If the Earth were 100 pixels wide • Hacker News Board

Re: If the Earth were 100 pixels wide

#191

Post by redblacktree » Thu, Apr 04, 2013, 5:13 PM UTC

keiferski wrote: post #25

fusiongyro wrote: post #12

What's frustrating is how much better of a candidate Venus would be, if it weren't for its atmosphere. It's closer than Mars and larger too.

Theoretically, we could build floating cities on Venus: Landis has proposed aerostat habitats followed by floating cities, based on the concept that breathable air (21:79 Oxygen-Nitrogen mixture) is a lifting gas in the dense carbon dioxide atmosphere, with over 60% of the lifting power that helium has on Earth. In effect, a balloon full of human-breathable air would sustain itself and extra weight (such as a colony)…

Really cool. Thanks.

I also find it awesome that this man's name is Landis. Only two characters away from Lando (Calrissian), who also lived in a floating city.

Re: If the Earth were 100 pixels wide

#192

Post by tankbot » Thu, Apr 04, 2013, 5:54 PM UTC

drewolbrich wrote: post #95

tankbot wrote: post #54

Earlier quoted context omitted.

This is really cool, though I would like to see a version in higher resolution with some stars. Not oppressively bright stars, just a hint to remind you that there are billions of billions of violent, fiery balls of self-contained exploding gas out there...

If it was a real photograph, I do not think you would see any stars in the frame. The Earth is extremely bright compared to the stars. If the exposure of the film/video (or your eyes) was set to portray the Earth at that brightness, you wouldn't see any stars. Example: http://www.astrobio.net/images/galleryimages_images/Gallery_... This is a real image and is not CG. Another one: http://eol.jsc.nasa.gov/sseop/images/…

I like the accurate size/distance but it doesn't have to be a photorealistic representation for me. Pure black except for the earth/moon is boring for a desktop background, and stars are pretty ;o)

Re: If the Earth were 100 pixels wide

#193

Post by stcredzero » Thu, Apr 04, 2013, 5:56 PM UTC

sjwright wrote: post #125

marcosdumay wrote: post #122

Earlier quoted context omitted.

You can easily build an in 1:2e9 scale replica of the Solar System. You'll just need a 90cm sphere to use as the Sun, some 4-5 km of area do arrange things and a paquimeter for measuring the planets. At this scale, everything is just about as big/small as one can manipulate. Bu you won't be able to place the Voyager in there. For that you'll need a car and a road trip.

The satellite or the Intrepid-class starship?

Voyager isn't a satellite of any body.

Re: If the Earth were 100 pixels wide

#194

Post by danielweber » Thu, Apr 04, 2013, 6:06 PM UTC

MrBra wrote: post #168

joeycastillo wrote: post #35

One thing that's always gotten to me about this distance is what it means for communication latency. Mars is 20 light-minutes away. If we sent colonists, communication would be a 40-minute round trip. No phone calls home, no way to have a chat with friends or loved ones; at best they could send a message, and wait 40 minutes for a reply. That's far away.

if we could stretch a stick as long as the distance from earth to mars and use it to tap on mars ground something like a morse code to communicate, would that message be faster than a wifi message traveling at the speed of light?

Does everyone come up with this idea independently, or is someone suggesting it? It's a very common retort to speed-of-light communications, but someone told me about it before I thought of it.

Anyway, your idea wouldn't work. If you press on one end of the stick, it would issue a pressure wave along the length of the stick near the speed of light (depending on its material), so you haven't gained anything.

Re: If the Earth were 100 pixels wide

#195

Post by danielweber » Thu, Apr 04, 2013, 6:11 PM UTC

stcredzero wrote: post #99

"At the current state of space technology, it will take at least 240 days to get to Mars" Uh, no. The person who put this together obviously hasn't read a lot about proposed plans for Mars missions or even understands how transfer orbits work. 150 days is a likely practical limit for today's technology, but it's not a hard limit. Spend a little more fuel, and you could make it 149 days. http://www.universetoday.com/1…

You can keep on shortening the trip by another day, but it requires more energy each day you take off.

At a certain point (somewhere around 5-6 months) it makes more sense to use that energy to give yourself a bigger ship than to take another day off.

(I'm glad to see no one saying any more that the VASIMR could do it in 39 days. That was an annoying distraction.)

Re: If the Earth were 100 pixels wide

#196

Post by crusso » Thu, Apr 04, 2013, 6:22 PM UTC

maaku wrote: post #180

Steuard wrote: post #132

Earlier quoted context omitted.

Essentially all Mars missions under serious consideration rely on special alignments of planetary orbits to minimize the fuel required. That leads to very specific "launch windows" that may only occur every few years. For an Earth-Mars trip, the basic launch window is available roughly every two years, but there are particularly low-energy opportunities every 16 years or so. My understanding is that the next of those…

The difference between the Hohmann transfer orbit available every two-ish years and the low-energy opportunities is not significant enough to impact mission viability. The reason a mission to Mars is "scheduled" for 2030's is because that's the nearest date outside of government budgeting schedules. It would take us 10 years to put together a focused effort (like the Apollo program), there's absolutely no plan to do…

Exactly. The 2030s are just beyond what we could demonstrably prove ISN'T currently in the works.

Re: If the Earth were 100 pixels wide

#197

Post by romeonova » Thu, Apr 04, 2013, 6:31 PM UTC

I was hoping to see something new on the way back from Mars. well done though!

Re: If the Earth were 100 pixels wide

#198

Post by stcredzero » Thu, Apr 04, 2013, 6:40 PM UTC

KerrickStaley wrote: post #106

Mars is a desolate, inhospitable rock floating in an immense void. I can't understand why people are captivated by the idea of living there.

It has water, mineral resources, a CO2 atmosphere plentiful enough to consider using it as an industrial feedstock, soil that we know you can grow plants in, a 24 hour day/night cycle, and enough sunlight to support crops. It also is "closer" to the rest of the solar system in terms of delta-v. If civilization expands into the solar system, Mars will be analogous to North America in the 16-20th centuries.

Re: If the Earth were 100 pixels wide

#199

Post by tahoecoder » Thu, Apr 04, 2013, 6:45 PM UTC

You should speed up the rate a bit when going to mars, and just tell the user that the velocity is higher now. It takes up too much of our time, to be honest.

Re: If the Earth were 100 pixels wide

#200

Post by MrBra » Thu, Apr 04, 2013, 6:55 PM UTC

danielweber wrote: post #194

MrBra wrote: post #168

Earlier quoted context omitted.

if we could stretch a stick as long as the distance from earth to mars and use it to tap on mars ground something like a morse code to communicate, would that message be faster than a wifi message traveling at the speed of light?

Does everyone come up with this idea independently, or is someone suggesting it? It's a very common retort to speed-of-light communications, but someone told me about it before I thought of it. Anyway, your idea wouldn't work. If you press on one end of the stick, it would issue a pressure wave along the length of the stick near the speed of light (depending on its material), so you haven't gained anything.

No I am guilty of having thought about it myself :) But I would like to know more about these kind of anti-common sense examples regarding this subject. Do you have a website or some search keyword to suggest? Thanks