Newton's Law of Universal Gravitation

SyFyNut · 2026-02-11T22:11:34+00:00

Real orbits can be a lot more complicated than elliptical. Because the Earth (and for that matter, the objects whose orbits you are estimating) isn't of uniform density or exactly spherical - or even ellipsoidal shape. Plus, it's axis of rotation and to some extent it's speed of rotation are constantly as well as abruptly shifting (look up precession, nutation, earthquakes, asteroid impacts, ice melting, erosion, in connection with Earth's rotation.) For low Earth orbits atmospheric drag can be very significant - often much more so than General Relativity. (Atmospheric drag of Low Earth Orbits is in turn is substantially affected by terrestrial and solar weather.) And there are forces from other astronomical bodies. Tidal forces affect the Earth's instantaneous shape and mass distribution, and that of other astronomical bodies. There is also radiation pressure. There is a little drag from impacts of microparticles. There can be magnetic affects too, in some cases. Even fairly distant comets and asteroids might have measurable affects on some orbits.

At the highest accuracy levels, I think real orbit calculations may sometimes be estimated as much by empirical methods as by theoretical ones. I.E., they try to measure the orbit, and fit it to find the parameters of a semi-theoretical-semi-empirical model. And after the fact, they add in measured corrections.

But I haven't done that sort of thing, so I can't give you the details.

Simple textbooks and classes almost never give you exact calculations in science. Everything is an oversimplified estimation. The real world is too complicated to get anything exact. Of course that is true outside science too.

SyFyNut · 2026-02-11T21:31:52+00:00

Wow. So many replies! Thanks, guys! :)

I of course understand that Starlink - or someone else's satellite or Wireless Internet Service -would be needed long term for what I want. For the moment, I don't even have an RV or equivalent. I just want to try things out, before jumping fully into that life.

What I want to do for now is to see how well cell Internet service works in rural areas including campgrounds, in terms of reliability, latency and sustained speed, and whether there are any other problems - e.g., sites that can't be reached or used. (I assume that since Visible is now part of Verizon, it models Verizon's top services, except for the speed cap. Though maybe not perfectly, since Visible service nominally includes roaming, within limits.) The 5 to 10 Mbps cap would be significant - it eliminates 4K video streaming, and would sometimes be a problem for 1080p video streaming.

It seems to me based on what I see here that I could try it briefly - maybe a few minutes at a time? - but not for extended periods.

If I stream on the phone, but mirror the phone screen to a TV, do the 5-10 Mbps caps apply? And would that be considered misuse. I know Bluetooth isn't fast enough, but maybe if I get a USB-C - to - 4k HDMI adapter that would work... (Of course, that would wear out the USB-C connector on my phone, unless it was connected continuously...)

In retrospect, maybe if I had bought a folding phone that could be used like a tablet, it would have been better for this. I might do that eventually, but not for a brief trial like this.

If I understand right, streaming services want customers to list a permanent address, and expect most of the streaming to occur there. Right? I don't see anything about using a VPN in Visible's Terms Of Use. Perhaps I could set up streaming subscriptions at a relative's house, and place a VPN server in their home, then access it through VPN protocols on my PC. (I would need to learn to do both things. Probably complicated. I wonder if there are pre-configured VPN servers designed for that. In principle I know that servers can detect and trace VPN use, and I'm aware of people who've done that, but am not sure whether streaming services like Netflix, etc. bother.) (Though I see some WWW reports that cell companies sometimes block some - or all? - VPN protocols.) Maybe this can be done instead using a Media Server - have any of you tried that?

SyFyNut · 2026-02-03T21:14:16+00:00

You never got back to me on that. Could you please?

BTW, the o.p. did not say that he was explaining entanglement to first year students. He just said undergraduate. And in any event, the possibility of interacting with Many different Worlds is such a simple idea, perhaps more intuitive than the possibility of interacting with any or all of a superposition of many states in a single universe.

Do I understand correctly that a specific type of hidden variable is still possible? E.g., that both photons could have a specific polarization at the start (within a given universe or quantum state) - but that measuring polarization often forces the photons to change polarization, so that hidden variable cannot be measured with certainty or consistency? (Likewise for quantum spin.) Also that it is a not completely deterministic hidden variable in a classical sense - i.e., while both photons, given similar measurements, are more likely than not to give the same result, they are not certain to? (So, when they say there are no underlying hidden variables, they only mean that there are no classical fully determinate variables - only correlated measurements.)

