Subject: Can someone please explain?
Posted by: Mixamatosis
Date: Jan 21 17
I've read that it's dangerous to mix ammonia and bleach. Variously I've read that it can produce deadly cyanide gas, chlorine gas (which is said to be bad for you) and even explosions.
However swimming pools are kept fit for use with chlorine, and our urine contains ammonia but then we may clean toilets with bleach. Also many cleaning products contain either ammonia or bleach and it would be easy to use them unthinkingly in combination.
How is it that people aren't generally harmed by these dangers when swimming in swimming pools or doing daily cleaning, or are we being harmed at low level and is the harm cumulative?
Posted by: Mixamatosis
Date: Jan 21 17
I've read that it's dangerous to mix ammonia and bleach. Variously I've read that it can produce deadly cyanide gas, chlorine gas (which is said to be bad for you) and even explosions.
However swimming pools are kept fit for use with chlorine, and our urine contains ammonia but then we may clean toilets with bleach. Also many cleaning products contain either ammonia or bleach and it would be easy to use them unthinkingly in combination.
How is it that people aren't generally harmed by these dangers when swimming in swimming pools or doing daily cleaning, or are we being harmed at low level and is the harm cumulative?
526 replies. On page 8 of 27 pages. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
Mixamatosis 
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Brian, I don't know what system your phone uses, but if I want to do something technical, and I don't know how to do it I just google it, starting my enquiry with the words "how to". Inputting the enquiry "how to turn off auto-correct on my cellphone" brings up information for android systems and also iphone. Reply #141. Aug 18 17, 2:31 PM |
brm50diboll
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There's like five menus but I did what you wrote and googled how to disable autocorrect and now it looks like it's finally disabled, since now if I intentionally misspell a word, say "alot" (no such word), instead of automatically correcting it, it just underlines it in crooked red. Much better. Thanks Mix. (The incorrect "word" above should actually be written as two separate words: "a lot". But I trust myself better to do things right than that darned autocorrect.) Reply #142. Aug 18 17, 5:58 PM |
| Mixamatosis
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That's good. Glad it worked :-) Reply #143. Aug 20 17, 10:41 AM |
| Mixamatosis
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You can find out how to do almost anything on the internet now. If I'm having work done on the house or doing it myself I look up how it should be done so that I understand the work and procedures involved. I've also used it to solve computer problems. It's helped enormously. I've avoided some pitfalls that way and also saved money by doing things myself whenever possible. Reply #144. Aug 20 17, 11:01 AM |
| brm50diboll
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Although estimates of distances to the more distant galaxies had very large uncertainties in Hubble's time; nevertheless, it was still possible to get a very rough idea how far those galaxies were from us. When Hubble correlated his distance data with the radial velocities for galaxies beyond our Local Group, he discovered that the farther away a galaxy was, the faster it was moving away from us. The mathematical form of that relationship is known as Hubble's Law, and the parameters in the equation have been refined over the years as the accuracy of our data have improved. But without getting into the mathematics of it, Hubble's Law is striking because of what it implies about the nature of our universe. In order for all more distant galaxies to be receding from us ever faster than closer ones, the universe itself must be *expanding*. Why? Consider a model. If you take a partially inflated balloon and put dots on it to represent galaxies and then fully inflate it, all the dots will have gotten farther away from each other as the balloon expands. Furthermore, if we pick *any* single dot as our "home galaxy", we will see that the other galaxies will have moved even farther away from our designated "home galaxy" in such a way that the most distant ones will have moved the farthest, no matter which dot we picked. So Hubble's data doesn't show the Milky Way to be the center of the universe - there is no center. It shows the universe itself to be expanding. Now the balloon model shows a two-dimensional surface expanding into an unseen third dimension. What is happening in our universe is our three dimensions are expanding into four-dimensional spacetime, which we cannot see but can be mathematically calculated. Of course, if we run the model backwards in time, then the universe was ever smaller the farther back in time we go, and, at a certain point in time, the entire universe must have been concentrated at a single point and then expanded from there. This is the origin of the Big Bang Theory (not the comedy TV show.) Reply #145. Aug 28 17, 8:44 AM |
| brm50diboll
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Einstein, when developing his General Theory of Relativity, saw that his equation predicted that the universe would expand over time. This was well before Hubble and his work, and Einstein could not accept this possibility, so he introduced into his equation for General Relativity a sort of a "fudge factor" he called the "cosmological constant". By adjusting the value of the cosmological constant, Einstein could keep the size of the universe constant. Years later, after Hubble's work and the development of the Big Bang Theory which showed the universe was indeed expanding, Einstein said that his introduction of the cosmological constant into his equation for General Relativity was a mistake; he felt he should have recognized and accepted the implications of his original equation at the time - that the universe must be expanding. Also, it is interesting to me that the very term "Big Bang Theory" was proposed not by an advocate of the theory, but by an opponent, who coined the term to mock the idea. It was coined by Fred Hoyle, a very well respected astronomer who advocated a competing cosmological theory known as the "Steady State Theory" that maintained the universe was expanding, but that there had never been a specific instant of creation and that, instead, matter was continuously being created as the universe expanded. Hoyle never accepted the Big Bang Theory, although he was the individual responsible for giving it its name. Reply #146. Sep 07 17, 10:06 PM |
