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[stuart]

Question posed: What do you think will be the most significant discovery (or discoveries) in astronomy by 2010? By 2020?

[Blue Fire]

Hmmmm.... by 2010 eh? Only 3 years away. I'd go for a confirmed discovery of an Earth-sized planet at a similar distance from it's sun.

By 2020, I'm thinking that good evidence of microbial life on an extraterrestrial body might be in order.

Good question, Stuart! I'll have to think about it some more,... as I try to sort out discoveries that I hope for as opposed to discoveries I think likely.

[dmill1220]

Im hoping to see some kind of amazing discovery made when the large hadron collider goes on line soon. (2010) and
by 2020, new techologies that remove our dependency on petroleum products,
Maybe mass use of Fuel cell Technology in our vehicles.
Dennis

[Dragon Star]

I'm a ditto on Dennis. Both would be fabulous.

However, I will add that somewhere in-between there will be some amazing work in the medical field, and with Robotics. Both are going to explode with discoveries soon.

[Blue Fire]

I ran across an article recently that mentioned that scientists are still hoping to see the huge cosmic strings (from string theory) that some predict ought to be still flopping around somewhere in the universe as leftovers from early on in the universe's expansion history. Now, That would be cool - maybe by 2020?

In a related article, they have narrowed down the possible size of the extra dimensions of string theory (through gravity experiments) to less than half the width of a human hair - many think these dimensions are much, much smaller. Perhaps the Large Hadron Collider that Dennis mentions will get to the bottom of it.

[Dragon Star]

Huh? I thought the extra dimensions predicted by M Theory were proposed to the physical attributes to the strings themselves?

Expand the nucleus of an atom to the size of the solar system and a string would be approximately 3 meters long. I would say that's slightly smaller then half of that of the human hair.

I must be missing something here, perhaps there are dimensions both dealing with the geometry of the strings and our physical surroundings as well...

[Blue Fire]

Originally Posted by Dragon Star

Huh? I thought the extra dimensions predicted by M Theory were proposed to the physical attributes to the strings themselves?

Expand the nucleus of an atom to the size of the solar system and a string would be approximately 3 meters long. I would say that's slightly smaller then half of that of the human hair.

I must be missing something here, perhaps there are dimensions both dealing with the geometry of the strings and our physical surroundings as well...

First off, ooops - the cosmic strings I mentioned are indeed different from the the strings of M theory. From The Encyclopedia of Astrobiology Astronomy and Spaceflight:

Hypothetical, bizarre, massive objects that may have formed shortly after the Big Bang; they can be thought of as tubular samples of the universe from about 10-35 second after the beginning of time. Cosmic strings are entirely distinct from the subatomic strings predicted by superstring theory. If cosmic strings exist at all they are predicted to be infinitesimally small in cross section but enormously long, perhaps forming loops that could encircle an entire galaxy.

But as to the size of the extra dimensions of M Theory: http://www.sciam.com/article.cfm?art...m&chanID=sa003

If extra dimensions of space exist, they must be smaller than about half the width of a human hair, according to new measurements of the strength of gravity at short distances. Researchers found that the same law governing the gravitational pull between planets continues to work when objects are separated by as little as 56 micrometers. The finding rules out extra dimensions of 44 micrometers or larger, they report in this week's Physical Review Letters.

Discovering extra dimensions with the relatively huge size of a few micrometers would offer spectacular confirmation for string theory, the still unproved body of equations that may unify gravity with the normally incompatible realm of quantum physics. "Even though we haven't seen anything, these results put boundaries on what people can legitimately propose," says experimental physicist and study author Eric Adelberger of the University of Washington. "Testing the inverse square law [meaning Newton's law of gravity] is the bombproof way to look for extra dimensions."

Also explained in this article are some details of the experiment and how it was done. I am unsure if string theory bases it's prediction of the size of ALL the extra dimensions (7, plus time, plus the 3 big ones we know ofl) solely on the physical geometry of strings themselves. The quote above seems to imply no necessary connection between string size and extra dimension size. To my knowledge, the extra dimensions predicted by string theory were necessary to make the mathematics work out. The size of the extra dimensions is not necessarily tied exactly to the size of strings themselves, but rather is of interest here as an explanation of why gravity is so comparatively weak in the big 3, since it is proposed that gravity may have a different (stronger) value at smaller distances, i.e., in the smaller dimensions - thus confirming string theory's prediction of extra dimensions and the different value of gravity within them.

Whew, hope I've made at least Some sense.

[Dragon Star]

Ah, I see. Thanks for clearing that up.