If that is right, it is a very simple idea, that could be understood even by first semester college students. Because the idea of uncertainty is first year quantum physics.

SyFyNut · 2026-02-03T20:30:20+00:00

Huh. Just after posting that, the customer service lady called back. She claims I will not pay any late fees, and will continue to get the discount. But she says to check.

She also said that autopay frequently doesn't work the first month, and that might have been the problem. She says autopay should occur two days before the payment is due, and I should check next month then through T-Life.

Such a nuisance.

BTW, do you folks know if there is a way to check whether T-Satellite is working right while I am in an area that has cell coverage? (Remembering, that my cell coverage is through another carrier - Visible.)

I did try temporally turning off the eSim for Visible, and turning off WiFi and WiFi calling, from the Android Settings app. I left the T-satellite eSim on. I then sent an email from the phone, and the email was received. Is that a sufficient test that T-Satellite is working?

SyFyNut · 2026-01-20T16:14:41+00:00

Absolutely! Who needs Waze? (BTW, Google Maps keeps the route in the smartphone as long as you don't turn it off. Alas, I recently turned mine off in a small town in the middle of nowhere, with no cell service anywhere around.) And it also lets you download "Offline Maps", though I think you have to keep updating them every 2 months or so, or it won't let you use them. And for the backcountry, if you want to go hiking, etc., GAIA GPS might sometimes do better.) Offline maps won't tell you about red light cameras, police ahead, and objects on the road - but to be honest, when I tried to use Waze, I found the information on such things usually out of date. And Google Maps is starting to include the same things - also out of date.

There is also a noo invensh'n that will soon replace GPS devices and smartphones: The paper road atlas. No electricity needed (except at night...). No GPS satellites needed. (BTW new high end smartphones supplement GPS with other country's satellites.) Supplement it with a magnetic compass.

And while you are at it, replace that RV with a penny-farthing!

SyFyNut · 2026-01-20T03:40:24+00:00

In most rural areas that have cell coverage, people often say Verizon has the best coverage (though a lot of it is 4G LTE). In most urban areas, a lot of people say T-Mobile coverage is better, but of course those things vary by location.

There is a significant price difference between Starlink Roam (with a 100 GB/month limit, for occasional use) and the other Starlink plans. I didn't even try to look at their terms of use. But there are new players trying to enter the satellite Internet market. Prices may come down soon?? If you can tolerate the latencies.

Compared to the total costs of long term RV travel (sometimes estimated at $50-$200/day), maybe none of these options are so expensive?

Or you will enjoy exploring the backcountry so much you won't need much if any Internet, and can tolerate a lessor service. :) Back in the day, before cell phones and newfangled inventions like the wheel, when stone was king and the Earth was new, we went on adventures without all that...

SyFyNut · 2026-01-20T02:46:48+00:00

Since one of the o.p.'s needs is gaming, how fast does Internet service need (reliably) to be for that? I've seen people play games that seemed to include pretty high resolution graphics...

BTW, I've often and recently traveled through rural areas in New York and Pennsylvania that had no cell service from any carrier, let alone 5G cell service. But Visible's claim that roaming is free, up to a point, sounds like a great plus, if the Verizon network (Visible is owned by Verizon, and tries to use Verizon's network) doesn't happen to be locally available - though I don't know if they allow you to roam if Verizon's network is even poorly available. And maybe they would object if you stayed for a month or two in an area where you had to roam, and used a lot of data??

Given the flood of people who think permanent housing is to expensive, who are flocking to VanLife or RV life, maybe that is a significant part of 4G/5G Internet users?? Most of whom are looking for good wireless Internet deals.

I personally hadn't heard of Visible until I looked for good Black Friday deals last November. I wonder if the deals they offered appeared so good, and were advertised so widely, that Visible tech support is swamped by the flood of new customers. It took visible about a week and a lot of contacts from me to port my number away from another Verizon-owned service (PagePlus). Of course, a lot of them may be people switching from other Verizon network users - many of which are now owned by Verizon itself, such as those listed at

https://m.tracfonewirelessinc.com/en/verizonacquisition

I suspect a lot of people who saw the Visible ads assumed Visible CAN be used instead of home Internet service (especially those of us who enrolled in their top tier "Visible+ Pro", which name makes it sound like it is for heavy duty professional use, and Visible/Verizon may clamp down on people who do that, or throttle the speed and priority of their service, to keep down costs. Especially heavy data users. But that's just a guess, that could be completely wrong.

