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  #1501  
Old 08-30-2017, 01:51 AM
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Default Re: A Question For The Lone Ranger

A mushroom I found in Elk Island National Park:

Img_0913.jpg

A little Googling and I think it's an Amanita muscaria var. persicina. Did I do my homework right?

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  #1502  
Old 08-30-2017, 03:18 AM
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Default Re: A Question For The Lone Ranger

It's pretty-definitely Amanita muscaria; the white "warts" are diagnostic. Most varieties of Fly Agaric are bright red when young, and fade somewhat as they age, but the persicina variety has much less red and much more yellow than do most other varieties, just as your specimen shows.

I think it might be variety guessowii, rather than persicina, however; persicina isn't generally encountered so far north. Don't let the pictures fool you; Amanita muscaria has the rounded shape when young, but opens up and flattens out as it ages. As such, though the shape as shown in the pictures from Wikipedia would seem to indicate variety persicina, the location makes it more likely to be guessowii, I would think.

As an aside, though I'm sure you didn't try to eat it, Fly Agaric, like most members of the genus Amanita, contains toxins. That having been said, it's much less toxic than are some other members of its genus (members of the genus include such well-named species as "Destroying Angel" and "Death Cap"). I've heard it claimed that if it's cooked properly, Fly Agaric is actually edible, but I've never been stupid/daring enough to try, personally.
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  #1503  
Old 08-30-2017, 03:29 AM
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Default Re: A Question For The Lone Ranger

Oow mushy!
Identifying mushrooms can be a pain, but I think you nailed it, there's some excellent online guides,
http://www.mycokey.com/newMycoKeySit...dentQuick.html

The 'warts' are known as a universal veil. The veil is a thin membrane that spans from the cap edge to the stalk to protect the gills. A universal veil covers the whole cap and the warts are a result of it ripping as the cap grows.

Muscaria doesn't contain the same toxins as Destroying Angels and other famous poisonous mushrooms and is way less deadly it also doesn't contain the same compounds as famed hallucinogenic mushrooms (it's possible at one point fruiting fungi diverged in their protective methods). Some people use them to produce a drunk like high, in some cases ritualistic use has seen a shaman/priest using themselves as a filter, the liver converts the main chemical into an active ingredient, which is then mostly excreted. Or in short, if you drink the shaman's piss, you get the fun without the hangover.

(But of course things like Destroying Angels are soo soo horrible that you should never eat any mushroom without positive identification.)
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Old 08-30-2017, 05:26 AM
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Default Re: A Question For The Lone Ranger

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Originally Posted by The Lone Ranger View Post
As an aside, though I'm sure you didn't try to eat it, Fly Agaric, like most members of the genus Amanita, contains toxins. That having been said, it's much less toxic than are some other members of its genus (members of the genus include such well-named species as "Destroying Angel" and "Death Cap"). I've heard it claimed that if it's cooked properly, Fly Agaric is actually edible, but I've never been stupid/daring enough to try, personally.
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(But of course things like Destroying Angels are soo soo horrible that you should never eat any mushroom without positive identification.)
Yeah, no eating. Having taken and taught wilderness survival we had a basic rule of thumb. "Most mushrooms will kill you. Do not eat wild mushrooms." Which is close enough to reality for the purposes of teaching teenagers how to survive a few days on their own lost in the woods.
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  #1505  
Old 09-04-2017, 10:37 PM
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Default Re: A Question For The Lone Ranger

The Lone Ranger, what in the hell kind of insects are these?

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  #1506  
Old 09-05-2017, 12:11 AM
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Default Re: A Question For The Lone Ranger

A wild guess ... nymphs of Homaemus proteus?
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  #1507  
Old 09-05-2017, 03:05 AM
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Default Re: A Question For The Lone Ranger

That's what they look like; I think JoeP has got it right.

