THE AUTHORS REPLY: Our article focused solely on current, and probable future, illicit manufacturers of counterfeit BoNT products. Nowhere in the article do we even hint that legitimate manufacturers, or their products, pose a security threat. As we wrote, referring specifically to the market for illegal BoNT and to its makers and distributors: “From a security perspective, this booming market is troubling because for manufacturer-distributors it is only a small step from selling counterfeit BoNT products for cosmetic uses to selling the botulinum toxin itself in bulk quantities directly to subversive interests.” To reiterate, our concern is that anyone with a credit card and access to the Internet, including criminals and terrorists, can contact illicit manufacturers of BoNT, purchase gram quantities of it and have the purchase delivered to an address of their choice. This is a new proliferation development that we have found is not being addressed by security agencies or international law and therefore needs to be publicized.
One Body, Many Problems
In “Asteroid Collision” [“12 Events That Will Change Everything”], Robin Lloyd discusses how to realistically prevent an asteroid or comet from impacting a high-value target on Earth. She cites the idea of slightly altering the path of the incoming object, using either a kinetic impactor or a nuclear charge. The menace might thus be diverted from, say, a megalopolis, or made to miss Earth altogether. But there’s a catch: the farther the object, the smaller the necessary nudge, yet the greater the uncertainty in predicting the point of impact. Given the notorious chaotic nature of the long-term gravitational many-body problem, a far enough slight nudge calculated to save a city might inadvertently end up turning a would-be comfortable miss into an actual bull’s-eye, might it not?
Dov Elyada
Haifa, Israel
LLOYD REPLIES: In the general many-body problem, it is indeed hard to make predictions. Here, however, the near-Earth object is too small to affect the orbits of the planets. Thus, it is just one body moving in a predictable environment. The hard part is to know how much of a nudge to give an object, because its properties, such as its mass, are difficult to measure from afar.
Gossip vs. Science
I am a longtime subscriber to Scientific American and enjoyed your June issue. But political satire as exemplified by Steve Mirsky’s “Presidential Harrisment” [Anti Gravity] seems out of place in the magazine. Mirsky usually makes an effort to have at least a tenuous tie-in to science, but even that is missing this month. You might as legitimately have a gossip column, sports results, wine comparison or travel log. Perhaps Mirsky should seek a position in one of the many fine publications devoted to politics.
William S. Haney
Onancock, Va.
MIRSKY REPLIES: The column was not about politics. It was about rationality, a necessary part of scientific thinking.
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29 Comments
Add CommentA Milky Way Standard Time would be meaningless to someone orbiting Saturn, for example, much less another Solar system. Standard time zones on Earth allow the maintenance of approximate local times relative to the progression of Earth's daily rotation within the illumination of the Sun.
Reply | Report Abuse | Link to thisHow could the progression of time on Earth or some other arbitrary location within the galaxy be meaningful to someone not subject to the 'standard' local rotational and orbital velocities?
Time is a model of reality. It is not reality. Mathematics is not reality. It is a very good model of reality in some ways for some things. Reality is a process, an evolution, cascade of cause and effect. Time is a way to compare a highly repetitive action with a non-linear action. Time does not exist and you cannot go back in it since you cannot unwind the chains of cause and effect that have occured. Nor can you extract yourself from it nor insert yourself into it at any point - that is non-sensical.
Reply | Report Abuse | Link to thisYour argument doesn't make sense.
Reply | Report Abuse | Link to thisI think you are confusing the measurement of time with time itself. Time is a dimension of the fabric of the universe, along with the other three physical dimensions. If any of them are missing physical existence becomes impossible.
If time did not exist you couldn't go back in it precisely because it doesn't exist, there would be no context within which to go backwards or forwards. Cause and effect would not exist either for the same reason. Same with space, it needs a "when" as part of the "where" to make any kind of location - uncertain or not. Even if you assume "always at these physical coordinates, that doesn't make sense in an expanding, moving and relative universe.
Funnily enough that is exactly what often happens in zen enlightenment, the time usually experienced in perception of a mental or physical object collapses and all else momentarily collapses with it(from the perspective of the perciever).
And it seems to do more good than harm, but despite knowing the illusory nature of spacetime and therefore physical existence such we go on to quite happily and perhaps more effectively to function in it.
You know, for a scientific website sometimes your are not very "scientific"; if you want to argue whether time is an illusion or not, you must define your terms. What do you mean by time? The fourth dimension? Is the 4th dimension real? Is that your question? The measurement of intervals between events? The incremental expression of the movement of the Earth around the Sun? What do you mean by "illusion" - consider an optical illusion (pick any one) do you mean to say the illusion is either "real" or "not real"? What would the difference be between a real illusion and an illusion illusion? This is silly, isn't it, and that's because you've started a casual conversation about a very technical, deep and as yet unanswered scientific subject.
