saac

1 hour ago, bosun21 said:

Especially if it's on a mountaintop in Chile.

My AsiAir wifi won't stretch that far  

Jim 

I think you have to get into this with open eyes and just be sensible with expenditure. I always think about the cost per photograph whenever I'm thinking about an upgrade and this helps moderate over expenditure.  I also look at it as a lifetime interest rather than a hobby so not looking for a quick return. I don't mind not getting out on a clear night if I have other priorities, especially on a school night lol.  Play the long game, it may help. 

Jim 

Simple naked eye observing can be just as rewarding. As @Ags suggested tieing this in to the passage of the seasons and weather can add to the enjoyment.  With the short days upon us I'm finding my evening walk with the dog can be a good opportunity to pick out some old friends in the night sky.   Other than that I think you are right about just waiting and don't let it upset you; sometimes I think we can put a bit of unwarranted pressure on ourselves re the need to observe at all cost. 

Just a thought, could you move the scope inside, maybe a conservatory even with a limited view of the sky and just take really opportunistic views of whatever is available. Ok not brilliant through a window but you are doing it in comfort with no setup burden. 

Jim 

On 20/09/2023 at 10:07, michaelmorris said:

I'm about to install the pier that will be used in my ROR observatory.  It's an Altair Astro metal pier which requires 4 x M12 bolts to secure it.  I have already put on a 1 tonne concrete block to bolt the pier to.  My plan is to drill 4 holes in this block and glue in 4 x lengths of stainless steel rod.  What resin/glue would people recommend for doing this?

Cheers 

A few months ago I had to move my existing pier to accomodate my new Esprit 120 in order to get the height clearance needed; this involved extending the pier foundation and shifting the pier base a few cm.  To bolt the pier to the new location I used exactly the same method as I used with the original pier -  12 mm diameter studs fixed with resin.  Screwfix supplied both the studs and the resin. While I used studs (some left over from different project), threaded rod cut to the required size would work equally well.  If you can get a hold of an SDS drill and a new drill bit it will make short work of drilling the holes.  If you do use the resin, you need to make sure the holes are free from debris and dust - a blower is best but I got away with using a short flexible poly pipe.  Wear safety glasses when blowing the dust out , it's surprising how much is in there and how far it blows out!  Follow the instructions on the resin container, use a large caulking gun and your bolts are good to go.  The resin sets in minutes but I think I let them rest for a few hours before properly tightening down the pier - the process is pretty straightforward really. 

https://www.screwfix.com/p/rawlplug-r-kem-ii-styrene-free-polyester-resin-300ml/32863?tc=MC9&gclid=Cj0KCQjw9rSoBhCiARIsAFOiplkF-TewnRlIckFS3dGPMgavAB9sp7QptIaggfjFAlLzIGDjvF5CPGIaAnxdEALw_wcB&gclsrc=aw.ds

https://www.screwfix.com/p/rawlplug-studs-bzp-m12-x-160mm-10-pack/3806f

Jim 

That is just lovely. A cosmic  Nessie looking down at us

Jim 

Go fast or go home.

Jim 

3 hours ago, MalcolmP said:

So it is best to say " we have detected dms as a possible sign of life" rather than " we have detected dms but without oxygen is is unlikely to be a sign of life"
 

I'm not sure they have said it is a sign of life - that is typical media laziness. What they have announced is detection of DMS in the atmospheric spectrum.  They further  acknowledge that DMS on Earth is predominantly released by biology.  Remember as well that for a large period of Earth's history our atmosphere was also depleted of oxygen it being dissolved and trapped in sea water.  

extract from NASA release 

"The abundance of methane and carbon dioxide, and shortage of ammonia, support the hypothesis that there may be a water ocean underneath a hydrogen-rich atmosphere in K2-18 b. These initial Webb observations also provided a possible detection of a molecule called dimethyl sulfide (DMS). On Earth, this is only produced by life. The bulk of the DMS in Earth’s atmosphere is emitted from phytoplankton in marine environments.  The inference of DMS is less robust and requires further validation. “Upcoming Webb observations should be able to confirm if DMS is indeed present in the atmosphere of K2-18 b at significant levels,” explained Madhusudhan."

