Other Than Mars Thread

Quote: rxwine

Makes perfect sense.

Almost. I mean, Galileo dropped a probe into Jupiter. If that didn't get us a good look, well...

And if we find a philandering deity hiding down there, that would have a huge impact :)

The wimps are just too wimpy I guess.

http://www.space.com/33497-dark-matter-search-comes-up-empty-lux-detector.html

Maybe even enough radiation to kill cockroaches.

Quote:

The spacecraft passed through Jupiter’s intense and deadly radiation belts, in 30 minutes absorbing the amount of radiation that several hundred million people will get in their lifetimes.

http://earthsky.org/space/juno-1st-jupiter-flyby-august-27-2016

Quote: rxwine

Maybe even enough radiation to kill cockroaches.

Not unless it's in the form of a shoe...

Warm-core planets are tricky. On the one hand they produce a magnetic field that helps to keep cosmic radiation away from the surface. On the other, they have magnetic fields that trap some cosmic radiation in belts around the planet.

Overall it's a good deal for beings who want to remain alive.

With reports like these, I have to double check to make sure I'm not reading something out of the National Enquirer.

Quote:

A powerful signal has been spotted coming from the vicinity of a sunlike star, and now astronomers are trying to figure out what it means.
In May 2015, researchers using a radio telescope in Russia detected a candidate SETI (search for extraterrestrial intelligence) signal that seems to originate from HD 164595, a star system that lies about 94 light-years from Earth, the website Centauri Dreams reported over the weekend.
The astronomers have not yet published a study about the detection; they plan to discuss it next month at the 67th International Astronautical Congress (IAC) in Guadalajara, Mexico, according to Centauri Dreams' Paul Gilster, who wrote that one of the team members forwarded him the IAC presentation

http://www.space.com/33893-seti-investigates-strong-candidate-signal.html

Quote: rxwine

With reports like these, I have to double check to make sure I'm not reading something out of the National Enquirer.

Wouldn't the Enquirer have also claimed the signal reveals some secrets of famous people, or involves some sort of scandal?

Such signals are not common, but not entirely unheard of. The thing is that, for the handful of odd signals that have been recorded, there's been no recurring signal afterwards. I assume none encoded any information either.

Now there's grumbling about how the info on the signal was published, lack of use of appropriate channels, etc. etc.

In other words, be extra-skeptical of scientific results as related by the popular media, and even by scientific publications. Always take the headline with a half-ton of salt, regardless of source, and add salt as the sensationalism of the headline goes up.

Above all, always wait and see. Preliminary findings usually carry a lot of uncertainty and a larger probability of error (ie faster-than-light neutrinos).

You may not know this, but physics is experiencing a crisis.

1) Dark matter still hasn't been identified, despite having detectors that can register a single photon from the hypothesized dark matter interactions.

2) The LHC results obtained recently, strongly suggests that up to the considerably high energy limits, of its operation, there are no new particles to be found, be they hypothesized or unexpected. These might exist at even higher energy levels, but for hypothesized particles, at least, it's very, very, very, very unlikely. One implication is that String Theory might be very, very, very wrong as currently formulated at least. Another is that Super Symmetry has one and a half feet in the grave.

3) Dark energy remains a complete mystery.

This is very good news.

No, really. I mean, it sucks for the scientists who've spent decades in String and Super Symmetry research (who must be sick of hearing that "negative results are still results"), and for the people working on the very sophisticated dark matter detectors, and for those at the LHC, even though it continues to provide multiple avenues for other high-energy research. But for physics as a whole, it's good news.

Around the end of the XIX century and the beginning of the XX, physics faced a similar crisis:

1) Newton's Theory of Universal Gravitation, which had proved extremely useful in astronomy and had other practical applications, was proved wrong (or incomplete) every time the orbit of Mercury was calculated, as it never matched the orbit as observed.

2) The atomic structure as determined experimentally by Rutherford and his team, meant that, according to all known laws of dynamics (motion), atoms shouldn't exist.

3) At that, there was no clear proof that atoms existed, which shook atomic theory something fierce.

4) According to ever more delicate and sensitive experiments, either the Earth was completely motionless with respect to the whole universe, or Maxwell's laws of electromagnetism were wrong (or incomplete), and again these had proven very useful and had practical applications.

What grew out of this massive crisis, what solved it, was three great advances in the understanding of the nature of the universe: 1) Quantum Theory by Max Plank, 2) The Theory of Special Relativity by Einstein and 3) The Theory of General Relativity also by Einstein.

Quantum theory led to quantum dynamics, which explained the dynamics that allowed atoms to exist (along with a mathematical proof of atoms by Einstein*), It would also alter prove invaluable in the field of electronics. Special Relativity extended and complemented Maxwell's laws, and showed the Earth moved but the speed of light did not (in a way). General Relativity extended and complemented Newton's laws (BTW, if you use GPS in any way, both parts of Relativity are essential to keep the satellite signals useful enough to provide accurate information; and they use atomic clocks made possible by Quantum theory).

So the good news with the current crisis is that we're in need of new major discoveries about the nature of the universe.

I'd like to say we're on the verge of doing so, but there's no way to tell. We may have many answers this time next year, or we may have few or no answers this tie one century from now.

Interesting times


(*) IN addition to all that, Einstein also explained the nature of the photoelectric effect. Had he published his papers on atoms, the photoelectric effect, and special relativity a few years apart each, he'd surely have been awarded multiple Noble prizes. As it is, he published them all together (yes, in a rather obscure periodical), and got but one Nobel Prize (which is about 1 more than 99% of scientists usually get, I guess).

Dark matter makes me think of fog. Invisible until you look through enough of it, then it has enough thickness you can detect it.

Perhaps identifying it will be something weird. Like finding an object in your house not by turning a light on, but turning a light off.

Reminds me in fact of a trick if you drop a very small object in a room. Turn out the lights and shine a flashlight level with the floor and the tiny object will cast a long shadow.

Quote: rxwine

Dark matter makes me think of fog. Invisible until you look through enough of it, then it has enough thickness you can detect it.

recently a galaxy's been spotted with very few visible stars, or luminous fog. The measurements (motion, gravity, luminosity, etc.) suggest it's made mostly of dark matter. What can be seen is few stars (for a galaxy), and nothing else.

Quote:

Perhaps identifying it will be something weird. Like finding an object in your house not by turning a light on, but turning a light off.

Reminds me in fact of a trick if you drop a very small object in a room. Turn out the lights and shine a flashlight level with the floor and the tiny object will cast a long shadow.

There's detecting it, and there's identifying it. In your example, a small object you're not looking for will cast a shadow as big as the object you want. But if the latter is near, say, a table leg, it won't cast much of a shadow at all.