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Matt Swain wrote: Yeah, back in the days when it took a giant dish to contact a satellite...
c
Depending on terminology it still does. In the interest of embiggening knowledge there's three broad types of interaction an antenna on the ground can have with a satellite.
1 Receive only, antennas can be really small. There's most likely one in your cell phone receiving GPS signals. Not really contacting.
2 Use as a pass through. Only interaction is as a bent pipe but probably what you're thinking of. Alot of the antennas are in the 3 -10 feet range with sat phone antennas being even smaller. However smaller then antenna the slower the data rate you're passing through.
3 Establishing a command and control contact. Direct interface with the satellite itself. Still uses the larger antennas for point to point although there's an effort to used phased array to contact multiple satellites at a time with one antenna. Normally when you say satellite contact this is what satellite people think of..
One thing discussed at length in one of my university courses (I want to say it was a sociology course), was that the Sickle Cell genetic trait, often ascribed in the US as being an African-American or "black" trait. . . . well, per capita more people of Greek origin and living in the Greek regions of the Med/Aegean seas. And while it certainly can cause some health problems, apparently it has the benefit that people with the trait are basically unaffected by malarial mosquitos.
Now, mind you this was a sociology course, not a genetics course, so anyone who definitely has more knowledge in this area, feel free to enlighten us on this.
Yay my education is relevant! Here's basic run down;
-Sickle Cell disease is a recessive trait. You only get the actual syndrome if you 'double up' on that recessive trait. If you have half sickle and half normal you do not get sickle cell disease.
-Generally speaking in terms of natural survival (as in, before modern medicine) if you get sickle cell you die. Accordingly there is a strong natural selection to remove this from the gene pool, but it is still there and quite common to boot.
-Generally speaking in terms of natural survival, if you get malaria you are likely to die. BUT if you carry the sickle cell gene (read: you don't have to have full-on sickle cell, just carry it recessively) you are resistant to malaria and still don't have sickle cell.
-Thus, natural selection pushes the population to carry a recessive sickle cell gene, and this produces more adaptive fitness because the number of people who end up dying because they inherit full sickle cell disease is less than the number of people who would die to malaria were the gene not present.
Matt Swain wrote: Yeah, back in the days when it took a giant dish to contact a satellite...
c
Depending on terminology it still does. In the interest of embiggening knowledge there's three broad types of interaction an antenna on the ground can have with a satellite.
1 Receive only, antennas can be really small. There's most likely one in your cell phone receiving GPS signals. Not really contacting.
2 Use as a pass through. Only interaction is as a bent pipe but probably what you're thinking of. Alot of the antennas are in the 3 -10 feet range with sat phone antennas being even smaller. However smaller then antenna the slower the data rate you're passing through.
3 Establishing a command and control contact. Direct interface with the satellite itself. Still uses the larger antennas for point to point although there's an effort to used phased array to contact multiple satellites at a time with one antenna. Normally when you say satellite contact this is what satellite people think of..
I may be wrong, but i've assumed small military units 'out in the field' had access to satellite communications, implying a 2 way satink can be carried pretty easily. Or is that just saomething seen in so many movies and tv shows it becomes 'assumed reality'?
"But the universe is a big place, and whatever happens, you will not be missed..."
A little bit of reality and a little bit of assumed reality. Simple answer, Comm falls under number 2 (bent pipe) although alot of times number 1 gets mixed in. (sat phone type to talk but use recieve only to send troops in field a picture for instance) and the movies just mix those together. Your general soldiers would most likely have access through vehicle mounted antennas. Special forces probably have some sort of ruggedized satellite phone that encrypts the crap out of the discussion. So Hollywood will show the everyone has the satphones but that they work as well as the vehicle mounted so modified reality.