| brm50diboll
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Another piece of evidence for the Big Bang Theory is the cosmic microwave background radiation, discovered by Penzias and Wilson in the late 60s. This radiation is what is left over from radiation that occurred during "decoupling" after the Big Bang when temperatures had dropped enough for space to become transparent to light. In the thirteen-odd billion years since then, those light photons have become extremely red-shifted so that today they are all the way down into the microwave portion of the electromagnetic spectrum. The frequencies at which the cosmic microwave background radiation are found match the blackbody curve for the baseline temperature of deep space, which presently is a mere 4 kelvin or so. Penzias and Wilson at first thought the radiation they detected coming from "everywhere" may have been spurious due to pigeons roosting in their radio telescope, but, once they ruled that out, they developed the theory that they ultimately won the Nobel Prize for. Humorous story, I think. Reply #147. Sep 17 17, 12:51 PM |
| Mixamatosis
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BRM50diboll. I've been thinking about this today. Do you know the answer? In areas of the world (like the Amazon Basin) which create the most oxygen, is the percentage of oxygen in the air higher than elsewhere (however fleetingly) or does it always even out its distribution around the world? Reply #148. Sep 27 17, 2:48 PM |
| brm50diboll
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It evens out very rapidly. Oxygen concentrations do change over geologic time spans of millions of years, but it is quite fixed worldwide everywhere over shorter spans of time. Altitude, however, strongly influences oxygen concentrations. So the higher you go (anywhere), the lower the oxygen concentrations. But at sea level, it is pretty much the same everywhere in the world, be it barren deserts or tropical rain forests. Gases diffuse extremely rapidly. Reply #149. Sep 27 17, 3:41 PM |
| brm50diboll
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A great deal of oxygen production occurs in the oceans from algae, not terrestrial plants. Oceans cover 70% of Earth's surface and were the original source of oxygen production, long before plants existed. Algae should not be ignored. They thrive on warmer ocean temperatures. Reply #150. Sep 27 17, 3:44 PM |
| Mixamatosis
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Thanks brm. On some days I feel there's less oxygen in the air, but it's probably just me. I've had a bad cold and I have (controlled) asthma. I do worry about those acres and acres of Amazon forest being destroyed. Everything is being destroyed by degrees. Algae may be useful I guess but it's not much of a substitute aesthetically speaking. Reply #151. Sep 27 17, 5:39 PM |
| brm50diboll
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After a long excursion into the outermost reaches of space, I've decided to return closer to home - our Solar System. There's lots to talk about just in our cozy neck of the woods, especially with all the recent data we've obtained from numerous unmanned probes, which I will be sure to mention, starting with Messenger, the probe that spent several years orbiting and studying Mercury, the innermost planet. Messenger was quite a technological triumph, actually. Before Messenger, it had been very difficult to study Mercury. Ground-based astronomy is extremely limited, because Mercury is so close to the sun. And the Mariner probe could only fly by Mercury, not orbit it. The problem is that, from Kepler's laws of planetary motion, objects that move closer to the sun (as any probe headed to Mercury must) accelerate. The result of this acceleration is that as a probe approaches Mercury, it is going too fast to be able to enter into orbit around it. Messenger solved that problem by having multiple flybys of planets that it used to use gravity to decelerate. After its launch, Messenger had one earth flyby, two Venus flybys, and three Mercury flybys before it had slowed enough to finally enter into orbit around Mercury. It took over five years from time of launch to orbital insertion around Mercury, but it was worth it. So even though Mercury is much closer than Jupiter, for example, it took over twice as long to get into orbit around Mercury as it did for Galileo to get into orbit around Jupiter, because of the acceleration problem. On the surface, Mercury is very similar to our moon. But internally, Mercury is much more dynamic than the moon. It is denser and more metal-rich, with an unusually large core which suggests that at some point in its past it may have had a loss of part of its outer layers, perhaps in some sort of catastrophic collision, which may also explain Mercury's unusually eccentric orbit. Mercury posses a magnetic field, unusual for a small planet with a relatively slow rotation. Because of its lack of atmosphere, Mercury, unlike Venus, is extremely cold on its night side. And near Mercury's poles are deep craters that are *never* sunlit (at least in recent geological time), and evidence of water ice has actually been found in these polar craters. Reply #152. Oct 04 17, 7:39 AM |
| brm50diboll
