Sunday, November 22, 2015

Interstellar

Space! The Final Front... wait a moment,

I'm sorry Dave, I'm afrai.... no, not that one,

So, in some ways this movie, Interstellar, reminds me a lot of other space movies we have watched this semester. Though the resemblance is much closer to 2001 than Star Trek. Where Star Trek goes to great lengths to appease fans and Hollywood rather than physics, 2001 and Interstellar went to great lengths to keep the physics intact, with only minor gimme's for Hollywood's sake. Of course, that is ignoring the whole, "Fall into a black hole, discover it is a created 3-D tesseract designed by super advanced humans some indeterminately long time in the future just to make sure Matthew McConaughey got to send a message to his daughter that saved the human species" ridiculousness. (Time paradox anyone?)
Ow
But, Kip Thorne worked hard to make sure the movie was as close to physically accurate as possible, and he did a good job. One of the most fascinating parts of the movie to me was the planet referred to as "Miller's planet", after the explorer that landed on it. Orbiting close to the super-massive black hole called Gargantua, there were many oddities about this planet as a result of it's orbit. The first one, is the passage of time on the planet. Being that close to a black hole, the gravity of the black hole causes time to run slower on the planets surface than away from the black hole. According to the movie, one hour on the surface of the planet is 7 years back on earth or on the space ship.
Location of Miller's orbit


In Kip's book on the physics of the movie, he states that in order to have that much time dilation, The planet has to be incredibly close to the black hole. We already knew that, but Kip goes into a bit more of the implications there of. So, in the movie we see the giant waves that seem to circle the planet and pass by any given point once every hour, based on time given in the movie.
Ouch
These waves dwarf any waves we have ever seen on earth. For comparison, the largest wave seen on earth was 100 feet tall. These waves are estimated at around 4,000 feet tall. So, it seems pretty obvious that these waves are caused by Gargantua's massive gravity, which is why they dwarf our own waves, only created by the gravity of the moon, which is minuscule by comparison. But a good question to ask is exactly how they are formed. Well, the first part of the puzzle is realizing that Gargantua pulls Miller into the shape of a football, like so:
Any one up for some handegg?
As you can see, this causes massive bulges on the planet, which is why most of the planet is only about knee deep with water. However, assuming the planet is tidally locked to Gargantua (which is necessary for the planet to not shake itself apart), why do the waves move? Without the planet rotating, the "waves" would just stay in place, making a really awesome planet wide ocean that is about knee deep at the equator, and thousands of feet deep at the poles. And while that would be awesome, and more habitable than the reality, that's not how the planet is depicted in the movie.

Instead, Kip proposes the planet is tidally locked to Gargantua, but rocks back and forth. If this is the case, then a possible explanation is a phenomena called tidal bores. In essence, tidal bores are what happens when the tide changes rapidly enough or with enough force to create waves that move with the tide. On earth, these are at times spectacular, but rarely devastating or dangerous to those outside of the flow of the water. However, a tidal bore caused by Gargantua's massive gravity, could result in the massive, 4,000 ft tall waves every hour.
Tidal Bore on Earth
Finally, there is an interesting observation that Kip makes in his book. If we make an assumption that Miller's planet was formed while the universe was still young, say around 12 billion years ago in Earth time, then following the time dilation of Miller, then at "present day" when Cooper & co make it to the planet, it is only 200,000 years old. It is interesting to think that they could have set foot on a planet that in the universal sense is incredibly young, and undeveloped. That's some time travel crap right there.

Sunday, November 15, 2015

Star Trek (The Reboot)

And what a reboot it was. Even though I never was a trekie, and haven't really watched any other Star Trek stuff, and am completely unqualified to make that statement, I just want to say:


Now that the silliness is out of the way, I want to approach two of the technologies in Star Trek, why they are unfeasible, and why they were necessary for the over all plot of the movie. Aka, why Kirk and Spock would not have bravely defeated Nero without:

1. Warp Drive!!!!!!
So. The idea of Faster Than Light travel is nothing unique to Star Trek. Basically every sci fci universe worth it's salt has some form of FTL woven in somewhere. The way Star Trek's works is generating large amounts of energy through the reaction of deuterium with anti deuterium (matter with antimatter), using the reaction to produce highly energetic plasma, which then was used to create a warp field, which encompassed the ship, allowing the ship to enter subspace and move at "warp speed" aka very very fast.

I see several problems here. Do you? Even ignoring the whole antimatter thing (supposedly controlled by dilithium, which is non reactive with antimatter when put inside an EM field.... wat?), there is the whole underlying issue that according to Einstein, nothing moves faster than the speed of light. It just can't happen. However.... It is undeniable that warp is central to the entire concept of a "star trek", let alone the movie Star Trek. 

To explain why, lets do an example. Take the distance from Earth to the Moon. Something humanity has already traveled, so its something we can somewhat wrap our heads around. Hop in your BMW (cause who cares about emissions in space?) and drive your way to the moon (just bare with me, its an example, I'm suspending the non-relevant laws of physics) and lets see how long it takes you. Well, the distance is 384.4 million meters. That is 3.84 x 10^8 meters. Let's be generous and say you are driving your BMW on a German Autoban pointed straight at the moon, and you floor it. The BMW i8 has a top speed of 120 km/h. In meters per second that is right around 70 m/s. So you make it to the moon in.... 63.5 days.

The actual Apollo 11 mission that first made it to the moon made the trip in around 3 days. For a faster spacecraft, hop in the New Horizons spacecraft, which hit speeds of about 15730 m/s, and you make the trip in just under 7 hours.

Light would make the trip in... 1.28....... seconds.

