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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

#531

Post by pavel_lishin »

delecti wrote: post #157
wallace_f wrote: post #128

Earlier quoted context omitted.

Is it plausible for anything we'd build to travel .998c and survive the journey?

Just going that fast isn't really risky at all (assuming you don't hit anything, which isn't actually a safe assumption). The tough part is making something capable of a constant 1g of acceleration for a 7 year trip. Most of the craft we make only accelerate for the first small percent of a trip. We can do accelerations that high, but not for very long, and we can't even manage acceleration for such a long duration e…

> The tough part is making something capable of a constant 1g of acceleration for a 7 year trip.

Isn't that just a building with an engine in the basement? Seems like one of the harder parts would be making sure it can survive freefall at launch, turnaround and arrival.

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

#532

Post by fudged71 »

twoodfin wrote: post #51
rubicon33 wrote: post #9

I was reading up about earth alternatives recently, and upon realizing the distance was always going to limit us, no matter how perfect the planet, I realized we need to travel at the speed of light. I think our "best shot" at that right now, is to digitize humans. If we could store consciousness in binary, we could then transmit it at the speed of light (like we do with data every day!). You'd need a receiver on the…

If you're going to assume heavy equipment on the other end (ours or "someone else's"), it's not ridiculously beyond our current capabilities to simply transmit DNA sequences along with enough digital training material to "grow" and raise a human population from scratch.

has a mammalian fetus ever been developed to maturity outside of a natural womb?

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

#533

Post by 31reasons »

tuyguntn wrote: post #278

Every time I hear such news, I try to imagine how it feels being there, billions of miles away, looking at sky and saying "wow", I don't think we will be able to travel to distant planets in our lifetime, but thinking about it and trying to create that feeling always feels amazing to me.

If we use what we know about it and recreate the system in VR we could technically experience at least the visuals of being there.

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

#534

Post by Dylan16807 »

shawn-furyan wrote: post #513
DougWebb wrote: post #272

Earlier quoted context omitted.

I always thought that Firefly's scenario of a bunch of Earth-like worlds in close enough proximity to have regular trading ships flying between them was unrealistic. Now, not so much. This system even fits in with the "Abandon Earth en-mass, move to new set of worlds" backstory. So, what did J.J. know, and when did he know it? And for that matter, how did he know?

Corrections aside, it is an interesting observation that Firefly is less outlandish with this discovery (not a criticism, Firefly is optimized for fun, not scientific plausibility). Still, assuming light speed travel, Firefly's inhabited planets are still a heck of a lot closer, since the crew doesn't seem to noticeably age between the half dozen or so star systems that they visit, and don't appear to have any kind o…

> Still, assuming light speed travel, Firefly's inhabited planets are still a heck of a lot closer, since the crew doesn't seem to noticeably age between the half dozen or so star systems that they visit, and don't appear to have any kind of tech to reversibly[1] halt their metabolisms.

Closer than what? This system is significantly smaller than Firefly's. Or do you mean closer than this system is to Earth? Don't worry about that, since in Firefly it's one super-system with five main stars. http://i.picresize.com/images/2013/02/06/BMhCv.jpg It's about 55 light hours across.

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

#535

Post by zhan_eg »

dcposch wrote: post #496
dmix wrote: post #6

My favourite part of the press release: > The planets also are very close to each other. If a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth's sky. > In contrast to our sun, the TRAPPIST-1 star – classified as an ultra-cool dwarf – is so cool that liquid water cou…

> The planets also are very close to each other. If a person was standing on one of the planet’s surface, they could gaze up and potentially see geological features or clouds of neighboring worlds, which would sometimes appear larger than the moon in Earth's sky. this reminds me of one my favorite films ever. it is just four minutes long http://www.erikwernquist.com/wanderers/

Thank you, this is truly amazing. For all the people interested in any way in space - watch this :)

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

#536

Post by dragonwriter »

pavel_lishin wrote: post #531
delecti wrote: post #157

Earlier quoted context omitted.

Just going that fast isn't really risky at all (assuming you don't hit anything, which isn't actually a safe assumption). The tough part is making something capable of a constant 1g of acceleration for a 7 year trip. Most of the craft we make only accelerate for the first small percent of a trip. We can do accelerations that high, but not for very long, and we can't even manage acceleration for such a long duration e…

> The tough part is making something capable of a constant 1g of acceleration for a 7 year trip. Isn't that just a building with an engine in the basement? Seems like one of the harder parts would be making sure it can survive freefall at launch, turnaround and arrival.

> Isn't that just a building with an engine in the basement?

No, it turns out that the requirements of generating thrust (which require generating energy and using it to toss something out the back of your ship) end up running into hard limits in the delta-V you can carry based on the available thrust-generating technology. Surviving 1g of constant acceleration in easy (well, I mean, it requires a certain degree of structural strength, which as mass gets large--which it will even with something delivering a minute payload--becomes challenging because of square/cube issues), but building something that can actually generate 1g of constant acceleration for 7 years is a non-trivial engineering challenge.

> Seems like one of the harder parts would be making sure it can survive freefall at launch, turnaround and arrival.

No, surviving free fall is a non-issue. Literally, that means surviving not having external forces acting on it. There's nothing to it.

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

#538

Post by 31reasons »

Taniwha wrote: post #418

So how come when NASA tells us there are tiny invisible planets light years away we all applaud, but somehow when they point to the evidence of climate change right here right now it's all a big con?

"It is very hard for a man to believe something when his salary depends on not believing it"

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

#539

Post by Arizhel »

maverick_iceman wrote: post #461
Arizhel wrote: post #415

Earlier quoted context omitted.

What exactly are you saying? That once we really figure out gravity, faster-than-light travel will become possible? I've been saying that for years, and I'm no physicist. It's fairly obvious that gravity is not well understood by our physics. All we really know is that it correlates to the presence of mass: lots of mass (like a planet) equals a noticeable amount of gravity. Unlike electromagnetism, where we have the…

General relativity gives a very solid and accurate understanding of gravity.

It does? Great; please point me to some instructions on how to build an anti-gravity device. I can easily build myself an electromagnet with some wire and a battery, so if our understanding of gravity is so great, I should be able to do the same with gravity, right?

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

#540

Post by techdragon »

RileyJames wrote: post #388
kitrose wrote: post #360

Earlier quoted context omitted.

Can someone explain to me why we don't replicate some of these key platforms like the Hubble and James Webb ST? It seems like the major limitation for discovery is getting enough observation time for whatever certain point in the sky that scientists are researching. Why don't we launch a second copy of James Webb?

It looks like the James Webb cost $8.7B to launch. The Hubble $4.7B at launch and $10B through till 2010. So it seems cost is the limiting factor. Replicas might be cheaper, but they wouldn't be kickstarter cheap.

I'd love to see a breakdown of R&D vs Manufacturing, Launch and ongoing operations.

I'm under the impression that R&D is a significant component of the cost in these sorts of "one off" science projects/devices and consequently, manufacturing, launching and operating a second one might not cost anywhere near as much as the first one.

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