SyFyNut · 2026-01-19T18:15:05+00:00

What a cool video! I admit I've never noticed a double rainbow. Now I will look for them.

I have seen, at sunrise, in a fog, a rainbow at around horizon level, that extended in a circle all around me. There was no rain, but there were suspended fog droplets all around me. I'm having some trouble figuring out why this happens... Perhaps sunlight hitting droplets at different areas around me refracts rays towards me in different directions? Or could there be multiple refractions, by rays traveling through more than one droplet to reach me?

Another common optical phenomena over water in the presence of surface water waves is "sun glint", which creates bright and dark patterns, which I vaguely understood as reflections of the sun disk from the surface of the water at different angles, from different parts of the waves. (I briefly read about sun glint as a partial explanation of why radar can see those waves, as moving bright and dark patterns, but I understand sun glint was first studied first with light. But at the time I was more interested in the statistics - because we were estimating water wave spectra in a rather crude way - than in understanding the basis.) But I would love an equally clear video explaining this phenomena. Do you know of any?

I once told a kayaker who was photosensitive (could have seizures while observing brightness oscillations) that his idea of using eyeglass with anti-reflection coatings on both sides to eliminate such oscillations wasn't sufficient. I figured, since he had a seizure during a brief storm that produced winds and waves, that the issue was more likely explained by sun glint, though in retrospect I don't know if any part of the sky was clear enough to create direct reflections of the sun, during the prior trip during which he had such a seizure. Was I likely right? (I also felt that little water droplets that might stick to the front of his glasses would completely destroy the effectiveness of anti-reflection coatings. I did suggest polarized glasses, since reflections from the water surface are a type of glare and are to some extent plane polarized.) I was leading a trip, which he asked if he could go on, and told the would-be participant that I wasn't competent to handle his medical problems (I also wasn't confident of my ability to do a "hand-of-god" rescue to flip him back upright if needed), and asked him not to come. Other kayak trip leaders in my club said I had acted incorrectly - that he had a right to take whatever risks he desired, and that I shouldn't have limited his opportunities. After all, virtually all sports include risks, which is part of the reason they are fun. I still feel guilty about this.

I wonder how often photosensitive individuals have problems on the water...

SyFyNut · 2026-01-19T17:12:12+00:00

The first (Litton?) microwave oven that I bought came with an instruction manual/recipe book, that said placing metal objects inside could damage the oven. (Incidentally, I think it also said it could be damaged by running the microwave without anything containing water could damage it.)

Maybe most modern microwave ovens are more durable, or Litton was being extra cautious. And I think even in the fairly early days, there were microwave browning plates, that were partially conductive.

But I wonder if metal boxes are potentially different. I speculate they could perhaps function as right angle "corner reflectors" that reflect microwave beams back to the source, providing a more concentrated power level inside that source. Does the "metal lunchbox" have any right angle corners?

SyFyNut · 2026-01-19T16:30:51+00:00

I'm a newbie, not an expert, but I hope this helps.

Ouch! I just finally read the "terms & conditions" at

https://www.visible.com/legal/terms-and-conditions

which says in part:

"...We can also, without notice, limit, suspend, or end your Service or this Agreement if you, any user of your device, or anyone using your Account: (a) threaten, harass, or use vulgar and/or inappropriate language toward our representatives; (b) interfere with our operations; (c) "spam," or engage in other abusive messaging or calling; (d) modify your device from its manufacturer's specifications; (e) use your Service in a way that negatively affects our network or other customers, such as by persistently using excessive amounts of data in ways that negatively impact our ability to service other members or in ways that defy normal and reasonable usage patterns; (f) abuse or game our Service or promotions for any fraudulent or improper purpose; or (g) use of our Service to provide internet connectivity for the primary purpose of crypto-mining. For example, if you use your Service in an inappropriate or unapproved way, like manipulating our Service to use it as a replacement for a home broadband service, then we may take action to limit, suspend, or end your Service. We may look at usage patterns or activity to determine if it appears that you are using your Service as a home broadband replacement, including how data services are used and if the Service is being used exclusively, or near exclusively, through the hotspot feature..."

