We Went to the Moon!

Posted on November 13, 2010 by danielfeldman

Hi everyone. Before I continue with this entry, I want to pay homage to my friend Chris Jordan, who first gave a presentation on the ludicrous nature of Apollo hoax theories, and who inspired this entry. He deserves some credit for my desire to write this, and for much of my knowledge of why people are so stupid. Now, on to the show!

Despite the belief of between 5 and 25 percent of people, I can tell you that we have been to the moon. Not only is there overwhelming scientific proof, but the theories themselves are often so ridiculous that only the most gullible and scientifically illiterate people would believe them. Some theories seem plausible, but become debunked upon closer testing and inspection. I will present here a few of the theories, and tell you why they are not true. Hopefully I will get you all to be believers in science.

The main theories usually tend to focus on the photographs released by NASA during the Apollo missions. One theory is that it was fake because the photographs are of impossibly good quality. I think the debunking of this one is simple—if you have good photographs and bad photographs, which would you want to show people? NASA had both good and bad quality photos taken by the astronauts, but OBVIOUSLY they only released the ones of superior quality.

<3

Another problem with the photos, according to conspiracy theorists, is that the footprints on the moon seemed to be too well preserved, considering the fine grains of moon dust. To them, it appears to be as if set in wet sand, which is impossible due to the lack of moisture on the Moon. Indeed, the Moon is drier than the deserts on Earth, but you cannot think of Moon dust as you do Earth dust. On Earth, dust and sand grains are weathered and smoothed out—this does not happen on the Moon, and so the grains are much more jagged, allowing them to stick together better, giving them a consistency akin to “wet sand or talcum powder”, as described by astronauts. If you don’t believe me, watch “Mythbusters”, who did an episode on debunking these theories, and this was one they tested. Case closed.

Another picture issue is that they see crosshairs behind objects. Well, this one is easy to debunk—when bright objects are overexposed, crosshairs appear as it saturates the image and starts to leak out into the black areas. You can actually see this with real images for astronomy research:

Real picture from the COSMOS Field, taken by Hubble. Note the crosshairs, also known as artifacts.

The best theories are the really dumb ones. According to one theory, there was a large solar flare while the crew of Apollo 16 headed to the moon. Not only is there no record of such a flare, but last time I checked, the crew of Apollo 16 were still alive…

Apollo 16 crew members are ghosts, of course.

Yet another theory is that astronauts could not survive cosmic rays and other radiation sources out in space. It is true that radiation is a serious problem, however NASA isn’t made up of idiots—the aluminum hull of the spacecraft is enough to protect the astronauts. Still, some radiation gets through, and it actually serves as evidence of the mission! Many astronauts suffered similar illnesses believed to have been caused by the radiation. Take that, science-denying filth!

Perhaps the most famous argument is the one surrounding the flag planted by Apollo 11 astronauts, which appears to move in the photographs taken. This is actually an optical illusion, and is explained by numerous sources. In pictures, the flag appears to be rumpled, which seems to indicate movement. In fact, you can look at photos taken at different times by the same camera at slightly different orientation, and see that it is completely motionless. There is actually a 30 minute film in which you notice the flag stay motionless the entire time. When touched by the astronauts, the flag does not wave, but instead swings like a pendulum, due to the absence of air.

In addition to debunking radical theories, there is evidence for the landings that are easily confirmed. The best example of this is the presence of retroreflectors on the lunar surface. Let me explain via diagram:

Science--it works.

Convinced? I hope so, for your own good. Face it—we went to the Moon, and it was glorious.

I’m experimenting with drawings (and mouse-over text! yay!) … feel free to comment and tell me what you think! Keep the drawings or go back to the old way of posting? I promise you won’t get spammed by viagra sellers and male enhancement ads if you give your email in order to comment on this. Also, feel free to suggest topics you’d like to see me cover. Thanks, see you for later for some more science!

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Infrasound Blues?

Posted on November 4, 2010 by danielfeldman

Ever wonder why you can enter a room, and suddenly feel a sense of dread, or fear? Well, most people have chalked it up to places being haunted! Indeed, it’s an easy conclusion to come to when you feel uneasy in a room, and even see blurry images around the room. Often, in many places, different people, without prior knowledge of each other and their situations, can feel or see things in the same place. So it must be haunted, right? WRONG! Science to the rescue!

Assuming you haven’t been awake for 4 days straight (because that can cause these things too), the culprit is very likely to be something called infrasound! Infrasound is sound just below the human range of hearing, which is roughly around 18Hz in frequency (cycles per second). Despite human’s inability to hear infrasound, our ears (or even body via vibrations!) can detect them, and studies have shown that we often feel dread or fear when we pick up the sounds. This easily sets the stage for horror movies and haunted houses, but does it really go deeper than that?

Indeed, infrasound, if at the right frequency, can actually resonate with our eyeballs. When something resonates to a certain frequency, we mean it is subject to vibrate when subjected to sound waves of that frequency. Tuning forks have specific pitches because when we make them vibrate, it will have a specific frequency that corresponds to a pitch’s given frequency. If our eyeballs pick up the infrasound’s frequency that it resonates at, it will vibrate and can cause us to see images of figures that aren’t actually there. Indeed, if you wear glasses with slight dust specks on them, the vibrations can cause the eye to register the static flake as being a moving blur. Infrasound can make you experience pain, and perhaps even bleeding!

Don’t get me wrong though, infrasound isn’t just a bad thing. In fact, there may be an evolutionary reason as to why we feel these things when our ears detect infrasonic waves. Some of the natural phenomena that produce infrasonic waves are volcano eruptions, earthquakes, and avalanches, just to name a few. This could give us a subconscious way of knowing that danger is near! It is believed that many animals use infrasound to detect such disasters to give them ample time to adapt or run. They can do this because infrasound can travel over very long distances without encountering too much interference. In fact, elephants can produce infrasonic waves through the ground using their feet to communicate over distances of 2 kilometers!