In order to do the type of exploration and travel that happens in the Star Trek universe, where distances between stars are measured in light years, or 9.461e+15 meters, we have to move faster than the speed of light.

The other technology I have an issue with is:
2. Transporters

The way transporters work is they essentially deconstruct a person, convert them into a data packet, shoot the data packet at a destination and recreate them on the molecular level at the destination. 

Besides the obvious technological and physical issues with this tech, I want to draw attention to a moral one: if we actually did this in real life, would the person reconstructed on the other end really be the same person? Would breaking someone into their constituent molecules, turning those molecules into data, and then undoing the process on the other end produce the same living being with all the thoughts, emotions, and personality of the original? 

And if the answer is yes, then it raises another question: are we more than a sum of our pieces? If someone took a collection of atoms and organized them in the exact same configuration as your body, would that new collection of molecules actually be you? It is a frightening thought, one that touches on the very nature of what makes us living creatures.

Now, as far as the plot is concerned, teleportation (as that is from a non-sciency stand point what transporters are) is probably one of the most convenient, widely useful, and profitable abilities ever. Imagine, being able to be at school, realize you forgot your super important, final grade determining paper at home. No more lame excuses, just walk over to your transporter, beam home, and grab it. On the flip side, if you are driving your spaceship full of red matter in a suicide rush at the big baddy's ship, but don't want to die, just have your friends teleport you back to your home ship, safe and sound. What could possibly be not to love about transporting?

Sunday, November 8, 2015

Fat Man and Little Boy & Gojira

This week we had a double feature, watching the movie Fat Man and Little Boy and the original, Japanese Godzilla. The commentary was very evident, and both sides of the story were shown, questions were raised, and moral questions left unanswered.

In Fat Man and Little Boy, the scientists near the end of the movie slowly face a realization of the magnitude of the project they are working on- a device that could easily kill thousands of people with basically the flip of a switch. As they realize how dangerous and deadly this device is, they start to dig their heels in, try to back out or provide reasons for why there was no need to use it. Eventually however, as we know, they do use it, the world finds out about it, and an arms race begins that plunges the world into the First Cold War. Men such as Oppenheimer created the tool that would shape much of war for the next millennium and beyond.

In Gojira, the scientist Serizawa creates a devastating object, called the oxygen destroyer, that removes all oxygen from water, ruining the ecosystem and eradicating all life inside that patch of water. When the monster Godzilla shows up, he at first refuses to use his weapon, for fear that others would discover it and use it for terrible things. Eventually, he agrees to use it, but he burns all his notes, removes all evidence to how it was built, and even sacrifices his own life to make sure no one can learn the secret to how it was built. 

In both, the scientists worry about the consequence of the usage of their weapon, however in the end they decide that the benefits of using it out outweigh the risks, and that there is no other option.

I have often thought about creating weapons for the military to use. I am a strong supporter of the military, and feel that they are our bastion of defense against those that would threaten our way of life. Knowing that my tools could be use to protect the lives of American soldiers and civilians would give me pride in my work, and make me feel good knowing I was able to help others and my country. We live in a world where our enemies are many, unwavering, and ruthless. We have to be the same to stand up to them. As long as we keep our humanity in the process so we can separate ourselves from those we are fighting.

Sunday, November 1, 2015

Day After Tomorrow

Alright, this movie actually made me laugh. Multiple times. For those of you wondering, Day After Tomorrow is actually an amazing movie, and well worth the watch. If you go in expecting a comedy. If you go in expecting a super accurate physics representation of global warming, the end of the world, and temperatures falling at 10 degrees a second.....

However, this week I won't be evaluating the physics of this movie (which is a shame, there are so many great places I can go with "10 degrees a second"). Instead, I will be talking the problem of global warming. Specifically, How does the modern rise in temperatures compare to historic fluctuation in global temperature. Surely everyone remembers learning in elementary school about the ice ages and the mammoths running around every where. And that one land bridge in the Bering strait that they always thought was so important to teach everyone. So clearly the planet has had some cool points, and seems to be in or on its way towards a hot point now. How does this look throughout history?

Well, Humanity as a species started taking measurements of the global temperature all the way back in the 1880's. Unfortunately, I was only able to dig up records dating until the 2010's, but it still should give us some sort of an idea, right?

From NASA's records

OH DEAR GOODNESS WE ARE GOING TO DI..... wait, the entire y-axis covers only 2 degrees Celsius. However, the global temperature is right around 0 degrees Celsius according to NASA. If one of the scary things about global warming is the polar ice melting, ice melts at 0 degrees Celsius. Obviously, the poles are cooler than the global average, that is what an average is after all. But if you start increasing the global average, the poles will increase too. Eventually, the poles hit 0 degrees Celsius and then....

So, that is only dating back until 1880. We know the ice ages were a bit further back. So how are we supposed to know what the temperature is before we took measurements? We can actually estimate what the global temperature was using clues from things such as tree rings and other proxy data sources. You take a bunch of proxy data sources from as far back as we can figure and put them together, and you get something that looks (something) like this:


Ok, so the scale on this graph is a bit bigger, but it points out an interesting note: The Earth seems to have been hotter, much hotter, in years past. Considering best evidence dates humans anywhere from 200,000 to 10 million years ago, we as a species likely didn't live through the incredibly hot temperatures, however there is a chance we have lived through temperatures hotter than the current ones. What does that mean for modern man and global warming? Well, I leave that to someone smarter than myself.

P.S. in case you were wondering, in 3015, global warming has not ended humans. Not to say it won't, but so far we are still kicking.

P.P.S. Why on earth is the movie called "Day After Tomorrow"? It never references that line at all, the whole movie takes place over a week or two, and just in all ways the name seems ripped out of nowhere. But whatever.