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ask me anything astronomical

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posted on Mar, 14 2004 @ 02:24 AM
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Originally posted by cmdrkeenkid

Originally posted by ET3
How many times the speed of light would I have to go to get half way across the known universe in 2 hours?


let's say the universe is about 14 billion years old, so 14 billion light years wide. half way across then would be 7 billion light years.

distance = rate X time
7 X 10^9 = r X 2
divide each side by 2
3.5 X 10^9 = r

so about 3.5 billion times the speed to get half way across the universe in two hours.


Hey man, I'm sorry, but if you go 3.5 billion times the speed of light, you will get halfway across the universe in two years. Your original calculation on the width of the universe was not in light-hours, but light-years. I think the number you are looking for is more like:

3.07^13 times the speed of light, or thirty trillion seven-hundred billion times the speed of light.

Oddly enough, thats only 4x the national debt.




posted on Mar, 14 2004 @ 02:29 AM
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If one were to be travelling at the speed of light, and were to have a companion 186000 miles ahead of oneself as well, if one were to, say, shine a flashlight at ones friend, would he ever see the beam?



posted on Mar, 14 2004 @ 04:09 AM
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Here is a relatively simple one....Why are planetary orbits elliptical instead of round?



posted on Mar, 14 2004 @ 11:09 PM
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Originally posted by Cascadego
Hey man, I'm sorry, but if you go 3.5 billion times the speed of light, you will get halfway across the universe in two years. Your original calculation on the width of the universe was not in light-hours, but light-years. I think the number you are looking for is more like:

3.07^13 times the speed of light, or thirty trillion seven-hundred billion times the speed of light.

Oddly enough, thats only 4x the national debt.


ah, crud. i knew something was off on that. i was doing it way early in the morning, so my math skills wern't too on the ball. thanks for the correction though!



posted on Mar, 14 2004 @ 11:11 PM
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Originally posted by Cascadego
If one were to be travelling at the speed of light, and were to have a companion 186000 miles ahead of oneself as well, if one were to, say, shine a flashlight at ones friend, would he ever see the beam?


yes, since the speed of light is relative. this is also considering that one and one's friend are traveling at the same speed.

EDIT: by the way, your subject line was a good one, so naturally i had to copy it.


[Edited on 3/14/2004 by cmdrkeenkid]



posted on Mar, 14 2004 @ 11:23 PM
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Originally posted by groingrinder
Here is a relatively simple one....Why are planetary orbits elliptical instead of round?


because the center of gravitation isn't in the direct center of the sun. this is due to the tidal forces of other planets. this is because the focii of gravity are off center. it's kepler's first law of planetary motion.

if you want to know more i suggest these websites: www.go.ednet.ns.ca... or home.cvc.org....



posted on Mar, 14 2004 @ 11:47 PM
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Since all elements heavier than H are solely created within stars, how can there be any radioactive elements/isotopes with halflifes present on earth? Logically they should all have decayed since: 1. The process by which these heavy metals accumulated in the Earth's crust is on the order of billions of years. 2. The halflife of even the most stable elements dictates that only tiny microgram quantities of these elements should be left.



posted on Mar, 15 2004 @ 12:10 AM
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Originally posted by Cascadego
Since all elements heavier than H are solely created within stars, how can there be any radioactive elements/isotopes with halflifes present on earth? Logically they should all have decayed since: 1. The process by which these heavy metals accumulated in the Earth's crust is on the order of billions of years. 2. The halflife of even the most stable elements dictates that only tiny microgram quantities of these elements should be left.


i'm really not sure, nor is it something i've put much thought into. i thought that trace amounts were all that could be found on earth, and that most were formed in reactors and accelerators. some elements have extremely long half-lifes though. for instance, if radioactive:
Potassium (K) 40 has a half-life of 1.3 X 10^9 years.
Technetium (Tc) 98 has a half-life of 4.2 X 10^6 years.
Indium (In) 115 has half-life of 5.1 X 10^14 years.
Lead (Pb) 204 has a half-life of 1.4 X 10^17 years.
Thorium (Th) 232 has a half-life of 1.4 X 10^10 years.
Uranium (U) 233 has a half-life of 1.6 X 10^5 years; 235 has a half-life of 7 X 10^8 years; 236 has a half-life of 2.3 X 10^7 years; 238 has a half-life of 4.5 X 10^9 years.


also, i believe that there is fission going on in the earth's core, so that could lead to some elements becoming radioactive.



posted on Mar, 15 2004 @ 01:02 AM
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Perhaps i can ask you as a matter of opinion then, approximately how long would a particular atom of a heavy element need to endure for it to be created within a +sized star, scattered into a nebula upon solar collapse, and to eventually coallese into the crust of a planet, to be dug up out of the dirt 7 billion years later?

