Obviously this is a problem for radio astronomers. I keep hoping we’ll build the proposed Lunar Crater Telescope so we can have a truly silent view of the universe.
For multi-mode (full duplex) you would still need a power amp repeater every 500 meters, which requires a lot of power and create noise. You can’t be quiet with noise.
Yes, because there’s no way to transmit power or data anywhere without being loud af in any signal spectrum. It’s physically impossible.
Even with fiber, you need a laser to beam the signal, and a powerful amp on the moon to recieve the signal and boost it with fuck ton of high power repeaters to the other side of the moon which is also loud af
Be that as it may, it’d be minimal compared to the interference that terrestrial radio observatories have to deal with.
I guess I’m just saying that I don’t understand why you’re being so negative about the concept when it’s clearly going to be orders of magnitude better than existing antennae.
If your instance is any indication of location: there’s an eclipse visible in most Oceania and SE Asian islands in 2028. For a good chunk of Australia and NZ, it’ll be a total eclipse. For further info, check it here.
For me (South America) there’s one already in October, but it’ll suck from my region (14% coverage). And another in 2027 (~75% coverage).
The big difference is how close the sun is to solar maximum this year! The sun is at a point of peak electromagnetic activity, something that happens every 10 to 13 years, which is reflected in more chance of witnessing bursts of energy (flares and ejections) during the eclipse.
Me too, the clouds overhead parted just before totality and the corona was so dazzling and magnificent. I really hope there aren’t clouds in the way during this one.
I would love it if publications could just limit their headlines to one misleading term per story. The rocks are a ‘city’? Sure. The geysers looks like ‘spiders’? I guess. But when you start putting them together in the same headline it feels like your breaking the fourth wall or something
Yeah its hard to read as quote spiders unquote quote inca city unquote. New articles should not be doing this. geez at least put so called or something.
his stupid fucking internet satellites make planning getting things into orbit real hard. also it’s not even his tesla in space. he stole it from mark eberhart
And his 6,000+ starlink pieces of trash in orbit have made earth based telescopes worse. They get in the way of the shot, and the emissions are something like 10x worse than promised.
Him and that tetraethyl lead guy. Just absolute stains.
SpaceX rockets don’t add Methane to the atmosphere. When you burn something, you’re not adding that thing to the atmosphere, you’re adding byproducts from the combustion, and Methane isn’t one of the byproducts of any rocket fuel.
Starship uses methane as a fuel, but that’s not at all the same thing. Methalox engines are one of the cleanest burning rocket fuels after Hydrolox. When burnt, methane just becomes CO2 and water vapor along with a bit of NOx (Nitrous Oxide, aka laughing gas, aka that boost you see in Fast and the Furious) as well.
Falcon 9 and Falcon Heavy are Kerolox (Kerosene, RP-1) engines. RP-1 is basically just a highly refined kerosene. When burnt, it will produce CO2, water vapor, NOx, carbon soot, carbon monoxide (which again mostly becomes CO2) and a little bit of sulfur compounds. The exhaust is nasty but it is not that different from what a normal internal combustion car produces. And even with the large amounts, it is still lower than what cars/trucks/SUVs output to get everyone in your city back and forth to work, the grocery store, and home on a daily basis.
Rocket engines don’t just immediately start, propellant has to be flowing through the turbo pumps before the flames start. Same at shut down. On the video you can see vapour coming out. That’s either methane or oxygen. How much of either? We can’t say because spacex doesn’t talk much about it. Same with ‘venting’ which happens quite a lot as shown on the videos as well. Whether it’s a little or a lot, it’s definitely more than was there before launch.
And that’s on a successful launch. Scott Manly talks about the last launch and shows how the methane levels were draining on the ship way faster than the oxygen levels, pointing to at least incomplete combination and probably methane puking out the back. Methane may be ‘clean’ when it’s burnt under optimal conditions, when it’s conflagrated in a RUD it’s less so.
Yes, yes, “it’s a drop in the bucket, it’s a tiny percentage of blah blah blah” which works fine until they start launching 3 per day. Then the question of what methane (a highly potent greenhouse gas) does when it’s directly added into the upper atmosphere gets answered.
