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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

#661

Post by bb101 »

BinaryIdiot wrote: post #336
neaden wrote: post #301

Earlier quoted context omitted.

Isn't part of the problem that any ship capable of interstellar travel is also capable of being turned into a WMD? I imagine a lot of people would get really nervous if someone for instance parked a bunch of radioactive material in low earth orbit, and even with fusion there would be the fear that someone could turn the ship around.

To be fair kinetic bombardment is stupid easy to do once you can put stuff into orbit. Put a few, 20 foot long tungsten rods into orbit and you can effectively nuke, without radiation, any location that you orbit over [1]. Sure this is a problem but it's one that already exists today, not necessarily only when we start building space craft in orbit. [1] https://en.wikipedia.org/wiki/Kinetic_bombardment

If anyone is interested in kinetic bombardment, read Heinlein's "The Moon is a Harsh Mistress". Much like how the Fosterites in his "Stranger in a Strange Land" were a blueprint for Scientology, TMiaHM is a guide on how to plan and conduct a revolution, although in this case it was the Moon against Earth.

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

#662

Post by lukaszjb »

callumprentice wrote: post #607

A few months ago, I made a simple WebGL app to compare the sizes of our sun and the planets for my 5 year old daughter who was curious. I updated it today to include the TRAPPIST system and see how it compares to our own solar system. http://callumprentice.github.io/apps/celestial_bodies/index....

Nice done! I didn't know that earth is so small compared to sun.

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

#663

Post by [deleted] »

misnome wrote: post #583
blueprint wrote: post #555

Earlier quoted context omitted.

When it comes to physics, it does in fact mean you can use the principle you discovered in engineering technology. That's kind of the whole point.

By the same 'argument', understanding the laws of thermodynamics (which prohibit perpetual motion) allows us to exploit perpetual motion?

[deleted]

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

#664

Post by hkjgkjy »

e0m wrote: post #33

To get a spacecraft there it would take: Accelerating at 1g the 1st half, and decelerating at 1g the 2nd half, the traveler would experience 7.3 years of time. For observers it would take 41.8 years at a max speed of 0.998c If you had a near perfect hydrogen -> helium fusion engine, it'd take about 6 million tons of fuel (about the mass of the Pyramids of Egypt or 2,000 Saturn V rockets)

For others who don't know how much an American ton is, 6 mil of them = (5.44 * (10^9)) kilograms.

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

#666

Post by pharke »

stevewilhelm wrote: post #589
jameshart wrote: post #389

Earlier quoted context omitted.

Importantly, that means there is basically no way that a civilization that developed on such a planet would not at some point endeavor to travel to those other planets.

> no way that a civilization that developed on such a planet would not at some point endeavor to travel to those other planets. That seems like a very human statement. One could argue for a civilization to succeed it must be content with living on its home planet. And as a result, it would take good care of it.

You could also argue that a civilization has not succeeded until it is able to completely sever ties with its home planet and venture out into the galaxy on its own. Leaving the nest, so to speak.

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

#668

Post by nie »

When I looked at the image[1] illustrating size/mass/orbit periods of TRAPPIST-1, I was fascinated by the orbit period:

6.10 days, for example, for planet e! Suppose we were to be able to stand on that planet and stargaze outwards, won't that be extremely dizzy? :)

So what are the immediate (strange) properties brought forward by median of 6 days of orbit period?

[1] http://www.space.com/images/i/000/062/962/original/trappist-...

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

#669

Post by weavie »

joe636434 wrote: post #667

Why are people so excited about planet which is 39 light years away, when we are living in a society where 8 hours of slavery is required to survive. This is not listed focal.

That attitude is why you are subjecting yourself to 8 hours of slavery!

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

#670

Post by sanduu »

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…

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