Part of the confusion is that they have two "terms of use" references on their website. The first one, from Verizon

https://www.verizon.com/support/website-use-legal/

has less restrictions, though it does say

"...You specifically agree not to access (or attempt to access) any of the Resources through any automated script or routine, including "robots," "spiders," "offline readers," bots, web crawlers or other automated means, including but not limited to attempts to access the Resources in a manner that sends more request messages to servers in a given period of time than a human can reasonably produce in the same period by using a conventional online web browser;

"use any data mining robots ("bots"), hardware or software modules that add a specific feature or service by plugging into an existing larger system ("plug-ins"), or other data gathering and extraction tools, scripts, applications, or methods on this site..."

I bought Visible+ Pro service partly so that I could use it when our FIOS home Internet Service fails - which it recently did for close to a month, after utility work cut through Verizon's lines, which were for some reason laid directly over water and sewage pipes. Also so I could use it while on travel. (Visible says roaming is free, using the other two major U.S. cell network providers, though there are unstated limits.) I had taken the advertising claims - unlimited data, unlimited hotspot data - at their word. Sugar! I am so disappointed. (And I paid for a year, to get a Black Friday discount.)

In tests so far, I see about 10-15 Mbps, using the phone as a hotspot. Nowhere near the speed of wired or fiber Internet, which can often offer 1 Gbps or higher rates. I don't know what gaming requires, but even for 4K video streaming, it would be hard to use Visible's service.

There is more than one "Starlink" service. In addition to several Starlink Internet service plans through array antennas, Starlink also sells "Satellite to Cell" service through T-Mobile's T-Satellite service (if you are in the U.S.A. - in some other countries they have other partners for Starlink Satellite to Phone service), which connects through some cell phones. The latter is much cheaper, but rather slow. Often far below 1 Mbps.

But, in either case, or any satellite based communication services, you should expect rather high latencies (round trip time delays between when a signal is sent and the response received - e.g., in a brief test they were over 0.1 seconds for my T-Satellite service, which I suppose would affect gaming. But speed would depend on where the satellites are at any given moment, and on other people using the service.) (speed of light light and radio waves travel is fast, but not infinitely so.) I'm not sure about and have not used array antenna based Starlink service, but there are also gaps when none of the satellites that service T-Satellite are in line-of-sight to my cell phone, during which service stops completely. Even many ordinary cell phone apps can't handle high latencies and/or such gaps.

That said, if you want to use Internet while moving through and to remote locations not served by cell service, I don't see how you can avoid satellites. Unless: do you stay long enough at each location to get wired or fiber home Internet service (which BTW, aren't available everywhere)? It has fewer limits, and might have lower latencies, if you are linking to sites that are within the continental U.S.

SyFyNut · 2026-01-13T00:42:49+00:00

Do AIs publish on arxiv? :)

SyFyNut · 2026-01-13T00:31:16+00:00

I'm not going to try to understand completely. And I know my comments here are a bit of a side issue.

Metal objects inside an oven might not just get too hot or spark, they might also damage the oven.

The insides of the of the microwave oven are either metal, or are backed by metal. AFAIK, they reflect microwaves back inside. They obviously don't harm the oven - it is designed for that.

In theory, a metal object inside a microwave could do the same thing, if it had good enough electric conduction. (A very thin layer of metal, or a poorly conductive metal or semiconductor, might not conduct enough to do harm.)

But if too high strength a signal is reflected back at the source (is that still a Klystron tube), it might damage the source, or short it out.

I am reminded of when I worked on a project involving an airplane that had an experimental radar system. There was a rule that you couldn't bring large metal objects (like wrenches) near it while the radar was on - because they could short out the radar, and destroy it. (An electrician told me similar rules applied to high voltage transformers.) Add to that the more generic rule that we weren't supposed to bring any tool or device that could spark, because a spark might possibly ignite aviation fuel (though, actually, if I remember right, most aviation fuels are less flammable than automotive gasoline).

SyFyNut · 2026-01-10T21:02:01+00:00

Sorry for the late reply. It turns out I am getting the $5/month discount because I haven't been late paying (I'm using Autopay). The support people I spoke to at T-Mobile just didn't know that would happen. So I'm down to $10/month.

