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If the Earth were 100 pixels wide (distancetomars.com)
996 points by oseibonsu on April 3, 2013 | hide | past | favorite | 208 comments


I'd really like to see a few more markers:

1) 3100 px: Farthest humans have been from Earth (Apollo 13, April '70: 400,171 km)

2) 10 px: Gemini 11, farthest from Earth on non-lunar mission (Sept '66: 1,374.1 km)

3) 3 px: Apogee of ISS (farthest a human has traveled for... a while: 424 km) (I'm probably forgetting something, can't find a good list of spaceflights by distance...)

Sources: http://en.wikipedia.org/wiki/List_of_spaceflight_records#Far...

http://en.wikipedia.org/wiki/International_Space_Station

http://en.wikipedia.org/wiki/Earth

Taking Earth's diameter as 12,742 km (though it bulges by about 43 km in the center), we're saying that's 100 px. So if my basic algebra is right (no promises) you can convert the above km values to px by dividing by 127.42.


I think the value of this is in its focus and simplicity. There have been other websites using zooms and/or scrolling to visualize scale differences (e.g. http://scaleofuniverse.com/), but this is an elegant statement about just one fact, and I think that's more likely to get the ball rolling in someone's brain and amaze them than inundating them with trivia all at once (but thanks for the trivia just the same :).


Every time I see that page it makes me realise just how small and insignificant we are in the grand scheme of things, and how badly I really want to go exploring everything that is out there.


Yet you could spend an entire lifetime exploring everything that is 'here', and still not manage it.

Space is unfathomably big, and we are a grain of sand on the beach of the universe. But that grain of sand contains enough complexity and variety to fascinate for a practically unlimited period of time.

Mars is cool, and grand, and inconceivably different. I'd rather see the cherry blossoms in Japan, or go for a walk in the outback, or see tierra del fuego (sp?). And really, it's not even just the big things on my (long) list, but the billion other little things that one can do and see on this world given time and resources to wander from place to place exploring and experiencing.


Space is boring. Flyunder territory.


Several years ago J. Richard Gott and Mario Jurić of Princeton put together an awesome logarithmic map of the entire universe:

http://www.astro.princeton.edu/universe/


"3) 3 px: Apogee of ISS (farthest a human has traveled for... a while: 424 km) (I'm probably forgetting something, can't find a good list of spaceflights by distance...)"

You're forgetting STS-125, the last Hubble Space Telescope Servicing Mission, March 2009, Apogee 578 Km.


I made a 3D render of a flyby. I should have added markers from the space programs into the video. The video shows how long it would take to reach all the planets, if you flew at a constant velocity (about 10x light speed).

http://www.youtube.com/watch?v=wM0JMaM_tdQ


well done!


I would like to see Voyager 1 (about 1.847×10^10 km, accordingly to wikipedia [1])

[1]: http://en.wikipedia.org/wiki/Voyager_1

[EDIT] 1000 to 10^10 :P


Thats about 144953696 px if my calculations aren't failing.


Is anyone else a little bothered by the fact that the reported speed was 1/5 the speed of light, yet the flyby necessarily increased to well over the speed of light in order to actually get you to Mars before you got bored and closed the tab? Traveling at the speed of light would have taken 5-20 minutes. Traveling slower than that would have taken even longer...


Travelling at the speed of light would have taken 0 seconds for you, the traveller, but 5-20 minutes for your observer.

However, the Lorentz factor at 20% of the speed of light is ~1.02. This means the distance you travel is only about 2% shorter, so relativistic effects aren't the reason for the discrepancy.


Plus, if it was large enough to have an effect on perceived time, it would affect the apparent distance as well, thus negating the point of the demo!


What is bothering me most now is that if Earth is 100 pixels wide then 1 pixel is 127.42km and Mars should be something like 54600000/127.42 = ~428500 pixels away, not the claimed 857000. The radius of planets has been used where it should be diameter and this error seems to have been carried forward throughout the demonstration.

EDIT: This has now been corrected - nice one!


Yeah, I hadn't realized that they were doing that, and it does bother me. I don't mind the idea that we're going FTL, but they should explain that in the text, not just report 20% of the speed of light. Ironically, it makes the distances seem shorter than they are, in a thing that seems designed to make you understand how long they are.


Speed of light: 1.07925285 × 10e9 km/h Reported speed: 200,000 km/h

So more like 1/5000 the speed of light. But as pointed out below the reported speed may be way off.

I wonder if a mistake about the speed of light was made; it's about 300,000 km per second.


Right, but the original comment is also quite right that the speed is being misreported and the actual speed you're going (reported as 7000 pixels per second) is 3x the speed of light:

    (12742 km) / (100 px) * (7000 px)/s / c = 2.975


Yes; mine was more a comment on the site.


I also wish they would have noted the acceleration. Not doing so in fact undermines the point they're probably trying to make (giving users a visceral feel for the distances involved). Can't say it bothered me, though.