NOx is not Nitrous Oxide and is not short for Nitrous Oxide. Nitrous Oxide is specifically N2O. NOx refers to both Nitric Oxide (NO) and Nitrogen Dioxide (NO2), both of which are far, far more damaging to health and atmosphere than N2O. NOx emissions are the reason diesel is generally nonexistent in US passenger vehicles - not even great mpg numbers have sufficiently-low NOx emissions.
Even if it included N2O, using nomenclature with a variable like “NOx” and grouping it all together as one inert byproduct vastly underrepresents harm. Imagine if you referred to another group as “COx” but saying it’s relatively inert and easily detected by way of a burning lung sensation but feeds plants so it’s not all bad because Carbon Dioxide (CO2) has that effect. Carbon Monoxide (CO) is completely left out of that description and will silently kill you.
The part you’re not talking about is that there’s no catalytic converters on rockets tough, so it’s more like running a carbureted car than a modern car.
that he keeps metering access to because he has a clear favorite in that war and it ain’t Ukraine. have you talked to any Ukrainians how they feel about the world’s richest nazi? because the Ukrainians i’m in community with fucking hate that guy and actively seek technological edges to treat starlink as actively hostile to their usage.
Not really here, this would have been a dummy weight either way since it was the test payload for Falcon Heavy. So *something *was going to be sent up. The Tesla specifically was a publicity stunt, but a similar weight was going into a similar orbit.
The bigger question is why they lost tracking on it in the first place to where they weren’t sure what it was. This wasn’t from any sort of failure, this was a planned and fully successful launch payload into a planned orbit.
Tracking doesn’t necessarily have to be lost for this kind of thing to happen. The Rosetta spacecraft was accidentally given a provisional asteroid designation in 2007.
“Tired light” has been theorized before, and it just doesn’t hold up to most of the evidence gathered.
It’s entirely possible that there’s something there, but most data currently backs up the Lambda-CDM model of the universe. en.wikipedia.org/wiki/Lambda-CDM_model
Only time will tell if this theory pans out, but I wouldn’t put much money on it.
Discreetly insulting both Australia and Pluto in one sentence! Absolutely love this; will share it with all my Australia and Plutonian friends! If Earth gets attacked, it’s not my fault, but yours :'P
As with nearly everything in astronomic optics, it’s named after people associated with its creation. Robert Jones and Thomas Bird are the two in this case. Here’s a thread on Cloudy nights with good info.
my fav from that thread (and i propose to make this a copy pasta):
My entire gripe around these scopes is the instruments being offered today, the sub-aperture lens arrangement is not doing any corrections. The lens is a straight up Barlow, nothing more.
If you look at the Bird-Jones design, the design is very specific in the design of both the primary & correcting lens. This means that both elements need to be not only matched but also well manufactured in order to work as designed. When you then look at the few true Bird-Jones instruments that were manufactured, such as the Tasco 8V (which was manufactured by Vixen), the Celestron G8-N and one other (escapes my mind right now but I’ll add it when I remember), these scopes were not cheap but pushing flagship status for these brands & supplied with swish mounts. And none of these scopes can be readily collimated by the end user as the alignment of the optics is so precise it is done in-factory. The 8V alone still maintains almost cult status.
The Bird-Jones design is not without its own shortcomings. It is not perfect without aberration. It is important to remember the ideas behind its design, to provide a short tube OTA option with what was able to be readily manufactured at the time, that being good spherical mirrors.
What is made today is a far cry from what a Bird-Jones offers performance wise. Made cheap with a poor spherical primary & that they are totally collimateable by the end user shows these are not a precision scope. Add to this that not a single Bird-Jones instrument is to be found anywhere else besides these cheap things. Doesn’t this say something?
These cheap instruments, really all cheap instruments are a double edge sword. They make astro more accessible, yes, but their poor quality ends up killing off more people’s enthusiasm for astro than firing it up. Add to this that for many novices if the mount is not a complicated equatorial one then it isn’t an astronomical instrument, & the difficult manner of using a wobble-tron mount & tripod with the mental gymnastics required just too much for most people who buy these and just give up way too soon.