A little more detail without going too crazy. In order for a comm path to work you have to close the link budget, by that I mean your transmitted power + gains and - losses has to be high enough for the receiving antenna and that works both ways and is heavily frequency dependent. In general the frequencies that experience less atmospheric losses use bigger antennas. Bigger antennas increase gain. Technically with enough power you can get anything to close just don't get between the transmitter and reciever or you'll get cooked. Another important factor is distance, Iridium, one of the original satcom phones is in a low earth orbit (485 miles out). Most of the comm satellites are in Geocentric orbit (22,000) miles out, that makes a huge difference in losses, you aren't going to use something the size of a satellite phone to communicate through that. If you're going to establish a C2 contact with a GEO sat, yeah you still need a big antenna.
So I made this post elsewhere but then I thought about this thread and I think it kind of fits?
PSA:
Because of COVID-19, JSTOR has made much of it's collection available for open access.
JSTOR is an online database and repository of accredited academic journals, community libraries, and university press resources. A list of associated publications is here. If you ever used the library at your college or university, you've probably come across it at some point. It's an invaluable resource because much of academia is there and easily accessible. For the seriously hardcore, it even includes out of print publications going back to the 1800s (a historiographers wet dream).
In the past, the big issue was that you needed a library to get to it. Just a few years back, JSTOR was not something you could just use. The service was explicitly designed for libraries and educational institutions and getting a subscription cost a few hundred dollars. More recently, JSTOR has started opening up the doors to the ivory tower, bit by bit. The first deal was the release of a, still pricey, but actually affordable subscription model for individual ($20/month or $199/year) granting full access to JSTOR.
In terms of dollar value, it's actually the greatest deal on Earth, if you're actually going to read that much.
IMO, one of the best things about JSTOR are that it makes scholarly journals easy to access. Big book history can be dry, long winded, boring, and a slog to get through. Individual academic articles are imo, often much more accessible for the layman. They tend to be very focused on a particular question or topic, don't spend lots of time on lengthy anecdotes or excessive detail and just... cut to the point. There's a big dividing wall between the world of academics and everything else, and it often rears it's head in bizarre or even (in politics) destructive ways. Opening up the ivory tower and making academic research more available is one of the best things I think scholars can do for the world today.
Another bonus to JSTOR is that it cuts the chafe.
An example: I searched "Viking History" on Amazon. Out of the 20 books offered on the front page, 1 was a rigorous academic work (actually pretty hardcore). Children of Ash and Elm by English Archeologist Neil Price. Three were "pop histories" written by people with academic backgrounds or baking: The Oxford Illustrated History of the Vikings. The Sea Wolves: A History of the Vikings, and Saxons, Vikings, and Celts: The Genetic Roots of Britain and Ireland. These books are not complete bunk, but they're also not rigorously scholarly and are intended to try and bridge the gap between academia and lay people.
The problem is that separating those four works from the rest of the page and knowing that the rest junk history that will probably give bad information or impressions or fail to actually explain anything going on in academia is basically impossible to know without doing lots of legwork.
JSTOR saves you the trouble. They aren't carrying the entire Barnes and Noble catalogue, and while being on JSTOR isn't an assurance that a source is good, being on JSTOR at least means academics are talking about and using it and it exists within the stream of what scholars and experts are doing. No need to search Google Scholar, University faculty pages, or any of the other tips and tricks to finding good stuff.
So yeah. JSTOR is a great thing. It's still pricy but at least it's kind of affordable and if you like reading lots on economics, history, science, or what have you, JSTOR is currently the best resource there is.
Public service announcement complete
This message was edited 1 time. Last update was at 2021/02/12 19:23:06
I've long felt that academic publishing needs to break out of the shell of only pitching and selling to universities. I've seen a good few interesting books that are priced in the hundreds and up and are clearly only ever bought by libraries or the super keen.
Opening up knowledge to a bigger roster of the public and without them having to be at uni to use it means a huge amount to lay people. Plus I think it also helps nurture those who are out of the university system, but whom still have a core interest in those fields of study and can make use of the material.
Hopefully if they can get enough marketing behind it to make people aware, making prices cheaper will mean more users and that means price can come down.
This kind of mass market cheap monthly/annual system can work wonders - I know Adobe now uses it extensively for their software and its made it more accessible to people at the same time its brought them more constant and steady profits. I'm sure JSTOR can hopefully achieve similar.
