What Astronomer Vera Rubin Really Accomplished

Picture Credit: Astronomy Magazine

On Dec. 25, 2016, astronomer and Vassar alumna Vera Rubin ’48 sadly passed away at the age of 88, a solemn yet graceful conclusion to a life rich with brilliant research and revolutionary ideas on both the universe and the role of women in the sciences. But upon the announcement of her death, countless news publications have fallen into the trap of over-dramatizing Rubin’s life and achievements by establishing her as the person who “discovered” dark matter.

An article by The Washington Post labeled her as a pioneer who “confirm[ed] the existence of dark matter,” while an article by NPR ran the headline, “Vera Rubin, Who Confirmed Existence of Dark Matter, Dies at 88.” Even Vassar’s own webpage on Vera Rubin stated that “Rubin is credited with proving the existence of ‘dark matter.’”

This is not true. Vera Rubin did not discover dark matter, nor did she confirm its existence. In fact, no one has. Dark matter remains an unproven theory, a hypothesis that researchers are still studying today. Vera Rubin herself has stated several times that she didn’t “prove” anything. What she actually did was uncover a strange oddity while studying galaxy rotation rates and postulate that the conventional understanding of our universe was flawed. In order to truly appreciate Rubin’s legacy without exaggerating her achievements, we need to understand the importance of what she noticed and why this anomaly remains a highly controversial topic among modern astronomers.

In the early 1970s, the entire world was embroiled in the matters of astronomy as the Space Race between the United States and the USSR reached its peak following Neil Armstrong’s first steps on the moon in 1969. At the time, Rubin was studying galaxy rotation curves with her colleague W. Kent Ford Jr. at the Carnegie Institute of Science. Her goal was to map the distribution of mass in spiral galaxies by measuring how fast the stars in those galaxies were rotating around the center.

According to Newton’s law of universal gravitation, the star closer to the center of the galaxy should orbit faster than the star that is farther away. This is because the closer the star is to the center, the more it feels the gravitational pull of the galaxy’s center, and the faster it moves. Prof. Colette Salyk, an assistant professor of Astronomy at Vassar, compares the rotation of the stars to swinging a ball tied to a string: “The harder you pull on the string, the faster the ball will travel…Gravity has everything to do with the speed of stars, since gravity provides the force that keeps the star in orbit.”

In other words, Vera Rubin was tracking how fast the stars were moving in order to determine the force of gravity they felt and thus how much mass they have. By this logic, the stars at the edge of the galaxy should be moving slower than those near the center. However, Rubin discovered a contradiction: The stars at the edge of the galaxy were not orbiting slower than those near the center.

In fact, they were moving so fast that the galaxy should have been flying apart. Given this discrepancy, Rubin proposed that some sort of unseen mass was holding their orbits together. This invisible mass that doesn’t radiate light is what people commonly refer to as dark matter.

To reiterate, Vera Rubin did not discover dark matter in this instance. The concept of invisible matter holding together galaxies has been around since Swiss astronomer Fritz Zwicky first suggested it in 1933. What Rubin’s discovery really did was provide detailed calculations regarding dark matter that swayed many astronomers to believe in its existence. By the time Rubin finished her investigation, she determined that each spiral galaxy possesses a “halo” of dark matter and that more than 90 percent of the universe is composed of this material. At that point, many astronomers were already convinced.

But as stated earlier, the dark matter hypothesis is still a hypothesis. Once the scientific community agreed on the concept of dark matter, they did everything they could to find decisive evidence for it. Unfortunately, even after three decades of intensive searching and developing expensive technology specifically designed to detect dark matter, astronomers have yet to find any signs of ever getting close. The latest blow to the dark matter hypothesis came in January 2017 when the promising XENON100 dark matter detector failed to offer any positive results.

Astronomer Stacy McGaugh at Case Western Reserve University aptly surmised the grim situation: “This generation of detectors should be the last. If we don’t find anything, we should accept we are stuck and need to find a different explanation, perhaps by modifying our theories of gravity, to explain the phenomena we attribute to dark matter.”

In truth, Vera Rubin herself began having doubts as early as 2006. In a 2011 interview, Rubin wondered whether the galaxy rotation problem that brought dark matter into fame was actually a flaw in our understanding of gravity. When asked if she really believed that dark matter wasn’t the solution, Rubin shrugged and asked “Why not?” And this response illuminates what science is really about: The willingness to broaden our understanding of the universe, even at the expense of one’s pride. The value of science stems from this pursuit of knowledge, not the fame and prestige that come with a scientific discovery.

However, it is not as if the theory of dark matter has been disproven. There are still countless astronomers who are hard at work in search of dark matter. But, one significant contribution that is not up for debate is Rubin’s role as a pioneering advocate of women in the sciences. All throughout her life, she faced brutal and humiliating opposition towards her position as a scientist.

Teachers and colleagues alike pushed the notion that science was a men-only field and Rubin was often chastised for intruding where she didn’t belong. Yet, she continued to break boundaries, becoming the only astronomy major to graduate from Vassar in 1948 and eventually receiving the National Medal of Science in 1993. As Rubin once stated, “There is no problem in science that can be solved by a man that cannot be solved by a woman.” That alone should be enough for us to honor her legacy as a truly brilliant scientist.

Originally published on February 1, 2017, in The Miscellany NewsPublic misconceptions of Vera Rubin’s career pervade news cycle


Elon Musk’s Insane Plan to Colonize Mars


Picture Credit: Business Insider

Elon Musk is at it again. During the 67th In­ternational Astronautical Congress held in Guadalajara, Mexico, last Tuesday, Sept. 27, the billionaire entrepreneur formally presented his grand vision to send humanity to Mars.

