Science desk | ||
---|---|---|
< June 5 | << May | June | Jul >> | June 7 > |
Welcome to the Wikipedia Science Reference Desk Archives |
---|
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages. |
When i just first learn quasi-satellite, I don't get it really. On Earth article it said earth has 8000 artificial satellites. Venus only have one temporarily quasi satellite. I don't know if that one body around Venus will crash into Venus. Is their quasi-satelltes or flying asteroids around Mercury. Because few centuries in the future it won't matter if Earth will get swallowed up by sun because technologies are constantly shaping. I hear one proposal is to use flying asteroid to manually move Earth outward which actually can let earth's life last 5-6 billion years longer. I don't know is there flying asteroids around Mercury and Venus, if technologies can alter its orbits. With the nudging effects can it be used with any random asteroids or only quasi-satellites around the parent planets.-- 69.233.254.115 ( talk) 02:42, 6 June 2013 (UTC)
A stationary light clock is shown in the following link in which a light pulse traces out a path of length 2L in between the two mirrors separated by a distance L in the physical space of three linear dimensions.
http://en.wikipedia.org/wiki/File:Time-dilation-001.svg
Although it seems a pulse back and forth in between the mirrors separated by a distance L but in reality the same pulse covered a greater distance than L in its progression of time and therewithal traces out a path equal to the apothem of light cone.
Explanation:
Please click on the animation “A race: There and Back two runners and a time-keeper, a meterstick”in the following link.
http://physics.syr.edu/courses/modules/LIGHTCONE/events.html
If this doesn’t work then click on the following link
http://physics.syr.edu/courses/modules/LIGHTCONE/
Scroll down and then click on EVENTS and SPACETIME of PRIMEVAL RELATIVITY. Scroll down and then start playing animation of “A race: There and Back two runners and a time-keeper, a meterstick”
Let’s the two runners run in between two points A and B separated by distance L. Although they covered a distance of 2L in the physical space of three linear dimensions but in reality [4-dimenional space] it’s not 2L in their world lines as you can see clearly in the animation.
When they start running from point A to B
1- Each runner reaches B diagonally at later (in time) and
Similarly when they starts running from point B to A
2- Each runner reaches A diagonally at later (in time)
This means none of the runners returns to their original position (in past and this impossible) A or B but reach there at later (in time).
Now an example of this animation can give you a quick idea of a pulse moving from A to B and then from B to A in the aforementioned stationary light clock in the physical space of three linear dimensions as well as through space-time if you imagine one of the runners is a pulse.
"Since a pulse never comes back to its original position (past) in its space-time continuum therefore is the distance of 2L appeared in stationary clock authentic and time dilates in aforesaid [stationary] clock?" (Is time dilation / length contraction Real?) 162.157.235.1 ( talk) 05:05, 6 June 2013 (UTC)Eclectic Eccentric Kamikaze
Let’s try this way
We all know that the speed of light in vacuum is exactly 299,792,458 metres per second. Apparently, a pulse covers a distance of L = 299 792 458 m in one second but in reality (4-dimensions) the same pulse covers a greater distance than L in its space-time continuum.
Let A and B are the two points in a vacuum separated by distance L = 299 792 458 m. Although it seems both A and B are moving on the surface of cone as time progresses in forward direction (upward in the light-cone diagram) but in reality both original points A and B are left behind in the past as soon as a pulse starts moving from point A to B in time t.
A’ ----------------------------- B’
A ----------------------------- B
This means after one second, a pulse reaches point B’ (original point B was left behind in the past due to progression of time ) diagonally from point A which was left behind in the past (not from point A’ which can be seen progressing with time) unless i am missing something. So we get a distance AB’ after joining A and B’ with a straight line thus a pulse a cover a distance of AB’ > L = 299,792,458 m. 162.157.235.1 ( talk) 05:29, 7 June 2013 (UTC)Eclectic Eccentric Kamikaze
For this, do we not need another nearby event in the space-time. Anyway it's not applicable here.
