Earth, shot on iPhones

June 9, 2017

You've seen the ad campaigns for iPhones appealing to your sense of beauty in photographs. Image form Daily Billboard.

You’ve seen the ad campaigns for iPhones appealing to your sense of beauty in photographs. Image form Daily Billboard.

A twist on the old saw: Put millions of good cameras in the hands of millions of people, and beauty will result.

Not that beauty will ALWAYS result, but that there will be much beauty found, if for no other reason we have a really beautiful planet.

It’s a commercial, sure. I still like it.

With poetry from Carl Sagan. (It’s not poetry? That’s just the way he wrote?)

And if  you want to share it, here’s the YouTube version from Apple:

Spoken text (done by Sagan himself?) comes from Pale Blue Dot, Carl Sagan’s paean to Earth:

The Earth is a very small stage in a vast cosmic arena. In our obscurity, in all this vastness, there is no hint that help will come from elsewhere to save us from ourselves. The Earth is the only world known so far to harbor life. There is no where else, at least in the near future, to which our species could migrate.

Like it or not, for the moment the Earth is where we make our stand. It underscores our responsibility to deal more kindly with one another and to preserve and cherish the only home we’ve ever known.

I wish I’d had this stuff when I was younger; so many beautiful places and people I must recall with only the images in memory!





Can’t get it together; it IS together

January 2, 2014

Earth on January 1, 2014.  Looks pretty good from this angle.

Can we make it look this good down here on the ground?

NASA caption: Happy New Year! This image shows the Earth today, January 1, 2014, a few hours into the new year, as seen by the Geostationary Operational Environmental Satellites (GOES) satellite. Geostationary describes an orbit in which a satellite is always in the same position with respect to the rotating Earth. This allows GOES to hover continuously over one position on the Earth’s surface, appearing stationary. As a result, GOES provide a constant vigil for the atmospheric “triggers” for severe weather conditions such as tornadoes, flash floods, hail storms, and hurricanes. Image Credit: NASA/NOAA GOES Project #nasa #earth #space #goes #irl #today #happynewyear #planets #solarsystem #newyear #2014 #nye #home

More, perhaps related:

If the Moon were replaced by other planets, what would we see?

August 17, 2013

Odd and interesting idea for a video, from Yeti Animation:  What if the Moon disappeared, and were replaced by other planets in the solar system?  What would it look like?

I like the nonchalance with which the passing auto drivers and passengers treat these views.  Droll.

The ambitious filmmaker, YetPic1, describes the real science and non-science in the film:

Published on May 2, 2013

This is a visualization of what it might be like if the Moon was replaced with some of the other planets at the same distance as our moon. Planets Rendered in 4K resolution! On Change Quality click on “original” to view in 4k. You need a 4k Monitor to watch. otherwise just watch in 1080p or lower

SATURN!.. The super close moon is Dione, the one slightly further out is Tethys
Both are *tiny* but *very* close

In order show[n]:


Mercury is intentionally left off as it isn’t Much bigger than our Moon (and hence is boring)

on Jupiter, you might be able to make out the 4 big moons, They all have orbits larger than our moons orbit. but I stuck them on the far side of jupiter so that they could be seen so it looks as if they are closer (to Jupiter) than they really are.

Video creation method
I created an Earth Moon system in 3dsmax, with accurate sizes and accurate orbital distances.. I than matched video of the real Moon with my video camera, against my model. I also researched the correct FOV of my video camera. I used both methods to verify my Virtual camera’s FOV (around 47 degrees). I next modeled up the rest of the planets in proper scale (Real values) set at the distance of the moon (center to center) (also real values), created the animation of them rotating around, and composited the whole bunch.

Scales used in Visualization:
Celestial Body Radius (in km)
Moon: 1738
Mars: 3397
Venus: 6052
Neptune: 25,269 (equatorial) 24,340 (polar)
Uranus: 25,559 (equatorial) 24,973 (polar)
Jupiter: 71,490 (equatorial) 66,854 (polar)
Saturn: 60,268 (equatorial) 54,360 (polar) (not including rings)

Distance to Moon 384,000km
Faq: (faq shrunk from other video for “reasons”)

1, We would not be engulfed by Jupiter or any other planet, Jupiter’s radius is 71,490 km and the distance to the Moon is 384,000km

2, We would suffer from really really horrible tides and earthquakes(and radiation)

3, I *did* model the Ring of debris around Uranus, I actually modeled 8 of them, but you can mostly just make out 3, This was actually the tipping point for me to render this out in 4k resolution

4, I love Pluto, and Mercury. They are left off because they are too small. Pluto is smaller than our Moon, and Mercury is not significantly larger than our Moon.