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Possesses, not posses. I wish I could see my whole post before I hit the submit button. Reply #153. Oct 04 17, 7:42 AM |
| brm50diboll
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Venus is the closest planet to us but has not been explored as thoroughly as Mars because of its extremely inhospitable climate. The most successful mission there, in my opinion, was Magellan, which orbited, mapped, and studied Venus for several years. The Russians did actually land on Venus twice with their Venera probes, which managed to send back a few photographs of Venus's surface for a few minutes before the extreme heat fried the electronics and destroyed them. The idea of a manned mission to the surface of Venus is practically unthinkable with present-day technology. Venus has an unusual volcanism quite different from the plate tectonics on Earth that is not fully understood. Perhaps the lack of water contributes to that difference. The atmosphere at ground level is ninety times thicker than Earth's and overwhelming composed of carbon dioxide, which is responsible for Venus's extreme heat. Venus has a very slow retrograde rotation, but despite its very long nights, it is almost as hot on the night side of Venus as the day side, because of the greenhouse effect. Clouds cover practically the entire sky, obscuring the surface of Venus as viewed from Earth. The clouds are not water, though. They are sulfuric acid. Sulfuric acid "rain", technically virga, does form but does not reach the surface because Venus's clouds are much higher up in the atmosphere than Earth's (many miles up), so the droplets evaporate in the intense heat long before reaching the surface. There is some debate among astronomers as to whether Venus, billions of years ago when it was a very young planet, may have once had a more hospitable climate with liquid water, maybe even oceans. The evidence, to me, does not seem fully conclusive, but I strongly doubt liquid water, in any amount, ever existed on Venus. Without liquid water, carbonate rocks such as limestone cannot form. Without carbonate rocks, carbon dioxide has nowhere to go but into the atmosphere. So my view is that Venus's atmosphere was dominated by carbon dioxide from the very beginning and was in full "runaway greenhouse mode" from the very origin of the planet 4.5 billion years ago and liquid water at the surface never had a chance to form there. Since Venus lacks a magnetic field (because of its extremely slow rotation, most likely), its atmosphere is unprotected from solar radiation. Consequently, any water vapor that once may have been present in Venus's atmosphere has long since been broken apart by the radiation inti hydrogen and oxygen. The hydrogen was then driven off into space by the heat (as was most of the oxygen that did not react to form carbon dioxide or other oxide compounds at the surface.) There is no environment in our solar system that is more hellish than that of Venus. But manned orbital flights to Venus and exploration of its upper atmosphere by humans may well be possible in the distant future someday. Reply #154. Oct 13 17, 11:39 PM |
| brm50diboll
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Into, not inti. Typos are such a bugabear with long posts. Reply #155. Oct 13 17, 11:42 PM |
| brm50diboll
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Now the moon (Earth's moon) is quite interesting. As the closest celestial body to us, it has been studied extensively and is the only celestial body outside earth humans have set foot on (with the Apollo missions (which weren't faked, despite the views of some who could stand to have a better science education, as could the flat-earthers (hard to believe such people exist, but they do))). The moon is unusually large with respect to the earth when compared to moons of other planets, where the moon:parent planet mass ratio is much smaller (except for Charon:Pluto, but that's another story). Explaining the relatively large size of our moon as well as various other peculiarities about the moon requires a viable theory of the moon's formation, which has emerged only quite recently and still isn't fully nailed down yet. The leading theory today about the moon's formation is the so-called Giant Impact Theory, which holds that only a few million years after earth's formation, earth was struck by a protoplanet about the size of Mars (called Theia), which splattered part of Earth's material into orbit as a temporary ring around earth which coalesced into the moon. Originally, the early moon was much closer to earth than it is now and the earth's rotation after the impact much faster than now (around a five hour day). As the eons have passed, tidal forces and angular momentum conservation has caused the moon to gradually spiral away from earth, and earth's rotation has slowed as a result. Current data clearly show that the moon is continuing to slowly spiral further away from earth and earth's rotation is continuing to gradually slow down. In a few million years, total solar eclipses will become impossible as the moon will be too far away for its umbra to reach the surface of the earth. As it is now, many solar eclipses already are annular because the moon's orbit is elliptical, and total eclipses cannot occur when the moon is in the more distant part of its orbit at the time of an eclipse. The moon's lack of an atmosphere makes it somewhat of a toned-down version of Mercury in that it is very hot on the day side and very cold on the night side of the moon. Because of tidal locking, the moon always keeps the same face pointed to earth (with some "rocking", known as libration.) So the lunar day and the lunar month are the same, about 29.5 days. So daylight on the moon lasts a little over two weeks, making sunrise and sunset on the moon very slow. Contrary to Pink Floyd, there is no Dark Side of the moon. All of the moon experiences daylight and nighttime in its cycle. It is a myth that the Far Side (the correct term (not the Gary Larson cartoon)) is *not* always dark. During a new moon, for example, the near side is dark but the far side (which we cannot see) is in daylight. Many questions about the moon still exist and unmanned missions continue. Manned missions, while technologically possible, are very unlikely to occur in the foreseeable future because they are enormously expensive, and while the moon does possess minerals, the cost of trying to mine them would vastly exceed the value of the minerals obtained, so the despoiling of the moon by humans "jest ain't gonna happen". Enjoy the pristine view of our moon. Even a slave labor force of amphetamine-stimulated replicants (I've watched too much science fiction, I know), won't make moon mining profitable. Reply #156. Oct 23 17, 7:35 PM |