Yeah. I never got to deep dive into Crusade history as much as I wanted because in English there's really only one source of primary sources; Oxford. Oxford publishes translations of these primary sources in massive encyclopedic collections that can cost thousands of dollars. Qatar has recently started digitizing everything in it's national archives and holy gak it's a lot, but the organization and translation are terrible. Oxford remains the best resources but it's way out of anyone's price range.
I am not made of money and while I understand the reasoning for why institutions want to cling to and control access to primary sources (they have to support themselves financially to preserve them at all) I am eternally saddened that these materials can't just be made available to people.
For JSTOR I'd really like to see something like a "History Package" where you can buy access to their History journals for like, $10-12/month. I'm not really reading the international affairs, business, economic, or physics journals. That deal would be fantastic. They've been opening up more and more the past few years so maybe we'll see something like that.
This message was edited 2 times. Last update was at 2021/02/12 19:45:31
Yep and its not just that, by limiting to Universities it often means that many publications they do have often get lost. As noted above they don't really appear in Amazon or major book retailers - you might get some at somewhere like Blackwells that pitches to universities as well; but broadly speaking many key references will be basically unknown unless you're really into the academia side of things.
So its not just that there's a price barrier, but also just basically knowing the references even exist in the first place.
For JSTOR I'd really like to see something like a "History Package" where you can buy access to their History journals for like, $10-12/month. I'm not really reading the international affairs, business, economic, or physics journals. That deal would be fantastic. They've been opening up more and more the past few years so maybe we'll see something like that.
Its funny, JSTOR and EBSCO host and other journal hosting repositories already do something similar to this for universities. When I was at my uni, the librarians kept asking, "did you check this one for your history articles?" and I'd remind them, "no you didn't pay for history on that database, only this one" . . . like, it was genuinely confusing at my school which database hosted which field of study.
I'd definitely be down for it, right up until they started doing the same things that killed of cable TV: "ohh, you want the english literature articles? Well then you need the Humanities Premium Plus, it also comes with poetry, world religions, and underwater basket-weaving"
I think subdivision can be more complex than people think. Its easy to say split off the histories, but they'll include a lot of scientific elements or elements that rely on the sciences. Does radio carbon dating fit into physics or history? How much fits into each one - will you be ending up with some of the meatier discussions on the technical side being only in physics or even chemistry or such whilst users of the method in history will only be able to read about history documents that used the method etc...
IT can sound like a neat way to lower costs to the individual, until you realise how many subjects criss-cross over each other and suddenly what sounded like a cheaper deal, actually works out to be a more expensive deal.
A single access system does at least provide a simple setup for both sides of the coin. In theory it also makes it easier to access and thus more amenable to mass-market access with the view that instead of making more per-person you'd make more from a larger population. If the price is low enough even to the point where you end up with many signed up and paying users who are not currently active users.
Heck Adobe charges me £10 a month (bit less) for using Photoshop and Lightroom. If I go a month or two not doing any photography, in theory, I should cancel those months; however in reality I just overlook it. So I'm paying for a service that I'm not, at that moment, using. Journals would be the same, ideally if they target 3rd year students they can encourage many to sign up "50% off if you sign up at the end of your graduation etc....". So you're cornering them when they've an interest with the hope that many will turn into long term sleeper subscribers.
It was 2011/2012 when I first encountered it, and I think 2016 the last time I tried to use it.
Their interface was so dated. It's like they've never upgraded the site since the late 90s. It's far less user friendly than JSTOR so JSTOR became my preferred platform. Looking at it now though I does look like they've managed some upgrades but it's gone the hyper minimal route that I've never really liked XD
I think that style must be more usable for some people though because lots of sites use it and twitter is huge.
This message was edited 1 time. Last update was at 2021/02/13 15:59:01
It was 2011/2012 when I first encountered it, and I think 2016 the last time I tried to use it.