5, The “Sun” I used for lighting the planets is completely off from reality,

7 Orbiting! Yes! we would be a moon of Saturn, Jupiter, Uranus, and Neptune. They are much more massive than the Earth. Venus is about the same size of the Earth and we would orbit around a center point between us

8 Rotation rates and axial tilts are not accurate to anything

9 Radius of the Sun is 695,500 km, and hence if it were where our Moon is, we would be engulfed by it

10 Scales are Accurate, Every few days someone says my scales are wrong, Or that someone says I’m presenting Saturn as being bigger than Jupiter. I’m going to go through some of the arguments I keep hearing (paraphrasing each)

a. “You’re showing Saturn larger than Jupiter”: I am not, Saturn is clearly smaller than Jupiter in the video, Saturn+ring system *IS* larger than Jupiter (in terms of radius) This is easy to look up.

b. “Jupiter is 300 times larger than Earth! therefore it’s wrong in your video (or 1000 times larger etc)” : There are many sayings about how much larger Jupiter is than earth. 300 is Probably referring to Mass… 1000.. is probably referring to Volume. Without actually specifying the Dimension the argument is pretty moot. I will say this Jupiter’s Radius is about 11 times that of Earths, which fits precisely with my video.

c. “I saw another video where Jupiter Filled the sky!, therefore you’re wrong”: I am very familiar with the video. I even Like the video. However the FOV (field of view) of his Ground does not match the FOV of the planets. In other words, he has a wide angle lens on the ground, and a zoomed lens on the planets. To his own credit he admits this in his own description. In my video My ground FOV and my planet FOV are the same, and hence graphically matched and very reasonably accurate.

d. The confidence I have for my scales being correct is exceptionally high. The dimensions used for the planets and rings has at one point been triple checked along with the earth moon distance. It’s interesting to see how a *few* people have gotten completely worked up over their misconceptions on scale. The size of the Moon is a bit of an illusion, I Think if you still have misconceptions you should hold a dime out to arms length , and hold it against the moon, Or even go out with your own camera,, Zoom out all the way.. and take a photo of the Moon. It really is Tiny against the sky. It’s only about half a degree in angular diameter.

Thanks to everyone for watching, I enjoy making these

Tip of the old scrub brush to Lady Rhian.


Planets of the Solar System

Planets of the Solar System not to scale – Wikipedia image

Carl Sagan explains how science works: Eratosthenes and the size of the planet

January 23, 2013

It’s not exactly a hoax.  It started out as just bad reporting of history.

In his search for an easier route from Spain to China, in which he stumbled into the Americas, Christopher Columbus knew with  certainty the Earth is a round ball.  The story that he proved the Earth round, or rather than he laid the foundations for Magellan to prove the Earth round, is only a story, mostly devoid of fact.  Sailors knew something was up just from their having watched things while sailing on the ocean.  One can deduce the ball shape of the planet by watching other ships as they sail away, and sink below the horizon.  Were sailors of a more scientific bent, they could have made much of the fact that the guy in the crow’s nest could see a ship moving away — or an island or a continent — for a time longer than those a few dozen feet below, on the deck of the ship.

Long before that a Greek librarian and polymath, Eratosthenes, figured out that the surface of the Earth is curved, deduced that the planet is basically a ball, and calculated very closely how big the ball is, merely by noting the different shadows cast by the sun at the Spring/Vernal Equinox.  Carl Sagan used this story way back in his famous PBS series, Cosmos.  It’s still interesting, informative and instructive today (surely Texas 9th grade geography teachers use this example all the time, no?  9th grade math teachers?  Say, what?).

You can find this and more Sagan videos at the Carl Sagan Portal on YouTube.

How did he do it?  Wikipedia — as usual — has a good, relatively lay explanation:

Visual representation of Eratosthenes's calculations of the size of the spherical Earth.

Bathtub Art Figure 1:  Eratosthenes’ measurement of the Earth’s circumference.

