How I would fix that scene in Gravity with the questionable physics

Letgo_mobileI know I’m late to the party, but I finally saw Alfonso Cuarón’s space movie Gravity last night. Like Neil deGrasse Tyson and nearly everyone else, I really enjoyed it. That’s why it’s gnawing on me that a pivotal scene relied on some dubious physics.

It’s the one in the promotional image to the left. (If you’ve haven’t seen it yet, I’m shocked, but SPOILER ALERT.) Astronauts Dr. Ryan Stone (Sandra Bullock) and Matthew Kowalski (George Clooney) are in space suits, trying to board the International Space Station. Unfortunately, they approach it at high speed and ricochet around, at the risk of bouncing or sliding off into space, never to come back. Fortunately, some cable catches Stone’s ankle, and she in turn catches a loose tether attached to Kowalski’s suit, forming a chain. They stop in this position to have a conversation, but it’s clear that Kowalski is being pulled out into space, and he eventually releases his tether in order to let Stone survive and return to the ISS.

As many have pointed out, the question is: What the heck is pulling Kowalski out into space? In many, many, many, too many movies, this scene appears like so: Character 1 is hanging over an abyss, with only character 2 to hold him or her, usually by the wrist. Gravity is pulling down, and character 2 either is or isn’t strong enough to hold character 1, so either saves or drops him or her. (In a twist, sometimes character 1 lets go as a self-sacrifice to save the other person, as Kowalski does.)

But in the movie Gravity, the force of gravity is not in play, since it takes place in space. So there’s no reason that Kowalski, once stopped, should float out into space once released. He should just stay where he is. In fact, it’s worse, as Tyson tweeted:

ClooneySome have argued in favor of the physics in this scene, but even if there is some reasonable explanation having to do with momentum or centrifugal force, there’s clearly something wrong when smart people like Bad Astronomer Phil Plait is in the audience wanting to scream, "'CLOONEY DOESN’T HAVE TO DIE!’"

I’m with Plait, of course, but I’m not content to just scream silently in my head. I want to fix this, dammit. As I lay awake after watching it, this is what I came up with as an alternative to this scene:

We start in the same configuration as in the promotional image, with a cable insecurely looped around Stone’s ankle. It has stopped her from floating out into space. She is holding Kowalski’s tether, arm extended, and he has also stopped moving. (I would venture to say that it’s highly improbable that they would actually end up in this position, but the movie is built on improbabilities that are physically possible, so I’ll allow it.)

It appears they are saved. Now all that’s needed is for her to pull him to her, and for them to use the cable to get back to the ISS. But as she pulls, her leg makes a stray kick, accidentally releasing the cable; worse, kicking it just out of reach. Instead of Kowalski coming to her, she and Kowalski move together.

BullockNow they are floating within spitting distance of the ISS (especially in space, where the spit would fly forward forever), but with no way to get there. He has no fuel in his jet pack, and she is quickly running out of oxygen. There’s only one thing to do: He will push her toward the station so she can board it. As a result, he will go flying off in the other direction, never to be seen again. Just like in the original, he sacrifices himself to save her, but in a way that makes physical sense. As he floats away, they have the same touching conversation as in the film.

So that’s my solution. I think it both makes the physics more realistic and avoids the clichéd cliffhanger scene that I have come to resent.

But, gosh, I could be wrong, either from the standpoint of physics or of dramatic integrity. As I was doing the necessary thought experiments to reimagine the scene, I realized that it’s harder than it would seem to work out cause and effect in zero gravity. (I kept going back to the cool frictionless sleds we had in teacher Aaron’s physics class at the fabulous Edmund Burke School in Washington, DC.) That gave me all the more respect for the rest of the film, which gets it really right a very large portion of the time. Seriously, it’s spectacular.

So I very humbly submit this alternative to the interwebs, not so much in the spirit of a movie critique as in the spirit of fan fiction.