Also, as a followup to the relativity question, what would happen if the same system were to feature the addition of a stationary observer? This observer would be gifted with information on the position of the light beam at any given instant, the position of the two travelling entities, and the exact instant the light was projected by the 1st party, and received by the second party. Would the speed of the light beam appear to be 186k mi/s, yet have traversed twice that distance in a second?

[Edited on 15-3-2004 by Cascadego]



posted on Mar, 15 2004 @ 06:28 AM
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Originally posted by Cascadego
Perhaps i can ask you as a matter of opinion then, approximately how long would a particular atom of a heavy element need to endure for it to be created within a +sized star, scattered into a nebula upon solar collapse, and to eventually coallese into the crust of a planet, to be dug up out of the dirt 7 billion years later?


i had thought of that, actually. and frankly, i don't know. longer than said element or isotope's half-life, though. that's why i believe that there is fission going on in the earth's core.

though if the elements that made up our solar system came from a larger star, say small giants and upwards, then it would be feasible. stars 3 solar masses take approximately 100,000 years to become actual stars, while only having lifetimes of 500 million years. stars with 10 solar masses take about 10,000 years to reach the main sequence, and have lifetimes of about 50 million years. also, the isotopes and much heavier elements would have been created in the supernovae of stars, and not within the stars themselves.



Also, as a followup to the relativity question, what would happen if the same system were to feature the addition of a stationary observer? This observer would be gifted with information on the position of the light beam at any given instant, the position of the two travelling entities, and the exact instant the light was projected by the 1st party, and received by the second party. Would the speed of the light beam appear to be 186k mi/s, yet have traversed twice that distance in a second?


i think that the speed of light would appear be double, and highly redshifted.

this is somewhat similar to how we detect neutrinos. they travel at the speed of light in a vacuum, then hit the earth, go through a detector filled with water, and are detected (hopefully). the speed of light in water is slower than the speed of light in a vacuum, but the neutrino particle is still traveling the speed of light in a vacuum when it goes through the water. so in essence it's traveling faster than the speed of light.



posted on Mar, 15 2004 @ 03:41 PM
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Cough Cough... this has been removed due to incredible lack of clarity resulting from the altered state of consciousness of the poster following several hours of math-lecture.
[Edited on 15-3-2004 by Cascadego]

[Edited on 16-3-2004 by Cascadego]



posted on Mar, 15 2004 @ 11:59 PM
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Cascadego... i had to read that like three times, and i'm still not sure what you're saying. i even tried drawing it out, and i'm still having a bit of trouble understanding what you're asking. sorry, could you clarify it some more perhaps?



posted on Mar, 16 2004 @ 04:11 PM
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Sorry my man, sometimes i forget what the world looks like to people outside the Math Department here at the school. How's this: (ooh and if the physical bodies interfere with the abstraction, do pretend they are just infintesimal points instead)

Picture the earth with two moons instead of one.
These moons are opposite each other on the same orbital path, and are named Alpha and Beta.
These moons are orbitting at light speed, clockwise.
The gravity well of the earth is accomodating this "somehow".

Alpha decides it is going to send a laser-message to Beta.

1. Will this message ever reach Beta since both bodies are travelling at light speed? (the message will, of course, follow the orbital path of both bodies).

2. Us observers here on Earth can see this Alpha-Beta message in transit. Will it ever appear to reach Beta?



posted on Mar, 16 2004 @ 04:29 PM
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Originally posted by Cascadego
Sorry my man, sometimes i forget what the world looks like to people outside the Math Department here at the school. How's this: (ooh and if the physical bodies interfere with the abstraction, do pretend they are just infintesimal points instead)

Picture the earth with two moons instead of one.
These moons are opposite each other on the same orbital path, and are named Alpha and Beta.
These moons are orbitting at light speed, clockwise.
The gravity well of the earth is accomodating this "somehow".

Alpha decides it is going to send a laser-message to Beta.

1. Will this message ever reach Beta since both bodies are travelling at light speed? (the message will, of course, follow the orbital path of both bodies).

2. Us observers here on Earth can see this Alpha-Beta message in transit. Will it ever appear to reach Beta?


okay, that's along the lines i was thinking, and actually what i drew (except i had them rotating counter-clockwise). just attempting to do it so late at night wasn't so hot of an idea. the only part i didn't get was that second part, so that's for clearing that up.