Jim 

1 hour ago, billhinge said:

I taught myself the maths and physics of GR to tensor level from the standard grad level books ( beyond what I did at  3rd year BSc specialisation) I don't claim to be an expert but I know my Riemann tensor from my Ricci\Weyl tensor from my Ricci scalar, my covariant from my contravariant  and now that I'm about to be semi retired I'm going back to study for a physics masters to enjoy it with a 'desire' to to do further study afterward if possible (I can afford to self fund  if required) . No need to find a job at the end or get involved in the typical student social activities 😉 

I think criticism (I don't mean flat earth and other mystic woo woo)  is an important part of science because it forces physicists to defend what they preach - they often disagree after all

Do real physicists really have their feelings hurt if they are criticised on youtube?

I'm not sure Physicists "preach" nor is disagreeing any detriment, I think it is more a reflection of how hard won the secrets of the universe are that leads to different opinions.   I doubt any of the professional (physicists, engineers, medics or others ) would feel their feelings hurt by the unqualified ramblings from remote corners of the internet (YouTubers, TickTokers); I think they would be too busy paying attention  to those who are qualified and have skin in the game with a proven track record. Who knows, Profs Brian Cox and Jim AL Kahili may take refuge here on SGL for some light hearted relief from academia    It's a little like Education when the armchair generals give you the benefit of their wisdom on how to teach or fix the ever present travails of the education system.  

Jim 

43 minutes ago, MalcolmP said:

Which we presume they looked for and didnt find, especially Oxygen,  but the beeb item at the top of the topic didnt say either way.
I have found a NASA item about it and that does not say either, which means that they did not find any - as that is an indicator of higher life forms. When it comes to peer review would that be a problem if they had not looked for Oxygen ?

Can DMS be produced by any non-oxy-producing life (as we know it Jim) ?
 

Exactly, they didn't find any of what may be termed advanced industrial markers! So fairly safe to say they (our cosmic DMS emitteres) haven't invented the radio yet, or invented it and then abandoned it as suggested lol    We can but wait with intrepidation !

Can DMS be produced by non biological processes?   Yes it can - however the reason it is an exciting find is that here on Earth the majority of DMS apparently has a biological origin. 

Jim 

ps - here is a link which contains the atmospheric spectral analysis of K2-18B

https://www.nasa.gov/goddard/2023/webb-discovers-methane-carbon-dioxide-in-atmosphere-of-k2-18b

2 hours ago, andrew s said:

Indeed, but I am always amazed by what we do know 😊

Regards Andrew 

A point often missed by the armchair physics fans beloved of U Tube/Tiky Toc who freely criticize with what must surely be little understanding. 

Jim 

1 hour ago, Mr Spock said:

We have no clue who, or what is out there, and have no direct evidence of such. I suggest, as a weak and feeble species, we not poke the bear, or whatever creatures may be out there 

Nah, I think "they" are the ones keeping quiet, they have seen what we can do !  If there are any cosmic bears out there we will poke them for sure. 

Jim  

51 minutes ago, MalcolmP said:

" few million years for the DMS producing lifeforms to evolve and then develop radio"

Good afternoon all,
How do we know that "they" did not already do that Xbillion years ago, and stopped using it Xby +100y ago ?
Our use of multi kilowatt transmitters (mult megawatt erp) is probably coming to an end soon after only 100 +/-y
Thinks - I must reinvestigate this planet/system - how far away is it? Do we have the tech to detect their radio if they are still using it domestically. I mean domestically, not deliberately beaming a "hello" towards us ?

But I really jumped in to say :- Darwin's survival of the fittest is very persuasive, so I am with the "keep our heads down" brigade.  
 

Coz there would be other markers (both bio and non bio) in the spectrum other than DMS.  

Jim 

I think we may need to wait a few million years for the DMS producing lifeforms to evolve and then develop the radio before we can say job done.

Jim

Looks like they have delt themselves a free hand with that one, like I said flights of fantasy, or maybe it should be fancy. It's all in statistics!!

"The observation of life on Earth is commonly believed to be uninformative regarding the probability of abiogenesis on other Earth-like planets. This belief is based on the selection effect of our existence. We necessarily had to find ourselves on a planet where abiogenesis occurred, thus nothing can be inferred about the probability of abiogenesis from this observation alone. "

They are pushing against an open door with that one to be honest.   The truth remains we have no clue how life started abiogenesis or otherwise, we only have a good analogue for its development.  If I was spending money looking for life elsewhere I know where I'd be hanging hat  with respect to what I'd be looking for.  