Celebrate toilets with a little bit of toilet tourism

P1010540In pursuit of a story on a chilly late-summer day this year, I descended into the warm bowels of a technical school in Vienna, Austria, where teenagers can learn to be plumbers, carpenters and locksmiths. There, Kurt Pant (pictured left), a teacher in the Sanitär- und Heitzungs Technik department (commonly abbreviated as SHT), has collected historical toilets, sinks, bathtubs, and whatever bathroom installations people will donate from their basements, sheds, and abandoned buildings. He is slowly constructing life-size dioramas to illustrate how people did their business in the past.

The collection has a dozen or so vintage toilets, including one that's more than 100 years old, which is made of the highest-quality ceramic and decorated with an chinoiserie lion. He also has an American toilet that was one of many donated by the United States to Austria after World War II. It's in mint condition, since it never could be installed thanks to different pipe diameters in Europe and the United States.

This is a big year for toilets. A toilet innovator won the Stockholm Water Prize, the United Nations declared November 19th World Toilet Day, and the Gates Foundation announced the first-round winners of the Reinvent the Toilet Challenge. Oh, and I wrote this story about toilets for Nautilus magazine. I suggest we all celebrate this Miracle Year of toilets by engaging in a little bit of toilet tourism. I found my visit to Vienna's Sanitation History Museum quite enlightening, and it turns out that there are many toilet tourism destinations around the world. Here are a few you could try:


(Courtesy Sulabh Toilet Museum)New Delhi, India -- Sulabh International Museum of Toilets 
This museum (pictured right) documents the sometimes weird history of how we go, with the noble goal of raising awareness of the importance of toilets, especially in India, and breaking down the taboos that stand in the way of progress. You can see plenty of photos in this story from the UK's Daily Mail. 

Suwon, South Korea -- Restroom Cultural Park
The newest toilet-themed museum, this complex is in the hometown of Samsung. I think the sculpture garden of squatting figures looks great. The BBC did a video report on it. 

AUSTRIA TOILET ATTRACTIONS (these came to my attention because I live here)

Gmunden, Austria -- Klo & So, the Museum of Historical Sanitation Ceramic 
This area was a center of ceramic production, and that included ceramic for toilets. Here you can see the rich decoration on early toilets. The decoration ultimately disappeared because people feared that it could hide dirt.

Vor_Graben_22-WC-Anlage-IMG_9261Vienna, Austria -- Graben Toilets
Vienna is home to one of the world's greatest public bathrooms, the 19th century Wilhelm Beetz loo in the Graben in the city center (photo on left from PictureObelix on Wikimedia Commons). I visited it for the first time while researching the Nautilus story, and wow. I will be taking all future tourists there. 


City of Industry, California, USA  -- Magic Restroom Cafe
As I was researching and writing the Nautilus story, I came to the realization that toilet news is everywhere -- we just don't notice it most of the time. This gem came to me by way of Gina Pace, a former fellow fellow and hilarious food and wine writer for the New York Daily News. A Taiwanese chain is testing the concept of a toilet restaurant in southern California. The chairs are toilets, the plates are mini-toilets, and I assume the toilets are toilets. I'm not going to make a special trip, but I wish them luck. 

Do you know of other toilet tourism sites? Let me know and I'll add them.

Recycling and upcycling at Vienna Design Week

P48-buzzilightThe morning after the opening party of the Vienna Design Week, the event's organizers were feeling, quite understandably, a little rough. But they had scheduled a press tour for 10 a.m., so they rallied, leading us on a journey through several of the festival's 47 locations.

The exhibits in the festival are eclectic. Some are purely theoretical, others are already commercially available. On the commercial side, I was taken by the products from Buzzispace. The company is deeply offended by excess noise -- in particular, reverb. I happen to share that sentiment; I still get enraged when I think about noise levels in New York City. (Why don't taxis have to disable their P1010640horns when they enter Manhattan? Why is the music so loud in restaurants that it makes everyone  scream over it?) To combat unwanted noise, Buzzispace has designed sound-absorbent, felt-like materials out of recycled PET plastic and recycled wool. These are used to construct cool furniture for offices and, to a lesser extent, homes (like the lamps in the photo above, or the pouf to the right, occupied by Vienna Design Week co-organizer Lilli Hollein). Buzzispace's prices are a little daunting, but the exhibit, in the festival's center in the fourth district, inspired me to put more fabric into my high-ceilinged, echoey apartment.

