cubes)

You really can't visualize four spatial dimensions. It's just meant to explain how a hypercube would be made.

[IN PHIL WE TRUST]


Quote by Trowzaa
I only play bots. Bots never abandon me. (´・ω・`)

#180
I find a good way to try and understand the concept of extra dimensions is to think of sliders, like say for instance colour sliders – you've got your three sliders for hue, saturation and brightness, in the same way that 3D space can be defined by x,y and z. Just imagine more parameters and you've got yourself a multi-dimensional entity.

A fourth spatial dimension is impossible to visualize as an image, so I think the best way is just to think of it as having other attributes.

Edit: I realise this is a pretty simple answer, I don't think I understand hyperspace completely either, I gotta read that book
- - - - - - - -
When I think of the perpetual journey through life
When it always feels like autumn
The wind moves slowly to the north
And the flowers die
Rain falls in my dreams

- - - - - - - -
Last edited by papershredder at Jul 2, 2011,
#181
It's a good one, takes a lot of time to chew on.

[IN PHIL WE TRUST]


Quote by Trowzaa
I only play bots. Bots never abandon me. (´・ω・`)

#182
Quote by LukeyEL
Does anyone else have a way of explaining extra dimensions? I tried picturing the 'Hypercube' thing but when it came to putting the 8 cubes together i can only picture a larger cube of double the length, width, breadth (hence
8 times the volume, composed of the 8 cubes)


There really is no way to visualize any extra dimensions. You could, however try a 4D Rubiks cube http://www.superliminal.com/cube/applet.html . Or wait for this to come out: http://www.youtube.com/watch?v=w_4L3FtClxI&feature=related

Otherwise, you can just think of a fourth dimensional space as having an infinitely many 3D spaces and assigning a real number to each. After all, in math, a classic example of an n-dimensional vector space is just the set of n-tupels with the usual addition and scalar multiplication. If you start out with Euclidean R^3 space, then going over to 4 dimensions "adds an extra element to each vector", which you could consider as a counting variable. Eh I don't know how to explain this better through text, but that's how I like to think about it.

Also, Klein bottles are pretty cool:

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

Quote by LukeyEL

When i did Astronomy at uni to explain universe 'curvature' the lecturer said to imagine all matter in the universe to exist on the surface of a balloon. As the universe/balloon expands, the distances 'from A to B' in the universe expands as the balloon does. Nothing exists in the space within the balloon but if we could somehow travel through this 'nothing' we could get from 'A to B' along a shorter straight line distance, a 'wormhole'.

Did i just answer my own question? Im not sure. Don't know if this is directly related to string-theory etc. either.

I still have the a problem with the balloon analogy though in picturing the 3 known dimensions on the 2 dimensional surface of the balloon.



The balloon analogy's main intent is to highlight key features of the expansion of the universe, i.e. everything is moving apart, but there is no distinct center of the expansion. This stuff is related to cosmology, I would say. Maybe read this thread about the balloon analogy:

http://www.physicsforums.com/showthread.php?t=261161

Cheers
"In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move."
Last edited by keinerniemand at Jul 3, 2011,
#183
Quote by keinerniemand
There really is no way to visualize any extra dimensions. You could, however try a 4D Rubiks cube http://www.superliminal.com/cube/applet.html . Or wait for this to come out: http://www.youtube.com/watch?v=w_4L3FtClxI&feature=related

Otherwise, you can just think of a fourth dimensional space as having an infinitely many 3D spaces and assigning a real number to each. After all, in math, a classic example of an n-dimensional vector space is just the set of n-tupels with the usual addition and scalar multiplication. If you start out with Euclidean R^3 space, then going over to 4 dimensions "adds an extra element to each vector", which you could consider as a counting variable. Eh I don't know how to explain this better through text, but that's how I like to think about it.

Also, Klein bottles are pretty cool:

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


The balloon analogy's main intent is to highlight key features of the expansion of the universe, i.e. everything is moving apart, but there is no distinct center of the expansion. This stuff is related to cosmology, I would say. Maybe read this thread about the balloon analogy:

http://www.physicsforums.com/showthread.php?t=261161

Cheers


That Klein bottle thing is pretty trippy

Thanks for the help.
#186
A few days ago i bought the latest issue of the Astro magazine Australian Sky and Telescope. Found an interesting article in it about Exoplanets (planets in other solar systems), a hot topic in terms of discussion of the existence of alien life forms.

The article is specifically about the findings of the NASA 'Kepler Space Telescope' which is just 4 months into its 3.5 year mission. Having only completed roughly a tenth of the mission, it has already discovered 1235 exoplanets. This is compared to the 513 exoplanets discovered by all other projects since 1993!!

To summarise the findings;

* Multiple-planet systems found: 115 doubles, 45 triples, 8 quadruplets, 1 quintuple and 1 sextet.

* Size: 68 are roughly earth size, 288 greater than earths size, 662 roughly the size of Neptune, 165 roughly the size of Jupiter and 19 that are much larger than Jupiter (ie. BIG!!).