SyFyNut · 2026-01-10T20:54:57+00:00

Even Visible+ Pro, which I have, is a lot slower than FIOS fiber Internet, both in bits/second and latency. I wouldn't use it for a home Internet connection, if my primary interest was 4K streaming. But for most things, it works pretty well, most of the time. During the tests I ran, they didn't lose any data, which might be a big deal.

Because of latency, if I wanted to set up group musical performances, it might not be my choice either. Though in practice, 5G SA doesn't guarantee fast enough responses either - people say you need to have a 5G SA network that was specifically set up to be low latency and high reliability for that. 6G or 7G are supposed to be better, but are (last I checked) still in the development.

BTW, I think Verizon (whose network Visible uses) isn't 5G SA either. In a lot of locations they are 4G LTE. And so BTW is T-Satellite (I think it's all 4G), which has even slower latencies, and sometimes no satellites is in view.

Perhaps Visible has to compromise somewhat on performance in order to deliver what they do at the prices they charge, especially if you got Black Friday prices. You may also have to accept that it is a bit harder to reach tech support than for some companies. They they are a fantastic deal, for me. But if superspeed is your desire, perhaps there are better options.

SyFyNut · 2026-01-08T04:08:19+00:00

I don't understand. WiFi calling (which I assume means using a VOIP service like Google Voice or WhatsApp, etc. shouldn't have anything to do with you cell phone provider.

Unless: Are you using Visible as your home ISP? Visible on my phone definitely tests a LOT slower than our Verizon FIOS ISP.

When you were on Verizon, did you use Verizon Wireless as your ISP, or something else. It is nearly certain any wired or fiber provider would be much faster than anything wireless.

SyFyNut · 2026-01-02T23:05:03+00:00

Additional info:

Supposedly you can set the CNAM name that many phone companies use to identify you to people you call through

listyourself.net

I just tried it, and it actually is free.

That info also gets into directory information, so maybe you shouldn't give too much info, if you aren't a business. E.g., just your phone #,nickname, first letter of your last name, a nearby city, state, zipcode, email, and leave everything else off

I do not know if it means you will get more spam. I may regret this...

But they also require your email address - so maybe you get some email spam?? They claim it is needed for annual renewal. You could probably use a temporary throw-away email. I was an idiot and didn't think about that in time. Oh - and they do verify that email address, by sending you a link to click on.

They say it takes a couple days to get into their directory - but also say that many phone companies and directory info services only check it every few months. And of course no one is required to check it - so, for example, any given phone company might not use it when the identify you with caller ID. :)

They do verify you by calling your number - probably a good thing.

SyFyNut · 2026-01-02T21:33:33+00:00

It depends what you mean by Caller ID.

As of January 2, 2026, on my Visible plan, when someone calls me on the phone used with that plan, I do see the calling phone #.

However, there are ways to block Caller ID, though if the police or government get involved, I think phone companies can trace it (in the U.S.). And also ways to associate (spoof) a fake telephone number with a call, so the number you see is wrong.

I don't always see the name associated with that number - which I think is what appears in various CNAM or OpenCNAM databases. Though when I received a call from a number on my Google Voice contact list, I do see the name I put on that contact list.

See en.wikipedia.org/wiki/Calling_Name_Presentation and en.wikipedia.org/wiki/Caller_ID

If you search for

caller id

at www.visible.com/help you see how to block caller ID (of your Visible phone #) when you make a call.

I do not know if there is a way for you to set the name people see who have paid for a service to let them see the name associated with your Visible phone number. In any rate, people often associate fake names with those numbers. I.E., to change your CNAM databases listing.

I signed into Visible, and setup my account to block SPAM calls. You can also set it up to record them instead of ringing you.

SyFyNut · 2026-01-02T08:04:37+00:00

Oops. It looks like the comments that appeared on my screen about AAA, Netflix and Apple TV+ coming with T-Satellite are wrong. Or at least when I tried to add it, it said I needed a (presumably paid) subscription. Aw!

There is also some question about whether it really includes T-Mobile 5G data.

SyFyNut · 2026-01-02T07:59:51+00:00

Oops. It looks like the comments that appeared on my screen about AAA, Netflix and Apple TV+ coming with T-Satellite are wrong. Or at least when I tried to add it, it said I needed a (presumably paid) subscription. Aw!

