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Roger's Equations

This blog is all about science and technology (with occasional math thrown in for fun). The goal of this blog is to try and pass on the sense of excitement and wonder I feel when I read about these topics. I hope you enjoy the posts.

NASA's Investigation Into EM Drives - What if?

Posted April 30, 2015 3:56 PM by Roger Pink

Science (Fiction) Sells!

There's been a bunch of sensationalist headlines flying around lately:

Is NASA one step closer to warp drive? - CNET
Has NASA Accidentally Invented the Warp Drive? - Huffington Post UK
So NASA May Have Just Invented the Warp Drive - MTV

The first thing you'll notice are the sources. There are no articles from Discover, Scientific American, etc. None of the usual scientific magazines/news sites have mentioned this "warp drive" at all. That's usually an indication this is purely speculation and or hype.

However...

Whenever you hear about a new amazing technological advancement, it usually will fall within three categories. Either it's a scam, a mistake, or far less often an actual breakthrough / anomaly. The vast majority of the time it usually is the first two. That's most likely the case this time too. Still... this doesn't sound like a scam. It sounds more like a mistake. To understand why, I recommend reading this excellent article on the EM Drive at NASA. When you read about it, I want you to remember that, although the team working on it works at NASA, please be sure to understand that they are most likely a small, underfunded, unimportant group and project. This is not something NASA is taking seriously, as far as I've seen. At least not yet.

http://www.nasaspaceflight.com/2015/04/evaluating-nasas-futuristic-em-drive/

Hopefully you've had a chance to read the article above. In a nutshell it says that NASA Eagleworks - an advanced propulsion research group led by Dr. Harold White at the Johnson Space Center (JSC) has tested Electromagnetic (EM) Propulsion in a vacuum and recorded thrust measurements that seem at odds with classical physics (see article for more details).

This matters because the objections to previous experiments measuring thrust from an EM drive have centered on the fact that they haven't been tested in a vacuum. Critical scientists had used the lack of vacuum testing to suggest that the effect measured was probably convection heating of the air outside the EM drive, not thrust derived from the ground state of the vacuum (see article). The latest results seem to indicate that that objection couldn't be correct. Something else is going on.

Now please keep in mind that this doesn't mean that NASA has discovered warp drive as the sensationalist article titles I provided earlier suggest. It could just be a more complicated effect that falls within the realm of classical physics. However, if the EM drive does indeed work in a vacuum, things just got interesting.

Propellant is heavy and expensive. If a resonant microwave cavity could provide thrust, even a tiny amount of consistent thrust, it could change the way we currently travel space. Suddenly our nearest neighbor stars are within reach (the trip will still take over 100 years). Traveling to the outer solar system would only take a matter of years instead of decades round trip. Mars would be a quick trip away. Colonization could become a realistic goal.

Yay! Warp Drive Like In Star Trek!!!

No, not quite. It sounds exciting, and you can't blame MTV and CNET for the sensationalist headlines. Is this real? Is the EM drive truly creating thrust? (seriously, read the article). There hasn't been enough work done to know. It appears that way, but science is tricky and there are plenty of opportunities for mistakes and misunderstandings (see cold fusion). Most likely this will turn out to be something complicated and not useful for spaceflight...but still, if it is a real effect...that could be something amazing. Just don't get your hopes up too much!! At least not until a few other reputable institutions confirm the result. Anyway...

If you've come across any interesting articles on this subject (supporting or damning), please post them below. Best Regards! - R

12 comments; last comment on 05/04/2015
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The Laniakea Supercluster (Our Home)

Posted April 28, 2015 10:24 AM by Roger Pink

A Pale Yellow Dot...

The Milky Way, our galaxy, is a small part of a much larger structure called the Laniakea Supercluster. Laniakea is a relatively new concept, defined in 2014 in a paper published by astronomers from the University of Lyon. The structure of the supercluster is determined by the relative peculiar velocities of galaxies.

