8: The Bootstrap
Chapter Eight: The Bootstrap
Interstellar space is vast. Science fiction books and other entertainments gloss over the distance by a simple literary device: They make things up. They say that, somehow, the ‘light barrier’ has been broken and we can travel faster than light. But Einstein’s formulas show us that it even if we could apply all of the energy in the universe to try to accelerate even the tiniest object (say an electron) to the speed of light, we would not succeed.
In fact, other limits would kick in long before a craft got close to the speed of light. The problem involves collisions. At speeds more than just a small fraction of the speed of light; the collisions will have incredible power. For example, if an object is traveling at 75% the speed of light and it hits another object that is 0.001 KG (1/1,000th of a KG, or 1 grams), the collision will generate a force of 758 TJ (terrajoules) of energy. For comparison, the Hiroshima bomb generated energy of about 67 TJ. This means that at this speed, the collision would generate 11 times more energy than the bomb. To survive, the vessel would have to be built to be capable of surviving this collision.
If the vessel is moving more slowly, the collision wouldn’t be as dangerous, but it would still be more than most materials could withstand. At a speed of 20% of the speed of light, the same collision would generate about 36 TJ of energy, about 1/20th as much as the bomb. This is still a lot of energy.
To translate it into something that has energy levels that are easier to imagine and compare, let’s deal with energy in terms of 1 KG TNT equivalent. 4,184 KJ (kilojoules of energy). If the craft hit a 1 gram object at 20% of the speed of light, the collision would have a force equal to about 430 kg of TNT. We can calculate the amount of energy for a collision with a smaller object by dividing the weight. For example, if the craft hit an object with a mass of 1 mg (1/1000 of a gram), the collision would have a force of 430 grams of TNT, or roughly 1 pound of TNT. If the craft hit an a speck of dust that weighed 1 mg, it would have the impact force as a pound of TNT.
How fast could a group of intelligent beings reasonably send an object from one star system to another? If we accept that the laws of physics are as currently accepted, they wouldn’t be able to send it a significant percentage of the speed of light. It would have to be much slower. For reference, fastest speed so far of a human built craft is 17 KM per second; Voyager 1 is reaching this speed as it heads out of the solar system into space. This works out to 0.0057% (57/1000ths of 1%). We might expect that the speed of the craft would have to be somewhere between these two speeds.
How long would it take?
There are 512 star systems within 100 light years of the solar system and roughly 1.73 million star systems within 500 light years. For the sake of example, let’s say that the star system sending life is 500 light years away. At the faster speed, 1/5th of the speed of light, it would take 2,500 years to get from the other star system to the solar system where we live. At the slower speed—a speed we know we could manage, because we have sent craft traveling at that speed—it would take 8.8 million years.
Is this a lot?
It depends on your perspective.
Bear in mind that it took more than 3 billion years for the cyanobacteria to produce the atmosphere the Earth now has, and make it able to support advanced life. In terms of ‘the length of time of an average science fiction movie,’ or even ‘the length of a human lifetime, 8.8 million years is a very long time. Even 2,500 years is a long time. But if we compare it to the 3 billion years it would take to terraform the Earth, even the long figure is not very long. It seems logical that if a group of beings with intelligence wanted to send life to other worlds, and had accepted a time frame of 3 billion + years for the generation of the oxygen atmosphere, a few more million years wouldn’t make much difference.
We KNOW that the speeds of 17 km per second are achievable because we have sent craft traveling at this speed. Almost certainly, much higher speeds are achievable. As long as we are patient, or the beings sending the craft are patient, they would do it.
Could We Do It?
Humans don’t yet have the technology to manufacture DNA from nothing.
We can make DNA, however: CRISPR is a tool that whoever or whatever beings or processes created DNA included with the package. It allows us to alter DNA. Although the CRISPR gene sequence was only discovered very recently, and scientists haven’t yet worked out the tools to use this edit genes to exact specifications, scientists have done enough tests to confirm that it has the capability to and will eventually allow us to create genetic material that matches whatever specifications we work out.
We can make DNA.
If we wanted to send the raw materials needed for life to another world, we would be able to do so.
The Voyager 1 spacecraft was launched September 5, 1977. It weighs 825 KG (1,820 pounds).
