Category Archives: Science

Caught in Orbit Tonight with Ion Drives – Vesta and Dawn

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Vesta as seen from Dawn spacecraft

Image of Vesta taken during approach of NASA's Dawn spacecraft. NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

If years of planning and work pay off, NASA’s Dawn space craft was just now gravitationally captured, as of 10pm PST, by an asteroid that lives in the wide region of our solar system between Mars and Jupiter. The asteroid is named Vesta.

It’s thought that Vesta, which is only 326 miles in diameter, once had lava flows. If Vesta did once have lava flows, it makes no sense with our current understanding, since Vesta is too small to contain a molten interior. The Dawn spacecraft will spend a year orbiting Vesta investigating its composition in an attempt to shed some light on this puzzling situation.

Some people believe Vesta may have a high concentration of radioactive elements, such as Aluminum-26, that fell together from a nearby supernova explosion, and worked its way to the core of the asteroid, resulting in geologies similar to what we find on Earth and Mars. Hopefully, we’ll know soon enough.

After a year, Dawn will depart from Vesta heading toward the nearby dwarf planet Ceres. This will mark the first time any spacecraft has managed to orbit one celestial body, then move away to orbit another.

Ion EngineNASA accomplishes this feat through the use of ion propulsion drives rather than chemical rocket drives. The Deep Space 1 mission years ago proved the viability of using ion propulsion drives for space exploration. Ion drives allow spacecraft to travel considerably faster than chemically-propelled rockets. Although chemical rockets produce a lot more up-front force, ion drives produce a small force over thousands of days, which gives you much faster speeds, and incredible “gas mileage”. In fact, at full throttle, the ion propulsion drives will produce little more force than a piece of paper does when held in your hand.

Tomorrow night around this time we’ll know for certain if Dawn was captured by the gravitational field of asteroid Vesta, and the science will begin. It could well be we will learn some important facts about how our solar system coalesced into this big ball of dust we’ve come wandering out from. Here’s hoping!

Nothing is Not Undefined in Relationships

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NullData can be arranged relationally. When you order data with relationships in mind, it can be important to know what type of data we’re talking about.

Data types can be many things; numeric, integer, floating point, text, binary, dates, times, addresses — data types can be anything a database daemon was designed to support.

A problem can arise when you have a data container that is empty, awaiting data. For example, if your data type is integer, you may believe that a 0 represents nothing. But a zero represents a 0, not nothing, even though a 0 can represent nothing to us. Some databases might automatically place a 0 in a data container if no other value was provided. Other databases might not be so bold and reckless.

The problem is more apparent when considering text, or strings. If your container is meant to contain a string, yet you find yourself with no string to put in it, you have to ask yourself a question: “is the fact that I have nothing to put in it purposefully nothing – an empty string – or is it instead that it is an unknown, or undefined?”

Consider being told that you will have something done for you on Thursday. That’s great. It fits nicely in the date container. However, the Tuesday before, when you re-query the person, you find out that it may or may not happen on Thursday. If that confluence between a date and an event were to be filled, should it be an empty value, or an undefined (NULL) value?

Really, it depends upon the person who may or may not show on Thursday. Most people would say not to even define an event until that event is a “real” event. You can always add or delete things at any time. But that takes measurable work, and it consumes resources, and you have no built-in way to know if it’s tentative or not – it either is, or it isn’t going to happen.

A null in this case is very good at stringing people along. The event will easily be update-able to be happening or not, yet will never cause a conflict with any other overlapping event because it has an undefined value – NULL.

Interestingly, database users still argue over the usefulness of nulls in databases. Opponents of nulls claim that nulls easily confuse people and that any facts of known, unknown, or undefined values should live in the logic of the program running, rather than in the structure of data reality.

On the other hand, proponents of nulls claim that nulls reflect the reality of experience, in that some data must have the potential to be undefined when it has not specifically been set, even to nothing — because in doing so you can then claim data related to that thing may also be unknown or undefined.

Unfortunately, the real reality is that people and their languages are not always the best at accommodating undefined things – whether they are the ones generating the undefined things,  attempting to process them, or just simply to sensibly store them, in relation to any knowns.

Personally, I like nulls. Because they tell a story — and a fuller, richer one at that. Just keep in mind your own logic and language issues. Oh, and of course, those same things of others.