Hi everyone, I was thinking this would be, technically speaking, a medical question, so I've decided to ask here. I was watching an old Indonesian film, Darah Perjaka (1985), which deals with a gang of marijuana dealers who are shipping their product as "tea" (I have no idea if the producers were aware of the English-language slang, but that's not relevant here). The main characters discover that the tea is actually marijuana after someone uses it to brew tea then gets high ("smashed" would probably be a better term, as he was completely out there) after drinking some. Physiologically speaking, would that even have an effect (assuming only one or two glasses of "tea" for a 100 kilograms (220 lb) man)? The marijuana "tea" was mixed with hot water, if that has anything to do with it. — Crisco 1492 ( talk) 07:47, 6 June 2013 (UTC)
What's the difference in general between combined cycle power plants and coal-fired power plants in terms of carbon emmissions? Thanks, 163.202.48.125 ( talk) 08:46, 6 June 2013 (UTC)
What is the biggest mystery in science? (Or biggest mysteries) Pass a Method talk 11:07, 6 June 2013 (UTC)
I once saw a boy who had a service pet, a dog, whose job was to let the boy and his parents know if his blood sugar was getting too low by barking or otherwise getting the masters' attention (it was trained to only do so when it should). I wonder, what changes about a human whose blood sugar is getting too low that comes off their body that the dog can detect? Olfactory obviously, but what, is my question. Is there a different chemical in higher or lower than normal concentration in the exhales or perspiration of hypoglycemics? 20.137.2.50 ( talk) 15:48, 6 June 2013 (UTC)
Is it useful to put a finger in your windscreen during hail to prevent it for breaking?-- 90.165.116.251 ( talk) 15:51, 6 June 2013 (UTC)
Hello! I am a grade 10 student who received a physics quiz (on geometric optics) back recently, and I am having a bit of dispute with two true-or-false questions.
The first, which is likely very open to interpretation, is, "A light ray is either reflected or transmitted when it strikes a surface such as a piece of glass." This particular chapter is on refraction of light, and I said false, arguing that (1) in this particular situation it should be "reflected or refracted" instead of "transmitted" and (2) in some (if not most) situations, can't glass do both?
The second, "Blue light bends more than red light, so blue light travels slower than red light." I said true, because in a note (incidentally straight from the textbook) it said, "Dispersion occurs because each colour of visible light travels at a slightly different speed when it goes through the glass prism. Violet light slows down more than red light when it enters the prism. That is why you see violet light being refracted more than any other colour (that is, bending more toward the normal than any other colour). Red light is refracted the least" (bold for emphasis). Since blue is closer to violet than red, I said it was true.
It was just a quiz, but it means the difference from an 89% to a 95% :P. Was I right? Was I wrong? Thanks for your input! 174.93.65.84 ( talk) 20:27, 6 June 2013 (UTC)
Hi! I am also a grade 10 student from India. I know scattering of light is inversely proportional to the fourth power of wavelength; that is why blue light scatters more than any other visible light color. Is this the same reason (=inversely proportional to the fourth power of wavelength) why blue light refract more than any other visible light color? 106.209.202.129 ( talk) 05:47, 10 June 2013 (UTC)
Is there any Medical Diagnosis whatsoever referencing to a state in which one's body produces more lactic acid than normal, so that a person feel pain while doing aerobic exercise? Ben-Natan ( talk) 23:36, 6 June 2013 (UTC)
Science desk | ||
---|---|---|
< June 5 | << May | June | Jul >> | June 7 > |
Welcome to the Wikipedia Science Reference Desk Archives |
---|
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages. |
When i just first learn quasi-satellite, I don't get it really. On Earth article it said earth has 8000 artificial satellites. Venus only have one temporarily quasi satellite. I don't know if that one body around Venus will crash into Venus. Is their quasi-satelltes or flying asteroids around Mercury. Because few centuries in the future it won't matter if Earth will get swallowed up by sun because technologies are constantly shaping. I hear one proposal is to use flying asteroid to manually move Earth outward which actually can let earth's life last 5-6 billion years longer. I don't know is there flying asteroids around Mercury and Venus, if technologies can alter its orbits. With the nudging effects can it be used with any random asteroids or only quasi-satellites around the parent planets.-- 69.233.254.115 ( talk) 02:42, 6 June 2013 (UTC)
A stationary light clock is shown in the following link in which a light pulse traces out a path of length 2L in between the two mirrors separated by a distance L in the physical space of three linear dimensions.
http://en.wikipedia.org/wiki/File:Time-dilation-001.svg
Although it seems a pulse back and forth in between the mirrors separated by a distance L but in reality the same pulse covered a greater distance than L in its progression of time and therewithal traces out a path equal to the apothem of light cone.
Explanation:
Please click on the animation “A race: There and Back two runners and a time-keeper, a meterstick”in the following link.
http://physics.syr.edu/courses/modules/LIGHTCONE/events.html
If this doesn’t work then click on the following link
http://physics.syr.edu/courses/modules/LIGHTCONE/
Scroll down and then click on EVENTS and SPACETIME of PRIMEVAL RELATIVITY. Scroll down and then start playing animation of “A race: There and Back two runners and a time-keeper, a meterstick”
Let’s the two runners run in between two points A and B separated by distance L. Although they covered a distance of 2L in the physical space of three linear dimensions but in reality [4-dimenional space] it’s not 2L in their world lines as you can see clearly in the animation.