Laniakea subsumes the prior defined local supercluster, the Virgo Supercluster, which is now a section of the branch we are on. In the image to the right, the red dot represents the location of our galaxy. If you travel up the branch we are on, that first bright section you hit is the Virgo Supercluster. Laniakea consists of 100,000 galaxies over half a billion light-years. It contains four major subsections, the Virgo Supercluster, the Hydra-Centaurus Supercluster, the Pavo-Indus Supercluster, and the Southern Supercluster.

The Great Attractor, a gravitational anomaly located near the Hydra-Centaurus Supercluster pulls all galaxies and galaxy clusters in our area toward it. It now is known to be the center of mass of the Laniakea Supercluster.

If you get a chance, please watch this great video created by Nature on the Laniakea Supercluster:

Nature Video on Laniakea

8 comments; last comment on 04/29/2015
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The Fermi Paradox

Posted April 13, 2015 10:45 AM by Roger Pink

"By denying scientific principles, one may maintain any paradox" - Galileo Galilei

The Fermi Paradox

There is a paradox that states that given the vastness and age of the universe,there should be signs of "technologically advanced" civilizations, and yet none have been found. This paradox, attributed to the physicist Enrico Fermi yet stated by many others before him, remains an open question to this day.

There have been several theories put forth to explain this paradox. Some of the more popular answers are:

1. Advanced Civilizations are very rare, far apart, and/or destroy themselves quickly after obtaining advanced technology (the pessimist).

2. Advanced Civilizations hide themselves from us until we reach a certain technological level (the optimist)

3. World Governments have hidden the detection of Alien civilizations from the general public (the conspiracy theorist)

My question to you is, do we really know what we're looking for?

The Geocentric Model

It made perfect sense that the Earth was at the center of the Universe. After all, the universe was created for humans and humans are on Earth. Plus all the evidence seemed to point in that direction. The Sun and Moon seemed to move through the sky in similar ways. The motion of the planets and stars seemed to make sense in this model. It was logical.

Of course, it turned out to be wrong. As it turns out, the Earth orbits the Sun, which is a star on the outer fringes of a galaxy, which as it turns out is not even the biggest galaxy of our local group of galaxies (Andromeda is) and even our local group is relatively tiny compared to other galaxy groupings (Virgo Cluster). In other words, we aren't at the center of anything, much less the universe.

Likewise, it used to make perfect sense that Homo Sapiens evolved from less intelligent human-like species. If we look back, we should be able to see a clear transition when modern man evolved from the lesser primates. Early fossil finds seemed to support this theory.

The only problem is the more we looked back, the more we found, the less clear the transition seemed to be. There were multiple species of humans that had fire, tools, art, buried their dead, and interbred with each other. Worse yet, Jane Goodall went into the jungle and came out to tell us that chimpanzees even used tools. Soon we started to realize that many animals use tools. In other words, human intelligence isn't remarkable. If we were to disappear, under the right conditions, a completely different species could possibly take our place as the "intelligent" species of Earth (in millions of years).

But life is rare, right?

Probably not. We have cellular filament fossils dating back to 3.5 billion years, which is impressive considering the Earth's oceans didn't even exist until 3.9 billion years ago. You see the oceans were being vaporized by bombarding meteorites up until then. Basically it looks like the second the Earth was remotely habitable, life emerged. Not to mention that the most common atoms found in our bodies are oxygen, carbon, hydrogen, and nitrogen which also happen to be the 3rd, 4th, 1st, 7th most common atoms in the universe. So the materials for life are pretty abundant.

Ok, so by now I assume you get my point. We are not special. Our planet, star, galaxy,and local group are not special. Life as we know it isn't very special. Intelligence isn't special. As a general rule, we, nor anything associated with us, is not particularly special.

So Where Are All The Other Civilizations?

So let's take another look at the Fermi Paradox. It states that given the huge size of the universe (true), and the large amount of time it has existed (true), and how relatively easy it is for life to form (true), and how it is reasonable to expect intelligent life to emerge a certain percentage of the time since it isn't particularly special (true), why aren't we detecting advanced civilizations?

