Heartland

http://www.nzherald.co.nz/topic/story.c ... d=10400645

Is discovering whether the big bang theory is correct or not really worth even that small of a chance of world destruction?

Well, it's known that the "big bang" is correct (more specifically it's "the inflationary model" -- "big bang" was coined as a derogatory term for early versions of the theory by Fred Hoyle, who disagreed with it) as far as it goes; the cosmic background microwave radiation is the left-over "glow" from when the whole universe was still hot and opaque. And the CBMR is still everywhere.

The Large Hadron Collider will push our knowledge that bit further. It might produce results that confirm, or on the other hand falsify, various string theories, 'brane theories and what-not. Cosmology is a bit arcane (even for me and I'm a total science geek) but knowledge is always worth pursuing for its own sake IMO.

We face more of a chance of being wiped out by a supernova within 100 light years (luckily there aren't too many candidate stars that could go foom that close) or by an asteroid impact.

"* They estimate the possibility of accidentally destroying the planet as extremely low."
Since when do they employ trolls at Reuters?
Reporters shouldn´t play Half Life, if the can´t handle it mentally..

I'll give it 10 seconds before some bloody fool thinks they could use it as a weapon, and 10 years before some even bigger bloody fool tries to create a weapon based on it. We should never have come out of the caves.

In a positive light, hopefully it'll disprove that whole "dark matter/dark energy" hogwash once and for all. We don't need to go invoking hobgoblins to explain stuff we don't understand.

Well, either dark matter and dark energy are real, or there's something seriously wrong with gravitational theory...

markfiend wrote: Well, either dark matter and dark energy are real, or there's something seriously wrong with gravitational theory...

My vote goes to the latter. We know a lot for sure, and we are able construct good models of how things work, but we should never assume that our theories are absolutely correct.

They remind me of the whole "luminiferous ether" thing, which was invoked to explain anomalies in then-current theories.

My hunch is for there being something wrong with the theories too. Intuitively at least, the idea that 80%+ of the universe is pretty much undetectable is just too out-there.

Mind you, a lot of quantum physics is out-there and non-intuitive too, so I don't know.

Indeed. Mark... I think the answer must lie in the 'brane type principles where an unseen force acts on this dimension, and that simply cannot be put into a theory until it is better known.

I find trying to get my head around the idea of other dimensions- New Scientist recently mentioned 11- when they cannot be seen (and when you think about it it makes your head hurt) - interesting but you can't let it affect you too much or you can't sleep

I know, 11 dimensions? I have trouble visualising more than three. I suppose our brains aren't really capable of coping with 'branes.

Oh my god I really have to get my coat after that.

Well there's a couple of holes. And not the black type.

The big one is that it's based on the assumption that our current understanding of physics is 100% correct. BIG MISTAKE.

Secondly, it's putting theory before observation, and using theory to twist observation. Historical precedent (epicycles, anyone?) should have shot that attitude down.

Thirdly, our current understanding of physics is a very complex model, with all sorts of mysterious doo-dahs, widgets and fudges required to make the numbers add up. Complex models have never been correct, and there's always been a simpler one that did the job better. Epicycles again, the ether, the steady state and all the rest were previous examples.

Overall, I get the feeling that physics and cosmology is heading for one of those "rip it up and start again" events (it's actually probably overdue one). While we feel that our current models are very good indeed, and while we may sometimes scoff at the ignorance of our ancestors, the same could have been said of those ancestors and their respective ancestors. We have a theoretical model that needs a whole load of unnecessary baggage to crutch it up, and despite all predictions we still don't have nuclear fusion, for instance. That sounds too familiar to the state that the whole Newtonian model was in at the end of the 19th century.

Overall, it's the same kind of monstrous scientific arrogance (and far far too much respect for the "Great Names") that has held back progress in the past. No, we don't understand what goes on in stars. We do understand it better than previous generations, but to claim a full underatanding is only fooling ourselves. Otherwise, where's my domestic fusion generator?

Phew! Had to get that out!

culprit wrote:Indeed. Mark... I think the answer must lie in the 'brane type principles where an unseen force acts on this dimension, and that simply cannot be put into a theory until it is better known.

I find trying to get my head around the idea of other dimensions- New Scientist recently mentioned 11- when they cannot be seen (and when you think about it it makes your head hurt) - interesting but you can't let it affect you too much or you can't sleep

Well here we go.

In Ye Olde Days, when natural philosophers were faced with an observation that didn't match their theories, they tried to protect their theories by invoking mysterious agencies which cannot be observed. God and his angels.

Nowadays, because we're so much more enlightened and civilised, when scientists are faced with an observation that doesn't match their theories, they try to protect their theories by invoking mysterious agencies which cannot be observed. Dark matter and 11 dimensions.

Same difference, really.

Yeah, I think you're right. However, I think there's a possibility that Dark Matter could be real - the hypothesised WIMP is no more intrinsically unlikely than the neutrino. (Neutrinos themselves are a form of dark matter, but they're "hot" dark matter, and the theories need "cold" dark matter)

As I recall, the first indirect evidence for dark matter was the rotation of spiral galaxies. If the mass of a galaxy were contained in its stars, the edges of galaxies should rotate far slower than the middles, (like Pluto's orbital speed is way slower than the Earth's for example; Kepler's orbital laws) so you'd end up with the galaxies' spiral arms "winding up". But it was discovered that they don't; the edges of galaxies rotate at much the same speed as their centres.

