jtankers

However, I like the "science wants to describe"-notion you're using there, TheRealVeon. I've often run into people whose system of belief doesn't run well with today's scienctific knowledge - and who keep attacking science with the words "you don't know for sure". Tiring as it may be, they're completely right.

We don't know, why and if there is indeed a small/zero-dimensional object, called electron. It's enough that if everything works well with the model, we can describe the world a little better - and frankly, I don't care if it's a little fairy bearing the charge or a lifeless lepton...

(On second thought, I may come to like the fairy theory: Coming to think about it, all those free electron-fairies must be having a hell of a cascading party in our plasma reactors! I knew it! ... ahm ... well, I should go to bed. Now. G'night.)

AbedneGoTo

First: space-time is a physical dimension in this universe. It is not a "logical construct". It exists. We can measure the its effects and the effects of objects passing through it. Frame dragging, gravitational lensing and time dilation are several examples which have been empirically verified. If we look at a supermassive galaxy cluster and see light being bent around it, we don't see it because of some logical syllogism. We see it because it actually exists.

Second: In your next paragraph you say that: "It makes no sense unless you understand exactly how gravity works. And no one understands that." You are implying that since we cannot know every little detail about how gravity works, we really know nothing about how it works. This is totally false.

It is true that we do not know everything about gravity. We do not know with metaphysical certainty what anything is. But that isn't the point of doing science. Science is a method and a tool for describing the universe. Through science we can say an electron has a negative charge with respect to other particles. It has a spin. It has a velocity. But we can't say what it is metaphysically in the context of the greater universe. But not only is it not the point, it is also a waste of time. Once we have described it, and can predict its behavior, does it really matter that we can't say for certain what that electron's ultimate purpose is?

The same applies to gravity. We can describe its behavior, and come up with explanations for its interactions with other things is the universe. Not only is that all that really needs to be done, it's all we can do. If you expect absolute knowledge and certainty from science, you'll be perpetually disappointed.

Third: This isn't really a major point, but you seem to be treating inertia as a force. It's not. A force is anything which accelerates an object. Inertia is just the word we use to describe how moving objects stay moving and stationary objects stay put. There is no inertial "force".

TheRealVeon

Well, first off...the space/time continuum is a logical construct, not a physical one. Like Newton explained gravity with the apple metaphor, so does Einstein with the "fabric" metaphor.

So, when I'm describing the behavior of inertia and the underlying gravity affects, I'm talking logical constructs. It makes no sense unless you understand exactly how gravity works. And no one understands that.

In my theory, you are not actually pushing anything out of a gravity well. You are pushing the gravity well itself. Nothing ever moves in this universe, it's the universe itself (the fabric) which moves.

FrankenPC

RAHfanboy

RamseyAgdistis

No, these things aren't just numbers in an equation. Multiple lines of evidence point to them. For dark matter, it is not just that the universal expansion is too slow with respect to all the "light" matter. Evidence for it also comes from the rotation of galaxies, gravitational lensing and others. We can understand how it interacts with itself by observing colliding galaxies. We can even measure it's temperature by observing its density.

If this site wants to branch out into general science reporting, I'm all for it. I think that everyone should have a good understanding of science simply because it is so important is so many aspects of our lives. It's also really interesting and fun. Unfortunately I see a lot of misconceptions of science everywhere. I was surprised to see it here. I've always believed that science fiction consumers were more science savvy than the general public.

Many of the comments seem to say that in some unspecified time in the future we will have completely overturned relativity and look back on the current time with bemusement. No, the general concepts of relativity will never be overturned, only refined. Did we completely throw out Newtonian physics with the advent of Einstein? Do we look back on the physicists of the nineteenth century as simpletons for using such obviously wrong notions? No. We still use Newton's equations. We have just refined them through general relativity. Any discovery in the future will further refine our understanding of the universe, not throw out the old one.

The bottom line is that these theories, such as relativity and big bang cosmology, are based not on some equations filled with numbers tuned just so they work out the way we'd like them to based off of our emotional investments in them. They are based on real world observations. Those observations will be valid throughout time and any explanation for them will have to fit.

Could we be wrong. Absolutely. But by this point in our understanding of the universe, any major disruption to one field would likely cause shock waves throughout the rest of science. If there is something seriously wrong with our understanding of the universe, it would probably have shown up not just in one field but in many related ones as well. Again, we don't know everything and we never will. But when we do develop new ideas, they won't completely override and overturn old ones, they will be incorporated and supplement our current understanding.