Maybe the problem is how we define "advanced civilizations".

As a kid I used to love to watch reruns of Star Trek (The Original Series) on Saturday mornings. One of the campy qualities of the original series was how all the aliens basically looked like slightly modified humans. For instance, Spock (We will miss you Leonard Nimoy!) was a Vulcan, an alien species. However the only physical indication of his alien-ness was his pointy ears. No doubt this approach saved a lot on wardrobe, but it did reflect a certain attitude of the time as well. Since then it has become generally accepted that aliens need not look like us at all and likely won't.

And yet, when we look for alien civilizations, what do we look for? We look for signs of our technology in the far off stars. Does this make sense? Is it right to expect other civilizations to use the same technology and science that we use? Is it truly correct to expect that at some point, all alien civilizations will emit radio waves just as we do? Or are we doing what we have always done, are we assuming that our version of civilization is special? Are we giving our civilization pointy ears and calling it "alien"?

Obviously I don't know the answer. We really won't know till we start discovering life out there. Until then though it's fun to guess/debate. What do you think?

74 comments; last comment on 04/18/2015
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String Theory and Umbral Moonshine

Posted April 08, 2015 8:12 AM by Roger Pink

Don't Let The Name Fool You!

The mathematical terms you are about to read are going to sound bizarre, but please keep in mind that most new physics and math terms sound bizarre at first. Think about it, we live in a world of charm quarks, imaginary numbers, strange attractors, quasars and nebula. So when you're reading the article I'm passing along below, and you come across the terms Moonshine and Umbral Moonshine, just remember that these are mathematical objects that people will take for granted in the future just as we take for granted the terms transcendental numbers and manifolds.

String Theory As a Mathematical Bridge

Ok, so there are some interesting things happening in mathematics right now. In a paper recently posted to archiv.org, some mathematicians have presented a numerical proof of the Umbral Moonshine Conjecture. It is important for many reasons including that a greater understanding (and proof) of this conjecture could go a long way in helping physicists combine general relativity and quantum mechanics convincingly through string theory.

Here is a quick wikipedia link that describes Moonshine.

Below is a Scientific American article on the recent arxiv.org paper and its implications in this areas of mathematics and physics. Enjoy!

Mathematicians Chase Moonshine's Shadow

In 1978, the mathematician John McKay noticed what seemed like an odd coincidence. He had been studying the different ways of representing the structure of a mysterious entity called the monster group, a gargantuan algebraic object that, mathematicians believed, captured a new kind of symmetry. Mathematicians weren't sure that the monster group actually existed, but they knew that if it did exist, it acted in special ways in particular dimensions, the first two of which were 1 and 196,883. McKay, of Concordia University in Montreal, happened to pick up a mathematics paper in a completely different field, involving something called the j-function, one of the most fundamental objects in number theory. Strangely enough, this function's first important coefficient is 196,884, which McKay instantly recognized as the sum of the monster's first two special dimensions.

Most mathematicians dismissed the finding as a fluke, since there was no reason to expect the monster and the j-function to be even remotely related. However, the connection caught the attention of John Thompson, a Fields medalist now at the University of Florida in Gainesville, who made an additional discovery. The j-function's second coefficient, 21,493,760, is the sum of the first three special dimensions of the monster: 1 + 196,883 + 21,296,876. It seemed as if the j-function was somehow controlling the structure of the elusive monster group.Soon, two other mathematicians had demonstrated so many of these numerical relationships that it no longer seemed possible that they were mere coincidences. In a 1979 paper called "Monstrous Moonshine," the pair-John Conway, now of Princeton University, and Simon Norton-conjectured that these relationships must result from some deep connection between the monster group and the j-function. "They called it moonshine because it appeared so far-fetched," said Don Zagier, a director of the Max Planck Institute for Mathematics in Bonn, Germany. "They were such wild ideas that it seemed like wishful thinking to imagine anyone could ever prove them."