Their interface was so dated. It's like they've never upgraded the site since the late 90s. It's far less user friendly than JSTOR so JSTOR became my preferred platform. Looking at it now though I does look like they've managed some upgrades but it's gone the hyper minimal route that I've never really liked XD
I think that style must be more usable for some people though because lots of sites use it and twitter is huge.
One of the things I liked about my uni library is that our computer nerds put into our library webpage an interface where you could put in your search terms and it would pull from whichever databases you checked, and then you'd open a direct link to whatever article it was, so at no point was I directly ever using JSTOR or Ebsco (although I did at a couple points jump onto JSTOR directly for history stuff, when search algorithms didn't pull up enough relevant stuff)
Mad Doc Grotsnik wrote: Possibly a tinderbox question, so I shall simply ask and not elaborate. Please keep answers similarly.
Can anyone recommend a layman’s terms, bipartisan book (or books) on the American Civil War?
If you just want a history of the war itself, I think James McPherson's Battle Cry of Freedom is a good and concise narrative history of the war itself. Though it does cover other things, it's just that a lot of the books I know are focused on questions other than just retelling the events of the war. This is the one book I know off the top of my head written with layman in mind and is primarily a history of the war.
I'll offer the reading list from my post-grad class on the subject. Layman history they're not per se, but I find all but maybe Ruin Nation and War Upon the Land are very accessible.
Spoiler:
Calculating the Value of the Union: Slavery, Property Rights, and the Economic Origins of the Civil War by James Huston. I EXTREMELY recommend this book. It can be dry but it touches on a lot of hard truths and uses raw data to back them up. Huston proposes that the origins of the Civil War were fundamentally economic in nature, hinged on the value of slaves, the economies on which slavery operated, and how perceptions of property and rights played into the politics of the period. I think his overarcingy argument is overstated, but he's got raw data for a lot of his sub-themes and it's hard not to agree with many of his subtler points and proposals.
Shifting Grounds: Nationalism and the American South, 1848-1865, by Paul Quigley is a history that examines the trends and ideologies that would lead to succession in the Southern States and their role in the Civil War. I don't remember this book well XD
War Upon the Land: Military Strategy and the Transformation of the Southern Landscapes during the American Civil War by Lisa Brady. Brady is an environmental historian, and this book is actually really fun imo. Environmental history in general is very fun. Brady examines the impacts of the war on the southern landscape and its geography, which also means she talks a lot about the war itself. Great book as I remember it.
In the Presence of Mine Enemies: The Civil War in the Heart of America, 1859-1864 by Edward Ayers.EDIT: And I confused this with another book. In the Presence of Mine Enemies is focused on two counties, one in Pennsylvania and one in Virginia and examines their similarities and differences. I'm actually not sure what the book I was thinking of was titled. Looking to see if I can find it.
Mothers of Invention: Women of the Slaveholding South in the American Civil War by Drew Faust, is largely about women and the home front. I don't remember this one much either because it's a bit dry at times, but it's an interesting look at an aspect of the war that is often discussed by historians but rarely takes center stage.
Ruin Nation: Destruction and the American Civil War by Megan Nelson is specific examination of whether or not the Civil War qualifies as a total war. Nelson proposes (and I think provides a good case) that it was not, but it came very very close. It's a military history with a lot of focus on the North and its war strategies, policies on civilians and property, and how we regard and think about the war culturally. She is especially interested in how the war's destruction and physical realities have largely been forgotten with time as more ideological conceptions of the war have come to dominate perceptions of the conflict.
What this Cruel War was Over by Chandra Manning. This is the opposite of Ruin Nation. Manning deep dives into memoirs, letters, and diaries to examine how soldiers, North and South, Black and White, viewed the war. She proposes that the war initially started with soldiers holding political views about the conflict and then gradually shifted as it went on and slavery's preservation/destruction became overarching in the minds of fighting men. It's a very good history though I remember little of it. It focuses on how common people thought and what they said.
Also on the list:
A book you'll also want to read is Reconstruction: America's Unfinished Revolution by Eric Foner, which is the definitive history of Reconstruction and has been since it was published. This book comes in two versions because the original is MASSIVE. I recommend the second abridged version; A Short History of Reconstruction. It's got some hiccups, but it cuts a lot of the bulk data he used in the full version and just sticks to a narrative history that makes the shorter version much more readable.
