Whether it has been driven by the science fiction aspect of entertainment in our lives today

Whether it has been driven by the science fiction aspect of entertainment in our lives today, or a general interest about our neighboring planets, we’ve always wanted to know if there is life on other planets. According to NASA, fueled by the research with by the Opportunity and Curiosity rovers, there was a time when Mars was capable of supporting life.

A resent NASA conference (available below) explored the results of experiments conducted during the exploration of Mars with Curiosity and Opportunity, two of the rovers that have been sent to the Red Planet for remote analysis. The most recent rover, Curiosity, was sent with what is essentially chemistry lab on wheels, as well as a massive laser for more in-depth experiments on the surface of Mars. The discovery of an ancient streambed by the Curiosity team has allowed them to state definitively that there was a time when microbial life could have thrived on the surface of Mars.

Curiosity’s SAM and CheMin instruments have been working with sampled picked up from the streambed, and have discovered what are considered key chemical ingredients needed to support life. The Gale Crater sediment was found to contain hydrogen, oxygen, nitrogen, carbon, and sulfur among other necessary ingredients. This information leads scientists to believe that there was a time where the surface of Mars was wet, and these materials would have existed in clay that lay under the water. At some point, a dramatic change led to the harshly acidic and salty surface that covers Mars today.

NASA scientists are now able to picture an ancient Mars that would have been grey with life instead of the red that exists now. The Mars Science Laboratory notes that these discoveries are just the beginning to reveal the history of this planet, and what may have existed on the surface well before we started looking up and wondering if we were alone in the Universe. Curiosity has everything on-board needed to continue researching the surface for years to come.

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Engineer Mehdi Sadaghdar makes YouTube videos in which he answers questions about electronics and technology

Engineer Mehdi Sadaghdar makes YouTube videos in which he answers questions about electronics and technology. One question he apparently gets quite often is which type of electricity hurts more, AC or DC? You have to respect the commitment Sadaghdar has to his audience. To answer the question, he applied increasingly potent electrical shocks… to his tongue.

In AC, or alternating current, the flow of electrons periodically reverses. DC (direct current) is simply unidirectional flow of electric charge. Most electrical systems in the world run on AC (50-60Hz), but many devices require DC power. In these cases, a power supply steps the power down to DC. If you’re tinkering with electronics, there are plenty of places you could get a nasty jolt from either form of electricity.

Sadaghdar wanted to figure out which type of shock would be more painful, but without using huge (read: dangerous) amounts of voltage. It stood to reason he should use the body part with the lowest resistance, which turned out to be his tongue. There are a few incidents during the testing process, which should serve to remind you not to try this at home.

With DC, Sadaghdar started at 1 volt and ramped it up to 12 volts, where he was forced to stop. Before the actual AC testing got underway, Sadaghdar demonstrated how the frequency of AC causes the muscles of the tongue to contract. It’s an effective visual aide. As for how painful 60Hz AC is, he had to stop at about 6.5 volts.

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Do you know what today is?

Do you know what today is? The mathematically inclined among you will instantly proclaim that it is, in fact, Pi Day. This impromptu holiday happens every year on 3/14 (like 3.14 at the beginning of pi). Of course this only works in the American date format, but let’s all look past that to celebrate this crazy mathematical constant together. Bonus: it’s also Einstein’s birthday!

The dry mathematical definition of pi is the ratio of a circle’s circumference to its diameter. That’s cool, but what does it mean? If you take a perfect circle, no matter how massive, and divide its circumference by the diameter, you always get pi. Thus, a circle’s circumference is always 2π. This value is hugely important in physics and engineering.

Because pi is an irrational number, it repeats forever. Some mathematicians have made it a challenge to continuously calculate more and more digits of pi. The current record for this noble endeavor is 10,000,000,000,050 decimal places, held by Alexander Yee and Shigeru Kondo. It took them 371 days to make the calculation with a dual-core Xeon PC running 96GB of RAM and 58TB in total storage.

Here’s a visualization of one small part of that data. Each pixel in this image represents one digit of pi. Make sure to check out the interactive version as well.

Maybe you didn’t plan ahead for the Pi Day festivities. Well, then maybe you’ll want to wait for Pi Approximation Day this summer. On July 22 (or 22/7 in the day-month format) we get the value 3.1428… it’s close enough.

Pi Day was first organized by physicist Larry Shaw in 1988. He envisioned it as an excuse to walk around in circular rooms eating pies (which are round, so you can justify it). I think that sounds pretty good.

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