As an aside, the title has got it right, for once; they are bugs. To an entomologist, a "bug" is an insect in the order Hemiptera; entomologists tend to get miffed when people refer to spiders, isopod crustaceans, and all sorts of other little arthropods as "bugs" when the creatures in question are most-definitely not hemipterans.
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  #1508  
Old 09-05-2017, 08:44 AM
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Default Re: A Question For The Lone Ranger

The more important question is why do they behave like that? - following each other, and moving for a bit then stopping. It looks like a children's game.
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Old 09-05-2017, 12:28 PM
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  #1510  
Old 09-05-2017, 07:39 PM
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  #1511  
Old 09-24-2017, 04:25 PM
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Default Re: A Question For The Lone Ranger

I was recently musing on something kind of sort of sci fi related when I had a thought. The measurement of a light year is arbitrary. I don't mean in regards to the quantity of the distance traveled by light in a vacuum in any given year as that is constant. I mean the tying of the light year measurement to an Earth year as that is arbitrary.

You could just as easily tie the light year measurement to a Venusian or Jovian year. Anyway, my question for The Lone Ranger is whether or not he agrees with this assessment.

Also, on the issue of a light year. Is it even possible to derive a measurement that isn't arbitrary? For instance, if we met an alien race whose homeworld had a year equal to 300 Earth days by our measure, their measurement of a light year would be different from our own. This is what I meant in my previous paragraph. Is it possible to derive a measurement system for light over great distances that would be understood between different hypothetical interstellar civilizations?
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  #1512  
Old 09-24-2017, 08:40 PM
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Default Re: A Question For The Lone Ranger

Well, our version of a "light year" is certainly arbitrary inasmuch as any aliens out there would almost-certainly have a "year" that differs in length from ours, and so their version of a "light year" would be different from ours.

I suppose you could pick a unit of measurement such as "1/1,000,000 the distance across the galaxy" or some such, but even then, that will be somewhat arbitrary. (The galaxy doesn't just stop, after all, and aliens might not agree with us on where, exactly, to draw the line that marks the galaxy's edge. That having been said, it should be pretty close.)

Of course, any unit of measurement that we make up is going to be arbitrary, but it should be possible to come up with something that aliens would be able to understand without first knowing how long our year is, or whatever.


For example, we used to define a "meter" as equal to "1,650,763.73 wavelengths of the orange-red emission line in the electromagnetic spectrum of the krypton-86 atom in a vacuum." Sure, you'd have to carefully explain something like that to your hypothetical aliens, but at least they'd get the same result that we do.



The current definition of a "meter" is with reference to the speed of light. At first, that sounds good: one "meter" is equal to "the length of a path traveled by light in vacuum during a time interval of 1/299,792,458 of a second" -- but then, you'd have to find some way to explain what a "second" is. Perhaps you could do that by explaining that a "second" is equal to "1,000 rotations of a particular pulsar." (Of course, you'd have to give precise directions to locating that particular pulsar ...)


I don't think there's any way around it: any unit of measurement we pick is going to be somewhat arbitrary. We can use universal constants like the speed of light to help us define our units, but even so, we're still going to have to then explain what we mean by things like how long a "second" is.
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  #1513  
Old 09-24-2017, 08:46 PM
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Default Re: A Question For The Lone Ranger

It's all arbitrary.

You could try to make some measure on the basis of the size of, say, hydrogen atoms, and other measurements could flow from there (base unit of time could be how long it takes for light to travel 10n distance units, based on some amount that seems convenient).

But even that's arbitrary, and your choice of numeral base for the units will be arbitrary as well.

Suppose we say that our basic unit of length will be a 10 billion times the van der Waals radius of a hydrogen atom, which would be about 1.2 meters... ok, but the choice of base 10 was arbitrary, as was the choice of using 1010. We could just as easily use 109, about 12 cm, as our basic unit length. Or we could use a base 2 or base 8 or base 12 or base 16 system instead...