Eratosthenes calculated the circumference of the Earth without leaving Egypt. Eratosthenes knew that, on the summer solstice, at local noon in the Ancient Egyptian city of Swenet (known in Greek as Syene, and in the modern day as Aswan) on the Tropic of Cancer, the sun would appear at the zenith, directly overhead (he had been told that the shadow of someone looking down a deep well would block the reflection of the Sun at noon). Using a gnomon, he measured the sun’s angle of elevation at noon on the solstice in his hometown of Alexandria, and found it to be 1/50th of a circle (7°12′) south of the zenith. Assuming that the Earth was spherical (360°), and that Alexandria was due north of Syene, he concluded that the meridian arc distance from Alexandria to Syene must therefore be 1/50 = 7°12’/360°, and was therefore 1/50 of the total circumference of the Earth. His knowledge of the size of Egypt after many generations of surveying trips for the Pharaonic bookkeepers gave a distance between the cities of 5,000 stadia (about 500 geographical miles or 927.7 km). This distance was corroborated by inquiring about the time that it takes to travel from Syene to Alexandria by camel. He rounded the result to a final value of 700 stadia per degree, which implies a circumference of 252,000 stadia. The exact size of the stadion he used is frequently argued. The common Attic stadion was about 185 m,[9] which would imply a circumference of 46,620 km, which is off the actual circumference by 16.3%; too large an error to be considered as ‘accurate’. However, if we assume that Eratosthenes used the “Egyptian stadion”[10] of about 157.5 m, his measurement turns out to be 39,690 km, an error of less than 2%.[11]

Description of Bathtub Art Figure 1:

Syene (S) is located on the Tropic of Cancer, so that at summer solstice the sun appears at the zenith, directly overhead. In Alexandria (A) the sun is \varphi south of the zenith at the same time. So the circumference of earth can be calculated being \frac{360^\circ}{\varphi} times the distance \delta between A and S.

Erastothenes measured the angle \varphi to be 1/50 of a circle and his access to knowledge of the size of Egypt gave a north/south distance \delta between Alexandria and Syene of 5000 stadia. His circumference of the Earth was therefore 250 000 stadia. Certain accepted values of the length of the stadia in use at the time give an error of less than 6% for the true value for the polar circumference.

Tropic of Cancer sign in Western Sahara

Tropic of Cancer sign in Western Sahara, placed by trans-Sahara racers, in English and Hungarian Photo: Wikipedia

A fun little exercise, but a remarkable achievement for anyone about 240 years before the birth of of the Biblical Jesus.  Syene, now known as Aswan, is on what we now call the Tropic of Cancer (the “tropics” were named by the Greeks, but I am uncertain whether the line had that name in Eratosthenes’s time).  The date is probably not important, so much as the observation that the sun was vertical at noon on a given date — and then Eratosthenes’s experiment to see whether that were true in Alexandria, and then his understanding of what that might mean and his work to assemble the data to make the calculations.   High school students — heck, junior high school students — should be able to figure all that out today, if they had the basics down.  I suspect that knowing this story would be a spur to students to learn the elements of the mystery and how it was solved, and what it might mean for later navigators of the oceans, land and air, for astronomers, for farmers and for mathematics.

I also like this story because it presents a strange conundrum, a paradox about what people know, and what they may reason from the foundation of what they know.  Our friend and frequent commenter Morgan, whose blog he calls the House of Eratosthenes.  I suspect he thinks himself some latter-day Eratosthenian (“Latter-day Erats?”).  He says as much in his blog FAQ:

I’m just like Eratosthenes peeking into a well here, and I don’t know what it means yet.

It’s an entertaining read and more enlightening that one might think from his forays here, so you probably ought to go read the FAQ and the reasons Morgan misbelieves liberals miss out on Eratosthenes’s wisdom.  Morgan has an explanation of Eratosthenes and his discoveries which I find too brief to be accurate (and I’m not sure why Morgan finds the name “Beta” to be dubious; being a polymath was not a small thing then, or now; second best in everything means one is first in the All-Around, first in the academic centathlon or millathlon — no mean set of feats at all).  I find that funny because, while he makes a pretense and some effort to following Eratosthenes and scientific methods, to me he seems to find science and logic things to run away from, as in our recent discussion where he ends up defending Anthony Watts’s erroneous views because Watts’s critics didn’t link to Watts (see comments in “It’s raining crazy,” and see also Morgan’s own post, which defies explanation).  Eratosthenes would find that funny, too, I hope, but not a demonstration of Eratosthenian logic and calculation.

Does anyone doubt where Carl Sagan would be in the debate between the dozen serious scientists and hundreds of political wankers who deny climate change, and the thousands of scientists and good citizens who recognize that it occurs and think we should get on with saving the future?

(Did James Burke cover Eratosthenes in his brilliant series Connections?  Which episode?)

Tip of the old scrub brush to Fred Clark at Slacktivist, whose compilation posts often overflow with stuff you ought to know or see, and whose post today sent me to Joe at It’s Okay to Be Smart and “Top 10 Reasons We Know The Earth Is Round.”


