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Seven earth-sized planets discovered circling a star 39 light years from Earth

nature.com

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Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#641

Post by RugnirViking »

neaden wrote: post #557
maverick_iceman wrote: post #449

Earlier quoted context omitted.

Jet planes can also be used to destroy skyscrapers. People don't seem to get really nervous about them.

We've created a giant security apparatus based on Jet planes. They are not something we just let anyone buy or fly and if you deviate from your flight path these days you stand a good chance of getting shot down. People definitely get nervous about them.

Are you implying that rockets capable of transporting several hundred kg of tungsten to orbit are -not- tightly controlled? I imagine if you assembled anything close to this size without seeking extensive permissions you would be quite severely punished

Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#642

Post by andygates »

sixdimensional wrote: post #588
antiviral wrote: post #548

Earlier quoted context omitted.

Just as interesting is a recent news story about a plan to build an interstellar space ship, propelled by giant solar sails to travel about .2c (20% of the speed of light). In other words, we could get to the Trappist-1 star system in about 145 years.. practically in the blink of an eye. https://www.gizmodo.com.au/2017/02/how-an-interstellar-stars...

Nuclear pulse propolsion... Project Orion... if only we could figure out the darn problem with the fallout and treaties/bans.

Tsiolkovsky is unforgiving. You'd need an amazing amount of fuel.

Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#643

Post by a_imho »

thangalin wrote: post #563
pwython wrote: post #384

Earlier quoted context omitted.

A Hubble or James Webb is easily a billion dollar effort, making it THE major limitation for discovery. No one is investing that sort of money for no return. Honestly, even if they did, it would be frowned upon considering the more important humanitarian investments at hand.

"In 1970, a Zambia-based nun named Sister Mary Jucunda wrote to Dr. Ernst Stuhlinger, then-associate director of science at NASA's Marshall Space Flight Center, in response to his ongoing research into a piloted mission to Mars. Specifically, she asked how he could suggest spending billions of dollars on such a project at a time when so many children were starving on Earth." I encourage you to read his reply. http://…

The voyage to Mars will certainly not be a direct source of food for the hungry. However, it will lead to so many new technologies and capabilities that the spin-offs from this project alone will be worth many times the cost of its implementation.

Supposedly he is right and NASA money is well spent, it still not implies it is efficiently spent. Furthermore, he seems to writes off aids as a net loss in his analogy, without considering the benefits of children not starving (to death). Which is especially weird with the follow up

We need more young men and women who choose science as a career

/devils advocate

Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#645

Post by contras1970 »

dragonwriter wrote: post #317
mi100hael wrote: post #284

Earlier quoted context omitted.

It's an incorrect and jarring usage of the phrase. Plenty of folks on HN are non-native speakers who benefit from knowing when colloquialisms are used incorrectly.

The transitive form "Begs the question " is long attested, quite common, very clear and readily distinguishable from the intransitive form "Begs the question" [with no direct object], which refers to the petitio principii fallacy, when people prefer a translation into somewhat archaic English to the Latin. In fact, the attempts I've seen to quantify usages (including those by prescriptivist pedants still trying to pe…

s/pedal/peddle/

Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#646

Post by kk_cz »

ant6n wrote: post #307

It seems that this could be an interesting system to be targeted by a FOCAL mission. It is the idea to use the sun as a large telescope by using its gravitational sense. One would have to have a telescope placed about 550 AU or so away from the sun, on the opposite side of the system you want to look at. The magnification could be large enough to analyze features on exoplanets. My dream would be to build a telescope…

I was having hard time imaging 550 AU, so for context ( distances from the Sun):

- Jupiter: ~5.2 AU

- Pluto: ~39.5 AU

- Voyager 1 ~137,75 AU

Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#648

Post by mtgx »

hcarvalhoalves wrote: post #394
mtgx wrote: post #42

Earlier quoted context omitted.

I doubt we'll attempt serious inter-stellar travel before we figure out antimatter or black hole-powered engines. So we may have to wait a century or two. This century we should be more worried about making fusion-powered intra-solar system travel a common thing, and about establishing large colonies on Mars and several moons.

> So we may have to wait a century or two. It took some thousands of years to be able to circumnavigate the planet, and some centuries after that to do it quickly and safely. It feels IST in a matter of centuries from now is extremely optimistic.

100 years if probably too optimistic. 200 years probably isn't. Don't forget our technological progress has been exponential. We've had more progress in the past 100 years than in the entire human history.

We're also supposed to create the "singularity" this century, which will give us orders and orders of magnitude higher intelligence than what we have today. Hopefully we can use that intelligence to create those engines.

Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#649

Post by kk_cz »

pshposh wrote: post #155
h4nkoslo wrote: post #41

Uh oh. The "great filter" hypothesis is essentially that the rarity of intelligent life has to be explained by some parameter of the Drake equation, and that whatever the "small" parameter is is either in our past or in our future. If the "great filter" is the rarity of habitable worlds, then clearly we don't need to fear it, since we already found one. But if habitable worlds aren't rare, then it's more likely it li…

But what if we are the first and no filter exists at all?

Isn't that highly unlikely due to the age of the universe vs age of the Solar System?

Re: Seven earth-sized planets discovered circling a star 39 light years from Earth

#650

Post by mtgx »

kakarot wrote: post #243
mtgx wrote: post #42

Earlier quoted context omitted.

I doubt we'll attempt serious inter-stellar travel before we figure out antimatter or black hole-powered engines. So we may have to wait a century or two. This century we should be more worried about making fusion-powered intra-solar system travel a common thing, and about establishing large colonies on Mars and several moons.

I don't know about all of that speculation, but you did give me a nice mental image of a barren, battle-scarred solar system littered with battleships containing black holes, ready to cause catastrophe at any moment, much like the nuclear wastelands of the Arctic.

Yeah, black holes scare me, too. But to me it looks like the most "realistic" solution for travelling 10+ light-years. If we learn how to create cheap antimatter, we may be able to use that, too, but I'm not so sure if we could store that much on the ship for the roundtrip. A blackhole could last us a lot longer (I think around 100 light years, last I read about it - I don't remember the space ship's speed, but probably like 30% of light speed).
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