And our choice of basic unit will be defined around convenience, since we tend not to want to use huge numbers to discuss ordinary occurrences ("We're running late, the plane starts boarding in just 3.6 million milliseconds!"). Of course, we can and do use more than one named unit (seconds, minutes, hours, days, weeks, years)... Those have varying correspondences to each other, but there's no reason we couldn't simply call a kilometer a mile, or a centimeter an inch, or a kilosecond an hour.
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Old 09-24-2017, 11:31 PM
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Default Re: A Question For The Lone Ranger

Imagine communicating with very distant aliens by radio and wanting to explain our measurement units to them. You only need to define a mutually agreed time or distance. Once you have one you automatically tell them the other by saying, "Light in a vacuum travels one metre in three nanoseconds" or whatever.

If there's a pulsar both parties can observe that's one way of agreeing on a time unit - but there's no need.

Our second is now defined in terms of how many billions of vibrations of a particular kind of caesium atom you count in one second - that's how atomic clocks are made. Any aliens with the technology to communicate with us would already have their own atomic clocks and though their clocks might not use caesium, they, like us would already have measured the vibration rate of all the atoms.

Once you told them that we use caesium and count up to whatever, they would quickly calculate and say something like, "Our time unit, the plthrargh, is 4.32667854689... of your seconds."

You could also tell them a unit of mass, such as a kilogram by telling them how many billions of hydrogen atoms you need to have that total mass. Once you have a time unit, a mass, and length unit defined (length and time being linked by the speed of light) then all other units such as volts, watts, and so on can be defined easily.

Interestingly, it used to be thought that there was no way of telling aliens left from right unless both parties could observe the same object and say, "That galaxy's spiral arms go clockwise" or similar. But recently it's been discovered that some phenomena observed with fundamental particles in atom smashers exhibit handedness - so you could tell them how to do the experiment and say, "The positron spirals clockwise" or whatever - and once you have a mutually agreed version of clockwise, then left and right are easily explained.
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  #1515  
Old 09-25-2017, 12:43 AM
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Default Re: A Question For The Lone Ranger

You can combine fundamental physical constants to get units of a certain dimension (length, time, mass, etc.)

For a distance, you could use the Planck length, which you get by combining Planck's constant, the gravitational constant and the speed of light. Any alien civilization as advanced as us would know about this quantity. The downside is that you need to measure the gravitational constant, which is tricky, so we only get 6 or 7 decimal places of accuracy right now.

You can build units of any physical dimension like this.
Planck units - Wikipedia
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Old 09-25-2017, 02:09 AM
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Default Re: A Question For The Lone Ranger

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Once you told them that we use caesium and count up to whatever, they would quickly calculate and say something like, "Our time unit, the plthrargh, is 4.32667854689... of your seconds."
I can't believe they're still on the plthrargh system, haven't they converted to the llaphrzd system yet? It's like they're stuck in the middle ages.
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  #1517  
Old 09-25-2017, 06:01 AM
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Default Re: A Question For The Lone Ranger

Here's a history of fundamental units:

Time -- Second:
  • 1/86400 mean solar day (antiquity)
  • 1/31,556,925.9747 of year 1900 (1960)
  • 9,192,631,770 periods of the Cs-133 hyperfine-transition radiation (1967)
  • Proposed: another atomic-clock definition
Length -- Meter:
  • 1/10,000,000 of half a meridian (1795)
  • Length of a certain bar of platinum (1799)
  • Length of a certain bar of platinum-iridium (1889)
  • 1,650,763.73 wavelengths of light from a certain electronic transition of krypton-86 (1968)
  • The distance that light travels in a vacuum in 1⁄299,792,458 seconds (1983)
Mass -- Kilogram:
  • The mass of 1 liter of water at 0 C (1795)
  • Mass of a certain cylinder of platinum (1799)
  • Mass of a certain cylinder of platinum-iridium (1889)
  • Proposed: fixing of Planck's constant, defining mass as (time)/(length)^2
Temperature -- Celsius / Kelvin:
  • Celsius: 0 = freezing point of water, 100 = boiling point (1740's, several inventors)
  • Kelvin: 0 = absolute zero, degree division same as for Celsius, making the freezing point of water 273 K (1848, William Thomson: Lord Kelvin)
  • Triple point of water = 0.01 C = 273.16 K (1948)
  • Proposed: fixing of Boltzmann's constant, defining temperature in energy units
Proposed redefinition of SI base units will include not only fixing Planck's constant and Boltzmann's constant, but also the elementary charge and Avogadro's number.
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Old 09-25-2017, 06:49 AM
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Default Re: A Question For The Lone Ranger