| brm50diboll
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Mars is the planet that gets the most attention for unmanned missions. Oddly enough, a fairly high percentage of these missions have failed one way or another (failed to enter orbit, crashed landing, main antenna malfunction, etc.), but a tremendous wealth of information keeps pouring in. I am quite pessimistic about the prospects for any manned missions there anytime in the foreseeable future - my lifetime, to be egocentric about it). I've joked about this in the past: politicians always seem to promise we'll have a man on Mars in 20 years, always in 20 years, and they've been promising this for 40 years, it seems. And while I'm on this rant, where's my flying car everyone was promised back in the 50s? But the cost of a manned mission to Mars is quite prohibitive, in my opinion. We know now that when Mars was younger, it had a much thicker atmosphere and was warm enough to support liquid water (even oceans), but Mars' weak gravity, its lack of a protective magnetic field, and solar UV radiation has resulted in the loss of most of its atmosphere, putting in into a deep freeze. Too bad. I don't believe in terraforming. Mars is what it is. Reply #157. Nov 02 17, 11:15 AM |
| Mixamatosis
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The 20 years promise you refer to reminds me of the frequent promise that tourist travel into space will be possible "in the near future". Many deadlines have come and gone for this assertion and I'm sceptical that it will happen in our lifetimes. Reply #158. Nov 03 17, 2:03 AM |
| brm50diboll
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Yes. I have commented about that sort of thing before on other threads. There is an emerging private industry approach to spaceflight, but claims that it will become profitable by doing things like mining celestial bodies or arranging private flights of billionaires into space or to the moon are vastly overblown, in my opinion. I do think in the long run (greater than 50 years), private industry will provide a useful role in space. But in the near future, spaceflight is extremely expensive and incapable of making back even a fraction of the costs incurred, so, as much as a good capitalist as myself hates to admit it, only governmental spaceflight programs will make much progress in the near future, because only governments can afford the financial losses involved. And I can understand why citizens would prefer that governmental money be spent on other concerns than space. Reply #159. Nov 03 17, 6:08 AM |
| brm50diboll
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Phobos and Deimos are the two moons of Mars, and are believed to be captured asteroids. Capturing asteroids by planets is actually quite a rare process. It is much more likely for an asteroid to collide with a planet than to be captured into orbit around it. This is because when an asteroid makes a close approach to a planet, its velocity relative to that of the planet is almost always too fast for it to enter orbit around the planet. Most likely, the asteroid will simply shoot past the planet, although the gravitational effect from the "close encounter" may alter the asteroid's orbit so as to make future close encounters and eventual collision more likely. In order for the asteroid to be captured, several very unlikely things have to happen. The asteroid must make a very close pass to a planet without hitting it. When it is very close to the planet (a few hours' time window, at maximum), it must decelerate and change its course in such a way as to be captured into orbit. This happens all the time with manmade unmanned satellites because they are designed and programmed to fire rockets that put them into orbit when they are at just the right time and place. But asteroids don't have rockets. For them to decelerate at just the right time in just the right direction, they would need to have a very lucky collision with another body, most probably another asteroid. That would require two different asteroids to have a near miss encounter with a planet at the same time, an extremely unlikely event. Nevertheless, evidence suggests Phobos and Deimos were captured asteroids. Both Phobos and Deimos are too small for their umbral shadows from the sun to reach the surface of Mars. Thus, all solar eclipses by either Phobos or Deimos on Mars are partial eclipses. Total solar eclipses on Mars are impossible. The small size of these two moons relative to Mars means their tidal gravity effect on Mars is insignificant, unlike our Moon's tidal gravity effect on Earth, which has the effect (among others) of stabilizing Earth's axial tilt (currently about 23.5°, and varying very little over the geologic eons). So, without that stabilizing effect, Mars' axial tilt varies much more wildly over geologic time. It is actually a bit of a coincidence that Mars' current axial tilt is similar to Earth's. In other geologic eras, Mars' tilt was vastly different, resulting in very different climate patterns there from the present condition. Reply #160. Nov 12 17, 10:32 PM |
526 replies. On page 8 of 27 pages. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27
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