The moon

[rafezetter]

Thank god for some real information.
As part of my degree in physical chemistry - my major was nuclear chemistry.
Open your eyes, look and learn.
Just be careful who you learn from.

Lead (atomic number 82) is NOT depleted uranium (atomic number 92). Natural uranium becomes "depleted" through the fission process when it loses the majority of its isotope U-235. Depleted uranium is still uranium. The process for the most common form of uranium, U-238, to become stable lead, Pb-206, requires over a dozen alpha and beta particle decay phases and takes over 4.5 Billion years to complete.

pay attention boys and girls, class is in session.

https://en.wikipedia.org/wiki/Lead
"Lead has the highest atomic number of any stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements."

 

[mikej460]

pay attention boys and girls, class is in session.

https://en.wikipedia.org/wiki/Lead
"Lead has the highest atomic number of any stable element and three of its isotopes are endpoints of major nuclear decay chains of heavier elements."

hell, I just never considered this when having our roof done....

 

[mikej460]

Lead (atomic number 82) is NOT depleted uranium (atomic number 92). Natural uranium becomes "depleted" through the fission process when it loses the majority of its isotope U-235. Depleted uranium is still uranium. The process for the most common form of uranium, U-238, to become stable lead, Pb-206, requires over a dozen alpha and beta particle decay phases and takes over 4.5 Billion years to complete.

gosh, I just know that if I beat the sh*t out of it it goes where I want it to

 

[mudman]

I’m not sure about that. The way I’d calculate that is this:
Given the diameter of earth is about 12,000km, this is the max distance between viewing angles (at the equator). The max angle subtended from this distance to the moon (380,000km) is just under 2 degrees.

Like this:
View attachment 142392

Based on the angle at the moon being 2(arctan(6000/380,000)), assuming the flag is roughly central in the face we see, and the moon is of course tidally locked.

Edit: oops, those distances should be labelled in km, not m, but the ratio is the same.

Ah, but what you have there is the angle the Earth subtends at the eye of an observer on the Moon. What I was thinking is that the angle the flag will subtend at the earth will depend on the position of the observer on the earth. Something like this:

Where I assumed it was on and perpendicular to the line joining the Earth and Moon but of course, if at an angle to us, then like you said it does become all the more difficult to see. I suppose there are all sorts of conditions that make it more impossible than it is to see.

 

[HamsterJam]

We need zero. It is that point from which all else starts. Before I went to buy a cake, I had zero cakes. Then, afterwards, I had one cake. When I'd eaten half of it I had zero point five of the cake left and finally, when I'd eaten it all, I was back to zero cake.

You need to buy more cakes and restock before you eat the last one

 

[Stan]

The zero symbol plays a vital part in our modern ( not really that modern ) number system.

Consider the number three hundred and six when you don't have a zero symbol. How do you write it? You could write 3 6 or 36 or 3 , 6 but that would be confusing. With 306 it makes it clear what you mean. It forces digits to have a place value and enables calculation by writing numbers in columns.

Without zero, we would be using a system like the Romans, 306 = CCCVI. Try doing long addition/subtraction using just the Roman system. You will soon see why mediaeval people used counting tables and jetons.

 

[guineafowl21]

Ah, but what you have there is the angle the Earth subtends at the eye of an observer on the Moon. What I was thinking is that the angle the flag will subtend at the earth will depend on the position of the observer on the earth. Something like this:View attachment 142523
Where I assumed it was on and perpendicular to the line joining the Earth and Moon but of course, if at an angle to us, then like you said it does become all the more difficult to see. I suppose there are all sorts of conditions that make it more impossible than it is to see.

The two lines converging on the flag are meant to be the two most widely spaced observation points on the earth. If you could scuttle between them, your view of the flag would rotate by just under 2 degrees, as far as I can work out. The angles subtended by the width of the flag at the earth would be pretty much unmeasurably small, wouldn’t they?

I couldn’t find a clear depiction of where exactly the flag is on the moon’s face, but it apparently is in the Taurus-Littrow Valley, which is described as the south-western edge of the north-eastern quadrant, so for our purposes, somewhere near the centre.

 

[Thingybob]

Ah, but what you have there is the angle the Earth subtends at the eye of an observer on the Moon. What I was thinking is that the angle the flag will subtend at the earth will depend on the position of the observer on the earth. Something like this:View attachment 142523
Where I assumed it was on and perpendicular to the line joining the Earth and Moon but of course, if at an angle to us, then like you said it does become all the more difficult to see. I suppose there are all sorts of conditions that make it more impossible than it is to see.