Philosophers sometimes distinguish between necessary and contingent propositions. Necessary ones have a truth value from necessity. Mathematical propositions are well-known necessary ones. Contingent ones are true from historical circumstances and the like. "There is a tree in my house's front yard" is true, but it is contingent. There is no necessity that a tree should be there. How we represent mathematics is also contingent, as are languages in general.

So if wish to communicate with extraterrestrials, we should look for anything that is shared, like necessary propositions and shared contingent ones, and use them as references for any non-shared contingent ones. That would include the language(s) of the communications.

For instance, one would introduce numbers in unary fashion, because they ought to be easy to recognize that way, and then introduce a place system:
0 =
1 = X
10 = XX
11 = XXX
100 = XXXX
...
Though the sequence X, XX, XXX, XXXX, ... is represented in contingent fashion, it ought to be easy to recognize the necessary features in it. Likewise, one uses one's understanding of X, XX, XXX, XXXX, ... to work out what 1, 10, 11, 100, ... are.

Physics and chemistry are good sources for shared contingent features, since we and the ET's live in a Universe with shared fundamental features. Nowadays, there isn't a clear dividing line between the two fields, and I can't think of a good name for the combination of the two.

The meter and the second were first defined in terms of some contingent features that are difficult to share across interstellar space: the size and rotation of our homeworld. But they are now defined in terms of universally shared contingent features. The current definition of the kilogram is even more difficult to share: the mass of a certain cylinder in a suburb of Paris. But its upcoming redefinition will define it much like the meter and second.
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Old 09-25-2017, 07:18 AM
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Default Re: A Question For The Lone Ranger

Another shared contingent feature is the large-scale structure of the Universe. How much is shared will depend on the ET's' distance from us. The closer they are, the more that they will have in common with us. If they are 1000 light-years away (say), they should easily observe such bright stars as Deneb and Rigel and Betelgeuse and Antares, though those stars will be in very different positions relative to them.
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Old 09-25-2017, 07:23 AM
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Default Re: A Question For The Lone Ranger

As to resolving the parity or handedness of one's coordinate system, there are two ways:

Observe the large-scale structure of the Universe. Its details should resolve the parity very quickly.

The Reversal of Parity Law in Nuclear Physics | NIST
Quote:
The experiments at NBS showed that emission of electrons in beta decay of cobalt-60 nuclei is greater in the direction of the south pole of the nucleus (pointing toward the north pole of the magnet), as indicated in the drawing.
So they can do that experiment or similar ones to observe the parity violation of weak interactions.
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Old 09-25-2017, 09:48 AM
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As to resolving the parity or handedness

The Reversal of Parity Law in Nuclear Physics | NIST
Quote:
The experiments at NBS showed that emission of electrons in beta decay of cobalt-60 nuclei is greater in the direction of the south pole of the nucleus (pointing toward the north pole of the magnet), as indicated in the drawing.
So they can do that experiment or similar ones to observe the parity violation of weak interactions.
Could they though? How are you going to explain to them how to tell north and south poles of magnets apart before we have an agreed meaning of left/right? :chin: I suppose the Lorentz force lets you explain that (or maybe not?) - and in any case you need to be sure that the aliens aren't made of antimatter.
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Old 09-26-2017, 09:18 AM
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Default Re: A Question For The Lone Ranger