Reply | Report Abuse | Link to thisSeriously though, how do you define illusion? Is not reality itself the ULTIMATE illusion? We perceive the world around us as "solid", and yet we know now that it is simply energy fields in very tight groups. Given the physical distance between a neutron and any one of its electrons how can you conclude that "reality" is anything other than widely dispersed energy fields? Given that "illusion" of solidity, what can you possibly use to determine is time is real or not? If I can think of time, is not that thought "real"? If I tell a lie, something that is not true, is that an illusion or is it a real lie? Semantics, maybe, but essential to the core question of "reality."
Should I comment on this now or now.....
Reply | Report Abuse | Link to thisjimmywat is correct, Time does not exist. Time is the creation of the brain of a cognoscente life-form. Time is not a dimension, if it was we could move in it. In the universe things happen as a result of basic forces at work, but whatever happens is independent of time, you and I bring time into the equation, as a result of circadian rhythms that govern our lives.
Reply | Report Abuse | Link to thisRhythms create an illusion of time.
That last line should have read: Rhythms and Memory create an illusion of time.
Reply | Report Abuse | Link to thisThere are some good arguments here. Time is man-made not a Natural property. This gives us the opportunity to identify time being imaginary - mathematically imaginary. Given this property, we can posit our cosmos is 3-D physical dimensions and a 4th-D imaginary time. All that needs to be done is to determine, mathematically satisfying Nature, what the magnitude is of this 4th dimension.
Reply | Report Abuse | Link to thisSo far, our physical universe has been faithful to mathematical descriptions. If this continues to be true, we should be able to get a handle on describing time. Now the question first asked: What “time” could be established as a Universe-wide time. If one can be constituted, we may be able to describe whether or not 2 actions occurred simultaneously.
soaralone1
As a fourth dimension, along with its three spatial cousins, time must surely exist. How could an objective observable like the speed of light exist without a physically real spacetime? I think I see the nature of confusion about this in the comment by scientific earthling that "Time is not a dimension, if it was we could move in it". Time is a dimension but we do not actually move in it because every event is permanently fixed in its particular spacetime location. It is movement in time or a sense of "passing" of time, not time itself, that can be properly described as an illusion.
Reply | Report Abuse | Link to thisRhythms are cycles of time and happen within a context of the existence of time. No time, no context for a rhythm to occur in.
Reply | Report Abuse | Link to thisTry playing every note of Beethoven's 5th at once and see what you get, apart from the fact that the notes all played simultaneously, would still occupy brief period of time, you don't get a piece of music. Same if you try and have a universe happen all at once, existence needs time to separate events out just as much as it needs space.
I'm ok with the concept that time is an illusion in so much as physical existence can be said to be an illusion, but to have space but not time doesn't work.
promytius, above comes closer to the asking what the question really is.
We do move through time, forwards at a seemingly constant pace, so time is a constant at least from our point of view (In mathematics it seems there is no particular need for it to behave this way (pointing not so much to its illusionary nature as to the illusion of its rigidity), but this isn't what you seem to mean, content to have rhythm's but no time and discounting it as a dimension entirely.
You say it is a human construct, does an animal "experience" (it couldn't really be an experience, they take time) its birth life and death as a simultaneous and instantaneous event? It seems unlikely.
All words are symbolic contractions of reality. The time fabric you mention is just another symbol - it is not reality. Neither time nor time-fabric exist. They are models of reality - not the reality. It is yo
Reply | Report Abuse | Link to thisAll words are symbolic contractions of reality. The time fabric you mention is just another symbol - it is not reality. Neither time nor time-fabric exist. They are models of reality - not the reality. There are other models that work as well for other purposes.
Reply | Report Abuse | Link to thisFrom an earlier reply, I have posited that time is imaginary. I add that speed of light is real and imaginary; that is, it can be described as a vector with both a real and an imaginary property. The energy in the vector has 2 real values. Very simplistically, the 2 energies are equal in magnitude. Potential energy (PE) is volts and kinetic energy (KE) is current, their product is power - work per unit time, a very real property. I present these ideas here without the physics and mathematics that define these properties.
Reply | Report Abuse | Link to thisI am talking about the existence of time as a dimension in the universe. Rhythms, cycles, cause and effect all happen but only now exists.
Reply | Report Abuse | Link to thisLiving creatures have memory, and retain and record experiences as they occur, but that does not mean time exists.
I experience the pleasures of music, the pleasures and pains of a life lived and that will end, but it is all a creation of my mind. My comprehension of time is based on my lifespan, now greatly increased because of science.
As a physical entity like the three dimensions I live in, I can not see time as existing. Perhaps because the concept of imaginary numbers was so hard for me to comprehend. String theory is also a problem since I can not comprehend all those dimensions.
You can not move in time, because it does not exist. You feel time is real because you have memory. However there is only now.
Lets try a simple thought experiment, what if time did not exist, then everything would occur at the same instance, no delay among events. Even so, one could not decide the timing of macroscopic events with the microscopic. So are we confusing concept with reality?
