Earth: no longer the lonely planet

SpaceRef ^ | 9/26/03

[quietolong]

I don’t know about ants. But I know the fish in my Aquarium do!
When it’s around feeding time. they line up along the glass and stare at you to feed them.
And they do know the difference between different people. If someone they don’t know goes over. they go to the bottom. But if they know you. They come to the top and wait for you to drop a fly, ant ( they go nuts over them) or other food in!

[AFreeBird]

Just ask Colonel Hammond.

That Colonel O'Niell (two L's) who reports to General Hammond (of Texas).

And Major Carter is a BABE!

[Paulie]

"With about 100 billion galaxies in the observable universe, our result suggests that there are at least 10 trillion planetary systems in the Universe."

Way, way beyond my ability to comprehend!

[edwin hubble]

Alamo-Girl,

Your thoughts on dark energy, gravity and planet formation are intriguing.

When considering the counter-action of dark energy and classical gravity, I think about other instances where two known forces are in play and counteract each other.

OK...Strong force vs electromagnetic in proton-proton fusion: The strong force is more powerful in shorter range, while electromagnetic is weaker but has longer legs, and would be more cosmic (unlimited) in its effective distance reach were it not so bi-polar.

AND...Millikan oil drop: gravity vs electric (long range and weak vs short range and stronger).

BUT...Dark Energy has longer legs than classical gravity. Because you are looking at gravity-repulsion effects in a shorter-than-cosmic range, I thought of the EÖTVÖS EXPERIMENT: One hundred and three years of repeated experiments investigating the un-proven evidence of a (proposed) weak repulsive force that acts in a distance range of a few meters to a few thousand.

Link:
http://www.kfki.hu/~tudtor/eotvos1/onehund.html

Eotvos is serious classical science. The experiments repeated in the last few decades look at a different (lower force of gravity exhibited) based on the spin number, baryon number and other nuclear properties apart from the mass of the object itself.

The great difficulty here is the experimental apparatus and measuring gravity at very close ranges.

Anyway, the challenge will be to learn how Dark Energy really works.

[RadioAstronomer]

Thanks for the post. I should have pinged you also. Sorry.

[edwin hubble]

Thanks I look forward to more real observations (data) in this area. So the posts #8, 11, 26, 29, 30, and 33 (by 'demlosers') are of real interest. Particularly neat is the Darwin infrared interferometer array in orbit. (post #26). .

[RadioAstronomer]

Indeed. I was looking at those also. Darwin Interferometer", cool name as well. :-)

[Virginia-American]

Personally, I'm hoping that someday we can detect oxygen-rich atmospheres - IMO, a sure sign of life.

[tophat9000]

I think we will find a Earth like planet in 20 - 30 years. Any takers?

Any sooner? I'd like to move out of Calif.

[tophat9000]

I would call Earth-like surface livable with out pressure suit.. free standing liquid water ... farmable

[Oberon]

Our television signals have been bombarding the stars since we first began broadcasting.

Not nearly all of them, however... only the ones within a sphere of about a 65-light-year radius. That probably doesn't take in but so many Sol-like stars.

[Oberon]

Hate to quibble, but that Kzinti female's mammaries are too few in number, and in the wrong places!

[MikeD]

It's my understanding as well that Dark Energy has only been detected on a cosmological scale. Otherwise, we'd just consider it part of the usual gravity term. The weird thing is that we measure one effect (the usual 1/r^2 force) for nearby things, but some other effect (the dark energy term) for far away things.

What is dark energy? Beats the heck out of me. Is there a fifth force that only manifests at large distances? Is there another term in the gravitational force that only exerts itself at large distances? We don't know yet.

The more we learn, the more we realize we have yet to learn...

MD

[Victoria Delsoul]

It could be that close to 100 per cent of stars have planets.

"Given that there are about 400 billion stars in our Galaxy alone, it means there could be up to 400 billion stars with planets," he says.

"With about 100 billion galaxies in the observable universe, our result suggests that there are at least 10 trillion planetary systems in the Universe."

Wow! Thanks for the pings.

[RadioAstronomer]

I thought so. Sure am glad you young whipper-snappers are on top of things. :-)

[Alamo-Girl]

Thank you so very much for that fascinating article, edwin hubble!

Indeed, perhaps what we are calling "dark energy" will, in the end, be seen as the 5th field. I'm impressed with how many engaging concepts I've recently read from Hungarian science sources. Jeepers!

IMHO, the clarity that we seek in physics will be answered by geometry. IOW, I agree with Einstein's dream of transmuting the "base wood" of matter into the "pure marble" of geometry. To that end, I thought you guys might be interested in this article:

The Equivalence Principle as Symmetry (pdf)

I also want to thank you earnestly, Radio Astronomer, for that great website! The very first article I clicked was very helpful:

The Cosmological Constant and Dark Energy

[RadioAstronomer]

Big smiles. :-)

[Alamo-Girl]

Big, grateful hugs!!!

[Frank_Discussion]

Too easy to win that bet, Kevin. I'm suspecting any day now. Our telescopes are getting better and better, even terrestrially. Keck's interfermeter in Hawaii is proving to be astounding. And our orbital scopes are about to get an upgrade, IIRC.

[KevinDavis]

Once we do find a Earth like planet, forget Mars, I want to go to that planet.