* Inhabitable zones: of the 68 earth size exoplanets, 5 exist in the 'inhabitable' region of orbit of their star, where water could exist on the surface as a liquid under modest atmospheric pressure. 49 others exist in such zones but are larger than earth, some larger than Jupiter.

* Best example: an exoplanet-containing solar system located around 2000 light-years away containing the star 'Kepler-11'. This 'Sun' has 6 planets orbiting it with periods varying from 10 to 118 days. The densities of the 5 inner-most planets are 3, 2, 0.9, 0.5 and 0.7 g/cm^3 respectively compared to earth's 5.5. They are thought to contain cores or rock-iron surrounded by thick layers of 'ices' (water, methane and ammonia) and gas (such as hydrogen and helium). They can be considered miniature versions of our solar systems 'gas giants'.


Sorry for the long post but i think its a good follow up to previous exoplanet/alien-life discussion in this thread.

Basically, my belief is that with such discoveries as these (in close proximity to us in our own galaxy) its pretty narrow minded to think that life doesn't or hasn't existed 'elsewhere'

Cheers,
Luke
#187
Quote by LukeyEL
[...interesting stuff...]


It finds those planets by observing the luminosity change of the star when the suspected planet makes a transit (ie moves between the telescope and the star). It's always baffled me that we're able to observe that! By the way: I've been wondering if there should be any preferred orientation of the plane in which planetary orbits lie within our galaxy? (for the solar system they lie roughly in a plane, right) That could perhaps be argued using conservation of angular momentum? (like the explanation for accretion discs) Hmm I really should read up on this, it's kept me thinking for quite a while now.


There is also plenty of information on Kepler's homepage at NASA:
http://kepler.nasa.gov/

Also, google planet hunters for a way to get involved in the project!
http://kepler.nasa.gov/education/planethunters/
"In the beginning the Universe was created. This has made a lot of people very angry and been widely regarded as a bad move."
#188
Quote by keinerniemand
It finds those planets by observing the luminosity change of the star when the suspected planet makes a transit (ie moves between the telescope and the star).......


It's pretty clever really! Once they know the size, they then work out the planets masses by measuring the disturbances as they pass each other.

Knowing size (ie. diameter), they can calculate volume. Dividing mass by volume they find the density which then allows them to take guesses at the structure of the planet

(this is probably all outlined on the site, which i haven't looked at much yet, but the above was in the article from my last post).

Technology/methods such as these and others like parallax, red-shift measurement etc. really are amazing and are whats allowing us to learn so much about the universe.
#189
From the Kepler website which keinerniemand kindly posted, the field of view of the Kepler telescope. In the scheme of things, this really is a tiny area yet they have found over 1000 exoplanets within it ........

#191
At this point can we really keep calling it a dwarf planet? It seems like more of a sort of system to me, especially given the proportion of mass shared by Pluto and Charon.

[IN PHIL WE TRUST]


Quote by Trowzaa
I only play bots. Bots never abandon me. (´・ω・`)

#193
Quote by SteveHouse
....... It seems like more of a sort of system to me, especially given the proportion of mass shared by Pluto and Charon.


Found this point interesting and did a bit of research (all of 2 mins) and found on Wikipedia:

"The Pluto–Charon system is noteworthy for being the largest of the Solar System's few binary systems, defined as those whose barycentre lies above the primary's surface (617 Patroclus is a smaller example).[101] This and the large size of Charon relative to Pluto has led some astronomers to call it a dwarf double planet.[102] The system is also unusual among planetary systems in that each is tidally locked to the other: Charon always presents the same face to Pluto, and Pluto always presents the same face to Charon: from any position on either body, the other is always at the same position in the sky, or always obscured.[103] Because of this, the rotation period of each is equal to the time it takes the entire system to rotate around its common centre of gravity.[62] Just as Pluto revolves on its side relative to the orbital plane, so the Pluto–Charon system does also."



caption: "The Pluto-Charon system. Charon's orbit around Pluto is shown in green. Pluto's orbit around the Pluto-Charon system barycentre is shown in red. This shows that Pluto orbits a point outside itself. This is why Pluto and Charon are sometimes considered to be a double dwarf planet. The two small satellites of the Pluto-Charon system, Nix and Hydra, are not shown (they are on the other side)"

I wasn't aware of this. You learn something new every day huh!!

Luke
#194
You guys might appreciate the pictures in this aticle http://www.dailymail.co.uk/sciencetech/article-2014312/Milky-Way-pictures-Alex-Cherneys-photos-galaxy-seen-naked-eye.html#ixzz1S2rljIDG

Taken not too far from where I live
No man has the right to be an amateur in the matter of physical training. It is a shame for a man to grow old without seeing the beauty and strength of which his body is capable


@gossage91
@overtimefitnessau
#200
Quote by laid-to-waste
have you seen those scapes yourself? amazing



I went camping not too far from where those were taken, and saw a similar level of detail, but not quite as spectacular as those pictures. I have been to where those pictures were taken many many times, so I'm now determined that I'll go down there once on a clear night to see it for myself.
No man has the right to be an amateur in the matter of physical training. It is a shame for a man to grow old without seeing the beauty and strength of which his body is capable


@gossage91
@overtimefitnessau