NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth • Hacker News Board

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#281

Post by kinj28 » Fri, Jul 24, 2015, 9:32 AM UTC

eastbayjake wrote: post #76

phantarch wrote: post #5

At 2 billion years older than Earth, I can't begin to imagine what kinds of things could possibly be living on this planet. Given, of course, that it's got the right ingredients for life to arise. What if it's suffered huge extinctions recently? What if there's a domineering species out to conquer the planet just like humans? What if there's a society there more sophisticated than us? It's a very exciting discovery.

It's jarring to think that if intelligent life were on Kepler 452-b and observing Earth, we're so far away that they would be seeing our "civilizations" in 615 AD: shrinking global population as the old Roman and Byzantine empires are overrun by barbarian hordes and Arab conquest, with some pockets of human progress in China. They would have no way of knowing that the descendants of those squabbling warlords just coo…

I would want to wait for the day when NASA announces to watch earth from light years or light months away and show us earth back in time.

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#282

Post by TeMPOraL » Fri, Jul 24, 2015, 10:17 AM UTC

IanCal wrote: post #277

lovemenot wrote: post #274

Earlier quoted context omitted.

This solar system orbits the galactic center every 250 million years or so; making us a young adult of around 18 Galactic years old, living in a suburb of quite a busy galaxy. Every eighteen year-old suburbanite[1] has already been pretty well socialised by local interactions in the context of a global system of local interactions, performed massively in parallel. [1] metaphors mixed and units of measure utterly mess…

I love this galactic orbit measure of things. Dinosaurs like the Iguanadon were alive ~125mya, which means that the impressive thing when looking at a fossil is not that it's old, it's that it came from the other side of the galaxy . You can go and pick up a trilobite that's coming up to its third orbit. Yes, I know, it's still from Earth, but I do think it's a weird way of looking at dinosaur fossils. More other-sid…

Grabs the Iguanodon skull

- What did you see out there? What horrors and wonders hide on the other side of space? Tell me, what did you see?

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#283

Post by _ikke_ » Fri, Jul 24, 2015, 11:51 AM UTC

kinj28 wrote: post #281

eastbayjake wrote: post #76

Earlier quoted context omitted.

It's jarring to think that if intelligent life were on Kepler 452-b and observing Earth, we're so far away that they would be seeing our "civilizations" in 615 AD: shrinking global population as the old Roman and Byzantine empires are overrun by barbarian hordes and Arab conquest, with some pockets of human progress in China. They would have no way of knowing that the descendants of those squabbling warlords just coo…

I would want to wait for the day when NASA announces to watch earth from light years or light months away and show us earth back in time.

You'd have to travel faster then light to outrun the light emmited from years ago.

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#284

Post by [deleted] » Fri, Jul 24, 2015, 11:52 AM UTC

Gravityloss wrote: post #111

The significance is this: it's very likely that there are a lot more such planets a lot nearer to us. This is because Kepler can only detect planets which lie in the same plane as earth and the star so the planet occults the star. Assuming random distribution, there's probably thousand fold amount of off plane planets. There are 259 stars within about 30 light years. Communication could be conceivable with such dista…

[deleted]

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#285

Post by lhopki01 » Fri, Jul 24, 2015, 1:21 PM UTC

maaku wrote: post #251

vectorjohn wrote: post #208

Earlier quoted context omitted.

What? No, absolutely no we would not just see them with sensitive telescopes. Perhaps, if you're thinking of some sort of interstellar space travel, maybe we'd see the engines? But no, even that seems unlikely. Any space habitat of any plausible size will be completely undetectable, or at least indistinguishable from a planet. And I would think they'd be much smaller than that. And structured radio? Lots of possible…

I think you are completely misunderstanding the point. He have to vent heat somehow in the most efficient ways of doing so are not natural in their spectra. An encrypted radio transmission is still perfectly detectable -- you may not know what it says but you know that it is there. Artificial signals are blindingly obvious. And this is without getting into Dyson spheres and other efficient but detectable technology.

Encrypted signals are not blindingly obvious. An encrypted radio transmission will appear as pure random noise and no different from all the rest of the noise that we pick up.

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#286

Post by lhopki01 » Fri, Jul 24, 2015, 1:21 PM UTC

maaku wrote: post #251

vectorjohn wrote: post #208

Earlier quoted context omitted.

What? No, absolutely no we would not just see them with sensitive telescopes. Perhaps, if you're thinking of some sort of interstellar space travel, maybe we'd see the engines? But no, even that seems unlikely. Any space habitat of any plausible size will be completely undetectable, or at least indistinguishable from a planet. And I would think they'd be much smaller than that. And structured radio? Lots of possible…

I think you are completely misunderstanding the point. He have to vent heat somehow in the most efficient ways of doing so are not natural in their spectra. An encrypted radio transmission is still perfectly detectable -- you may not know what it says but you know that it is there. Artificial signals are blindingly obvious. And this is without getting into Dyson spheres and other efficient but detectable technology.