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Originally Posted by lpetrich View Post
The Reversal of Parity Law in Nuclear Physics | NIST
Quote:
The experiments at NBS showed that emission of electrons in beta decay of cobalt-60 nuclei is greater in the direction of the south pole of the nucleus (pointing toward the north pole of the magnet), as indicated in the drawing.
So they can do that experiment or similar ones to observe the parity violation of weak interactions.
Could they though? How are you going to explain to them how to tell north and south poles of magnets apart before we have an agreed meaning of left/right? :chin: I suppose the Lorentz force lets you explain that (or maybe not?) - and in any case you need to be sure that the aliens aren't made of antimatter.
One sends over the Biot-Savart law for the magnetic field, and one calculates what magnetic field will result from sending electrons through a coil. Like:

Look at the direction that electrons emerge from cobalt-60 atoms, and look at the surrounding electromagnet's electrons. When one is looking along the emitted electrons, are the electromagnet's electrons going clockwise or counterclockwise? I'd have to calculate which one is correct, but I'll use clockwise for illustration. It works the same way for counterclockwise.

So if they found the electrons going counterclockwise, they'd find that our coordinate handedness convention is opposite from theirs.


Our universe seems like it is entirely made of what we consider ordinary matter or koinomatter (Hannes Alfven's term), because there is no evidence of boundaries between koinomatter and antimatter. But an observer living in an antimatter part would consider it koinomatter and our matter antimatter. Antimatter is is just like koinomatter but with some signs reversed.

In an antimatter universe, the electromagnet electrons would be going counterclockwise instead of clockwise. So an antimatter observer would get our parity convention reversed.


To distinguish koinomatter and antimatter, one will need to look for CP violation - Wikipedia. That can be done by doing experiments on neutral different-flavor mesons like K0 (down-strange), B0 (down-bottom), and Bs0 (strange-bottom), and CP violation has been found for all of them. There ought to be some in D0 (up-charm), but such effects have not been found yet.

If one finds that CP-violation experiments yield the opposite sign of effect from our experiments, then one has discovered that one is made of antimatter relative to us.

They'd discover that our parity convention makes Co-60-experiment electromagnet electrons go counterclockwise, and if they found clockwise, then they'd know that we use the opposite parity convention.
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  #1523  
Old 09-26-2017, 11:10 AM
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Default Re: A Question For The Lone Ranger

Doesn't the Biot-Savart law include working out the sign of a closed curve integral? But if they don't know left from right then they might have their x-axis the opposite way round to ours and then they would get the opposite answer.

Let's say the Cobalt-60 electrons go the same way round as the electrons in the coil that produces the magnetic field. Then if you have no mutually agreed definition of clockwise that experiment won't provide one.
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Old 09-26-2017, 12:34 PM
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Default Re: A Question For The Lone Ranger

The way I understand it is you send them the description of the parity-violating process to define your coordinate system. If they pick the wrong convention (left handed or right-handed) they will have a process that doesn't happen that way in reality and they should understand that if they know the physics.
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Old 09-26-2017, 05:20 PM
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Default Re: A Question For The Lone Ranger

Yes, I agree with that - but if we're trying to tell them what we mean by left and right, it's vital that the description of the parity-violating experiment doesn't include any reference to left/right or clockwise/anticlockwise either explicitly or hidden (e.g. in the convention for what is a positive angle in polar coordinates, which comes from our x axis increasing to the right).

So far I'm not convinced that we have an example of a parity-violating process that doesn't include some sort of left/right assumptions in its description - though I admit I don't fully understand all the descriptions, so I could easily be wrong.

Is there a way of defining how to tell the north pole of a magnet from the south pole without one of these (possibly hidden) assumptions? If there is, then I agree that we can convey our sense of left/right to the aliens.
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Crumb (09-26-2017)
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