Ok so i have made those and ive got the three wedge pieces now what do i do with them (please remember this is a family forum)

 

[guineafowl21]

Ok so i have made those and ive got the three wedge pieces now what do i do with them (please remember this is a family forum)

Go and see the Headmaster. And no shenanigans on the way.

 

[Spectric]

I don't think that the Americans can accept we are really prisoners on planet Earth, there is nowhere else to live and therefore we should be maintaining this planet in better shape. Earth is the only planet in our solar system that supports life as we know it, the next one would take us more than 6000 years to get to with current technology and even then we do not know if it can support us. This then raises all sorts of further questions as to why we are on this planet going round and round the sun but maybe we were the unwanted rejects from somewhere else and were dumped here out of the way and against all odds survived.

 

[DrPhill]

but maybe we were the unwanted rejects from somewhere else and were dumped here out of the way and against all odds survived

Golgafrincham

 

[sawtooth-9]

The zero symbol plays a vital part in our modern ( not really that modern ) number system.

Consider the number three hundred and six when you don't have a zero symbol. How do you write it? You could write 3 6 or 36 or 3 , 6 but that would be confusing. With 306 it makes it clear what you mean. It forces digits to have a place value and enables calculation by writing numbers in columns.

Without zero, we would be using a system like the Romans, 306 = CCCVI. Try doing long addition/subtraction using just the Roman system. You will soon see why mediaeval people used counting tables and jetons.

You are right, zero is essential to our form of maths - and serves us well fo a "Newtonian" understanding of physics.
Still necessary in relativity.
So it's what we use.

But there are other number systems - and even those have a concept of zero.
We try to avoid this problem ( that zero and infinity do not exist ) by approaching zero as a "limit"

The REAL problem is the simplest of sums :

1 divided by 0, which we say is infinity ( which does not exist , you can get closer and closer - but never get there )

The axioms in the real number system are it's strength and weakness.
For example, in complex algebra, you can get the square root of a negative number - impossible in the real number system - but, gee it helps in electrical theory.

So as long as we accept the real number system as a base for our understanding, our understanding will be limited

 

[MikeJhn]

And the Chinese have found a shed on the Dark side.

 

[Sheptonphil]

And the Chinese have found a shed on the Dark side.

Did it have planning, and conform to regs as far as 2.4m if near the boundary?

 

[sploo]

hell, I just never considered this when having our roof done....

I can understand the nomenclature though, as:

• "Uraniumed roof" sounds cool, but maybe a bit dangerous
• "Depleted Leadium round"... doesn't sound quite so menacing

 

[thetyreman]

on a light note the technology needed to create the rockets that took man to the moon was created on the back of forced slave labour and anti semitism during nazi occupation of europe, so many millions had to die in brutal conditions just so we can go to space, was it worth it?

 

[Phil Pascoe]

I doubt Herr Schicklgruber had any thoughts of space exploration.

 

[Thingybob]

on a light note the technology needed to create the rockets that took man to the moon was created on the back of forced slave labour, anti semitism during nazi occupation of europe, so many millions had to die in brutal conditions just so we can go to space, was it worth it?

Dun no ask the Chinese

 

[sploo]

on a light note the technology needed to create the rockets that took man to the moon was created on the back of forced slave labour, anti semitism during nazi occupation of europe, so many millions had to die in brutal conditions just so we can go to space, was it worth it?

As far as I understand the history, Von Braun was working on rocket technology (and was interested in the idea of space flight) well before the rise of the Nazi party. His rockets were then used as weapons of war rather than being intended for space travel.

None of that excuses anything that happened during that period (or the US and USSR recruiting several of those involved in exchange for their expertise).

Unfortunately, the sheer scale and cost of spaceflight requires huge sums of money; meaning that governments will get involved, and will always want there to be some return (e.g. the space race between the US and USSR likely being motivated - at senior level - more by national pride than for science).

 

[D_W]

He probably used the nazis as much as they used him, but I would've been hard pressed to have invited him to the states afterwards to continue work (as someone did) given the history.

I guess the strategic value of what he could do was too much for government officials to resist.

Only just now did I read what he actually did in the states. If it's true, there's a curve ball I wouldn't have expected - his choice of locations after the war based on religion, and then his fervor after an introduction to a southern hotbox church here in the states after his comment that he initially had some disinterest based on the german notion that churches in the states were "country clubs".

(for those in the UK, hotbox church meaning churches generally were not air conditioned, many still aren't, and if you're in texas sitting in a building with no A/C, you could have some religious experiences just from the heat).