This implies that either our understanding of gravity on galactic scales is wrong, or that there's a lot of mass in the galaxies that isn't in the stars. There's way too much for it to be planets, after all, well over 99% of the mass of our solar system is in the Sun. (99.86% according to wiki) So the assumption is that there's something else.

The wiki entry on Dark Matter suggests that a new theory of gravity is not the answer; there are too many independent lines of evidence to show that a lot of the matter in the universe is invisible. One problem I have is that I don't understand why there doesn't seem to be any dark matter in the solar system; its gravitational pull should show up.

Dark energy is even weirder. It's basically "something" in empty space that's causing the expansion of the universe to accelerate. And it has mass too. I really don't understand that!

Anyway, here's a nice chart of the (currently understood) composition of the mass of the universe from NASA via wiki.



Edit to add: Cosmology hurts my brain. Weird shît can happen like: Galaxy A off in that direction is moving away from us at 40% of light-speed. Galaxy B is in the opposite direction, also moving away from us at 40% of light-speed. But if we look from Galaxy A, Galaxy B appears to be moving at 60% of light speed.

Note: these figures were pulled out of thin air, but I don't understand general relativity enough to work out the numbers. But the principle is sound (apparently)

You can´t understand the theory of relativity without the maths for it. It´s a thing of transformation of coordinates between moving systems. We can only understand what we experienced some day, and you´ll never have the chance to travel at, say 30% of the speed of light. Even if you did, you wouldn´t be able to sense anything. The theory of relativity is a freeky weird thing..
Not half as weird and freaky as the rest of the world though. That´s why it is easier to imply the answers were given out of the blue, burning bushes etc. thousands of years ago..

Well, as I understand it, General Relativity denies that there's any preferred frame of reference. So while in our frame of reference, we're stationary,* in a galaxy that we see receeding at 30% of light speed, a frame of reference that is there stationary would see us receeding at 30% of light speed.

But yeah, relativity is weird.

* Roughly. The Earth's orbit and rotation complicate things, but it is possible to write equations in GR which treat the Earth as a stationary and the rest of the universe rotating around it once every 24 hours. But the mathematics get horribly complicated

markfiend wrote:it is possible to write equations in GR which treat the Earth as a stationary and the rest of the universe rotating around it once every 24 hours. But the mathematics get horribly complicated [/size]

NO! don't!... brainache....

There is a website somewhere that treats this possibility as proof that the Earth is, in fact, immobile.

Seriously.

Although it might be a parody, sometimes it's hard to tell.

It´s a presumption often made to ease calculating orbits for stalites etc.
The interesting thing about physics is that two apparently contradicting theoryies may both be 100% functional, thus "true"..
Afact, that causes funny profesional illnesses of physicists..

I've always had an interest in cosmology but over the past couple of years I've got much deeper into it. Are you telling me I'm just wasting my goddamn time?!

boudicca wrote:Are you telling me I'm just wasting my goddamn time?!

Only if you don't enjoy it.

nick the stripper wrote:

boudicca wrote:Are you telling me I'm just wasting my goddamn time?!

Only if you don't enjoy it.

Well no worries there then, I love it. I don't know how anyone can't be facinated by these things. But it is somewhat depressing to think of being blown back to square one in our understanding of the universe...

Well, first it's depressing. Then it's just funny.

boudicca wrote: Well, first it's depressing. Then it's just funny.

Kind a like waiting for a new Sisters album

thhell wrote:

boudicca wrote: Well, first it's depressing. Then it's just funny.

Kind a like waiting for a new Sisters album

Or watching two turtles try to get intimate.

nick the stripper wrote:

thhell wrote:

boudicca wrote: Well, first it's depressing. Then it's just funny.

Kind a like waiting for a new Sisters album

Or watching two turtles try to get intimate.

Yeah, probably not the biggest of bangs...

boudicca wrote:

nick the stripper wrote:

boudicca wrote:Are you telling me I'm just wasting my goddamn time?!

Only if you don't enjoy it.

Well no worries there then, I love it. I don't know how anyone can't be facinated by these things. But it is somewhat depressing to think of being blown back to square one in our understanding of the universe...

Well, first it's depressing. Then it's just funny.

"first depressing, then funny", thus slightly nuts. You are heading in the right direction. I life doesn´t make you nuts, you simply didn´t get it..

Yes, space is curved. And you can probably tunnel through it by wormholes.
I´d still like to find out if one can quote a tunnel through Heartland and arrive at some other thread. If that would happen it would prove Heartland to be curved, maybe even twisted...

culprit wrote: I find trying to get my head around the idea of other dimensions- New Scientist recently mentioned 11- when they cannot be seen (and when you think about it it makes your head hurt) - interesting but you can't let it affect you too much or you can't sleep

The problem with more than 3 dimensions (such as the string theory suggests) seems to be that gravity wouldn't work the way it is observed in the universe -- for example, planets would crash onto the sun and not go around in stable orbits (or rather, would never have formed). But I'm not a physicist, and I've just read about that once. If there are more than 3, maybe the dark matter is hiding in them, but that's probably too naive thinking.