I'm more bothered by the authoritative fact that 'the timeline for a manned mission to Mars is the 2030s'. Says who, NASA?

They're not the only ones trying to get there.


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 will be the 2018/2020 launch windows, which is almost certainly too soon for a mission to be ready. So the following low-energy opportunities will be somewhere in the mid 2030's. That's not to say that it would be impossible to use a launch window in the mid-2020's despite the higher fuel cost (or even some other orbit entirely that didn't try to minimize fuel at all), but doing so would be substantially more difficult.

Here's a link that is useful primarily because it links to more thorough discussions: http://en.wikipedia.org/wiki/Exploration_of_Mars#Launch_wind...


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 so right now or over the next 10 years of the government budget. So by that sketchy line of thinking, the earliest this could happen is 2013 + 20 years, or 2033.

Maybe I'm showing my age, but I remember a decade ago "the Mars landing" was scheduled for the 2020's. In the 90's we were talking about the 2010's (now!). I bet you when 2020 rolls around, it'll be the 2040's that we're looking towards.


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


Does anyone else have a realistic more aggressive timeline?


I'm planning to head over tomorrow. I'll let you know how it goes.


Are you there yet?


Yes. HN is loading slower than normal, however, so you'll have to wait for a full assessment. This whole three-way handshake thing is not such a great idea from Mars.


so was i, wanna split the fare?


See "The Case for Mars" by Robert Zubrin (manned landing 10 years from project start, then every 2 years thereafter), or the various hints dropped by Musk in interviews as to his plan.


Not that I know. SpaceX has considered sending an unmanned mission based on its Dragon platform in the 2018/2020 window which would prove a lot of technology that they could used for a manned mission later.


See the response above - there is a window in 2018/2020 that private entrepreneurs will shoot for. I wish them luck, personally .. I'd love it if someone other than NASA got there first. It would truly ignite the human race.


The response above also suggests 2018-2020 is too soon. Are you aware of any private entrepreneurs realistically disagreeing?


Like the advent of nuclear energy!


For me it currently says "You're currently travelling at 7,000 pixels a second 200,000 km/h" - which is clearly wrong, as at that speed it would take an hour to get to the moon.

Good idea, well intentioned. But they got the numbers wrong...


100 pixel earth = 13KM

1 pixel = 0.13KM

7K pixels/s = 910 KM/s

910 * 60 * 60 = 3.3 Million KM/h


The Earth is not 13 km in diameter. Maybe you meant 13 Mm, or roughly 13 000 km? The result is ~3 billion km/h then. I haven't timed it, but that seems to align with how long the animation took (around half of a minute).


I timed it, and it was about a minute, so right in line with the 7k pixels/s. That does translate to about 3 billion km/h, or about 250,000 mh/s².


Distances are in pixels, with the Earth's diameter being 100 px.


Yes, he knows. But the point is: They say they're going 20% of the speed of light (in pixels). But the closest approach of Earth and Mars is about 4.35 light minutes away from each other. So if our virtual speed is 20% of the speed of light, it follows that the page should take more than 20 minutes to reach Mars. And it doesn't.

It doesn't even take 4.35 minutes, so the page must be continuing to accelerate past the 20% c measure, to superluminal speeds, in order to finish in a couple of minutes or so.

Which they don't mention.


The page flashes for me a couple of times, after which the starfield is still and then rapidly speeds up again. I assume this means that we're travelling with the assistance of warpgates or similar - and at 127km/pixel, it's unlikely that the warpgate or the ship would show on the map.


Nah, because if it's physical travel the starfield won't change at all. :P


It bothers me a little that they show the motion against a starfield like that -- the stars are so far away that they won't shift perceptibly even on a journey to mars.

I mean, I don't have any better ideas, but given that the whole point is to give an idea of scale I wish they'd come up with something else. :)


How about you just imagine the ship is rotating on an axis for artificial gravity generation. Then, if you were looking out the window, you would see the starfield whizzing by. :-)

Edited for smiley.


Interesting idea - all the scifi I've ever seen has had ships rotating around the axis of travel, but never orthogonal to it.


The axis wouldn't matter. You wouldn't notice which direction you were going (well I suppose if you noticed the sun, darn).


Sure, but then I have no sense at all of the distance traveled.


You're talking about a first-person view, aren't you? But we don't start with that, we start with a third-person view of Earth and then "pan" across the sky...

So wouldn't panning across the sky from whatever vantage point actually produce that movement? Same as when you point a telescope and pan, the stars move against your view...?


You're right, we do start with a 3rd person view of Earth .. but I still interpreted the motion as translation rather than rotation.

By your interpretation, the camera lens is at a fixed point and then simply "swings" from pointing at Earth to point at Mars. But, from such a supposed point, both the Earth and Mars would be fixed points rather than objects with "multi-pixel" width.

