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METEOROLOGY
Making your own small clouds with a hard squeeze: A plastic bottle, a bit of water, and a match will lead you to appreciate how some clouds form. If you have a thermocouple thermometer, you can dig a bit further. Here’s the link for the full story.
Cloud in a bottle: This is a simple demonstration of phenomena in forming clouds in nature.
Equipment: minimal, cheap.
You fill a clear, squeezable bottle with saturated vapor – you do that by putting a little water in the bottom of the bottle and shaking and swirling it around for, oh, say, a minute. Next, you light a match and put it in the mouth of the bottle and shake it to extinguish the flame and introduce smoke into the bottle, then quickly capping it. If you feel safer, you might light a longer piece of wood, or a cork punk. Now squeeze the bottle hard and then release it sharply. The interior will fill with mist, which is tiny water droplets that condensed around the tinier smoke particles. You can keep squeezing and then releasing the bottle several times to get the effect.
The principle is that the sudden expansion of the air in the bottle decreases its temperature to the point that it is below the condensation point of the water vapor. To put it technically, the expansion is adiabatic, without exchanging any significant heat with the outside air. There are several discussions of the temperature effect, which also explains the decrease of temperature as air goes to higher elevations in steady (nonturbulent) conditions; my explanation using the physics is on another post in these webpages. Of course, the squeezing is the opposite effect. To make the demo more detailed, you can run a fine-wire thermocouple thermometer into the bottle through a tiny hole in the lid, sealing it thoroughly. You can run the thermocouple end to a thermocouple thermometer as I’ve done in this picture. You’ll see the temperature rise on squeezing the bottle and fall on letting it expand.
PICTURE
Video for frames to grab – filling it with a bit of water, shaking it, lighting a match, putting it out to make smoke, sealing the bottle, squeezing it, releasing it, and doing it again
Picture of a cap with a hole
Picture of Omega TCT with lead and with reading
Picture of TC threaded into hole and sealed
Video of squeezing while viewing the TCT and the bottle contents
Let’s try the “Read more” insert. I’ll create the post in text (HTML) and insert “Read more” within this editing environment, which should avoid formatting errors that can occur if it’s inserted within the visual mode Continue reading “Post test read more”
Converting MathType equations to images:
Kutools converted very few equations to images!
Saving a docx as html had the same problem.
Then I simply copied any MT equation, pasted it in a docx like this one, and pasted it in with the 4th choice, as image!
The choice icon looks like a mountain scene!
Now check that this conversion to image does work. Put this document onto a webpage with Mammoth .docx conveter
This is classic one-over-r-squared law for the falloff of power with distance. With R = radius of the Sun (0.696 million km) and R’ = mean radius of the Earth’s orbit (150 million km),
If we want a planet with an energy flux density that’s the same as for Earth (so that it has about the same temperature), we want the total power of the star spread out at the planet’s orbital distance to be like that for the Earth:
Sidebar. The Hertzsprung-Russell diagram of star temperature and luminosity
Stars vary dramatically in color and brightness:
Sagittarius Star Cluster. credit: Hubble Heritage Team (AURA/STScI/NASA
Untold numbers of observations of stars show distinctive regularities in their attributes. Many of the stars cluster along a line called the Main Sequence when their luminosity (to be defined shortly) is plotted against their temperature or associated color (more light in the blue waveband than in the visible equates to hotter).
In the early 1900s two astronomers independently developed an eponymous plot that shows this: Ejnar Hertzsprung in Denmark and Henry Norris Russell in the US:
R. Hollow, Commonwealth Scientific and Industrial Research Organization
R. Hollow, Commonwealth Scientific and Industrial Research Organization
A bit about the definition of luminosity used in the plot: As astronomers even before the era of CCD-cameras made their observations, they quantified the brightness of stars. At our point of observation, it is the flux of photons per area of whatever we use to catch the radiation – our eyes, a photographic plate, a CCD camera recording. This apparent luminosity can be converted to an absolute luminosity, accounting for stars being at various distances from us (see below). The absolute luminosity can be cited two ways:
The physical origin of the tight pattern along the Main Sequence became clear as:
The physics, in brief: Going up and to the left we have stars that are hotter (therefore, bluer) and brighter, in a clear relation.
All told, then, mass determines temperature and luminosity in these stars, in a tight relation.
What about the stars toward the top and right? While the Main Sequence is a sequence in mass and not in time. The Sun will not move to higher or lower mass while burning hydrogen, outside of a fraction of a percent from mass-to-energy conversion. Still, stars in later life can move off the Main Sequence. Stars 10 times the mass of the Sun or more start fusing helium, inflating and getting cooler but very much more luminous. An example is monstrous Betelgeuse. Such stars fuse to a core of iron, the most stable nuclide. They then explode as type II supernovae. Betelgeuse is ripe to do so, in perhaps as few as a thousand years by some estimates. Stars not quite as massive can blow off their outer layers to leave a hot, very dense, but low-luminosity white dwarf. Some massive stars leave enough mass intact to become those enigmatic neutron stars or even small black holes (the really big black holes are huge accumulations of many stellar masses in the centers of galaxies). Some neutron stars, the magnetars, have mind-boggling magnetic fields that contribute to emission of intensely powerful beams of X-rays and gamma rays. All these special stars came into our ken long after Hertzsprung and Russell made their diagram. There’s always something new under the Sun, as it were.
There are many more details in the paths by which stars evolve. There are many online and printed sources to follow this topic.
Sidebar. The Hertzsprung-Russell diagram of star temperature and luminosity
Stars vary dramatically in color and brightness:
Sagittarius Star Cluster. credit: Hubble Heritage Team (AURA/STScI/NASA
Untold numbers of observations of stars show distinctive regularities in their attributes. Many of the stars cluster along a line called the Main Sequence when their luminosity (to be defined shortly) is plotted against their temperature or associated color (more light in the blue waveband than in the visible equates to hotter).
