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01/05/2006 02:46:36 PM · #51 |
Originally posted by scalvert:
Originally posted by David.C:
...we don't know that there is anything else there. Their presence is not the only thing that was inferred -- their very existence was as well. Inferred because thier existence was required by a theory |
Uh... no. The existence of dark matter is inferred from observations of its gravitational effect on visible matter. We know there is a big, dark planet near a star because of a wobble in the host star's orbit, or we know there is a black hole at a certain location because the speed of orbiting matter is too fast to hold together without a high-mass object present in a very small space at the center. This is Newtownian physics, not some new theory. |
Here your referring to matter that is measurable -- if it affects a neighboring star, that star is measuring it. It's not unmeasurable.
The dark matter I was referring to (and thought you were) is the matter whos existence was inferred to fill the holes in the theory of inflation. Matter that has a profound gravitational impact on the formation of the universe, and yet no matter how you look it can not be measured.
There are other theories out there that explain things just as well without having to resort to an ether-like substance. M-Theory, for example -- the theory that unified the various string theories -- calls for our universe to consist of vibrating strings attached to a huge membrain. A membrain that is only one of countless many. The phenomenon that led to the theory of the big bang are described by an instance of one of these membrains touching another -- and I believe everything being attached to a single membrain that reverberates from the impact would explain the background radiation well enough. But, M-theory has it's own problems with provability. One such problem is that it relies a great deal on the existence of a graviton (the particle that transmits the force of gravity) that is not tied to the membrain and able to move from one to another.
Regardless, the big bang, inflation or M-theory, they all have in common that they are speculations based on too little data to be able to speculate with any degree of accuracy. Any one or all of them may be true, but to accept any of them as fact until the observations they were born from are shown to be universal can only lead to folly.
David
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01/05/2006 03:19:01 PM · #52 |
Originally posted by David.C:
Matter that has a profound gravitational impact on the formation of the universe, and yet no matter how you look it can not be measured. |
You're contradicting yourself. A profound gravitational impact is obviously measurable. The whole point of dark matter is that it has mass, yet we can't see it. The theoretical "holes" you refer to are imbalances in mass calculations between what we can see and what we can't. This "dark matter" includes black holes, brown dwarfs, planets, subatomic particles and anything else that affects gravity, but isn't visible through telescopes. We can't see it, but we CAN measure its mass (see the article MQuinn just posted), otherwise it wouldn't balance the observed discrepancy.
We know from its gravitational pull that dark matter exists the same way we know there's something on the other end of a fishing line when the rod bends. The observed pull (in either case) is not speculation.
Message edited by author 2006-01-05 15:20:25. |
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01/05/2006 03:28:21 PM · #53 |
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01/05/2006 03:37:34 PM · #54 |
As Scalvert posted, the observed effects are exactly what we DO know about dark matter. There are alternative hypotheses that don't required dark matter as a balancing force, but as of this date, they all have "problems" in other areas. though it's not a slam dunk, it's looking like dark matter is real.
The more we learn about our universe, the more we find that truth is stranger than fiction. Einstein lamented the fact that that his Theory of General Relativity required a "fudge factor" to reconcile the math, and he regarded this as a failing of his theory. From a historical perspective, his "fudge factor" is looking better and better, LOL.
Perhaps our greatest failing is that in the 100 years or so since Einstein upset Newtonian Physics forever, we have failed to explain gravity in terms of quantum mechanics.
Hubble has truly been a testament to Man's history. Out of an initially flawed instrument, we have managed to extract incredible insight, proving once again that success through failure and perseverance pay off. Hubble is near or at the top of the most significant scientific instruments yet constructed by Man.
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01/05/2006 03:47:14 PM · #55 |
| Not bad for a 3.3 megapixel camera |
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01/05/2006 03:51:48 PM · #56 |
Common sense tells us a lot of things like; don't touch a hot pan, an icy sidewalk may be slippery, a knife may be sharp etc.
Common sense also used to tell us that the earth was flat, women were inferior, slavery was OK, fire was magic, everything in the universe revolved around the earth, heavy objects fall faster than light ones and many other fallacies.
Just because you can't wrap the grey matter in your gourd around the concept of Dark Matter, the Big Bang, or any other advanced concept doesn't mean that it is wrong.
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01/05/2006 03:53:58 PM · #57 |
Originally posted by notonline:
will that lense fit my XT or will I have to go for an upgrade??? |
lol I would love to see that len on a rebel xt :-)
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01/05/2006 03:54:37 PM · #58 |
Great image, that goes into the save file.
late to be responding, but..
Originally posted by cpurser:
Is it just me, or does anyone else here think that the idea of all this vastness and mass coming from a dot (aka, Big Bang) totally unbelievable, and frankly full of crap?
-Chad |
Of course it is unbelivable, I can't see it from my couch, and therefore don't belive in it. I don't belive in atoms, cells or germs either. I belive illness is caused by bad thinking and demonic possession. I have no proof that anyone else continues to exist when I close my eyes. Thank god that the funding to maintain Hubble has been cut, so we will have no more of such troubling images
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01/05/2006 03:54:48 PM · #59 |
Originally posted by d95vette:
Not bad for a 3.3 megapixel camera |
Hubble's Advanced Camera for Surveys (used for this image) is a 16 megapixel camera. Still... |
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01/05/2006 04:00:20 PM · #60 |
It cheeses me off that I'll have to die (and very soon, on the cosmic scale) and miss out on witnessing all future advances and discoveries.
I hope with all my heart that we either keep re-incarnating, or that we'll at least get to sit on our clouds and watch people struggling to come to grips with all this. |
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01/05/2006 04:02:26 PM · #61 |
I feel very small.....
Originally posted by Skyarcher:
If you would like to see just a small, itty bitty, tiny portion of why we are just a blip in the cosmic... then here you go. :)
Secret Worlds - The Universe Within - Powers of 10
That is URL that we give all new members of our club. Lest they think we 'Earth' is a big part of the universe. :D |
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01/05/2006 05:05:41 PM · #62 |
Originally posted by Skyarcher:
...If you would like to see just a small, itty bitty, tiny portion of why we are just a blip in the cosmic... then here you go. :)
Secret Worlds - The Universe Within - Powers of 10
That is URL that we give all new members of our club. Lest they think we 'Earth' is a big part of the universe. :D |
That's really cool! We are Nothing in the greater scheme of things... |
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01/05/2006 06:47:36 PM · #63 |
Originally posted by Kivet:
I feel very small.....
Originally posted by Skyarcher:
If you would like to see just a small, itty bitty, tiny portion of why we are just a blip in the cosmic... then here you go. :)
Secret Worlds - The Universe Within - Powers of 10
That is URL that we give all new members of our club. Lest they think we 'Earth' is a big part of the universe. :D |
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;) Just think how small that single proton feels. |
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01/05/2006 08:34:32 PM · #64 |
The image from Hubble reminds me of the end of Men In Black. Our galaxies are just big intergalactic marbles! :p
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