So the fact that both the Earth & Mars are viewable as non-point objects implies translation rather than rotation... and so GP's gripe stands =)

[edit: oh, and what shardling says too]


It is simple.

1. Choose a position where the proportional sizes of the Earth, Moon and Mars are what they are on the page. This is likely far away above the ecliptic (the plane the planets are in).

2. Choose a telescope focal length to set the right scale for the planets. Ie magnification.

3. Pan and imagine there is an object in the ecliptic plane at the center of your field of view. Mention the calculated speed of the object.

This all results in a moving star field.


Okay, it is problematic.

If the camera lens is at a fixed point and then swings from pointing at Earth to pointing at Mars, and we imagine how fast something would have to travel leaving Earth to remain at the center of the camera sensor as it pans - isn't the obvious question "how far away are we??" So it doesn't really work.

It also doesn't work because at different camera locations the Earth and the Mars would have different relative sizes... I suppose we should state that this will be an equilateral triangle formed between the Earth, Mars, and the Camera, the "height" of the equilateral triangle is x, and that Earth will be so many pixels wide on that camera when zoomed 2000x (or whatever).

This interpretation might be specific enough and also match the experience.


Hmm, I see what you're saying, but that's not what the demo is trying to convey. At one point it says "You're now traveling at [1/5 the speed of light]" -- that would be nonsense if it was conceived as a panning motion.

e: Ah, but as someone else points out, the trip must actually exceed the speed of light, so the whole thing is nonsense. The author should recast things the way you describe them, and thus solve multiple problems at once.


Let's get to the bottom of this. It is a panning motion, this much is physically, visually true. Does it still make sense to talk about 'speed of motion'?

Now I'm confused. What happens when you pan from the moon to the sun (during a new moon, when they're ostensibly both visible)? If you do it quite quickly you are panning faster than the speed of light? (In the interpretatio: 'if a physical object remained at the center of your scope as you panned, and started at the moon, it would have to move faster than the speed of light, to follow your pan?)

So if you pan from one thing to another and they're 1 light-minute away and you take one minute to pan, does it make sense you are 'panning at the speed of light'? For something that leaves one object and goes toward another?

What do you think of this?


Any comparison to the speed of light immediately invokes other concepts that wouldn't apply to panning, so it's probably a bad idea.

There might be situations where it makes sense to map an angular speed to some sort of absolute speed, but it just doesn't work in this particular example.


The specific situation where it makes sense to map an angular speed to some sort of absolute speed is if you're told - or have some way of figuring out or knowing - the distance of the camera to the two objects (including if it is very highly zoomed, which it obviously is, from the perspective we are shown).

in this sense - if there is an intuitive sense of the distance of the camera and the high level of zoom - it makes sense to speak of an object leaving earth at the velocity that lets it stay in the center of the frame as we pan.

doesn't it?


I think the best thing to do would be to provide periodic asteroids or rocks that go across the screen every now and then---it's very difficult to get a sense of speed with a repeating star field, not even including the fact that this wouldn't happen in the first place.

Since the starfield was periodic, it looked to me as if it were staying still or moving backwards at times (the wagon-wheel effect[1]) :(

[1] http://en.wikipedia.org/wiki/Wagon-wheel_effect


Does it bother you that Florida and the Mediterranean have gone missing? :)


What do I look like, a geographer? :P

But yes, while the project looks superficially nice, it seems to be riddled with small errors. Hopefully the author incorporates some of the feedback!


A little bit about the Mediterranean. But not at all to Florida, I think we all would be better off without Florida. (The geniuses that inhabit that peninsula need to go with it.)


This is the first time I've actually been able to comprehend the perspective of distances so big they don't mean much as a number. Thank you.


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.


There are these models too, already installed! https://en.wikipedia.org/wiki/Sweden_Solar_System


They did a nice job of this along the Melbourne waterfront boardwalk, here : http://lokenote.com/lokenote/OBWw7zwX

I think the scale is 1 to 1 billion

pics :] https://plus.google.com/photos/106795164119213709932/albums/...


The satellite or the Intrepid-class starship?


Voyager isn't a satellite of any body.


I was looking for the one in SE England, which turned out to be the Otford model. It makes for a pleasant afternoon hike.

But in the process I came across this: https://en.wikipedia.org/wiki/Solar_System_model


I think I remember a Bill Nye the Scoence Guy episode about this.


Isn't there such a thing in downtown Ithaca?


Apparently yes, http://en.wikipedia.org/wiki/Sagan_Planet_Walk

There are a multitude of others all around the world: http://www.waymarking.com/cat/details.aspx?f=1&guid=52fe...

The one close to me is in Helsinki-Espoo: http://www.waymarking.com/waymarks/WM8AJ4_Ursa_Model_of_the_... But this one's slightly bigger, scale is o to billion. You can still see the Sun from Neptune, if you have binoculars (4487 meters, the Sun is 140cm in diameter).