“What I really want to try to achieve here is to make Mars seem possible, make it seem as though it’s something we can do in our life­times,” Musk announced to a lecture hall filled with eager listeners.

In his presentation, Musk provided every­thing from engineering details to timelines and even a video simulation of an enormous space­craft carrying passengers to the Red Planet to show how much thought he and his company, SpaceX, have put into this incredibly ambitious plan. The audience was electrified as Musk talked about how he would use a huge 40-sto­ry rocket with 42 new and powerful Raptor en­gines to blast through space at tens of thousands of miles per hour.

Then, when he vowed to establish a self-sus­taining Mars colony of one million people in the coming decades, the crowd cheered as if they were at a rock concert.

There was certainly a lot of excitement and fervor at the conference. Not only did Musk de­clare that the first trip to Mars could take place as early as 2024, but he also promised to make the voyage reasonably affordable for everyone. Ac­cording to his calculations, the first few trips may cost about $500,000, but the price may drop to only one-third of that as time passes.

But here’s the thing: Musk is a madman. Hu­manity has made incredible technological leaps in recent times, but space travel isn’t something that should be accomplished on a whim. A lot of logistical issues and complications have to be addressed.

At least under Musk’s current plan, it would be nearly impossible for this “Mars coloniza­tion” scheme to ever succeed.

First and foremost, the rocket has to travel across 54.6 million kilometers of outer space to get to Mars. According to Musk’s blueprint, the SpaceX rocket (nicknamed “BFR” by the compa­ny’s employees, and yes, the acronym is exactly what you think) will have 13,000 tons of thrust to launch the spacecraft all the way to Mars, all powered by extremely cold liquid methane as fuel.

The rocket’s main selling point is that most of it, especially the propellant, will be reusable, which will allow the rocket to refuel itself in space and significantly cut down the cost. How­ever, the big issue here is that no one knows if any of this technology can actually be built. Nothing like this has been done before. While the plan may seem feasible on paper, construct­ing the right machinery and making sure every facet of the spacecraft works properly is an overwhelming task.

To put things into perspective, the largest and most powerful rocket ever launched, the Saturn V, had a thrust of 3,500 tons.

Musk has not only promised to build a rocket with boosters that are 3.5 times more powerful than that of the Saturn V, but the rocket must also be twice the size of Saturn V to effec­tively protect all of its passengers. Don’t for­get that this rocket is also planned to utilize 42 high-powered engines. The record-breaking Saturn V could manage only five.

Most importantly, there’s the issue of cost, about which I won’t bother to go into detail because at this point, anyone can tell that money is definitely going to be an obstacle for an endeavor like this. Yet despite all of these factors, Musk thinks that he can build his revo­lutionary Mars rocket in just a couple of years.

But let’s give Musk the benefit of the doubt. Say that the rocket was successfully built ac­cording to his blueprints and the Mars mission was ready for takeoff. Then the problem chang­es to making sure that all of the passengers sur­vive the voyage. According to Musk’s estimates, the trip would take 80 to 150 days. Scientists find these numbers difficult to believe.

“I couldn’t quite follow where [the estimate] was coming from,” said Bobby Braun, Associate Professor of Space Technology at the Georgia Institute of Technology. “When we send robotic missions to Mars, they tend to take nine months to get there.”

There’s also the issue of radiation exposure. The spaceship must have a shield in place in case a solar flare occurs and discharges dan­gerous waves of subatomic particles. For some reason, Musk didn’t felt the need to take this issue into account, calling it a “relatively minor” concern. Given how he en­visions numerous rockets making over 10,000 trips, the odds of a solar flare happening and killing all the passengers is not something for him to casually brush off.

We also have to examine the plan as a whole. Musk is thinking big. He’s not satisfied with just visiting Mars; he wants humankind to claim it for future civilizations. Musk has stated that his ultimate goal is to turn humanity into a “mul­tiplanetary species” so that our kind doesn’t die out in one fell swoop when an asteroid hits Earth.

But this goal introduces a plethora of ques­tions that Musk has failed to address in his talk. How will this self-sustaining civilization be cre­ated? How will the inhabitants acquire essential life-support systems that create breathable air and obtain water? How will they obtain food?

Since initial trips between Earth and Mars will be few and far-between (speaking of which, how will the rocket have enough fuel to travel back to Earth?), the first inhabitants will have to live off of the land. Unfortunately, the soil on Mars is suspected to contain deadly con­centrations of perchlorates, which are toxic to humans. Not only that, Mars itself has dangerous levels of radiation due to its thin atmosphere. These are all logistical issues that Musk never really addressed. He didn’t even mention exactly where on Mars would be most suitable for human life.

Last but not least, Musk doesn’t have a partic­ularly impressive track record. He is rather infa­mous for falling short of his ambitious promises. Several times, his company, Tesla Motors, has failed to reach over 20 targets for improvement that Musk himself had set.

It also doesn’t help that just recently, one of his rockets exploded during fueling just two days before it was scheduled to launch. Honestly, this is the guy who spoke on live television about nuking Mars to create two mini-suns in order to make the plan­et inhabitable. He’s not exactly someone I would trust with my life.

But if nothing else, Musk is getting people to talk excitedly about space exploration again. Considering how NASA is in constant danger of being defunded due to dwindling public inter­est, this is quite a feat. Maybe Musk’s ambitious, if not fantastical, plan to colonize Mars may in­spire others to form a more legitimate one.

Former astronaut Tom Jones comments: “I think he’s not going to be able to deliver on those promises…[but] I think it’s less important to him that he actually get to Mars personally than that he lay down some steps that will help somebody else get there.”

Originally published on October 5, 2016, in The Miscellany NewsEntrepreneur Elon Musk must tame his imagination