P1010612The Kunstraum Niederoesterreich, located in Vienna's center, exhibited another project inspired by concerns about the environment. Called "I love Brot," the artist, Kathrina Dankl, took old bread from a bakery, which would otherwise get thrown out, and baked it again into bread chips. Visitors are invited to take a bag of chips, taste them, and then pass judgment by putting a chip into one of three slots: "good," "has potential," or "not to my taste." I was impressed: I ate my vote.

I got the biggest kick out of a third exhibit with a related, "upcycling" theme. The Souvenir Transformation Center, by students from the Kunstuniversitaet Linz, takes on the stuff you have sitting around -- you know, the objects you don't have any use for but that you also can't get rid of due to se P1010619ntimental value or maybe just hoarding tendencies. At the Souvenir Transformation Center, you place the object on a conveyor belt, which transports it into a big white box (in fact the proverbial "black box," since what's inside is a secret). Some unspecified amount of time later it emerges on the other side in a new form, sealed in a vacuum pack. "You have the chance of freeing yourself from the material things of the past and reliving your relationship to the object afresh," the catalog declares. "Transformed" objects I saw included a necklace, a teapot, an apple, and an Eiffel Tower souvenir (photo left).

Vienna Design Week is an annual affair. This year it continues until October 6. I hope to go see more of it before then.

(All photos except the first, which is from Buzzispace, are mine.)

The largest subterranean lake in Europe

GlueckaufSome people go to the pool when it's hot; my friends and I go to a cave. What the Seegrotte Hinterbrühl, just 17 kilometers from the center of Vienna, lacks in beauty and wildlife, it makes up for in pure cold. Inside, it's 9 degrees Celsius all year round.

Not that the Seegrotte is completely ugly, though some of its history is. Its existence began in the late 1800s when miners dug it out in order to extract grey and red gypsum for fertilizer. So it's not really a cave at all, but a mine. Mining is a dangerous business; so much so that the traditional miners' greeting in Austria is "Glück auf!" a wish for luck. Mining can also be a sad business. The guide informed us that the horses used by the miners lived their whole lives underground, ultimately leading to blindness.

BoatIn 1912, the miners accidentally blasted through a wall that was holding back water. The result was that 20,000,000 liters flooded in, putting an end to the mining and creating the largest underground lake in Europe -- 6,200 meters in area and up to 12 meters deep. Twenty years later, the first tourists entered the cave. It is erily lovely -- the still, lifeless waters glow blue under artificial lights.

Disney decided to film parts of the 1993 movie The Three Musketeers there, and they left behind a spooky gilded boat and the set for D'Artagnan's prison. The boats that took us along the lake were more plain and practical than the movie version, but that's a good thing -- some tourists drowned in 2004 when an older style of boat overturned.

But that unfortunate accident is not even the most haunting thing about the Seegrotte. During the Second World War, the Nazis used the cave as an airplane factory. Concentration-camp prisioners were forced to work there, assembling parts for the first jet plane, which never went into use. At the end of the war, the German armed forces destroyed the factory, but quite a few airplane parts remain and are on display. Working in that cold, dark place must have been miserable.

Not having done my homework in advance, I went to the Seegrotte expecting bats or eyeless fish. What I found instead were ghosts.

(Photo credits to Rachael Lloyd (top) and Florian Pötscher (bottom).)

More on the northern bald ibis

I have a story in the latest issue of the very cool new science magazine Nautilus. It's about a project to reintroduce migrating northern bald ibises to Europe -- after about 400 years of extinction.

This video (not mine) will help you get a better idea of what these birds look like, as well as what it's like to fly with them.


The chicks are ugly/cute, which you can see in this next video (also not mine), taken from a new high viewing chair at the Burghausen colony. These chicks are expected to follow experienced older birds south in August or September.