Here is one in Zagreb, Croatia. Scale is 1:680,000,000. Sun is in the center of the town, and it is 2m in diameter.

http://www.spottedbylocals.com/zagreb/zagreb-solar-system/


Cool site, but it's "If the Earth were 100 pixels wide, ..."

http://grammar.quickanddirtytips.com/subjunctive-verbs-was-i...

</pedantry>


Thank you! I tweeted this link earlier and had originally copied the "was", then realized it sounded wrong and corrected it.


It's the only time we get to use a different word to express the subjunctive mood in English.


This simple graphic of the Earth and Moon and the distance between them, to scale, is also pretty thought provoking

http://www.traipse.com/earth_and_moon/index.html

edit: just large image: http://www.traipse.com/earth_and_moon/earth_and_moon_1280.jp...


You can draw a circle in the palm of your hand, then a smaller circle on the other. Spread your arms out to your side, and that's about the distance from the earth to the moon.

I would get that tattooed if I was into that kind of thing.


This would depend heavily on the size of the circles.


Indeed. With small enough tattoos you could put the Earth on your thumb and moon on your pinky.


Or the solar system tattooed up your leg. Starting with the Sun on your heel, and stopping at Uranus.


I see what you did there... Clever.


I saw a scale model at an exhibit once. I put my hands over the earth and moon, and my wingspan covered it perfectly with both fitting inside my hands comfortable. I thought it was a very interesting way to illustrate it.


wait.. wingspan?


Here is a photo of the Earth and Moon, with the to-scale distance between them. It makes a great desktop background:

http://www.traipse.com/earth_and_moon/


That's actually a pretty cool photo. I was staring at it, as my new background, and was thinking how amazing it is that their mutual gravitational influence is actually enough to keep the moon in its orbit. I guess I mean it's hard to tell just how massive yet, in contrast, how small something like the earth and moon are. That or it's the half bottle of beer I've had.


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/ISD/highres/AS17/AS17-1...


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)


Set it as my desktop background. Made me realize how dirty my monitor screen was. :)


Very rarely have I seen a single idea so perfectly illustrated. Impeccable timing and presentation. Unexpected, every step of the way. Kudos.


Yes this was really well executed. Kind of a shame to see a lot of the top comments dominated by the picking at any inaccuracy they can find (not surprising, it seems a trademark of HN these days). Ok it isn't a perfect scientific simulation but rather a rough visual guide to grasp the scale of space travel, and I think it achieves that well.


That's the thing: people are arguing that, as astonishing as the portayal seems, it still manages to give people a gross underestimation of how big these scales really are.

As portrayed, it seems like it only takes a minute or so to get to Mars at 20% of the speed of light. But really, they continue speeding up the starfield to multiples of superluminal speeds. As great as that distance seems, it's even more than an order of magnitude larger than depicted.


Hey guys, Dave here, made the site.. Really amazed by how much coverage this thing has got, and really surprised by how poor my maths were. Not surprising given I failed both maths and physics at college. Really happy to be inspiring debate, I've gone over my sums and given it another shot

Thanks!


"At the current state of space technology, it will take at least 240 days to get to Mars"

This makes it immediately obvious you haven't read a lot about proposed plans for Mars missions or even understand 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/14841/how-long-does-it-take-to-...


Not sure if it's a bug or a typo, but the "width" (diameter) of the Earth is 12,742 km, not 6,371 (which is the radius).


You're right! How frustrating. The most frustrating is that I was just about to share this with some friends and know that I now risk either: 1.) Them smugly pointing that inaccuracy out and failing to enjoy how cool this is otherwise, or 2.) The website author correcting it by the time my friends see the link so any "btw there's a typo" comment I make being confusing. I'm going to share it anyway!

EDIT: I fear this may be worse than we had initially thought. The diameters of the Moon and Mars suffer the same problem and the pixel distances appear to be based on those wrong numbers so actually all the "apparent" distances are twice as long as they should be. (My working was to check that the Earth was indeed 100 pixels on my screen, calculate that 1 pixel = 127.42km, multiply that by the claimed "6033 pixels" to the moon to get 768724.86 which is twice as large as it should be...)


So it's a bug after all :/ hope the author fixes it, such a neat idea otherwise.


I tweeted the error to the creator (David Paliwoda) and it's now been corrected.


Shouldn't it be something more like 20,000 km, since the equator is about 40,000 km long and we're looking at half of it? Anyway 6,371 can't be right though.


No, that's circumference - 3.14 * 12742 is approx. 40K. You are looking at the Earth side-on, so you only see the 2D projection of the half-equator. (EDIT: I think it should be "1D projection")

Another nitpick - presumably our view axis is perpendicular to the solar system plane. The Earth would not look like in the picture, we would see one of the poles but slightly off-centered.


Cool.

Unfortunately though, on my regular setup of Firefox on Windows, the background image abruptly 'runs out' shortly after the "You're currently travelling at 70000 pixels/second" message appears, leaving me with a blank white screen. I believe this is due to this browser bug I've just found out about: https://bugzilla.mozilla.org/show_bug.cgi?id=816917

Fine on Chrome though.


