Humans are a curious bunch. In their never-ending quest to make sense of an increasingly confusing world, they love nothing more than to sink their teeth into the great mysteries and unanswered questions of our time: What happened to Amelia Earhart? Who was Jack the Ripper? How the hell did they draw the giant Nazca Lines of Peru?

However, not all of the “mysteries” that fill our collective imagination are mysterious at all. A fair number of the stories that are widely perceived to be unanswered enigmas were actually solved long ago or perhaps were never mysterious in the first place.

Sorry for spoiling the party, folks.

The Bloop From The Murky Depths Of The Ocean

In 1997, a freak noise blasted deep in the south Pacific Ocean: “BLOOP”.

The noise, which sounds like a giant water droplet plopping into a bath of water, was picked up by a number of perplexed researchers over 5,000 kilometers (3,100 miles) away. Whatever it was, it was mighty loud, but that was about all they knew.

Unsurprisingly, many people believed it was the echoes of mermaids. Even scientists wondered whether it could be evidence of a vast, perhaps unknown, marine beastie.

It turned out, it wasn’t mermaids or a Kraken. It wasn’t even a giant squid. The NOAA quickly figured out that the now-famous Bloop sound was consistent with the wavelength created when giant icebergs that are cracking produce icequakes.

What Happened To Princess Anastasia?

In the small hours of July 17, 1918, the Bolsheviks bundled the deposed Russian Tsar Nicholas II, his family, and his staff into a cellar where they were shot, bayoneted, and beaten to death (among other things).

Thanks to some misplaced bodies and a certain Disney film, many are under the impression that Anastasia, the youngest daughter of the Tsar, made an escape just before the fateful execution and started a new life. Over the 20th century, dozens of women claimed to be the lost princess, seeking fame and fortune.

Unfortunately, we now know that Anastasia’s fate wasn’t so romantic. In 1991, nine skeletal remains were found in a mass grave in the forest outside Yekaterinburg, not far from where the family was under house arrest. Still, DNA evidence revealed that two of the skeletons – son Alexei and one of the daughters (Maria or Anastasia) – were missing.

Then, in 2007, a second grave was found just a stone's throw away from the mass grave, containing the son Alexei and a female aged around 18 years old. While forensic researchers couldn’t identify which female body belonged to which princess, all the Romanov bodies were now accounted for – nobody got away.

"Here we are able to give a full account of all of the Romanov family and can conclude that none of the family survived the execution," the 2009 study of the skeletal remains concluded.

The Bermuda Triangle

The Bermuda Triangle – a vaguely defined corner of Atlantic Ocean between Florida, Puerto Rico, and Bermuda – is often said to be a hotspot of vanishing planes and disappearing ships. Explanations for this urban folklore staple have ranged from paranormal forces and extraterrestrials to unexplainable natural phenomena.

However, most of what you hear about the Bermuda Triangle is total bullshit. No evidence suggests mysterious disappearances occur more often in the Bermuda Triangle than in other parts of the sea, according to NOAA.

That’s pretty surprising in itself for a number of reasons. First of all, this area is a busy trade route filled with freight ships and traveling tourists. Equally, it’s right in the path of the Gulf Stream, so it would be fair to expect aggressive and sometimes unpredictable changes in weather. Furthermore, islands around the Caribbean Sea are surrounded by shallow, rocky waters.

In spite of all this, the area doesn’t appear to be any more dangerous than any other large triangle of the ocean.

We Have No Idea How The Pyramids Were Built

The pyramids of Egypt are a favorite of ancient astronaut theorists who spent too much time on YouTube. It can seem unbelievable that humans built The Great Pyramids of Giza some 4,500 years ago, a time when mammoths still roamed parts of the Earth, with little more than wood tools and sheer manpower.

However, we actually know a fair bit – granted, not everything yet – about how they were constructed. Spoiler: very few aliens were involved.

One of the big points of contention is how the giant 2.5-ton blocks were moved from the quarry to the construction site. A study from 2014 argued that the rocks were most likely slid across wet sand. Along dry sand, the friction would be too great and the task would require a vast amount of energy. However, by wetting the ground, the sand grains bind together, thereby reducing the sliding friction and making the job considerably easier.

As for mounting the stones, many Egyptologists have developed theories that include impressively complex networks of ramps and inclines that could have placed the blocks high up on the pyramid. Other researchers have even worked out that 30,000 to 50,000 laborers could have done the job at a rate of one block every sweaty 10 hours – tough, but possible.

Back in 1997, a TV show even got a bunch of engineers, stonemasons, and archaeologists together to see if they could construct a pyramid using methods true to the time. They struggled. However, they concluded that it could have been achieved with more practice, or with generation after generation of artisans developing their craft.

Wow! Signals From Outer Space

In 1977 – the year Star Wars was first released, coincidentally – astronomer Jerry Ehman of Ohio State University was searching for extraterrestrial radio transmissions near a distant cluster of stars called Chi Sagittarii. A few days later while reviewing his work, he noticed something utterly mindblowing: they had received a signal. He was so blown away by the signal, he circled the reading on his computer printout with a pen and wrote in big, curly, red writing “Wow!”

But what was the signal? And what created it?

Understandably, the unusual signal got a lot of people talking about aliens and extraterrestrial civilizations. However, we are now reasonably confident that it wasn’t a lost alien scout giving us a “what’s up?” It was most likely two comets. According to a study published last year, the comets, known as 266P/Christensen and 335P/Gibbs, have vast clouds of hydrogen gas around them. The researchers noted that the signal had a frequency of 1,420 MHz, which just so happens to be the same frequency of emitted hydrogen.

Could this be a mere coincidence? Most scientists now think that the comets are the most likely culprit, as much as they "want to believe".