Editorial Reviews. From Publishers Weekly. Venter (A Life Decoded), a field giant of genetics, makes a persuasive case that synthetic biology will help us. Life at the Speed of. Light. The biologist J. Craig Venter is most praised for his success in mapping and sequencing genomes, including his own. But he is quite. Part history, part primer, part argument for a Nobel Prize nomination, J. Craig Venter's. Life at the Speed of Light: From the Double Helix to the Dawn of Digital .
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Peter Forbes on a biologist obsessed with the basis of life – and with himself. Life at the Speed of Light: From the Double Helix to the Dawn of Digital Life J. Craig Venter Viking, ($). Venter, the scientist famed for. constants should have been fine-tuned to make the emergence of life in the know that the speed of light, which is the maximum speed in the universe.
When they got home, everyone on Earth would have aged five years more than they had. Physicist Amos Iron at the Technion-Israel Institute of Technology in Haifa, Israel pointed out another limitation if one used a machine: it might fall apart before being able to rotate that quickly. Cosmic strings Another theory for potential time travelers involves something called cosmic strings — narrow tubes of energy stretched across the entire length of the ever-expanding universe.
These thin regions, left over from the early cosmos, are predicted to contain huge amounts of mass and therefore could warp the space-time around them.
The approach of two such strings parallel to each other would bend space-time so vigorously and in such a particular configuration that might make time travel possible, in theory.
Time machines It is generally understood that traveling forward or back in time would require a device — a time machine — to take you there. Time machine research often involves bending space-time so far that time lines turn back on themselves to form a loop, technically known as a "closed time-like curve. Image credit: BBCAmerica To accomplish this, time machines often are thought to need an exotic form of matter with so-called "negative energy density.
Such matter could theoretically exist, but if it did, it might be present only in quantities too small for the construction of a time machine.
However, time-travel research suggests time machines are possible without exotic matter. The work begins with a doughnut-shaped hole enveloped within a sphere of normal matter. Inside this doughnut-shaped vacuum, space-time could get bent upon itself using focused gravitational fields to form a closed time-like curve. To go back in time, a traveler would race around inside the doughnut, going further back into the past with each lap.
This theory has a number of obstacles, however.
The gravitational fields required to make such a closed time-like curve would have to be very strong, and manipulating them would have to be very precise. A classic example is the grandfather paradox, in which a time traveler goes back and kills his parents or his grandfather — the major plot line in the "Terminator" movies — or otherwise interferes in their relationship — think "Back to the Future" — so that he is never born or his life is forever altered.
If that were to happen, some physicists say, you would be not be born in one parallel universe but still born in another. Others say that the photons that make up light prefer self-consistency in timelines , which would interfere with your evil, suicidal plan.
Some scientists disagree with the options mentioned above and say time travel is impossible no matter what your method. The faster-than-light one in particular drew derision from American Museum of Natural History astrophysicist Charles Lu.
That "simply, mathematically, doesn't work," he said in a past interview with sister site LiveScience. Also, humans may not be able to withstand time travel at all. Traveling nearly the speed of light would only take a centrifuge, but that would be lethal , said Jeff Tollaksen, a professor of physics at Chapman University, in Using gravity would also be deadly.
To experience time dilation, one could stand on a neutron star , but the forces a person would experience would rip you apart first. Time travel in fiction Two articles by Space. Some methods used in fiction include: One-way travel to the future: The traveler leaves home, but the people he or she left behind might age or be dead by the time the traveler returns.
Examples: "Interstellar" , "Ikarie XB-1" Time travel by moving through higher dimensions: In "Interstellar" , there are "tesseracts" available in which astronauts can travel because the vessel represents time as a dimension of space. A similar concept is expressed in Madeleine L'Engle's "A Wrinkle In Time" , based on the book series that started in , where time is folded by means of a tesseract.
Currents in the opposite directions result in attraction, because from the first wire's point of view, the electrons in the other wire are more crowded together, creating a net negative charge.
Meanwhile, the protons in the first wire are creating a net positive charge, and opposite charges attract. This is because even though satellites aren't moving at anything close to the speed of light, they are still going pretty fast. The satellites are also sending signals to ground stations on Earth.
These stations and the GPS unit in your car are all experiencing higher accelerations due to gravity than the satellites in orbit. To get that pinpoint accuracy, the satellites use clocks that are accurate to a few billionths of a second nanoseconds.
Add in the effects of gravity and the figure goes up to about 7 microseconds. That's 7, nanoseconds. The difference is very real: if no relativistic effects were accounted for, a GPS unit that tells you it's a half mile 0.
Most visible light, though, just gets reflected. Gold is a heavy atom , so the inner electrons are moving fast enough that the relativistic mass increase is significant, as well as the length contraction.
As a result, the electrons are spinning around the nucleus in shorter paths, with more momentum. Electrons in the inner orbitals carry energy that is closer to the energy of outer electrons, and the wavelengths that get absorbed and reflected are longer. White light is a mix of all the colors of the rainbow , but in gold's case, when light gets absorbed and re-emitted the wavelengths are usually longer. That means the mix of light waves we see tends to have less blue and violet in it.
This makes gold appear yellowish in color since yellow, orange and red light is a longer wavelength than blue. Gold has only one electron in its outer shell, but it still is not as reactive as calcium or lithium.
Instead, the electrons in gold, being "heavier" than they should be, are all held closer to the atomic nucleus. This means that the outermost electron isn't likely to be in a place where it can react with anything at all — it's just as likely to be among its fellow electrons that are close to the nucleus.
And yet … Venter is one of those people Russell Brand comes to mind who, just as you've decided he is beyond the pale, disarms you with something perfectly reasonable and admirably clear-sighted.
Back on Earth, he has the estimable goal of using rapid sequencing and synthesis to speed up vaccine production. Venter's record of achievement in finding, sequencing and synthesising genes is indisputable, but his greatest drives seem to be different to those of most scientists.
Some critics of his most recent headline-grabbing feat — he created a synthetic life-form by chemically synthesising a bacterial genome, inserting it into an empty cell and, lo and behold, it came to life and reproduced — have wondered why it was necessary.
Every molecular biologist in the world was certain that if a synthetic genome faithfully copied every single bit of DNA, base by base, it would perform exactly as would the natural genome. So why do it? As his critics pointed out, Venter's synthetic genome had to be inserted into an already existing cell, without its native DNA.
This is the same technique used to create Dolly the sheep and all such cloned life-forms. The pre-existing cell is more than just an empty sack. Venter sometimes seems to recognise this — that DNA is not the be-all-and-end-all. Of an experiment to determine the minimum number of genes necessary for life, he writes: To disarm those critics who observe that, to prove his point, he would need to create life "from scratch", Venter writes lucidly about what "from scratch" really means: He gives a summary of the current knowledge of modular systems, such as cell membranes and the energy apparatus of cells, that were necessary, alongside the replicatory code, to kick-start life.