Reply | Report Abuse | Link to thistime should be linked to the entropy, which flows in the direction of the future,the arrow of time indicates the
Reply | Report Abuse | Link to thisbasic direction of increase of entropy, which is related to cause and effect. the entropy can only increase in the universe we live in,this should hold for for the arrow of time.both time and entropy are measured from
low to higher values.but not the other way round.
So far it has not been proven that time is not subjected to cause and effect. If time is different depending on direction and speed, there would be paradoxes, such as :
Reply | Report Abuse | Link to thisIf you go back in time and kill your grandfather, you will not have existed, therefor you could not have killed him...
Fury is the result of men's failure to believe Time.
Reply | Report Abuse | Link to thisTime is a frame of reference. Whether space is an illusion is not the question. A Milky Wat time frame is possible and will serve us well just like conventional time serves us today. The universe exist and events do occur. Perhaps the illusion rational here has more to do with our desire to control the universe. Do I exist in space time? More likely so? Am I an illusion? Possibly. This illusion however will have to be understood in space time still. The dynamic of the universe remains a mystery (relativity theories, chaos theories, string and quantum theories etc.)but the mechanism of galaxies is well understood. A Milky Way time will be constructed within the frame work of a galaxy. It will be imperfect but workable. It is actually very important to resolves this issue as we enter in full speed the space age.
Reply | Report Abuse | Link to thisI agree that our conception of the procession of time can certainly be subject to illusions.
Reply | Report Abuse | Link to thisHowever, I disagree with the assertion inherent in your statement: "Time is not a dimension, if it was we could move in it."
I think that all of the practical demonstrations that the the progression rate of time varies with the the relative motions of observers (incl. GPS) effectively proves that the progression of time is directly related to the traversal of the dimensions of space.
That time is not distinct from the dimensions of space and cannot be independently traversed is irrelevant to its dimensional status.
driesotto
Reply | Report Abuse | Link to this05:35
12/10/2010
time could be linked to the increase in entropy from a lower to a higher value (entropy can only increase).keeping this in mind,we could conclude that the arrow of time points in the direction of increased entropy.it seems that time points in the direction of ever increasing entropy.keep in mind that the entropy is one directional,therefore time should in fact be related to this property.(in the real world ,on grounds of the the above we would not observe time as
a dimension.
I agree, to the extent that the universe can be considered to be a closed system. However, the 'real world' does not operate locally as a closed system - entropy can and does locally decrease, especially as effected by gravitation.
Reply | Report Abuse | Link to thisSectioned time is a figment of imagination since quantum time is blocktime where the future can influence the present .Quantum physics sees time as an intrinsic variable and not extrinsic as in relativistic physics.Time and destiny and indeterminism are a consequence of the relationality principle in universe.Earnst Mach has succintly termed it as the global influence on the local due to interrelatedness inherent in nature.That is so because as Spinoza argued there is a logical inevitability for a singular substance in universe,which also implies relationality and destiny.Time is how destiny expresses itself in every day life and concourse of events,given the fabric of space.Space is itself due to the presence of matter in it.The ancient Indian metaphysical concept of Brahma and Karma summarises it all.Time is circular since it encompasses matter and that has its limitations.We see time as linear due to logical and sensory limitations.At a certain level of consciousness time ceases to exist.
Reply | Report Abuse | Link to thisSURESHKUMAR.S,SCIENTIST AND ADVISER,NIIST[CSIR],TRIVANDRUM,INDIA
Time is the fourth dimension. Special and General Relativity have already proven this fact.
Reply | Report Abuse | Link to thisIs it not obvious? The concept of time and space is but a manner to allow our perception to explain reality, not the other way around. When we place more meaning upon our concepts than reality then we err. Is it not obvious that when our science creates the non-empirical and unrealistic that these outcomes go beyond reason that we must therefore reconsider our own reasoning. Of what use is the science that does not allow a physics, ie, a science of measurement.
Reply | Report Abuse | Link to thisSee the document "Modern Physics" located at http://www.rufusgwarren.com/
Reply | Report Abuse | Link to thisTwo recent thoughts: first, the notes in Beethoven's 5th Symphony, whether played all at once, or according to the time signature assigned to it by the author, or played with a one day interval, would still be considered music.
Reply | Report Abuse | Link to thisSecond, from what most responders are saying, time is at least theoretically real. Even if it's an illusion, if we all agree we experience it (time and its passing)and we all agree how we measure it, then we can/should treat it as "real" until some proof moves into law, or makes it an "outlaw"; meantime it's a wonderful thing to think about; I do it all the time.
I have already commented on the question of time somewhere in this comment arena. Simply, time does not exist, it is an abstract creation of our response to the movement of our solar system and is exploited by those seeking power, and worshipped to the point of mathematical lunacy by those who believe in its reality. I am very much of the positivistic view.
Reply | Report Abuse | Link to thisNow is a relative term; one can speak of 'now' in reference to a period of years, or a few minutes, or an instant. Do not confuse the term with a precise period of time as judged by man.
Reply | Report Abuse | Link to this