Encrypted signals are not blindingly obvious. An encrypted radio transmission will appear as pure random noise and no different from all the rest of the noise that we pick up.

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#287

Post by mcdougle » Fri, Jul 24, 2015, 2:30 PM UTC

pi-rat wrote: post #279

IndianAstronaut wrote: post #188

Earlier quoted context omitted.

Why go that far? Titan, Saturn's moon, is loaded with far more hydrocarbons than are available on Earth.

Don't tell that to the politicians! We'll never get to leave the solar-system if they believe they can have all the oil they'll ever need right here in the neighbourhood!

That's probably the next logical step, though, honestly. Not necessarily oil specifically, but resources in general and even colonization of any nearby planets/etc. that will allow it.

How did we discover (and begin actually using) the Americas? Christopher Columbus was sent on a trip to retrieve resources from India. It was a financial trip, supposed to enrich the government, not an exploratory one.

That's kind of how it's always been. Societies have discovered new people, lands, and resources by accident while trying to expand their empires (generally).

Furthermore, as we continue to consume resources and grow our population, we should probably strive to expand our society to other locations before we overconsume and overpopulate to the point that it starts to cause problems.

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#288

Post by mcdougle » Fri, Jul 24, 2015, 2:34 PM UTC

dandelany wrote: post #79

cbhl wrote: post #68

Earlier quoted context omitted.

IIRC, the amount of radio waves leaking from Earth into space has decreased substantially over the last few decades. I wouldn't be surprised if energy efficiency gets to the point where, if a foreign alien civilization notices radio waves from Earth, by the time they transmit a round-trip back at Earth we'll have long since stopped leaking terrestrial radio waves by accident into space.

True, but our radio telescopes have also been improving. The Square Kilometre Array, under construction in Australia, would supposedly be able to detect "an airport radar system on a planet 50 light years away". I suspect that an advanced civilization 500 ly away would still likely leak enough radio for us to detect it with current or near-future technology.

Unless their technology developed along a completely different path, and the concept of radio waves is too foreign to them because they use an altogether different method of communication that we can't even begin to imagine.

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#289

Post by mod » Fri, Jul 24, 2015, 2:44 PM UTC

krapp wrote: post #220

evilduck wrote: post #195

Earlier quoted context omitted.

Maybe they tried and failed? Maybe they arrived on a sterile Earth 3.6 billion years ago with supplies and huge tomes of knowledge, promptly died off within a couple hundred years of arrival, tectonic movement subsumed their landing ship and all other physical records of their existence here and we're all just descendants of their gut flora?

All of this has happened before, and will happen again.

Can you explain that?

I wouldn't have expected every possible situation to have occurred given the finite history of the universe.

But I really have no idea what I'm talking about, so my request is serious.

Re: NASA’s Kepler Mission Discovers Bigger, Older Cousin to Earth

#290

Post by maaku » Fri, Jul 24, 2015, 3:29 PM UTC

lhopki01 wrote: post #285

maaku wrote: post #251

Earlier quoted context omitted.

I think you are completely misunderstanding the point. He have to vent heat somehow in the most efficient ways of doing so are not natural in their spectra. An encrypted radio transmission is still perfectly detectable -- you may not know what it says but you know that it is there. Artificial signals are blindingly obvious. And this is without getting into Dyson spheres and other efficient but detectable technology.

Encrypted signals are not blindingly obvious. An encrypted radio transmission will appear as pure random noise and no different from all the rest of the noise that we pick up.

If an astronomer picks up a radio signal it is extremely obvious whether it is an artificial source or not. Natural sources have very inefficient spectra of very specific types. Artificial sources have very clear frequency cutoffs, having come from an antenna. Even frequency-hopping sources may jump around in a way that makes eavesdropping difficult, but if you stick around long enough on a single channel (as radio astronomers do) you'll get little blips now and then as the signal hops through your channel and is gone again.

How do we know this? Because astronomers see these every single night and have developed sophisticated filters to remove them. But by checking how the source is moving it is quite easy to tell if source is local or not, and sure enough all these artificial sources come from satellites, the troposphere, or an unshielded microwave.

It is actually remarkably difficult and a challenging problem in itself to create a communication mechanism which looks like a natural source. It defies imagination to think that every single intelligent species out there has purposefully masked their existence in such a way, including giving up useful technology like ground control radar or mobile communications.