So one more site that works only in Chrome. Sad.


My favourite scale of the universe picture:

http://scaleofuniverse.com/universe-medium.jpg


Never seen that image before, that is quite scary really. When people state that there is no such thing as aliens really annoys me when you see visualisations such as this.


There's almost definitely aliens out there. The question is, will we ever get to meet them?


Of course we will, just will it be in the next 100 years, the next 1,000 or the next 10,000?


It could be more than 10+ million years from now. By that time civilization on Earth would be indistinguishable from aliens from our 21st century perspective.


"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/14841/how-long-does-it-take-to-...


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.)


I'd love to see the Sun included on the opposite side of the scale. Its diameter is 109 times that of earth, making it 10900 pixels. Would be just as impressive a demonstration.


I didn't go through much, but I'm quite sure that in that scale, It would be a flat line


I tried simulating it, and it's just enough curvature to get the point across. Assuming I didn't have a bug of course.


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) in midair. At an altitude of 50 km above Venusian surface, the environment is the most Earth-like in the solar system – a pressure of approximately 1 bar and temperatures in the 0°C–50°C range.

Because there is not a significant pressure difference between the inside and the outside of the breathable-air balloon, any rips or tears would cause gases to diffuse at normal atmospheric mixing rates rather than an explosive decompression, giving time to repair any such damages. In addition, humans would not require pressurized suits when outside, merely air to breathe, protection from the acidic rain and on some occasions low level protection against heat. Alternatively, two-part domes could contain a lifting gas like hydrogen or helium (extractable from the atmosphere) to allow a higher mass density.

http://en.wikipedia.org/wiki/Floating_city_(science_fiction)...

http://en.wikipedia.org/wiki/Colonization_of_Venus#Aerostat_...


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.


Kind of a silly thing to say though. If Mars had a "better" atmosphere too it'd be that much more superior as a colonization target.


It's an idle wish.


I like to imagine if Mars and Venus were swapped would Venus then be habitable?


No. Simply put: the core is likely solidified just like Mars and its magnetic field is very weak, causing the weather to be influenced by only its rotation and solar winds. It would be far more difficult to terraform than Mars really.

Also a Venusian day is something like 5,800 hours and its surface temperature is capable of melting lead.


Moving to a Mars orbit would have a significant effect on the surface temperature.

More of a problem is the bulk of the atmosphere being carbon dioxide (breathing even a 5% mix is excruciatingly painful for humans), but the real challenge would be dealing with the rains of sulfuric acid... at least Mars wouldn't be trying to dissolve your hermetically sealed environment.


Would the weather really stay the same if you lowered it's temperature so much by moving it away from the sun?


Where'd you get the idea that Venus has a solid core?


An extrapolation from the weak magnetosphere [1] I'd guess.

1: http://www.universetoday.com/36161/core-of-venus/



I don't follow.

What I posted above is simply a layman's summary of all the same things cited in your link.


You didn't see this line?

> Like that of Earth, the Venusian core is at least partially liquid because the two planets have been cooling at about the same rate.


Oh no, I'm very much aware of that reasoning.

I offered a guess as to how/why someone might think the core is solid, not an argument for that conclusion. I included an easily digestible article which touches on all the same theory as the Wikipedia entry which was posted in "response" to it.

Not all Internet communication has to be quippy argument.

Also, the context of that citation:

"By analogy with Earth, the core of Venus is at least partly liquid because the surface-to-volume ratios of the two planets in Figure 10.5 are virtually identical, which implies that they have been cooling at about the rate. If the core of Venus is at least partly liquid, then Venus should have a magnetic field similar in strength to the magnetic field of Earth as discussed in Section 6.4.5 and in Science Briefs 6.7.3,4,5,6 and 7. However, the Mariner 2 spacecraft determined during a flyby on December 14 of 1962 that Venus does not have a planetary magnetic field."

The book goes on to cover various theories about the absence of a magnetic field identifying a solid core as "not credible", slow rotation of Venus failing to activate convection currents as "possible", lack of a solid inner core due due to pressure (questionable) and temporary decay of the field (questionable).


Ah, I lost track of the thread and thought you were the initial poster who asserted that Venus was solid as if it was an established fact.

My apologies.


I like to believe we could circumvent some of these problems technologically. After all, there is no particular reason to feel bad about macroscopic terraforming on a lifeless planet. Yes, it would be more work than Mars. But it's also bigger than Mars and further from the asteroid belt. No planet but Earth is going to be ideal.


The amount of energy you'd have to expend to fix Venus would be far more costly than trying to keep Mars warm by using baseboard heaters on every square metre.

One of the largest issues facing Venus is that it is effectively a dead planet. Mars is a dead planet too but it's far easier to make it warmer than to cool down Venus so we can live on it. On top of that, Mars has water frozen at its surface and perhaps in liquid form beneath; Venus only has water vapour that accounts for less than 0.01% of the total atmospheric make up.