Worlds Without a Star

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Free-floating planet conception

Image credit: NASA/JPL-Caltech

We are small — very small — isolated in our ways, and environments. So rarely do we trouble ourselves to imagine beyond whatever sky contains us.

Astronomers do. Physicists do. As do philosophers, poets, and even some writers. Politicians unconcerned with their own petty gains imagine what might lay beyond for us, in what may become our future. There are few.

Perhaps it is a sad tail; a failed sun. Not quite enough mass to ignite, though larger than Jupiter — flung out from its stellar nursery before gathering enough of itself in.

Dark planets drifting through our space with no star to fall toward. Warping the background points of light, invisible but for the slightest noticeable effect. Through the force that binds all things despite any distance.

Small collapsing spheres of dust larger than our world — more numerous than the stars.

Japan and New Zealand working together discovered these “free-floating” planets by observing gravitational lensing effects. That is, they watched how something invisible was warping spacetime in the night sky, by seeing star positions distort as it passed. The level of detail they must observe is astonishing, particularly from ground-based telescopes.

Just look what we can see.

The Power and Responsibility of Truth in Science and Politics

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Mercury MessengerPeople can handle the truth. They may not always want it, and it may be confusing, but eventually they will handle it. As they learn about the world and themselves.

When you present people with disinformation they no longer learn about the world, or themselves in relation to that world. Instead, they learn only the world you present them. In a sense, you have taken away their sight, to be replaced with your own.

Tonight the Mercury Messenger spacecraft will spend almost 70% of its remaining fuel in its final major maneuver, with the goal of reaching orbital insertion around Mercury. No spacecraft has accomplished this feat. Mercury’s mass is very small while the nearby sun is enormous, which means the slightest miscalculation in the elaborately-winding path to Mercury will lose the Messenger to the heavy sun.

Disinformation would mean disaster. Even a small, honest mistake cannot be tolerated. The only chance of success is an almost religious adherence to truth – but not only truth; the accurate communication of information without any bias.

That’s not so difficult in the company of science, and scientists. But moving into the world of politics where exerting influence over large numbers of people is the goal, truth tends to become a tool to be utilized rather than an object of aspiration.

In its best light, disinformation is propagated not through lies, but through the strategic withholding of information. We find a current example in the nuclear radiation leaks at the Fukushima reactor in Japan, where scientists are calling for a release of more information so they might better understand and predict the impact of this disaster upon the Japanese people and the rest of the world.

In a worse light we see budgetary crisis with little or no explanation that are exploited to further political agendas and proffer economic prizes within a small circle, while providing citizenry with little more than sound byte propaganda with few and quite selective empirical facts.

And worst of all, the telling of blatant lies, that everyone is aware of – yet somehow these lies have become expected, tolerated and even considered business as usual.

We certainly wouldn’t get to Mercury with practices like that. With such ego-power-centric forces driving us, our Messenger would certainly miss its rendezvous, careening to burn into the sun, or flung out to slowly freeze in deep space.

It is our choice to know and discover truth. It is our choice to withhold what we know, or share it with others. It is our choice to manipulate and deceive people, to suit our own interests. It is our choice, to care or not.

Intel’s Defective New Chip and Your Lovely Machine

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Digital Rights ManagementThe recent $300+ million Intel chip recall has an interesting sideline. Apparently the chips have a design flaw that will cause data streaming to your hard drives to slow down over time, eventually resulting in only a trickle.

Interestingly, the Sandy Bridge chipset on board have Digital Rights Management (DRM) hard-wired into the Intel chips. The chips are designed to allow movie studios and television providers to command your computer not to record video.

Of course, Intel claims they have not built DRM into the chipsets, but that their chipset “gives PCs the level of trust that the studio needs to make their content available.”

Personally, I don’t like the idea of my computer’s capabilities being controlled by outside companies or entities.

The Free Software Foundation considers DRM technology to be inherently defective by design, and there is a long, ongoing campaign against DRM with some very good information available at http://www.defectivebydesign.org.

Here is a little letter I wrote the president of Intel, Mr. Paul Otellini:

To: paul.s.otellini@intel.com
Subject: No DRM in Sandybridge Please

Dear Mr. Otellini,

Please do not build DRM technology into your Sandybridge chipsets, or any other.

In fact, please do not build any technology into your hardware that monitors in any way the data I am processing. I will not purchase such products, and will encourage others not to do so.

I very much like your chip products. But not irrevocably so.

Thank you,
Mark Rushing