Bald ibises are graceful in long-distance flight, but can look awkward the rest of the time. This was apparent last year when I saw them collecting nesting materials and flying them up to their nests. They often missed their mark. One volunteer stood there and encouraged them, saying, "You did it! Congratulations! Very nice!" in German whenever they actually made it. I made a short video of it (that is to say, this one is mine).


If you have any questions about the bald ibis, the reintroduction, or the science of migration, please get in touch here or at the Nautilus site. I hope to write more about this fascinating and beautiful (once you get to know it) bird.

Astronaut or cosmonaut? Just don't call her a "space woman."

Tereshkova_l2As we walked to Vienna's Natural History Museum for the panel celebrating 50 years of women in space, my husband and I chatted idly about the terms astronaut and cosmonaut. How strange, we thought, that there should be a word that means "person who went into space with the American space program" or "person who went into space with the Soviet space program." Wasn't "person who went into space" specific enough? And were the differences still relevant now that the Cold War was over?

Little did we know that the word for "person who went into space" would be an unintended theme for the evening. The panel consisted of four women from different countries who had been in space. (Valentina Tereshkova, the first woman ever in space, was supposed to be there, but she had returned to Russia unexpectedly for "special professional reasons." She's the one in the photo above.) The moderator was a man who had been in space with the Soviet program, Romanian Dumitru-Dorin Prunariu. When the director of the United Nations Office for Outer Space Affairs introduced him, she accidently called him an astronaut. "Cosmonaut," she quicky corrected herself, embarrassed.

My husband and I looked at each other. Wasn't it funny, not only that these diverse words existed where one would do, but that they still carried enough weight to embarrass a U.N. official? Japanese astronaut Chiaki Mukai said in her presentation that the world is moving away from space travel for national pride, and into an era of international cooperation. But in the same presentation she not only used the words astronaut and cosmonaut, but also taikonaut, the new-ish word for "person who went into space with the Chinese space program." (And I think she may have used another term, but I didn't catch it. It might have been spationaut, sometimes used for French space travelers.) The continuation, not to mention proliferation, of these words certainly contradicted the notion that national pride was going out of fashion in space travel.

A point of etymology: The ending –naut means sailor in Greek. Astro- means star, and cosmo- means universe, both also in Greek. Taiko-, on the other hand, comes from a Chinese word meaning space (which is also the meaning of spatio- in Latin).

220px-Roberta_Bondar_NASAAlso a point of meaning: It's significant when I say "went into space." Someone isn't officially an astronaut until her first trip into space. The United States defines space as an altitude 50 miles; the Fédération Aéronautique Internationale says 100 kilometers. It's an open question whether space tourists, or just professionals, should get the title of astronaut. Spaceflight participant is currently preferred. Bummer for spaceflight participants.

Astronaut and cosmonaut didn't even exist when Canadian astronaut Roberta Bondar (pictured left) was growing up, she said to the packed crowd in the museum's atrium. Back then, nobody had gone into space, but if someone had, he would have been a "spaceman."  So when she was young, she said that she wanted to be a spaceman when she grew up. It was only when Tereshkova became the first woman in space (50 years ago on this coming Sunday, June 16) that she "realized that there was a difference between spacemen and spacewomen," she said.

At first, the difference was a pretty big deal, but over time, it has receded into insignificance. Experience has shown that both sexes are suited to the rigors of space travel, said American astronaut Janet Kavandi. She sat on the committee that selected the most recent class of astronauts for the U.S. program. Since the classes these days are so small, she said, the candidates must have a wide mix of skills and experiences – that is, they have to be exceptionally accomplished in more than one area, from science to electronics to medicine to fitness. The committee wasn't aiming for a specific sex ratio, she said, but "the women compete easily with the men." The outcome of the selection won't be announced until next week, but she indicated that class would be groundbreaking. Fifty percent women? More? "You'll be pleased to see the results," she said.

Aging telescope hopes for a fresh start

Percival_Lowell_observing_Venus_from_the_Lowell_Observatory_in_1910The Clark Telescope at Lowell Oberservatory is, at 117 years old, over the Mars Hill, so to speak.