In the early 1900s two astronomers independently developed an eponymous plot that shows this: Ejnar Hertzsprung in Denmark and Henry Norris Russell in the US:
R. Hollow, Commonwealth Scientific and Industrial Research Organization
R. Hollow, Commonwealth Scientific and Industrial Research Organization
A bit about the definition of luminosity used in the plot: As astronomers even before the era of CCD-cameras made their observations, they quantified the brightness of stars. At our point of observation, it is the flux of photons per area of whatever we use to catch the radiation – our eyes, a photographic plate, a CCD camera recording. This apparent luminosity can be converted to an absolute luminosity, accounting for stars being at various distances from us (see below). The absolute luminosity can be cited two ways:
The physical origin of the tight pattern along the Main Sequence became clear as:
The physics, in brief: Going up and to the left we have stars that are hotter (therefore, bluer) and brighter, in a clear relation.
All told, then, mass determines temperature and luminosity in these stars, in a tight relation.
What about the stars toward the top and right? While the Main Sequence is a sequence in mass and not in time. The Sun will not move to higher or lower mass while burning hydrogen, outside of a fraction of a percent from mass-to-energy conversion. Still, stars in later life can move off the Main Sequence. Stars 10 times the mass of the Sun or more start fusing helium, inflating and getting cooler but very much more luminous. An example is monstrous Betelgeuse. Such stars fuse to a core of iron, the most stable nuclide. They then explode as type II supernovae. Betelgeuse is ripe to do so, in perhaps as few as a thousand years by some estimates. Stars not quite as massive can blow off their outer layers to leave a hot, very dense, but low-luminosity white dwarf. Some massive stars leave enough mass intact to become those enigmatic neutron stars or even small black holes (the really big black holes are huge accumulations of many stellar masses in the centers of galaxies). Some neutron stars, the magnetars, have mind-boggling magnetic fields that contribute to emission of intensely powerful beams of X-rays and gamma rays. All these special stars came into our ken long after Hertzsprung and Russell made their diagram. There’s always something new under the Sun, as it were.
There are many more details in the paths by which stars evolve. There are many online and printed sources to follow this topic.
An investment in an impractical technology
Summary of the impracticality of Spinlaunch
The New Mexico Spaceport (https://www.spaceportamerica.com/), funded by taxpayers, started with Virgin Galactic’s space tourism entity as its anchor tenant. It has gained other tenants, thought not yet economically sustainable; space tourism may start in late 2019.
One new tenant is Spinlaunch, a company from Sunnyvale, California (http://www.spinlaunch.com/). They’ve raised $40M from investors (https://www.bloomberg.com/news/articles/2018-06-14/this-startup-got-40-million-to-build-a-space-catapult) including Google Ventures (now GV) and Airbus Ventures for a speculative technology, which I shall describe shortly below. They propose to use a large spinning platform to launch satellites from the ground (which must be with a rocket to complete the boost).
The idea sounded preposterous to me, so I worked out the limitations, which I claim are solidly against this being practical or even possible. Join me now:
The basic technology proposed is:
Calculations:
There are other niceties:
Conclusion:
The rest of the analysis uses equations set by MathType in Microsoft Word. These don’t come through in the Mammoth docx converter plug-in to WordPress, so I link here to a PDF version of the rest of the analysis.
This multilayered post can be followed from one PDF document, or by the explicit links given below in the description of the whole study. The post covers:
Back toward teaching: I wanted to verify that the photodiode circuit responded linearly to flux density. I made a simple error in using layer scattering media too close to the detector, invalidating Beers’ law for the direct beam alone. However, I then dove into the propagation of direct and diffuse light for its inherent interest.
The lead PDF document here has several sections:
Within the lead document are links to several others. The links are imbedded within the lead document; the links are also noted directly here:
Posted 11 December 2017.
Smart water: ads
As our son, David reported reading: “If you’re paying $4 a bottle for smart water, it’s not working!”
Start with the cost. Tap water averages about $2 per 1,000 gallons, which is enough to fill
Can it be any better than tap water? A tiny bit, perhaps. Regular tap water in almost all US water supplies is actually cleaner than most bottled water, according to independent labs. Save money, save the landfill waste, save the petroleum used to make the plastic bottles!
(Eau du robinet!)
What could be improved in Smart Water, and how?
Distillation – removes dissolved solids…and SOME of the volatile organic compounds, SOME
Adding in minerals, selectively – why not drink the natural minerals in your tap water?
The makers avoid sodium – fine, in our salt-laden cuisine…but we get so little sodium from our water!
No fluoride – but you need small amounts of fluoride (GO ON about fluorosis worry)
No heavy metals, arsenic, etc. – well, they’re in your food, unavoidably. We have lived with U, Hg, etc. our whole 2 Mya as a species
No gluten – ridiculous! Gluten only comes from wheat and barley, and I haven’t notice public works people tossing either into our water supplies!
What about water purity, in history?
Not a good record, until sanitation started big time in the mid-1800s
Reason to drink wine, beer (maybe! adulterated), strong spirits – why the temperance movement had a basis (along with the transport problem for grain from the US Midwest, e.g.)
Cholera spreads by contaminated water – English well XXXXX
In fact, broadening to sanitation, in general – it was the first major advance in human health!
For our water and food, and then in medicine – the sad story of Joseph Lister XXXX
GO out and thank an LC utility worker, a garbageman!
On, but if you’re a vegan, thank a little dirt in your food, for vitamin B12 …..