Author Archives: Xinhai Dude 辛亥生

About Xinhai Dude 辛亥生

The name Xinhai Dude 辛亥生 is a pun in Chinese, as it means both “he who was born in Xinhai” as well as “he who studies Xinhai”. I had an ambitious plan to write something about the great Xinhai Revolution of 1911, thus my blog https://xinhaidude.com. But after an initial flurry of activities the initiative petered out. One day I will still carry it through. But for now, this website has turned into a conglomerate of my work on various topics of interest to me, including travel pictures, RC model airplane flying, ice skating, classical music composition, science fiction short stories, evolution and atheism.

Inline skating as rhythmic falls and recoveries

Some of us argue that skating consists of repeated cycles of falls and recoveries. Specifically, a skater deliberately moves her upper body such that shifted center of gravity causes her to “fall”. During this fall, she continues to glide on one skate. But at the same time she moves her other skate, the free skate, towards the projection on the ground of her shifting center of gravity, with the aim to recover from the fall by planting the free skate onto the new projected center of gravity. The process now repeats, with the free skate becoming the gliding skate.

If this fall and recovery sound like walking… well, it is walking, but with a special skating gait. In the sequence shown, the skater leans to the left while gliding on his left skate. He is about to fall to the left, but during the fall he moves his right skate, the free skate, over to his left side. He catches his balance at the last second, by planting his right skate on the projection of his shifted center of gravity. Continue reading

Posted in Inline Skating | Tagged , , , , , , , | Leave a comment

How to Inline Skate

Since the pandemic of 2019, I’ve been regularly inline skating at Eisenhower Park after work. In these last two years, I’ve seen a large number of new skaters show up with a box of new skates at the park. They put on their new inline skates, and struggled around for a while. Most tried to walk around the rink by holding onto handrails at the outermost track. The brave tried to skate and fall. Very few approached me to ask for advise.

So a large number of first-time newbies showed up every week. But I almost never saw them a second time. Perhaps they went to a new park to skate. Perhaps they didn’t hang out around the rink after getting their footing, so to speak. But I suspect that a majority of them gave up.

This article is for those who attempt to learn to inline skate. This article is what I wished someone had written for me, when I was just learning to skate. Continue reading

Posted in Inline Skating | Tagged , , , , , | Leave a comment

Inline Skating Rink at Eisenhower Park

Eisenhower Park is one of the few places in Nassau County where an inline skater can practice at an outdoor rink when honing one’s skills, and then stroll leisurely on wheels along scenic trails when just hanging around with friends and family. The rink is accessible all year round, and you will see people there every day. However, skating at the rink in winter months is only for the most determined folks. This article is not about a skatepark with street and transition elements, but I include it as a honorable mention as a part of my Public Skateparks on Long Island series. Continue reading

Posted in Inline Skating | Tagged , , , , , , , , | 1 Comment

What is a 5M NaCl solution in wt% mass fraction?

What is the equivalent mass fraction of a 5M saline solution?

A 5M molarity NaCl solution is equivalent to a salt-water solution prepared at mass fraction of 24.53 wt%. Continue reading

Posted in Science | Leave a comment

What happens when you let saturated salt water dry up completely?

When you leave a saturated NaCl salt solution in a glass cylinder, what happens when water dries up? Likely you thought cubic salt crystals would form at the bottom of the glass, and then grow bigger as water evaporates. You have this mental picture perhaps from reading a textbook, or maybe watching an animated video. Eventually only salt crystals are left in the cup. Well, that’s not wrong. But that is also not the full story. Continue reading

Posted in Science | Tagged , , , , | Leave a comment

Rockaway Skatepark – public skateparks on Long Island

Rockaway Skatepark in Queens was destroyed by Sandy. It was rebuilt, then reopened in 2020. This new and large facility features butter-smooth surface at the writing of this article, with both street and transition elements, plus a long bowl which connects with the main skating plaza. Rockaway Skatepark is located at the west end of Rockaway Beach. The new boardwalk passes next to the skatepark. And the Atlantic Ocean is just 200 feet away. Its sister Far Rockaway Skatepark is located at the east end of the same beach, 3.5 miles away. This article is a part of my Public Skateparks on Long Island series. Continue reading

Posted in Being a Wikipedian, Inline Skating | Tagged , , , | Leave a comment

Oyster Bay Skatepark – public skateparks on Long Island

Oyster Bay Skatepark features both street and transition elements, plus three connected bowls. Despite the name, this skatepark is actually located at Bethpage, not Oyster Bay. In fact, it’s part of the Bethpage Community Park, which is not far away from the huge Bethpage State Park. This article is a part of my Public Skateparks on Long Island series. Continue reading

Posted in Being a Wikipedian, Inline Skating | Tagged , , , | Leave a comment

Manorhaven Beach Skatepark – public skateparks on Long Island

Manorhaven Beach Skatepark features both street and transition elements. There is a raise platform in the middle of the plaza, with traffic flowing around this platform. At the time of this writing, it is the only public skatepark on all of North Shore Long Island. This article is a part of my Public Skateparks on Long Island series. Continue reading

Posted in Being a Wikipedian, Inline Skating | Tagged , , , | Leave a comment

Long Beach Skatepark – public skateparks on Long Island

Long Beach Skatepark features both street and transition elements, plus a large bowl. It is located between an outdoor hockey rink and the Municipal Boat Launch Ramp. This article is a part of my Public Skateparks on Long Island series. Continue reading

Posted in Being a Wikipedian, Inline Skating | Tagged , , , | Leave a comment

Kennedy Skatepark – public skateparks on Long Island

Kennedy Skatepark is officially named Jarred A. Newallo Skatepark. It is located in the Town of Hempstead, in Nassau County. This article is a part of my Public Skateparks on Long Island series. Continue reading

Posted in Being a Wikipedian, Inline Skating | Tagged , , , | Leave a comment