Renewed Gravity Research Could Soon Yield Results

t482 writes "Dr. Michelle Thaller has a nice article describing the current thoughts on gravity. Why is it so weak? Detecting gravity waves has turned into a bit of a cottage industry. "We are close," says MIT physicist Rainer Weiss, a pioneer in gravity wave research for more than 30 years. "I think sometime in the next two or three years we will see something.""

Comments

Maligning Einstein??

[WTFmonkey]

Right, because it was Einstein's Theory of General Relativity, published in 1916, that proposed the existence of gravity waves -- ripples in the fabric of space-time that LIGO scientists hope to measure for the first time.

Wrong, because even the greatest genius of the 20th century never dreamed that humans would build something sensitive enough to actually detect a passing gravity wave.

Did Einstein ever actually say "We can never build a machine to detect these?" If not, then that's like saying that Plato was wrong because he never wrote about moon colonies. It just doesn't make sense. If he actually said, "We can never detect these things" then he's wrong. Otherwise he just didn't get around to thinking about it. Bad journalism.

And another thing

[WTFmonkey]

At those levels, scientists say they should be able to detect gravitational radiation from the first moments of the universe -- relic signals from the first second of the Big Bang.

I must be physics challenged. If there were waves created by the big bang, wouldn't they have moved away from the center much faster than the stuff that makes up our planet? Like 2 (3-d) ripples in a pond, one moving faster than the other? Or is this one of those "The universe is infinite and everything is moving away from everything else so there was no 'central location of the universe' because at the time of big bang the universe was only as big as the stuff was expanding" things. But.. but... if it's expanding, how is it infinite? If it's infinite, how is it expanding?

I wish I could wrap my mind around these things, because it's fascinating as hell, I just can't quite fit it.

Re:And another thing

[Yokaze]

Space is finite, but has not borders and is expanding.

The best likening I've heard of is the surface (2D) of a baloon.

The surface of the baloon has no borders, you can go around it like you want. Still, its space is finite. And if you pump it up, the space is expanding.

The mistake most people make in imagining the Big Bang is taking it literally. An explosion of material in space.
The point is there was no space in which the explosion happened and neither was material. Space happened. Material came even later.

Re:And another thing

[Nyphur]

"Space in finite, but has not borders and is expanding."

Think in terms of energy levels. If we take a perfect vacuum, a space in which nothing exists, there is no energy. Of course, even space isn't a perfect vacuum. Such a vacuum would be expected to be found somehwere outside the measurable distance of the universe. "Beyond the edge," as it were. Thinking in terms of energy levels, we can percieve matter to be the highest energy level. Matter being thought of as energy condensed and slowed to a stable coactive form is not a new idea, but it has been one of the most important principals of Quantum Phyiscs on such issues.
Taking this as true, matter cannot exist as an energy level without energy levels bneath it being full, otherwise the matter would drop down to the lower energy level and release a tremendous ammount of energy in the process. This again, is not that new of a way of thinking. "Zero point" energy, as it is called, is the lowest order of energy. It has been proposed that if we could tap into zero point energy, we could effectively get limitless energy for free, zero point energy being essentially everywhere since if there is a place for anything to exist, that place must have energy levels higher than the zero point and thus the zero point energy levels must be there. Even in a total vacuum, zero point energy exists. However, the potential of "mining" zero point energy is not in the energy you get yourself from removing it. Indeed, it would probably require a tremendous input of power in order to remove zero point energy from an area of space. The theoretical potential which exists for mning zero point energy is the fact that once it is removed, all energy levels above it must drop to fill in the space. Thus, if you took some matter and in the space in which the matter existed, mined out the zero point energy, the matter would convert into a lower energy form than matter, having no energy level to be based on as matter itself. This would, in essence, convert the matter to energy, releasing a tremendous ammount of energy. It is said that the resulting explosion from removing a small potion of zero point energy from matter filled space would make the largest nuke look like a firecracker.

This all said, we have to consider what exists at the "edge" of the universe. With amtter existing based on higher energy levels in places and no matter existing in others, it is reasonable to assume that the energy levels are concentrated towards some kind of central point and thus fade, the further you get from that point. The edge of the universe would then be an area which has few higher energy levels, eventually fading out into a point of having not even zero point energy. This point of not having zero point energy would result in a lack of space existing in the sense that we know it, making a final edge to the expanse of the universe. However, any matter approaching this edge would be converted to energy slowly as it passes the point where there is no energy level below matter in order that the amtter can remain matter. This means we can't actually send matter to the edge of the universe since it is of too high an energy order.
The energy levels diffusing and expanding from the central point of highest energy level (the big bang point, if you like) to lower points of lower energy levels, which is essentially, the universe expanding.

It's all just a theory of mine though.. pieced together from this and that. It works right in my head and I'll probably change it some time if I find out more on the subject.

I have a question.

[Mac73117]

Why couldn't we put this lab in orbit? That way we wouldn't have to compensate for so much extraneous gravitational noise. Or am I missing that fact that this equipment needs the Earth's gravity well to function.

Disclaimer: I am not a physicists, just a guy who likes science.

Re:I have a question.

[edgar_is_good]

There actually is a plan to put it in space called LISA. It would consist of satellites to study the waves. Different setups make you sensitive to different sources of gravitational waves and LISA will detect different sources than LIGO will.