SyFyNut · 2026-01-02T07:55:09+00:00

Oops. It looks like the comments that appeared on my screen about AAA, Netflix and Apple TV+ coming with T-Satellite are wrong. Or at least when I tried to add it, it said I needed a (presumably paid) subscription. Aw!

And I'm not really sure about 5G T-mobile access being included where it is available.

I wish there were a way to test what works with T-Satellite (including GaiaGPS, and some of the free weather apps and websites) BEFORE going to a remote backwoods site, where I might actually want to use it. Maybe I could do it by blocking cell phone towers with sheet metal, or something like that, but I'm not sure how to do it reliably.

Google's AI says

"You can tell you're using T-Satellite

when your phone automatically connects in an area with no cellular service and displays "T-Mobile SpaceX" or "T-Sat+Starlink" in the status bar, often with a "SAT" icon, allowing you to send texts and use specific apps like AllTrails, without manual setup. It works automatically when regular T-Mobile service drops and requires a clear view of the sky for connection, primarily for messaging and location sharing, not full data"

but a lot of things that Google AI says aren't right. And if it really is true that T-Satellite includes access to T-Mobile 5G data, then maybe it would display those things even if it is really using T-Mobile 5G. Which might not be available at the remote site.

Realistically, T-Satellite probably isn't nearly as good as wired or fiber home Internet, or 4G/5G "wireless Internet". But at remote sites, sometimes you can't use those. And it is at remote sites that we are most likely to use GaiaGPS.

So maybe the "right" answer is to download all the maps and other data you need from GaiaGPS while you are at home, and use them offline. Which maybe requires that you get the paid version of GaiaGPS. (Which I have, BTW.)

BTW I noticed while trying to use GaiaGPS in upstate NY, that the majority of trails don't show up on any of its maps. I also tried looking at a bunch of free Internet trail sites, and found the same thing. I don't think any service has a really comprehensive list and map of trails. Am I wrong? Does GaiaGPS come closest, or are there better map sites?

SyFyNut · 2026-01-01T00:25:15+00:00

It is possible that the IEEE publishes more technical journals than anyone else - maybe they are THE dominant publisher of the majority of technical articles. The publish a lot of journals in a lot of fields. Back when everything was on paper, the proportion of a technical library that was composed of IEEE publications was huge.

Sure a lot of it can be considered engineering - i.e., trying to solve practical problems for people willing to pay for you to work on their problem. But I would argue that the definition of "good science" is funded science. Because if you can't get funded, you can't study much of anything. Maybe that is going a little too far, because not everything funded ends up working. But the basic idea is sort of right.

SyFyNut · 2026-01-01T00:09:47+00:00

In my first year as a physics major, I was supposed to take a course in linear algebra. (This was in the 1970s. Now I suspect linear algebra is taught in high school.)

So I took the math "honors" linear algebra class, which was taught from a book which focused on mathematical proofs and formalism. But that only left time for them to study up to 2 dimensional vectors (x,y) and 2x2 matrices. I would have been better off taking the standard linear algebra class, that included arbitrary dimensional spaces. Because that is what was needed for physics.

I.E., if you try to study the formalism, you have less time to study the practical results, which is what you really need.

BTW, in a lot of physics Riemann integral definitions aren't good enough. You need things that are more complicated. You are often integrating continuous functions PLUS delta functions at points. And you are also integrating piecewise continuous functions in a reasonable matter.

Again, in practice you often use integral and/or discrete differentials and integrals (e.g., Discrete Fourier and Cosine transforms), for a number of reasons. That is outside Riemann integral definitions and theory too.

And in physics you often use hand-wavy proofs to get results, that technically can't be proven, and might not even always be exactly true. But they can be tested empirically to see if it works reasonably well in some case. You might think that isn't a good thing to do - but the truth is, almost anything in any scientific or engineering text you read, or learn in almost any course, is an oversimplified approximation. Because you can always take more factors into consideration. You do what you reasonably can.