Depending on your perspective, the world looks pretty good

January 2, 2011

If you’re a few dozen miles from the Earth, for example:

Earth full disc, December 30, 2010 - NASA, GOES

From NASA: The GOES-13 satellite captured a "full-disk image" of North and South America in an image created December 30 at 1445 UTC (9:45 a.m. EST), as the world awaits the new year. Credit: NOAA/NASA GOES Project; click on picture for larger view

Press information from NASA:

As the World Turns to 2011 GOES Satellites Watch its Approach and Look Back at 2010

The GOES series of satellites keep an eye on the weather happening over the continental U.S. and eastern Pacific and Atlantic Oceans and had a busy time with wild weather in 2010. Today, GOES-13 captured one of the last images of North and South America in 2010 as the world continues to turn toward 2011.

The Geostationary Operational Environmental Satellite called GOES-13 satellite captured a “full-disk image” of North and South America in an image created December 30 at 1445 UTC (9:45 a.m. EST) as the world awaits the new year. The stunning image shows cloud cover associated low pressure areas over the upper Midwestern U.S. and Colorado’s Rocky Mountains.

NASA’s GOES Project, located at NASA’s Goddard Space Flight Center in Greenbelt, Md., procures and manages the development and launch of the GOES series of satellites for NOAA on a cost-reimbursable basis. NASA’s GOES Project also creates some of the GOES satellite images and GOES satellite imagery animations. NOAA manages the operational environmental satellite program and establishes requirements, provides all funding and distributes environmental satellite data for the United States.

NASA’s GOES Project was very busy this year. GOES-13 monitors the eastern continental U.S., Atlantic Ocean, Gulf of Mexico and Caribbean, while GOES-11 monitors weather conditions over the western U.S. and the Eastern Pacific Ocean.

In 2010, GOES satellites were busy providing images and animations of weather systems from nor’easters to tropical cyclones that caused blizzards, flooding and wind damage.

Most recently, the GOES project used satellite data to create an impressive animation of the great Christmas weekend blizzard that pummeled the northeastern U.S. Prior to that, GOES imagery showed travel conditions for the holiday weekend when that low was over the Colorado Rockies.

On Dec. 19, the GOES-11 satellite captured an image of the famous “Pineapple Express.” Occasionally in the winter, a large jet stream forms across the mid-Pacific, carrying a continuous flow of moisture from the vicinity of Hawaii to California, bringing heavy rain and snow to the Sierra-Nevada for several days.

On Dec. 8 GOES-13 satellite imagery revealed a snow-covered, winter-like upper Midwest, several weeks before astronomical winter. On Nov. 24, GOES satellites helped Thanksgiving travelers figure out where delays may be happening.

During the summer, on July 25, GOES-13 imagery tracked one of the most destructive storms in years to strike Washington, D.C. and the surrounding area. Strong winds downed trees and power lines, leaving hundreds of thousands of residents without power, stopping elevators, and darkening malls and movie theaters. Falling trees killed at least two people. The NASA GOES Project created a satellite animation of the storm as moved through the region.

GOES-13 was busy in the Atlantic during the 2010 hurricane season. The Atlantic season started on June 1 and ended on November 30. The Atlantic season tied for third with two other years (1995 and 1887) as having the largest number of named storms at 19, and tied with two other seasons (1969 and 1887) for the second largest number of hurricanes, with 12. GOES-13 covered all of those tropical cyclones. GOES-11 didn’t see the action in the Eastern Pacific tropics that GOES-13 did, however. Because of a La Niña event, the 2010 Pacific hurricane season (which began May 15 and ended Nov. 30) was the least active season in terms of the number of named storms and hurricanes on record. All tropical cyclones can be seen at NASA’s Hurricane page archives for 2010 at:

On April 14, months before hurricane season started, GOES-13 became the official GOES-EAST satellite. GOES-13 was moved from on-orbit storage and into active duty. It is perched 22,300 miles above the equator to spot potentially life-threatening weather, including tropical storm activity in the Atlantic Ocean and Gulf of Mexico..

Before GOES-13 moved into the position previously occupied by GOES-12, GOES-12 captured a parade of three large storms the flooded the upper Midwest and Northeast in the second half of March. In the first half of March, GOES-12 covered storms as they dumped heavy rainfall in the Northeastern U.S.

On March 12, GOES-12 captured a very rare event in the tropics: the second–ever known tropical cyclone called Tropical Storm 90Q formed in the South Atlantic Ocean off the coast of Argentina.

During the first two weeks of February 2010, the GOES-12 weather satellite also observed a record-setting series of “Nor’easter” snow storms which blanketed the mid-Atlantic coast in two blizzards.

Whatever and wherever the weather in 2011, the GOES series of satellites will always go.

Related Links:

› GOES-POES web site
› NOAA web site

Rob Gutro
NASA’s Goddard Space Flight Center, Greenbelt, Md.

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