Article Continues Here

6 comments; last comment on 04/10/2015
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The James Webb Space Telescope

Posted April 06, 2015 7:39 AM by Roger Pink

Hubble's Successor

Hello all! I've recently written an article for Engineering360 (News & Analysis Tab above) about the James Webb Space Telescope. It's a pretty incredible piece of engineering scheduled for launch in 2018. If you're interested, check it out here. If you already know a little about the JWST, you may want to jump ahead to the section of the article that details its specs called "The Precision." I've done a bit of research here (NASA has some great webpages devoted to it) and provide a lot of details I haven't seen on other articles on the JWST. Here's a little sample of the article:

The Precision (and Promise) of the James Webb Space Telescope

...To protect its heat-sensitive infrared detectors and mirrors, the JWST will be launched to the Sun-Earth second Lagrange point (L2) some 926,811 miles from Earth, a trip that will take roughly three months to complete. It will have a five-layer 40 ft x 60 ft sunshield to protect its mirrors and detectors from the Sun, Earth and Moon. This shielding is critical since all the JWST detectors and optics need to be kept below -370° F. One consequence is that the JWST will not be able to view the solar system inside of its L2 orbit.

The NASA Deep Space Network will be used to communicate with JWST. It will be designed to operate for five years with a goal of 10 years. Since manned spaceflight does not currently approach L2, there will be no opportunity for maintenance; whatever condition the JWST arrives in at L2 in will be the condition it stays in. Engineers working on the JWST must get it right the first time... Article found here

6 comments; last comment on 04/08/2015
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Stanford Researchers Make Manufacturing Gallium Arsenide Cheaper

Posted March 29, 2015 10:54 AM by Roger Pink

Better! Faster! Cheaper?

I came across this article today and I thought I'd pass it along. It doesn't seem that impressive at first glance, but it could have important consequences if the cost savings in the manufacturing Gallium Arsenide translate to large scale manufacturing. In many ways Gallium Arsenide is a superior material to Silicon, except in the most important way, price. If the costs associated with manufacturing Gallium Arsenide could be significantly reduced, it could lead in a jump in performance in chips and solar cells as manufacturers switch to it from silicon.

New Stanford manufacturing process could yield better solar cells, faster chips

Silicon and gallium arsenide both begin their progression from raw crystal to electronic device similarly. Both materials are fashioned into what electronics manufacturers call wafers. These are flat, circular platters of purified material. Subsequent manufacturing steps create computer chips, solar cells or other electronic devices on top of these wafers. But it can cost about $5,000 to make a wafer of gallium arsenide 8 inches in diameter, versus $5 for a silicon wafer, according to Aneesh Nainani, who teaches semiconductor manufacturing at Stanford. The new Stanford process seeks to lessen this thousand-to-one cost differential by reusing that $5,000 wafer. Today the working electronic circuits in a gallium arsenide device are grown on top of this wafer. Manufacturers make this circuitry layer by flowing gaseous gallium arsenide and other materials across the wafer surface. This material condenses into thin layer of circuitry atop the wafer.

In this scenario, the wafer is only a backing. The thin layer of circuitry on top of this costly platter contains all of the electronics. To make the wafer reusable the Stanford process would add several steps to the manufacturing process. The researchers demonstrated the technique in their experiments. First they covered the precious wafer with a layer of disposable material. Then they used standard processes of gas deposition to form a gallium arsenide circuit layer on top of the disposable layer. Next, using a laser, they vaporized the disposable layer and lifted off the circuitry layer like flapjack on a greased griddle. They mounted this thin circuitry layer on a more solid backing and cleaned the costly gallium arsenide wafer to make the next batch of circuits. Nainani estimates that this reuse could create gallium arsenide devices that would be 50 to 100 times more expensive than silicon circuits - still a big differential but much less than what exists today. Clemens thinks the Stanford process could rekindle interest in gallium arsenide electronics.

Article Continues Here

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