And if it is size that you want to take into account, then think about this: it's far easier to fix a smaller planet that is geologically dead than it is a planet of our size.

Venus is never going to be colonised. Mars maybe not, but at least that is less of an impossibility.


I appreciate your taking the time to reply, but I think it's a little soon to be saying never. For one thing, we have spent a lot more time and energy trying to figure out what's going on with Mars than Venus.

Though of course Mars is a better prospect today. Frankly, I think the important thing is to have a backup, as it were, and to that end whatever serves will do. But if one backup is nice, two is even better, and the cost of making a good backup is highly justified.


In the case of Venus, the Soviets had sent several probes (Venera) from the 60s into the mid-80s. When the first probes were sent to land on the surface, it was discovered that the atmospheric pressure induced (about 100x the pressure here on Earth at sea level) was crushing the probes before they even touched down.

It took until 1970 for the Soviets to succeed and the landing device lasted a grand total of a half hour once it had landed on the surface. In fact, it barely survived due to the fact that the parachute broke and it ended up hitting the surface at 60 KM/h. It registered CO2 levels of 97% during its descent.

Venera 9 was similar in concept to the Viking landers and landed five years later, but it managed to last for almost an hour before failing due to the immense heat. The longest any Venusian surface programme by the Soviets was just shy of two hours.

Let's compare this to the Americans' probes to Mars: all of them have managed to out-last their stated mission. We have a rover that was intended to do its job within a 90-day period which instead has defied its masters and instead continued on to this very day.

The reason why I completely discount Venus as a place we'll ever visit or colonise for that matter is because it comes down the old principle that I like to follow: it's easier to bundle up than to bundle down. I can put on layers to keep my body heat in, but I cannot do much without expending energy to cool myself down.

Venus is not a backup.


I can appreciate that it isn't viable today. But looking back on the history of our species, things that seemed useless or even harmful frequently turned out later to be indispensable resources. Sometimes they did turn out to be simply unhelpful and harmful and I can appreciate that this is the current state of knowledge with Venus, and that it isn't especially economically meaningful to hammer on it further at this time. I just don't think it's safe to consider the matter settled for all time.


On the other hand, if it was where Mars is, it would probably have a different rotation speed (and thus a different length of day.)

The period of Venus's rotation is anomalously long, and whatever caused it probably wouldn't have been in effect had it been further out.


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.


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


No. As in air, the speed of sound in stick is still slower than the speed of light.


no i think you did not understand my example.


You're talking about using a mechanical compressive wave in a medium to transmit information. Whether the medium is 'air' or 'stick', the rate at which such waves travel is generally called 'the speed of sound in [medium]'.

Wifi signals to Mars travel at the speed of light in a vacuum. This is faster than any mechanical wave because the changing forces of compression between the atoms in the medium must still obey the speed of light.


mechanical compressive wave ,traveling at the speed of sound? Why do u introduce these? What has sound to do with my example? Imagine the stick not tapping on ground but just getting close. to it. Not an audio, but a visual way for the receiver to tell the 2 different singnal states. Then he'd grab his end of the stick and do the same. I am sure what you say is correct by itself but.. it feels there is just something from it that doesn't fit with my example.. Edit: reading again your comment and trying to understand what you say.. if i get it right then it's totally misleading to call it "speed of sound": it should be called speed of mechanical compressive waves


Like foreign country few hundreds revolutions of our planet around the Sun ago.


Good point. We have so forgotten how bad it used to be, that 40 mins seems so long. Kings weren't able to talk to their ambassadors in 30 mins, not that very long ago.


The few pixels to the low Earth orbit and ISS is gently depressing. When's the last time a human went further than that? 1972?


Oh this is fantastic! My father teaches astronomy to kids (he has a mobile planetarium that he takes around schools [1]) and one of the main pain points he has mentioned is communicating a sense of scale to them.

This is elegant because it mixes the concept of "imagine this orange is the earth, mars would be in <nearby town>" within the constraints of a web page.

Kids have difficulty visualising distances in an abstract way - but time is much simpler. And the length of the scroll to Mars really emphasises this.

Great visualisation.

1. http://www.starlincs.co.uk


That is super cool! Can you please ask him to put some larger images on there because I only get these tiny little thumbs.


It's nice but his scale is wrong. He states that the Earth is 6371 km large, while in reality, it's twice that, as 6371 km is just the radius of the Earth, and what you really see is its diameter.


Indeed, and it appears that 63.71km per pixel has then been used to calculate the pixel distances to the Moon and to Mars so in fact they are twice as many pixels long as they should be.


Nicely done. A biology scaled version would be cool. Like if a virus was 100 pixels wide...



Or.. an electron is 100 pixels wide..


Better use a proton instead.

Electrons are point-like particles, ignoring their wave characteristics, so don't have a "size" per se.