Jim 

1 hour ago, StarryEyed said:

Smart science is demonstrating the need for a bigger better experiment than the last one. Otherwise your out of a job.

We need a bigger boat lol.   Hey did you see the ELT on the Sky at Night, looks very promising. 

Jim 

2 minutes ago, StarryEyed said:

Just to bring it back on track this is a really exciting announcement. Can you imagine all the jaws hitting the floor when they saw the data.

Agree it really is exciting. It is remarkable that they can,with any degree of confidence, analyse the spectrum of the parent star through an exo planet's atmosphere.  It's almost the stuff of science fiction - I do love spectroscopy it's one of my favourite areas of physics when teaching. 

Although I can't help but wonder how this discovery could ever be conclusive or advanced, I don't think it could; shame the system is so far away.  In no way does it detract from what has been done and of course increments the science and technology.

Jim 

Hush, I will not hear a word against the blessed Brian Cox - can you tell I am fan  

Jim 

2 hours ago, Barry Fitz-Gerald said:

Well spotted.......... but,

Hypothetical means based on possibilities and not reality - not quite the same.

Anything is possible, it's  "probable" that makes them flights of fantasy  

Jim 

Flights of fantasy

Jim

An amazing image, beautiful. 

Jim

That is not shabby at all, very good. The SeeStar is going to deliver a lot of fun I think. 

Jim 

To be honest I think we are no where near the technical capability of terra forming.  It is well and truly in the realms of science fiction and not engineering reality. Look at the difficulty we are facing terra forming here on a hospitable planet where we already have residence  and all we need to do is drop CO2 levels a few 1/10 ths of a percent.   Talk of changing toxic acidic atmospheres of bone shattering pressure or replacing  atmospheric vacuums with oxygen rich atmospheres is fun but just fantasy.  Anyway, where is the imperative to spend that sort of wealth and resources which most likely does not actually exist anyway. 

Jim  

42 minutes ago, Michael Kieth Adams said:

Humans have always been real estate developers.  Right now we can barely leave the planet, but we will get there.  My money is on an elevator to low earth orbit.  Not saying at all to stop working on making things better right here.  There is plenty to do for everyone.  Respectfully, Mike

Yep we develop real estate for sure but isn't the mantra  location, location location. Venus just hasn't got it.  The Moon on the ether hand has a nice sea view, and Mars, well just look at those mountains. 

Jim 

29 minutes ago, Mark2022 said:

I don't believe we'll ever go anywhere off this planet. Not even the moon. I don't believe (for I have no proof) that there are rovers on Mars and probes around Jupiter and further out. I think  it is all total shenanigans. I don't trust a word NASA says.

Do a little 'thought experiment' with your living room wall: Your living room wall is likely to be about 8ft which is approx 240cm. Earth to Moon is approx 240,000 miles. Which means Apollo went a distance of your floor to your ceiling in 1969-72. Now, the highest  the shuttle ever went was approx 300 miles up. That's equivalent to 3mm (mm!) off your floor.

Anyhow, I know I'm a 'heretic' but I just wanted to add my tuppence. Also watch Apollo 16 moon buggy footage: It's a dummy! 100%.

Mark, the shuttle was designed to operate in low Earth orbit, 3 mm up, and no further. No great conspiracy there.  All it took to cover the 240,000 miles to the moon was knowledge of Newton's 1st law of motion - get the rocket going fast enough with a few orbits of the Earth, point it in the right direction, then wait 3 days!  No magic, nor any really fancy physics - just a hell of a lot of courage from the 3 astronauts on board and faith in Mr Newton.  

Jim

2 hours ago, Michael Kieth Adams said:

Mars is fairly easy.  A few quintillion dollars and centuries and viola!  Venus however is a lady and changing any lady is problematic.  First, how do you cool the hottest planet in the solar system?  Shade?  Probably a good first step.  How about rings of dust between Venus and the sun.  Then there is the super thick poisonous atmosphere.  Cooling first.    
Maybe  eclipses to create cool spots in the atmosphere  What do we do about the dang clouds?  How do you get sulfuric acid to condense?  Dust maybe?  It sounds easy but in many ways poison, pressure, and heat could be as troubling as near vacuum, low pressure and permaganates.  Got any ideas?

Yep, spend money on something else - maybe sort out the problems here!

Jim