It is currently traveling through interstellar space at a speed of 17 km/second. It will keep going through interstellar space at this speed until its speed is altered by the effects of gravity or some other force. If its speed is not altered, it will travel 500 light years in 8.8 million years.
We know it is possible to send a craft that weighs 825 KG to one of the 1.73 million star systems that is within 500 light years of Earth; with the technology we have available now. In fact, we could do this with the technology that we had in 1977 (actually earlier; the craft was built before 1977).
If we were sending genetic material to a planet that we know will have a carbon dioxide atmosphere that can be turned into an oxygen atmosphere, we wouldn’t even have to change anything in the DNA that exists on this world. We could send some cyanobacteria. We could send single-celled beings that reproduce asexually. We could send the raw materials for beings that reproduce sexually.
If we wanted to send genetic material to a world circling another world, we could do this.
The Bootstrap Problem
We could send genetic material to another world in another star system. We would not be able to send it in a living state.
Merely ‘being alive’ requires energy.
All living things on Earth require electricity to be provided to them continuously maintain life. If the electricity ever shuts off, even for a microsecond, the beings are no longer living beings. They are debris. All Earth life forms get their electricity from the same source: the breakdown of ATP into ADP. If the ‘hardware’ (the living things) that is sent to Earth has been rendered into a ‘living’ condition, and put on the craft for transport, it will require constant energy to keep it ‘alive’ until it gets to its destination. Shut down the energy, and the life ends and the operating system is lost. It is no longer life, it is just a bunch of space junk.
Some DNA-based life forms use very little energy. But they all require some. Some can go years without eating. They have mechanisms that allow them to break down food they have eaten in the past and turn it into glucose. This glucose then goes through the Krebs cycle (for aerobic life forms) or the far less efficient anaerobic process to create ATP. Most organisms are able to store enough ATP to allow them to continue to function for some time, even if they have no new ATP being manufactured. But even at the lowest practical power consumption levels—a state of deep hibernation—these beings will require many pounds of glucose or ATP per year to survive. A voyage of millions of years, or even thousands of years, with a living being would not be possible with DNA-based life forms as we see them on Earth. They could not be shipped in a living state.
Using the CRISPR and other tools, we may be able to modify genes into an embryonic state, what we may call ‘life ready’ genetic material, ready to load the operating system (essentially insert the spark of life) into the material and turn it into living material. You may consider a ‘life ready’ genetic material to be similar to an ‘operating system ready’ computer. The hardware is all there, assembled, and configured. The power system is either integrated into the machine or attached and ready. There is a ‘bootstrap’ that has changed the power state of the computer chips to make the transistors ready to receive their first instructions from the operating system. The operating system is in place and ready to load.
We don’t really know much about how the ‘operating system’ for living things gets into them.
Before conception, the human egg is just genetic material. It has the potential to turn into a living being, able to breathe and reproduce, but it is not a living being by itself. If it is not fertilized, the body gets rid of it; it is considered trash and removed.
Conception doesn’t really provide everything the person will need: a fertilized egg is still unable to survive on its own or do anything without help from the mother’s body. We can easily fertilize eggs outside of the body. But then they have to be put back into the mother’s body for the next nine months. Merely giving them nourishment isn’t enough. The mother provides a great many things for the growing living thing, turning it first into a zygote, then into an embryo, then into a baby. At some point during the later part of this nine-month period, the operating system somehow gets loaded into the growing mass of genetic material.
By the time if birth, the instruction set is in place. The baby can leave its mother and can survive (with care of course) without any physical connection to its mother.
The ‘bootstrap’ is the something that somehow causes the set of operating instructions to be loaded onto the genetic material, turning it into something that performs the complex functions of DNA-based life.
A bootstrap would be needed to send life to another world because of the vast distances. If the craft containing the life was sent from one of the more than 1.25 million star systems within 500 light years, it might take thousands or even millions of years to get there. If it had to come from farther away, it may have been in transit for more than a billion years before it arrived. Clearly, it could not be shipped alive. It would require a bootstrap.
What might this bootstrap look like?
As we learn more about DNA, we can start to see that a great deal of engineering went into this molecule and the life based on it. We humans are still very early in our understanding of DNA. We will probably not be able to understand even the basics for a long time. But if we understand what is needed to send life to another world, we will know what to look for. Then, when we see something that looks like what we are looking for, we will recognize it.