Author Archives: cheng yang ma

A Tiny Planet Far Away Reveals Insight Towards Planet Formation

Posted on April 4, 2019 | Leave a comment

A tiny, primordial, and bizarre-looking planet at the edge of our solar system could hold the key to understanding how Earth came to exist.

On New Year’s Day, 2019, almost 13 years after its launch, NASA’s New Horizons space probe flew by a tiny planet, 2014 MU69, around 7 billion kilometers away. MU69, nicknamed Ultima Thule, is an object in the Kuiper Belt, an asteroid belt located beyond the orbit of Neptune. Ultima Thule is the most distant object in the solar system ever visited by a spacecraft.

Here is a video with more info regarding the  New Horizons

Dr. Brett Gladman, a planetary astronomer from the University of British Columbia, studied MU69 in his recent paper. Dr. Gladman with his team estimated the density of the impacted craters on MU69 and confirmed the actual density with the images taken by the New Horizons space probe.

Here is a podcast containing the interview with Dr. Gladman.

Using this information, they were able to confirm the size distribution of the Kuiper Belt. They were able to deduct the size distribution from the impacted craters because of the collisions that occur in the Kuiper belt. The collisions leave a dent on MU69 and from there, objects that were not observable through a telescope from the earth can be indirectly observed through looking at the impact craters they have created on the surface of MU69.

The results of this experiment are that MU69 looks exactly the same as it did 4.5 billion years ago. The MU69 in the Kuiper belt barely had any crater impacts despite being formed for 4.5 billion years. This indicates that there were barely any collisions with other objects. This confirms that the objects in the Kuiper belt are very spread out.

With this newly obtained information, the astronomers are able to place a constraint on current planetary accretional models (planet formation models) as this should be the destination of all planet creation model. This is a big step forward observationally as a constraint on the theoretical understanding of how you make a planet, or at least the initial building blocks of planets.

Additionally, the spacious size distribution of the Kuiper belt explains the lack of new planet formation in our solar system since planet formation requires collision of the objects in space. For example, Pluto is thought to have formed closer to the Sun than where Neptune is today, and have gotten stranded rather than being formed in the Kuiper belt.

All in all, space is still a mystery to us and with the advancing technologies, we are able to slowly unveil the mysteries regarding space and the process of planet formation.

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Self-driving cars, dangerous or safe?

Posted on March 20, 2019 | Leave a comment

Self-driving cars have been a leading force in car making for a while now. A concerning question that arises with the development of the automatic cars is how safe is it to be safe enough?

WHAT IS THE IMPACT OF COLONOSCOPY TESTING ON COLON CANCER RATES?

The safety features of current self-dring cars developed by Waymo. http://www.justscience.in/articles/impact-colonoscopy-testing-colon-cancer-rates/2017/12/15

For human drivers, we have drivers test to validate the ability to drive on the streets. However, for these self-driving cars, what are the standards? Do the cars have to obtain their driver licence as well before they can go on the road?

In a 2016 study, Kalra and a colleague showed that self-driving cars would have to trek hundreds of millions or perhaps billions of miles to demonstrate with comfortable certainty that they caused fewer fatalities than the average person (about 1.1 per 100 million miles driven). Based on the current number of self-driving cars, that task could take decades or centuries to complete.

Tech developers hardly have that kind of time, so companies like Waymo assess their vehicles’ safety by pairing real driving time with practice on a private track and millions of miles a day in computer simulations.

However, there are still some concerning questions as simulations cannot account for some absurd situations that might occur. The University of Michigan came up with general guidelines for safe self-driving cars. Can self-driving vehicles compensate for contributions to crash causation by other traffic participants, as well as vehicular, roadway and environmental factors?  Can all relevant inputs for computational decisions be supplied to a self-driving vehicle?  Can computational speed, constant vigilance, and lack of distractibility of self-driving vehicles make predictive knowledge of an experienced driver irrelevant?

The hesitance to provide a safe enough vehicle has been one of the major hindering factors when it comes to the development of self-driving vehicles as no company is willing to take the risk in selling potentially dangerous cars.

Therefore, some test similar to the standardized crash test for regular cars should be applied to self-driving vehicles to assess the chances of accidents due to machine error and human driving errors.

Here is a video uploaded by Ted-ed explaining some other dilemmas when it comes to self-driving cars.

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Posted in Issues in Science, Science Communication, Science in the News

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Can one brain have two minds?

Posted on January 27, 2019 | 2 comments

Imagine a knife slicing down right in the middle of your brain and splitting it into two separate halves. This is the result of a corpus callosotomy.

Picture

A summary of the functions for the left brain and right brain

The brain is commonly believed to be split into the left hemisphere, the logical side, and right hemisphere, the artistic side. These two halves are usually joined together by the corpus callosum, a fibre tissue that allows internal communication between the halves. However, people with refractory epilepsy or some traumatic accidents have the corpus callosum removed as a treatment and this creates a split brain.

There have been researches such as the one conducted by Roger Sperry that have proven the isolation of each half of the brain. This led to the proof that each hemisphere will have its own perception and impulses to act. Additionally, there have been cases where people with a split brain have reported conflicts in their lives. For instance, when one split-brain patient dressed, he sometimes pulled his pants up with one hand and down with the other due to the conflicting actions in each half of the brain. Luckily, conflicts like this seldom occur and even if a conflict does appear, one hemisphere usually takes control over the other half.

These results leave a lot of researchers questioning, do split-brain patients have two minds? Imagine having the one side of the brain deciding to punch someone with your left hand and the half of the brain controlling the right-hand tries to stop the action.

A study in 2017 found strong evidence against the split conscious theory. Yair Pinto and his team conducted a series of tests on two patients. In one of the tests, the patients were placed in front of a screen and shown various objects displayed in several locations. The patients were then asked to confirm whether an object appeared and to indicate its location. In another test, they had to correctly name the object they had seen, a notorious difficulty among spit-brain patients.  One of the patients went through all the tests using only his right visual field and the other patient only used his left visual field. Shockingly, the results have proven the unity of the two brains since the patients were able to respond correctly by using their left hand, right hand, or verbally. However, the experiment has not been replicated yet due to the difficulty in finding participants.

This new finding led to a new debate between the scientists regarding the existence of two separate minds in one brain. Here is a full video of the long debate on September, 18,2018 between Elizabeth Schechter, who stands for the two-mind view starts her explanation at 9:26, Yair Pinto, who debates for the one-mind view starts his point of view at 25:00, and Joseph Ledoux, who has an intermediate view starts at 47:27, (uploaded by NYU Center for Mind, Brain and Consciousness).

In all, even though the answer to this question is still undetermined. If the existence of two minds in one brain is proven, this leads to the question of, are we really the individual we think we are or is there someone else living within us?

– Eric Ma

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