Reconstruction in the Cane Fields: From Slavery to Free Labor in Lousiana's Sugar Parishes, 1862-1882 by John Rodrigue, is a micro-history (see the title) that's also very fun and covers all kinds of neat stuff. Could you believe freedmen in the immediate aftermath of the Civil War managed to unionize and protect their rights for a fair while in Louisiana? This is a book about how they did it!
As for bipartiasn... I'm not sure there is one? Historians are largely in agreement about what the war was specifically about, and their disagreements are mostly in the fine details. There's been broad agreement about it since Foner first published Reconstruction in the 80s. Unfortunately the war's cultural memory and political legacy is somewhat distinct from how academics view the conflict. If you want books that avoid becoming petty political anachronisms, most of these should qualify.
This message was edited 7 times. Last update was at 2021/03/13 06:44:22
According to this, a layer of graphene, which is basically just carbon, has produced measurable, storable and useful energy from the heat in it's own atoms.
This is called Brownian Motion and up till now physics has said that due to entropy brownian motion cannot directly be used as a source of usable energy.
It looks like a sheet of carbon atoms has just said "Hold my beer!"
If this is true it will make some real changes to our beliefs about the laws of physics necessary. It even appears, at this point, to possibly output more energy that seems to be put into it which definitely violates physics as we understand them today and if true means a lot of physics os going to be rewritten.
Right now this is in an early stage and may not go anywhere, but if even some of this is true there are going to be big changes in our understanding of physics and a few things we used to believe were impossible might not be after all.
Here's hoping.
"But the universe is a big place, and whatever happens, you will not be missed..."
A Town Called Malus wrote: As a genral rule, if something says it is going to rewrite the laws of physics then you can pretty safely ignore it.
It is an interesting design, however. It remains to be seen whether they can miniaturise it to make it useful.
Well, there was a theory that graphene could coproduce energy from brownian motion way back in like 2010. This experiment was based on some years of research. It's still unformed and some people think it may be something like a crystal radio set, but if it was that easily disimssed i think we'd have seen it exploded by now, or at least thunderfoot would have done an annoying video on it.
"But the universe is a big place, and whatever happens, you will not be missed..."
My good friend and fellow Northumbrian Dr Rachel Pope recently released an article on some of the research she's been undertaking on "Celts". It discusses the Iron Age peoples of Europe and the Near East and is less about the weird modern "Celtic" identity that people have fashioned for themselves out of Victorian native/savage Romantic ideals.
The abstract if anyone is interested:
"This work re-approaches the origins of “the Celts” by detailing the character of their society and the nature of social change in Europe across 700–300 BC. A new approach integrates regional burial archaeology with contemporary classical texts to further refine our social understanding of the European Iron Age. Those known to us as “Celts” were matrifocal Early Iron Age groups in central Gaul who engaged in social traditions out of the central European salt trade and became heavily involved in Mediterranean politics. The paper focuses on evidence from the Hallstatt–La Tène transition to solve a 150-year-old problem: how the Early Iron Age “Celts” became the early La Tène “Galatai,” who engaged in the Celtic migrations and the sacking of Rome at 387 BC."
A Town Called Malus wrote: As a genral rule, if something says it is going to rewrite the laws of physics then you can pretty safely ignore it.
It is an interesting design, however. It remains to be seen whether they can miniaturise it to make it useful.
A thought i've had about this breaking an established physics model is that the older model was likely based on a mass of atoms that would be 3 dimensional and thus have infinite directions to disperse the energy of the motion into. Now graphene is a single layer of atoms, a 2 dimensional plane not a 3 dimensional mass.
Hmm, i wonder if confining the brownian motion of atoms to a single plane limits the way the energy of brownian motion can disperse and makes some part of it able to be tapped to produce energy.
"But the universe is a big place, and whatever happens, you will not be missed..."
Heresy World Eaters/Emperors Children 