Yes, there will be a few people who will be able to make these scopes work, being all they can afford, and all power to them. I will support such persons. But these are very few compared to the overwhelming number of people who just give up after the poor experience they get from these instruments. Too them astro is just all too hard, and mainly because of a poor instrument.
Call these cheap instruments what they are, a barlowed Newtonian.
This entire thread is filled with people that know absolutely nothing about Space but the basics modern “media” poorly conveys, but feel the need to comment and display their ignorance proudly just because they hate Musk. It’s quite sad actually for an actual Astronomy community, there’s worse discussion in here than reddit.
On 20 April 2016, the Sky and Telescope website reported a sustained brightening since February 2015 from magnitude 10.5 to about 9.2. A similar event was reported in 1938, followed by another outburst in 1946.[20] By June 2018, the star had dimmed slightly but still remained at an unusually high level of activity. In March or April 2023, it dimmed to magnitude 12.3.[21] A similar dimming occurred in the year before the 1945 outburst, indicating that it will likely erupt between March and September 2024.
And if I’m interpreting some of the other content correctly, it’ll come and go in one night? Maybe someone who knows more about these can confirm or correct me.. See update below.
Also …
Even when at peak magnitude of 2.5, this recurrent nova is dimmer than about 120 stars in the night sky.
Once its brightness peaks, it should be visible to the unaided eye for several days and just over a week with binoculars before it dims again, possibly for another 80 years.
Reminds me of when Betelgeuse, the orange upper star of Orion, went dim in 2020. Lots of amateur reports on its brightness, 3x per night, for a few months waiting for it to go nova. It settled down a bit before disappearing behind the sun for the season and came back just fine. It was kinda fun to monitor, but soooo many false alarms from people trying to call it first
That’s how it was for me in 2017. The path of totality went right over my house. I took the day off and strolled out to my back yard to watch it. We also smoked some meat and invited people over for a party, which was the most effort in the whole situation.
Radiation associated with Starlink satellites was detected at observing frequencies between 110 and 188 MHz, which is well below the 10.7- 12.7 GHz radio frequencies used for the downlink communication signals.
(The original article said 5M radiation, which should be around 60MHz.)
So Starlink is emitting RF in spectrum where they shouldn’t, which is avoidable, but takes effort.
My guess, and I could be wrong, is that this could be related to something other than the radio(s), such as switching power supplies finding opportunistic structures from which to radiate.
Starlink seems like a genuinely interesting and useful technology, in some ways.
But it also seems like it might not be worth having.
I’m thinking they might need to be deorbited, but I’m not confident in that yet. It sounds like it might be fixable in a new generation of Internet constellation satellites.
Idk how long the issue should be tolerated to wait for that, though. And while Starlink has a good amount of customers this kind of Internet is genuinely useful for, it’s still not a lot compared to all the other internet services.
Maybe Starlink deorbiting should come along with an expansion of the traditional communications network. But maybe it would be extremely expensive to reach Starlink’s customers with towers or cables.
Titan is a place where methane and ethane rain from the sky and have a hydrologic cycle like the kind we’ve only ever seen before with water on Earth. These organics form rivers and flow into seas, carrying sediment with them. This mission will be going to the equatorial desert to understand that sediment.
Titan, like Europa, is an icy ocean moon. Titan is even larger, though. While Europa’s ocean is measured to have about twice the liquid volume of all of the earth’s oceans combined, Titan’s ocean (which possibly has significant quantities of ammonia and organics and alcohols mixed in) has five times the liquid volume of all of the earth’s oceans combined.
Sitting atop this ocean is a thick icy crust, upon which is a surface that looks more earth-like than any other planetoid surface in our solar system. Although it looks earth-like, the chemistry is in fact fundamentally different. It is based around organic solvents instead of water as the dominant driver of weather and erosion. The water on titan is stored in the bedrock!
