Aug 29, 2019 04:15 AM
(This post was last modified: Aug 29, 2019 07:06 PM by C C.)
Quantum Gravity Could Reverse Cause and Effect (physics)
https://www.livescience.com/quantum-grav...ffect.html
INTRO: You've probably heard of Schrödinger's cat, the unfortunate feline in a box that is simultaneously alive and dead until the box is opened to reveal its actual state. Well, now wrap your mind around Schrödinger's time, a situation in which one event can simultaneously be the cause and effect of another event.
Such a scenario may be inevitable in any theory of quantum gravity, a still-murky area of physics that seeks to combine Albert Einstein's theory of general relativity with the workings of quantum mechanics. In a new paper, scientists create a mashup of the two by imagining starships near an enormous planet whose mass slows time. They conclude that the starships could find themselves in a state where causation is reversed: One event could end up causing another event that happened before it.
"One can devise this kind of scenario where temporal order or cause and effect are in superposition of being reversed or not reversed," said study co-author Igor Pikovski, a physicist at the Center for Quantum Science and Engineering at Stevens Institute of Technology in New Jersey. "This is something we expect should take place once we have a full theory of quantum gravity." (MORE - details)
The mysterious number 6174 (mathematics)
https://plus.maths.org/content/mysterious-number-6174-2
EXCERPT: . . . To get started, choose a four digit number where the digits are not all the same. Then rearrange the digits to get the largest and smallest numbers these digits can make. Finally, subtract the smallest number from the largest to get a new number, and carry on repeating the operation for each new number. [...] you'll get to 6174, every time, no matter what number you chose! ... why do you think that happens? If this mystery piques your interest, then you can find out why in this excellent article by Yutaka Nishiyama... (MORE - details, examples)
Why synthetic chemicals seem more toxic than natural ones (chemistry)
https://aeon.co/ideas/why-synthetic-chem...tural-ones
EXCERPT: . . . While it is not possible to compare the toxicity of all natural and synthetic chemicals, it is worth noting that the five most toxic chemicals on Earth are all naturally found. When it comes to pesticides, some of the newer man-made versions are remarkably safe to humans; and at high doses, these pesticides are as toxic as table salt and aspirin. Rats continually exposed to low doses of these pesticides (ie, doses found in the environment) don’t develop cancer or problems in growth and reproduction. In fact, toxins produced by plants cause cancer at the same rate as synthetic chemicals, and we ingest a lot more of the plant toxins.
I study toxicology: I look at the effects of substances on living organisms. All substances (natural and artificial) are harmful if the exposure is high enough. Even too much water consumed within a very short time can dilute the salts in the blood, and cause brain cells to swell. A number of marathon runners have collapsed and died because of consuming excessive amounts of water with no salt.
Toxicologists believe that nearly every substance is safe in certain amounts. Take the example of botulinum, the most poisonous substance on Earth. Just 50 grammes of the toxin spread evenly worldwide would kill everyone. But, in very minute amounts, it is safely used for cosmetic purposes in Botox. Thus the adage ‘the dose makes the poison’.
Apart from understanding what doses make a substance ‘safe’ or ‘unsafe’, toxicologists also love figuring out how a substance causes a harmful effect. [...] one can argue that, though there is no conclusive evidence presently to show that some chemicals cause health problems, it’s better to be safe than sorry and so restrict the chemical before health problems emerge. Yet while this idea is tempting, it ignores a basic truth: risk exists in nearly everything. ... We therefore need to understand probability: is the chemical exposure high enough for a high probability of adverse effects? We also need to know the risks of using an alternative chemical – or no chemical at all.
It seems that laypeople rank risks that receive more media attention or have more vivid imageries higher than the more commonplace risks. Today, the public perceives a higher health risk from genetically engineered crops than experts do. So while it is good to strive for the lowest possible risk, it is important to also consider any benefits, and not disallow things merely because of the risk they pose. The following examples explain this reasoning... (MORE - details)
https://www.livescience.com/quantum-grav...ffect.html
INTRO: You've probably heard of Schrödinger's cat, the unfortunate feline in a box that is simultaneously alive and dead until the box is opened to reveal its actual state. Well, now wrap your mind around Schrödinger's time, a situation in which one event can simultaneously be the cause and effect of another event.
Such a scenario may be inevitable in any theory of quantum gravity, a still-murky area of physics that seeks to combine Albert Einstein's theory of general relativity with the workings of quantum mechanics. In a new paper, scientists create a mashup of the two by imagining starships near an enormous planet whose mass slows time. They conclude that the starships could find themselves in a state where causation is reversed: One event could end up causing another event that happened before it.
"One can devise this kind of scenario where temporal order or cause and effect are in superposition of being reversed or not reversed," said study co-author Igor Pikovski, a physicist at the Center for Quantum Science and Engineering at Stevens Institute of Technology in New Jersey. "This is something we expect should take place once we have a full theory of quantum gravity." (MORE - details)
The mysterious number 6174 (mathematics)
https://plus.maths.org/content/mysterious-number-6174-2
EXCERPT: . . . To get started, choose a four digit number where the digits are not all the same. Then rearrange the digits to get the largest and smallest numbers these digits can make. Finally, subtract the smallest number from the largest to get a new number, and carry on repeating the operation for each new number. [...] you'll get to 6174, every time, no matter what number you chose! ... why do you think that happens? If this mystery piques your interest, then you can find out why in this excellent article by Yutaka Nishiyama... (MORE - details, examples)
Why synthetic chemicals seem more toxic than natural ones (chemistry)
https://aeon.co/ideas/why-synthetic-chem...tural-ones
EXCERPT: . . . While it is not possible to compare the toxicity of all natural and synthetic chemicals, it is worth noting that the five most toxic chemicals on Earth are all naturally found. When it comes to pesticides, some of the newer man-made versions are remarkably safe to humans; and at high doses, these pesticides are as toxic as table salt and aspirin. Rats continually exposed to low doses of these pesticides (ie, doses found in the environment) don’t develop cancer or problems in growth and reproduction. In fact, toxins produced by plants cause cancer at the same rate as synthetic chemicals, and we ingest a lot more of the plant toxins.
I study toxicology: I look at the effects of substances on living organisms. All substances (natural and artificial) are harmful if the exposure is high enough. Even too much water consumed within a very short time can dilute the salts in the blood, and cause brain cells to swell. A number of marathon runners have collapsed and died because of consuming excessive amounts of water with no salt.
Toxicologists believe that nearly every substance is safe in certain amounts. Take the example of botulinum, the most poisonous substance on Earth. Just 50 grammes of the toxin spread evenly worldwide would kill everyone. But, in very minute amounts, it is safely used for cosmetic purposes in Botox. Thus the adage ‘the dose makes the poison’.
Apart from understanding what doses make a substance ‘safe’ or ‘unsafe’, toxicologists also love figuring out how a substance causes a harmful effect. [...] one can argue that, though there is no conclusive evidence presently to show that some chemicals cause health problems, it’s better to be safe than sorry and so restrict the chemical before health problems emerge. Yet while this idea is tempting, it ignores a basic truth: risk exists in nearly everything. ... We therefore need to understand probability: is the chemical exposure high enough for a high probability of adverse effects? We also need to know the risks of using an alternative chemical – or no chemical at all.
It seems that laypeople rank risks that receive more media attention or have more vivid imageries higher than the more commonplace risks. Today, the public perceives a higher health risk from genetically engineered crops than experts do. So while it is good to strive for the lowest possible risk, it is important to also consider any benefits, and not disallow things merely because of the risk they pose. The following examples explain this reasoning... (MORE - details)