SailingNaked
SailingNaked t1_j680vmz wrote
Reply to comment by nicuramar in If you could instantaneously place a space telescope at any desired distance (LYs), from any planet/galaxy etc., where would it be and what would you be documenting? And for what purpose? by kennyarsen
That is where OP and you are wrong, and that's their point I wanted to clarify. The words are interchangeable. The Hubble flow has a speed and distance component... (km/s)/Mpc... speed over distance. Rate of expansion is just another expression of the speed of expansion that new space is created.
Edit: to try my hardest to clarify and settle this issue...
The expansion is given as (km/s)/Mpc.
That means that there is a rate over a distance.
If you take (10 km/s)/10 km or (20 km/s)/20 km... they are the same.
When the denominator is bigger the numerator will be bigger.
When the distance is greater the speed will be greater.
They are still the same...
(10 km/s)/10 km = (1 km/s)/1 km
(20 km/s)/20 km = (1 km/s)/1 km
The expansion rate/rate of expansion/speed of expansion are all the same everywhere.
SailingNaked t1_j67mdr0 wrote
Reply to comment by Anonymous-USA in If you could instantaneously place a space telescope at any desired distance (LYs), from any planet/galaxy etc., where would it be and what would you be documenting? And for what purpose? by kennyarsen
At any point in space, the Hubble flow is the same. That is why it's called a constant. It is the same everywhere.
The observation that farther things move away faster is just that - an observation. They aren't so much moving as they are just getting more distant. Every point between the observed object and the observer is expanding at the same rate. It's not expanding faster the farther away the object is... it is just observed to be faster because there is more space expanding in between.
The speed of expansion is the same. Just when you have more space expanding, you move apart faster.
Edit: Maybe I can make the point clearer...
The rate of expansion is the same everywhere.
The observation that the expansion rate is faster the more distant the observed object is just an observation.
The reason we observe it to be faster is because to our eye we see it moving away faster than something close.
The speed of expansion isn't faster for a distant object or a close object.
The more space (distance) there is between an object, the more space there is to expand.
That space expands at the same rate (Hubble flow).
The expansion isn't faster... only the amount of distance increases.
That distance increases proportionally (at the same rate) to the distance between observed and observer.
SailingNaked t1_j67kxbj wrote
Reply to comment by Mother_Nebula904 in If you could instantaneously place a space telescope at any desired distance (LYs), from any planet/galaxy etc., where would it be and what would you be documenting? And for what purpose? by kennyarsen
You are correct in a way. There is a visible distance limit that we can observe. This is because any light produced beyond that distance will never reach us... ever. Even traveling at the speed of light, the space between the source and the observer expands into a greater distance than the light can travel. It'll constantly head towards us, but it will never reach us. A little photon, lost in the ever expanding emptiness, continuing on to never be observed.
SailingNaked t1_j67k35r wrote
Reply to comment by Anonymous-USA in If you could instantaneously place a space telescope at any desired distance (LYs), from any planet/galaxy etc., where would it be and what would you be documenting? And for what purpose? by kennyarsen
Close, but one issue. The observation is relative to the observer. The speed of expansion is the same everywhere. But, I understand what you were saying.
SailingNaked t1_j65hx8p wrote
Reply to comment by danielravennest in Asteroid-Mining Startup Plans First Private Mission to Deep Space by psychothumbs
I agree.
My question was more of the economics of leaving the market in space instead of back to earth. There are very few buyers that have the capabilities of using material produced in space, and none of them have anything in space currently that can utilize that material.
If you make structural steel in space, you can't price it at what it would cost to send it up. There's no manufacturing in space yet. You'd have to price it below what it would cost to send up and build said manufacturing capabilities than it would just sending up the finished product.
The issue still remains, the only profitable market is on earth... for now.
SailingNaked t1_j65dsfv wrote
Reply to comment by danielravennest in Asteroid-Mining Startup Plans First Private Mission to Deep Space by psychothumbs
Great explanation, but with an oligopsony market, is that structural steel really worth $1m/ton?
SailingNaked t1_j63uimy wrote
Reply to comment by OkProof136 in Asteroid-Mining Startup Plans First Private Mission to Deep Space by psychothumbs
I'm not disagreeing with you. If you controlled your supply of precious space material z, yes you could control the price of "space material z."
But if you pull space iron and try to control the supply, you're going to have a hard sell of your space iron. It's not special or precious. There might be the odd ball billionaire that might want to make a stupid "truck" from "space iron," but that's your only market.
If you're a cinema, you say no outside food or drink. Sure some people buy the $15 popcorn, but pretty much everyone sneaks in their own candies and drink.
Long story short - fettered markets are an exception to supply and demand.
SailingNaked t1_j63s15c wrote
Reply to comment by OkProof136 in Asteroid-Mining Startup Plans First Private Mission to Deep Space by psychothumbs
Only works for precious things... the market's normal supply and demand determines the price of commodity.
SailingNaked t1_j6a3dyy wrote
Reply to comment by nicuramar in If you could instantaneously place a space telescope at any desired distance (LYs), from any planet/galaxy etc., where would it be and what would you be documenting? And for what purpose? by kennyarsen
You and OP are still wrong, and I am not arguing semantics. There are two things I corrected with my original comment, and they are not interchangeable.
The OP said the speed of expansion is different for something farther away. That is just plain wrong. The speed of expansion does not change just because something is farther away.
The correct thing to say would be the velocity (observation) of a distant object is faster than a closer object. That is what I said to OP in my original comment.
The rate or speed of expansion is the same no matter the distance.
A more distant object's velocity is faster than a closer object.
The velocity of a distant object is not the same thing as rate of expansion.
Velocity increases with distance, but the rate/speed of expansion stays the same.