Could make a cool animation showing off the fine structure constant going from classical electron radius to Bohr radius and Compton wavelength. That would be a total zoom factor of 18769 which is about right. The hard part would be designing an infographic to make sense to people who probably don't "get" what the bohr radius is, etc.


I'd love to see one of these for the other planets in our solar system. Maybe even Pluto!


I'm surprised no one has mentioned the scale model of the solar system strewn around the Boston metro area. If you live there, it's pretty fun to visit all the planets. One year the MIT Mystery Hunt had a puzzle related to it.


Using this site, I was able to make the Kessel run in less than 1200 pixels.


if I leave it running will I get to mars? just out of curiosity? ( i do have better things to do ).


Yeah, it's about 530,000 pixels away, kind of shows the grand scale of our solar system and that's just the parts have have a chance of reaching any time soon.


(spoilers ahead)

Yes.


Or you can turn off Javascript and hit the "End" key. Alas, there does not seem to be any real-life equivalent to that.


Scotty is yet to invent the warp teleportation theory...


Brilliant. I never actually reached mars - just the gut wrenching distance to the moon made me realise how amazing the Apollo program was - whatever gets us to Mars ...


Though not as cool as this, I used a similar scrolling idea back in 2011 to visualize a star that was one million times the mass of our sun — http://vjk2005.tumblr.com/post/4497783697/a-star-half-a-mill...


If the Earth were 100 pixels wide, then what we consider "space" is 1 pixel above its surface. One pixel...


Bug Report: I'm afraid this crashed between the Moon and Mars, just as some "you are travelling" text came in on the LHS and then it just went to whitescreen. Firefox 19.0.2 on Win7-64Home. In case you can catch it. (yeah ok so my laptop's not Linux, sue me!)


If the Earth radius was 100 pixels, the average depth of the ocean (~4km) would be less than 0.1 pixels. I once had a professor hold up piece of paper and say "this is my scale model of the pacific ocean". Took me a while to realize he wasn't joking.


The one my teacher used was the billiard ball, and told us "if the Earth were the same size as this, it would be smoother". A quick google suggests that is indeed true, but it would not be rounder. (http://blogs.discovermagazine.com/badastronomy/2008/09/08/te...)


Why not?

  (function () {
    var d=1;
    setInterval(function () {
       $('#Earth-Illustration').css({'webkit-transform':
       'rotate(' + ((d>36) ? d=2 : d++)*10 + 'deg)'})},100);
  }());
Please, consider Africa as Asia ;)


Perhaps you meant `transform`, which will actually work in WebKit browsers (you forgot the leading `-`) and also be translated by jQuery to other browsers' prefixed property names.


tested in Chrome only...and only "transform" didn't work, I had to add "webkit-" to work...to make simple, I prefered not put the moz line


On the way to Mars, there was a flash and the screen went white. I guess I didn't make it.


Mars is pretty far, but 240 days doesn't sound so bad. In the age of explorers, the first human sailors to circumnavigate the earth took 4 years to do it. A handful of them even survived the journey!


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.


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.


>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.

Mars' atmosphere has only 20 times more CO2 than Earth's does, CO2 is not a rare chemical. We don't know enough about Martian soils to be sure that we can grow crops there.

>Mars will be analogous to North America in the 16-20th centuries.

I see this analogy around a lot and I've never cared for it.

1) All successful settlements of Europeans in the new world had some economic purpose for existing. The first few attempts to settle North America by English settlers were dismal failures until they discovered that they could grow valuable tobacco there. What is Mars' tobacco? We'd need a product that is cheaper to manufacture on Mars and ship back to Earth than to make on Earth. We need this because...

2) Mars is a vastly more hostile environment than the new world. It would have been possible to set up fairly small colonisation groups that were mostly if not entirely self-sufficient and thus didn't need to find economically sustainable products to sell to the home country in trade for vital supplies. In fact, later settlement in New England followed this pattern - many people paid for their passage and bought some land and only needed a few imported goods rather than the whole-sale re-supply that the earlier settlers in Virginia had required.

The minimum local knowledge and technology base was essentially simple agriculture at first, followed by some village-level craftsmen for simple tools and such. This meant that only a small fraction of the local economy had to produce goods for export because most things could be produced locally.

That is very far from being the case on Mars. The minimum technology base required to have a mostly independent colony on Mars is a substantial fraction of our entire tech base on earth. Even if we assume that high-complexity, high value-density things like computers and other electronics are imported from Earth that still leaves us with a lot that needs to be made on Mars. If we want to build another settlement on Mars from our initial base, can we do that?

Can we build the environmental management equipment needed? Pressure envelopes, power generation and distribution? Even something like light bulbs would be hard to do. Individually, all of these things are totally possible of but when you add them all together you start to require an awful lot of machinery to take with you.

The alternative of course is to keep supplying these things from Earth but without a sustainable source of goods to export back to Earth that isn't going to be sustainable.