For some more information of this topic specifically, I would recommend the book: Dark Side of the Universe: Dark Matter, Dark Energy, and the Fate of the Cosmos by Iain Nicolson for a good introduction to dark matter and energy and why we think it is currently the best explanation for the state of the universe. It is good because it does not only talk about the current theories but it also addresses many of the criticisms and counter-theories (such as an alternate understanding of gravity). For some general science info (especially space related) I would recommend going to the Universe Today and Bad Astronomy websites. For a better stated and more eloquent discussion of how science works in modern society, check out the Skeptic's Guide to the Universe podcast.

TheRealVeon

Jeff-Minor

Slatz_Grobnik

jtankers

I propose that science will never be complete because it's based on math and Godel proved that math will never be complete. I think many of the physicists who claim that a Theory of Everything is just around the corner realize that all this theory will really do is just raise new questions and suggest new experiments.

Science is endless, and endlessly interesting despite what John Horgan thinks.

corpore-metal

Mister Adequate

[applause]

braak

Mathmos

pharago

Unfortunately science teachers tend to just say everything is moving apart.

SeanOHara

RAHfanboy

Grey_Area

Nyquil breaks up Phlogiston.

I think the best way to find the answer to this quetion is to build spaceships. Lots of them.

Big ones.

Seth L

Also, can I get a shake with that?

Belabras

Jeff-Minor

katieb: in charge of the war on the poor.

Ed Grabianowski

Besides, she was waving at the cosmologist standing behind you.

Ed Grabianowski

Loserface

AbedneGoTo

Also, this would suggest that gravity probably moves pretty slowly, instead of pretty quickly, otherwise it'd be easy for the gravity to catch up with the object.

Oh, also--if you hit and object that's in a gravity well and it kind of bumps out and then falls towards the well, doesn't that mean it should be falling towards you?

braak

RAHfanboy

Jeff-Minor

Here is my theory: All matter pinches the space/time continuum (creating a gravity well). The greater the mass, the larger the pinch. Inertia also corresponds with the reaction mass required to bump the mass out of it's own gravity well. Once the mass is beyond it's well (in theory, the well is now in front of the mass at this point) the mass will perpetually fall towards it's own well unless acted upon externally. At that point, the well resets itself back to the center of it's own mass as it comes to rest.

This pretty much explains the behavior of all matter in a perfect vacuum without the external influence of gravity.

FrankenPC

sheckykarmichael

Velireon

DeepFriar

braak

SavannahJack

tetracycloide

tetracycloide

Oh, wait, I have it here! It's New Scientist, so take that with a grain of salt (I don't know how reputable they are, I just like to read about crazy science). David Wiltshire proposed the theory in New Journal of Physics IX 377.

This was the March 8-14 issue.

braak

Did that make any sense? I hope so cause I love talking about space, but, clearly, I don't really know what I'm talking about.

Elaborate please.

katieb: in charge of the war on the poor.

katieb: in charge of the war on the poor.

jarvik7

Why do I have a feeling a few centuries down the line, someone is going to go out and prove that the Aether is real! And also sentient! And it has a fondness for vacuums, which tosses that old saying out the window.

Because I know jack-squat about cosmology and read a lot of bad sci-fi, that's why.

Ghede

NefariousNewt

But my read of quantum mechanics and Big Bang theory led me to believe that if the expansion of the universe after the Big Bang caused both a cooling of the primordial mass and the differentiation of the physical forces as the universe expanded, then given the relative size of the universe at present, who's to say what local conditions were like at the time the light we are seeing was generated? In essence, I have always wondered if Einstein's precept that the laws of physics are the same no matter where you go in the universe might not be entirely true. Perhaps the basic laws are the same, but what if the constants were not constant, but depended on your distance from the initial bang?

NefariousNewt

In five words: I would like a cheeseburger.

It's funny, but I guess it's how it has to happen: physicists don't understand a phenomenon, so they make up something that explains it. Aether, Dark Energy, WIMPS. At least it's a starting off point.

braak

We act like all the spacetime, matter and energy was created in the instant of the big bang- but why is creation only an instant?

Distant galaxies aren't moving away from us; new space is appearing between us and they.

t3knomanser

NefariousNewt

braak