1.) yes, the light beam still would reach object beta, since the speed of light would still be relative.

2.) it's hard to say. i want to say yes, but i'm not sure.
for stumping me on that part.

just out of curiousity, math department where? and what sort of interest in astronomy do you have? you seem to know a whole lot more than i, so i'm just curious.



posted on Mar, 16 2004 @ 05:26 PM
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Student in the Math department at the University of California, Berkeley. Currently Undergrad, anticipating degree in Applied Mathematics: Computer Science in Spring '06 (the extra year is b/c of all the neato other course they let us math majors take).

As to the question w.r.t relativity, it has always struck me as very odd how unreconcilable relativity was when stationary third parties were involved. Especially w.r.t the arguments in General Relativity based on synchronizing clocks, etc. In the orbital relativity, there should also be no time-dialation. If anyone can show me why im wrong, i would love to hear from you.



posted on Mar, 16 2004 @ 05:51 PM
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Originally posted by Cascadego
Student in the Math department at the University of California, Berkeley. Currently Undergrad, anticipating degree in Applied Mathematics: Computer Science in Spring '06 (the extra year is b/c of all the neato other course they let us math majors take).

As to the question w.r.t relativity, it has always struck me as very odd how unreconcilable relativity was when stationary third parties were involved. Especially w.r.t the arguments in General Relativity based on synchronizing clocks, etc. In the orbital relativity, there should also be no time-dialation. If anyone can show me why im wrong, i would love to hear from you.


that's awesome... good luck on the degree.


i agree what you say about time-dialation in orbital relativity. i would think though that from a stationary third party though that there would be. you'd probably know though, since you're a whole lot smarter than i in the math department. i just know about things in the sky.



posted on Mar, 17 2004 @ 02:44 AM
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Hey i got another question. Earlier today, i was trying to find some figures on Hydro-carbons in space junk (you know.. those big icy things and those other hard rock things?). Perhaps you can help me?



posted on Mar, 21 2004 @ 01:30 PM
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Originally posted by Cascadego
Hey i got another question. Earlier today, i was trying to find some figures on Hydro-carbons in space junk (you know.. those big icy things and those other hard rock things?). Perhaps you can help me?


here's some links...

Prospecting for Oil? Look In an Asteroid Crater

IDENTIFYING POLYCYCLIC AROMATIC HYDROCARBONS IN SPACE

those two are about the best i could find. other sites i found copied off of space.com or were just uninformitive in every way possible.



posted on Mar, 21 2004 @ 02:32 PM
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Ok, I have a question.

Dark Energy-Dark Matter. Why couldn't it be possible, that our "universe" is inside another universe, and Dark Energy-Dark Matter is leaking through, and overtaking our Universe? Are we for sure, that the "horizon" we see is the end of of the universe?

"This horizon describes the visible universe -- a region some 28 billion light years in diameter"

www.pbs.org...

What if it is the border of something around us?
Or is that where "multiple" universes come into play?



posted on Mar, 21 2004 @ 03:12 PM
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Originally posted by NetStorm
Ok, I have a question.

Dark Energy-Dark Matter. Why couldn't it be possible, that our "universe" is inside another universe, and Dark Energy-Dark Matter is leaking through, and overtaking our Universe? Are we for sure, that the "horizon" we see is the end of of the universe?


well, i could believe that our universe may be inside of another universe. in my book (head), just about anything is possible. though, i do not think that it could be material of another universe "leaking through." this is because we know that there is stuff behind it, through mass and light bending around it and what not. also, we can see other objects further out in space, where there is no dark matter obscuring the view.

i believe that we'll one day understand what dark matter is, we just haven't come up with any answers yet. it'll only happen in time.



"This horizon describes the visible universe -- a region some 28 billion light years in diameter"

www.pbs.org...

What if it is the border of something around us?
Or is that where "multiple" universes come into play?


who knows? not certainly i. let's say it's another universe. then, maybe we're pushing this universe in on itself as we expand, until it collapses and then undergoes its own bigbang. this universe then expands and pushes ours back together. just an idea.

though if it isn't another universe, i wouldn't know what it would be. god maybe? maybe our universe is just one blood cell of a giraffe in another universe.

that link goes on to say that it's theorized that what we see may not even be the entire universe, but just a part of it. i would have to agree. that would make earth the center of the universe basically, since the center is where the observer is.




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