3) The relative cost of transportation. Early settlers of the new world could use existing ships once they knew where to go. With Mars we know where to go but we don't have the ships. A moderately wealthy merchant could pay for the passage of his whole extended family to the Americas, even if the price drops dramatically that isn't going to be the case with a passage to Mars.

None of this is to say that I don't want to see permanent human settlement on other planets, but I think that comparing it to the settlement of the Americas is very unhelpful.


> CO2 is not a rare chemical.

Never said it was. The point is, that you can just pull it out of the Martian air in industrial quantities.

> We don't know enough about Martian soils to be sure that we can grow crops there.

Many experts would disagree.

> All successful settlements of Europeans in the new world had some economic purpose for existing.

Yes, there would be a considerable initial economic barrier. But given the potential payoff, and that it's well within the budgets of current major powers, it's bound to happen. Just a matter of time and political will.

> Even something like light bulbs would be hard to do.

With current tech, we need a population of about 500 million to sustain a comparable technological infrastructure. This is going to go down with advances in technology, however.

> None of this is to say that I don't want to see permanent human settlement on other planets, but I think that comparing it to the settlement of the Americas is very unhelpful.

Because you're mistakenly using the analogy as a descriptor of difficulty. You're right that it's much more difficult in both an absolute and comparative sense. However, it's meant entirely as a descriptor of potential payoff. Compare the investment involved in establishing initial colonies and the value of interventions that resulted in British hegemony over North America with the value generated by the US economy. For English speaking western civilization, the payoff has been astoundingly huge.

I strongly suspect that there are people in China and other emerging powers who are well aware of this as well.


What I had in mind when writing the original post is that there are many places on Earth that are far more accommodating which we will probably end up settling first (e.g. Antarctica, Siberia, the surface of the ocean, and all the interstices between where people are already living)


> What I had in mind when writing the original post is that there are many places on Earth that are far more accommodating which we will probably end up settling first

It's not a matter of "how accommodating." It's a matter of how accessible. It's the space equivalent of geography. There are vast energy and material resources in the solar system off-Earth. A Mars-centric civilization will have much better access to those than an Earth-centric one.


I'm semi-captivated by the idea. I'm not spending my (ha) fortune on it, but if the opportunity presented itself, I'd go.

You know how, for millennia, people have been drawn over the hill, to see new sites, live in places no one else has?

That's why.


The starfield should not move anyway, because of parallax. The stars are really far away and the sky looks the same on Mars and Earth.


Reminds me of this Bill Nye episode

http://www.youtube.com/watch?v=97Ob0xR0Ut8


Perhaps this is relevant: Opera's rendering glitches mean that we cannot go to Mars with the latest version of Opera on Windows.


Mostly worked for me in Opera 12.14 on WinXP. The first click showed white space instead of stars, but then the second click (after the moon) showed the scrolling starfield the whole way.


related: interactive scale of the universe http://htwins.net/scale2/


The whole time I was browsing that (incredible) site, all I could think of was the intro to The Big Bang Theory.


View in Safari on iPad, and change tabs while scrolling, then come back mid-scroll. Gotta love the iPad rendering.


Really cool. Anything that sheds light on how amazingly double awesome the Mars Rover Mission is makes me happy.


A little strange handling of the class attribute in source. I'm fairly sure it also requires an = after it.


Says we wont get to Mars until the 2030s, I think the Mars One project and others would beg to differ...


Did anyone else make the return trip and get disappointed there was no "welcome home"?


it says it is traveling at 1/10 th of light speed. it takes less than minute to get to Mars in pixels, but from other sources I know it takes 13 minutes for radio signal to get to mars. Something does not play here.


This is at the closest pass, when Mars is ~0.5 AU away from the earth; that's 4 light minutes.

It takes 13 minutes from light to get to Mars from the sun, and I think that'll also work out to be close to the "average" time from Earth to Mars.

In any case, you're right that apparently the demo exceeds the speed of light at some point, because it doesn't last for 4 minutes. Someone else suggests that the motion be interpreted as a fast pan rather than a physical motion, which is how this should have been implemented to not contradict the laws of physics. :)


I'd really like to see something like this for the anatomy of a cell! Nice work!


Amazing! Despite the factual inaccuracies, it's a wonderful job! Two thumbs up!


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


I was thinking there'd be a scary monster that would pop out along the way


Great stuff! Would be great to see some other planets or facts in there.


please also mark the Lagrange Points http://en.wikipedia.org/wiki/Lagrangian_point

plus Sun, that would be really cool!!


Beautiful, I love it!


I'm glad he didn't decide to do distancetobrunomars.com


And only 53 pixels wide? Is it even worth going there?


Some of the fonts look horrible in FF20/Linux x86-64..


I like this. Good job, very creative!


Very Cool!!


very cool - thank you.


Awesome. Thumbs up!!


Should have switched to warp 1.


Mars is fucking far.




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