It needs an overhaul, say the folks over there. So they're trying to raise $256,718. (Does that number also strike you as awfully specific?)

Here's what the Clark needs, according to them:

During the past several years, the telescope has become more and more difficult to move, due to the degradation of the main support bearings in the optical tube. If this problem continues, the telescope will become inoperable. To avoid this outcome, we will remove (using a crane) and dismantle the optical tube and replace faulty parts, most of which will be fabricated in-house.

We will also clean all components, including the primary lens, optical tube, and main pier. If necessary, we will strip and recoat the pier.   

Old wiring is a major safety issue with the dome, recently resulting in sparking and arcing. We will thus replace all existing wiring, as well as switch gear and load center.

We will also replace the shutter doors, which no longer operate properly on a regular basis (leaving us with no other option on some nights but to shut down the facility). Additionally, we will repair metal siding, particularly in areas where snow and rain enter the dome, and refinish the floor.  

Fig_clarkThis place -- and, in particular, this telescope and dome -- is one of my favorite in America, and it earned a big entry in our e-guidebook, A Traveler's Guide to Astronomy and Space in the Southwest. (It's possibly the biggest entry; I'd have to check.) The geek in me is begging to go there to see the work in progress, which will involve disassembling the historic 'scope.

Too bad the firm Alvan Clark & Sons isn't around any more to help.

(Image above: Percival Lowell, the observatory's founder, looks through the Clark Telescope. Image below: The Clark Telescope, as photographed by us in 2002. Second photo added 3/20/2013.)

I wish I'd thought of that!

AstronomySpaceSouthwest-Cover-smallFriends and colleagues have kindly passed on the word about my new co-authored e-guidebook, A Traveler's Guide to Astronomy and Space in the Southwest. Some clever phrases of theirs I plan to steal:

  • Helen Fields: "Nerd it up with this guide!"
  • Polly Shulman: "It's Sirius fun!" and "Go geek guidebook!"
  • Christie Aschwanden: "Your essential guide to astronomy in the Southwest"
  • Sarah Webb: "Like astronomy, the Southwest and travel? @chelseawald and Cyril Emery have written an e-book for you."

But not only were people clever, they were effective. First-day sales put the book at #1 in this category on Amazon:  Kindle Store > Kindle eBooks > Nonfiction > Travel > United States > Regions > West > Mountain

So, maybe that's because our amazingly supportive family and friends bought the book, but it's a great start.  If you want to check to see whether we kept that ranking, the Amazon page is

The book's website, where people can submit their own sample itineraries as well as corrections and omissions is

Spreading the word is hard, so if you have more clever ways of saying "Buy this book!" please help me out by letting me know.

Gluten-free in Vienna

Because some of my friends are gluten-free eaters, I've noticed that Vienna can be a tough place to get a gluten-free meal. I thought it would be helpful to post a list of the few places that label gluten-free options on their menus. They also tend to label vegetarian, vegan, and lactose-free options, as well. Please let me know (in the comments to this post or by sending me an email) if you have other eateries to add, or if you have thoughts about the restaurants listed.

A traditional wine tavern in the wine district. You can get gluten-free wiener schnitzel!
Kahlenberger Straße 22
1190 Wien (Nußdorf)
+43 (1) 370 22 22

A modern, casual restaurant in the center that specializes in inventive vegetarian food but also has fish and meat.
Wrenkh Wiener Kochsalon in Wien
Bauernmarkt 10, 1010 Wien
+ 43 (1) 533 15 26

A traditional beer hall in the Prater park that has gluten-free beer.
Karl Kolarik's Schweizerhaus GmbH
Prater 116, 1020 Wien
+43 (1) 728 015 213

A small international chain for the health-conscious in the center.
Herrengasse 5, 1010 Wien
+43 (1) 532 09 95

A bagel shop with gluten-free bagels
Blueorange Coffee & Bagel
Margaretenstrasse 9 1040 Wien
+43 (1) 581 17 70
Alserbachstrasse 1
1090 Wien
+43 (1) 908 15 04