In addition to natural sources, many man-made sources can create infrasound. This can cause vibrations in many objects, another sign of “hauntings” in your surroundings. In fact, we sometimes use it in music or movies to give people that feeling of unease. According to wikipedia, Paranormal Activity used infrasound in its soundtrack—I can believe it, a LOT of my friends were really scared by that movie, even the ones with strong resolve. Infrasound being produced by man-made devices such as fans and infrasonic whistles have been shown to be the cause of places being haunted, and since their removal, the place became “normal.”

So there you have it! Now you know a really good way to scare the living daylights out of your friends when you make your own haunted houses. Too bad we’re now in November and you just missed Halloween…maybe next year!

Posted in Biology, Physics | Tagged , , | 5 Comments

Fantastic Science Blog Entry

Posted on October 26, 2010 by danielfeldman

I was alerted to this fantastic blog entry written by Christoph Niemann, and I think I should share it with you all. Yes, I apologize that this entry does not include any new science from yours truly, but this is a witty and visual entry about the laws of physics, presented in a very funny and approachable way. Do check it out! The link is http://niemann.blogs.nytimes.com/2010/10/25/unpopular-science/?src=me&ref=homepage

That’s all for now. Updates and more science to come soon.

-Dan

Posted in Comics, Physics | Tagged , , | 1 Comment

Hot Water vs. Cold Water

Posted on October 22, 2010 by danielfeldman

I recently came across a really cool phenomenon, and I feel compelled to share it with you. We’re going to consider a thought experiment, something Albert Einstein and other scientists love(d) to have. In this experiment, we envision two pails of water—one of them has hot water in it, the other has cold water, each of equal water level. We then go outside on a cold winter morning and leave them in the snow. Now, we consider the following question: which will freeze first, the hot water or the cold water?

I know what you’re thinking. “Why are you asking me this? Clearly the cold water freezes first!” It would make sense, right? By the time the hot water gets cold enough to start freezing, the cold water should already be frozen. Common sense makes this seem trivial…but then science gets in the way. It turns out, the hot water may be able to freeze first! There are actually many scientific phenomena that are thought to be able to help the hot water freeze first. Here are a few of them.

The first one is evaporation. This is something we encounter all the time, though you may not think about it…it’s why you sweat! When you sweat, the water in it will evaporate off of your skin, and when this happens, it absorbs heat (it’s called an endothermic reaction), cooling you off. The water has to take in heat in order to make this phase change from liquid to gas, and so it can help cool your body down when it gets heated. The same thing happens to the hot water. The hot water will be evaporating off the surface, taking away extra heat from the liquid water still in the pail. This will also happen to the cold water, but on a much smaller scale. Additionally, because the water is more readily evaporating in the hot pail, there will end up being less water in this pail that needs to freeze.

The second effect comes from frost. The cold pail will be sitting in fluffy, airy snow. The hot pail will melt the snow around it, but as the water (and pail) cools and freezes, the melted snow will once again freeze, this time freezing around the surface of the pail. This snow is much more form-fitting, and will allow conduction much better than the fluffy snow around the cold pail (conduction is when two objects of different temperature touch each other—the heat from the hotter object will flow to the colder object until they are at the same temperature. It’s why if you stick a metal spoon into a fire, the other end you’re touching gets hot).

The third effect has to do with gas bubbles inside the water. The hot water is less likely to contain tiny gas bubbles dissolved in it, because they would have (at least mostly) escaped while being heated. The cold water therefore should have more gas bubbles dissolved in it. When gases are dissolved in water, it lowers the freezing point, and so the cold water is more likely to have a lower freezing point than the hot water!

Lastly, I’d like to mention the effect of convection currents in the hot water. As hot water cools, something called convection occurs—the temperature, due to movement of the water within the pail, will become non-uniform (different at various parts of the liquid). When temperature increases, the density decreases, and so hot water will rise to the surface, giving the water in the pail a “hot top”. Heat can then more easily be released at the surface, furthering the cooling effect on the water. The water in the hot pail will be more easily able to develop convection currents as it cools. Convection has a lot of cool applications for cooling—in addition to being a driver for global climate (convection currents in the ocean), convection is also used to help keep your computer cooled.

So, as you can see, the hot water can sometimes come out victorious! Often referred to as the Mpemba effect, this shocking phenomenon is one really cool application of thermodynamics, and can be easily tested. Obviously this doesn’t always work, and is highly dependent on your initial conditions (air temperature, environment, difference in temperature between the hot and cold water initially, etc.), but it is often shown to work. It has been highly tested, and it’s not fully understood what the main driver of this effect is.

A more complicated effect that I didn’t mention before, that is thought to possibly play a role, is supercooling. When water cools, it wants to go to the least energetic state possible (ice crystals), but in order to do so, it has to latch onto what are known as nucleation points. Nucleation points are places in which these ice crystals can begin to form (ice has to start freezing somewhere, right? The point is, the starting points for phase changes aren’t just random. An example of nucleation with gas bubbles occurs when you stick your finger into a glass of soda, and bubbles form around your finger). If there are no places for the ice crystals to form, then the liquid can stay a liquid at lower temperatures than the normal freezing point, and becomes “supercooled.” It is thought that perhaps the cold water can become (more) supercooled than the hot water, and so the hot water will have a higher freezing point.

This is the type of experiment that can be set up very simply during the winter. It’s now getting into late October, so in a few months, I encourage you to go out in the snow (or just a really cold day) and turn this thought experiment into a real one. If you do, feel free to come back and post your results!

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