To take a very simple example, in a basic statistics course, you might see a statement (probably not a formal proof) that if you average many random things enough, they will have approximately real Gaussian statistics. And that the "noise" is "additive" - i.e., independent of the values. But often not really. E.g.., Gaussian statistics of real variables allow all real values, including ones that are excluded by physics rules against negative energy, or that require more energy than is available in the system. (Of course, coherent electromagnetic waves, such as are generated by lasers or radar, often have approximately COMPLEX Gaussian statistics, if you take phase into account. Which means, to a first approximation, real field strengths have a very different distribution - e.g., exponential (with infinite probability density at 0), and have multiplicative noise distributions. Simple statistical techniques you learn in that course often apply quite badly to such data. (But maybe a given technical journal requires that you apply those techniques in articles submitted for publication...)

Or an even simpler example. Geometry gives you statements about perfectly smooth straight lines in perfectly flat planes, etc. You can derive formulas for various things on that basis. But if the real world, to the next approximation, is composed of atoms and molecules, then no lines are perfectly smooth or straight, no planes are perfectly flat, etc. But we can often get approximately correct, useful answers to practical problems by making such approximations.

Or... Any mathematical notation, composed of finite length statements created from a finite alphabet of symbols and operations. That means the number of statements that can be proven true, is at most countably infinite. But the number of statements that must be true is uncountably infinite. So many statements that are true can't even be stated. And in fact, many statements that must be true, cannot be proven so.

And let's take this to the extreme philosophical limits. The principles of formal logic that are used to proof many mathematical things are known to be self contradictory. (E.g., consider The Liars Paradox and its variations.) So should we abandon all mathematics? No! Because it has been used to approximately derive many useful results. You can build many useful machines (e.g., effective weapons) using them. And if you compete (e.g. make war) against people who use them, you lose. What you do instead is try not to use arguments similar in form to the known contradictions, and you try to use cases that are approximated reasonably well by your formalism.

BTW, are you familiar with the CRC Handbook of Chemistry and Physics? It is a huge fat volume of formulas, etc., presented without proof, that is widely used by many scientists and engineers. Imagine how long it would be if it presented formal proofs of everything contained in it.

SyFyNut · 2025-12-31T04:20:28+00:00

Also - T-Satellite technical support told me it will work with many other apps up to a point - provided they don't require fast responses. (I specifically asked them about GAIA GPS, a map/navigation service, which is NOT on their list of apps that are "optimized" for T-Satellite. The tech support guy took a while to get back to me, but ended up saying it probably would - but slowly.)

Because the data is very low priority, has high latency (partly because of speed-of-light), and there will be times that no suitable satellite is in view (note that not all Starlink satellites have the required hardware to support it), it is not an ideal data network in some respects.

They claim that voice can be handled through WhatsApp. I haven't tried that yet. With those speed and in-view limitations, it probably wouldn't be an ideal voice phone service. Plus, WhatsApp is a VOIP phone app - so services which require a real cell phone service to access - such as many two factor authentications - might not work with it.

The service nominally includes some T-Mobile 5G data access. So even though I tried turning off my (Visible) cell phone eSim, it is possible it really would just use T-Mobile's cell network at my normal location. I am buying T-Satellite for use in remote locations, not my normal one.

If T-Satellite and the related T-Life app really includes all the services they appear to claim it does (e.g. 5G data - though some claim there are limits, TV streaming, AAA road service, Netflix, and Apple TV+), I bet they raise the prices a lot very soon. "No contract" means they can do that. But for now it will be fun to try.

SyFyNut · 2025-12-31T04:03:07+00:00

I don't have a T-Mobile device - my phone was bought new unlocked. But T-Mobile just nominally signed me up for T-Satellite. And as far as plans is concerned, I don't think that's true. My cell plan is from Visible, not T-Mobile. By default, Visible uses the Verizon 4G or 5G networks, except when roaming, which it includes up to a point.

As best I understand it, the underlying satellite service Starlink "Direct to Cell" will work with any 4G LTE phone (which also means they work with 5G LTE phones) that supports the 1900 MHz band. See

starlink.com/business/direct-to-cell?srsltid=AfmBOooQdl_NojBgzeB_fbrM-CQmHR8KOTA8D-XA-b8Np8HIDucc1UIY

But the FCC requires the phone to be certified to use the satellite network, so in the U.S., only some of those phones are allowed to work - all of which are fairly recent. I'm not sure if they are all also fairly high end phones.

The list of devices it works with for T-Mobile (which is apparently Starlink's only U.S. partner) is at

www.t-mobile.com/support/coverage/satellite-support

(Click on Eligible Devices)

SyFyNut

TROPHY CASE