And the sediment on top? Well, titan’s atmosphere is 5% methane. That methane gets hit by UV light and turns into more complex organics. Titan’s atmosphere is also rich in nitrogen and carbon monoxide, which add Nitrogen and Oxygen to these complex organics. These organics sediment out and coat the surface. Around the equator, they blow into large dunes in a desert biome. Precipitation falls and erodes the tar-covered landscape. These complex organics get mixed together as sediment in the rivers and dumped into the beds of the polar lakes and seas.
Dragonfly isn’t going to the seas. Too dangerous for the first mission here. We don’t know what we’ll find, and it’s hard to communicate with earth, and there is complex weather and clouds called the “polar hood” that might interfere. Dragonfly is going to the desert, to observe the complex organics falling from the sky and gathering on the ground to be blown into dunes. These are the ingredients that will get mixed together in the seas. There is also a cool crater there that calculations suggest melted the H2O bedrock and created a water-filled pool for the organics that has long-since frozen over. However, calculations suggest that this liquid water pool full of organics may have stayed partially liquid for hundreds of thousands of years in the subsurface. This is a location where we can study: “what happens if you take a bunch of complex organics and add water?” How far along the path to life could they get before the snapshot was frozen?
Wildass hypothesis I just pulled out of my ass with an undergraduate degree in applied physics: maybe interaction with particles emerging from quantum vacuum?
Okay, that sounds like great technobabble. I’m going to watch star trek now ;)
It’s probably not that the light is losing energy it’s just that the distance it travels over time (the time we “know” is supposed to take for a given distance) appears compressed because of unknown/unseen gravitational forces.
Think of it like this: If there were only one star in the universe and it emits a particle of light we could calculate the distance it would travel over time. Yet we know that star will still have a gravitational effect on that light… No matter how far away it gets.
That’s what they mean by light “losing energy”. Is the energy actually “lost”? Not really. Is this slowing (aka appearance of lost energy) caused by dark energy/dark matter or something more fundamental like spacetime itself being stretched or compressed due to the gravity of astronomical objects we can see or “dark matter”/“dark energy” or… ? We don’t really know for certain yet!
It’s probably not that the light is losing energy it’s just that the distance it travels over time (the time we “know” is supposed to take for a given distance) appears compressed because of unknown/unseen gravitational forces.
This doesn’t seem to be at all what tired light proposes though. What you’re explaining sounds like red-shift due to an expanding universe. From what I can tell they claim it actually loses energy through interaction with “other things” in the universe.
This doesn’t answer the question in the context of this theory, but the current understanding is that light does lose energy as it travels through expanding space. As the space it’s in expands, the wavelength gets longer, and the energy goes down. It doesn’t go anywhere; energy just isn’t conserved in an expanding space-time.
If the light loses energy, then it must surely lose it to something? And if your last point that energy isn’t being conserved in our universe, in which case we are either in some deep shit with the first law of thermodynamics, or our universe isn’t an isolated system.
The thing about photons is that they redshift, losing energy as space expands. If we keep track of a certain fixed number of photons, the number stays constant while the energy per photon decreases, so the total energy decreases.
Ok. Smarter people probably thought of this, and probably found my hypothesis to be impossible. But what if… It is the the other way around. What if photons are losing energy because they are expanding spacetime. Like tiny little springs expanding out.
Further into the article he says that, "It would be irresponsible of me not to mention that plenty of experts in cosmology or GR would not put it in these terms. We all agree on the science; there are just divergent views on what words to attach to the science. In particular, a lot of folks would want to say “energy is conserved in general relativity, it’s just that you have to include the energy of the gravitational field along with the energy of matter and radiation and so on.” "
So energy is conserved on the whole, it’s just not conserved if you consider photons apart from their greater context.
The energy is actually not conserved across the universe in general relativity, as it is currently understood. Conversation of energy is due to the time symmetry, which the expansion of space breaks.
BTW, thanks! This comment sent me down a fascinating rabbit hole. It had simply never occurred to me that energy conversation didn’t apply in an expanding universe!
“Energy is conserved in general relativity, it’s just that you have to include the energy of the gravitational field along with the energy of matter and radiation and so on.”
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