When they start running from point A to B
1- Each runner reaches B diagonally at later (in time) and
Similarly when they starts running from point B to A
2- Each runner reaches A diagonally at later (in time)
This means none of the runners returns to their original position (in past and this impossible) A or B but reach there at later (in time).
Now an example of this animation can give you a quick idea of a pulse moving from A to B and then from B to A in the aforementioned stationary light clock in the physical space of three linear dimensions as well as through space-time if you imagine one of the runners is a pulse.
"Since a pulse never comes back to its original position (past) in its space-time continuum therefore is the distance of 2L appeared in stationary clock authentic and time dilates in aforesaid [stationary] clock?" (Is time dilation / length contraction Real?) 162.157.235.1 ( talk) 05:05, 6 June 2013 (UTC)Eclectic Eccentric Kamikaze
Let’s try this way
We all know that the speed of light in vacuum is exactly 299,792,458 metres per second. Apparently, a pulse covers a distance of L = 299 792 458 m in one second but in reality (4-dimensions) the same pulse covers a greater distance than L in its space-time continuum.
Let A and B are the two points in a vacuum separated by distance L = 299 792 458 m. Although it seems both A and B are moving on the surface of cone as time progresses in forward direction (upward in the light-cone diagram) but in reality both original points A and B are left behind in the past as soon as a pulse starts moving from point A to B in time t.
A’ ----------------------------- B’
A ----------------------------- B
This means after one second, a pulse reaches point B’ (original point B was left behind in the past due to progression of time ) diagonally from point A which was left behind in the past (not from point A’ which can be seen progressing with time) unless i am missing something. So we get a distance AB’ after joining A and B’ with a straight line thus a pulse a cover a distance of AB’ > L = 299,792,458 m. 162.157.235.1 ( talk) 05:29, 7 June 2013 (UTC)Eclectic Eccentric Kamikaze
For this, do we not need another nearby event in the space-time. Anyway it's not applicable here.
Hi everyone, I was thinking this would be, technically speaking, a medical question, so I've decided to ask here. I was watching an old Indonesian film, Darah Perjaka (1985), which deals with a gang of marijuana dealers who are shipping their product as "tea" (I have no idea if the producers were aware of the English-language slang, but that's not relevant here). The main characters discover that the tea is actually marijuana after someone uses it to brew tea then gets high ("smashed" would probably be a better term, as he was completely out there) after drinking some. Physiologically speaking, would that even have an effect (assuming only one or two glasses of "tea" for a 100 kilograms (220 lb) man)? The marijuana "tea" was mixed with hot water, if that has anything to do with it. — Crisco 1492 ( talk) 07:47, 6 June 2013 (UTC)
What's the difference in general between combined cycle power plants and coal-fired power plants in terms of carbon emmissions? Thanks, 163.202.48.125 ( talk) 08:46, 6 June 2013 (UTC)
What is the biggest mystery in science? (Or biggest mysteries) Pass a Method talk 11:07, 6 June 2013 (UTC)
I once saw a boy who had a service pet, a dog, whose job was to let the boy and his parents know if his blood sugar was getting too low by barking or otherwise getting the masters' attention (it was trained to only do so when it should). I wonder, what changes about a human whose blood sugar is getting too low that comes off their body that the dog can detect? Olfactory obviously, but what, is my question. Is there a different chemical in higher or lower than normal concentration in the exhales or perspiration of hypoglycemics? 20.137.2.50 ( talk) 15:48, 6 June 2013 (UTC)
Is it useful to put a finger in your windscreen during hail to prevent it for breaking?-- 90.165.116.251 ( talk) 15:51, 6 June 2013 (UTC)
Hello! I am a grade 10 student who received a physics quiz (on geometric optics) back recently, and I am having a bit of dispute with two true-or-false questions.
The first, which is likely very open to interpretation, is, "A light ray is either reflected or transmitted when it strikes a surface such as a piece of glass." This particular chapter is on refraction of light, and I said false, arguing that (1) in this particular situation it should be "reflected or refracted" instead of "transmitted" and (2) in some (if not most) situations, can't glass do both?
The second, "Blue light bends more than red light, so blue light travels slower than red light." I said true, because in a note (incidentally straight from the textbook) it said, "Dispersion occurs because each colour of visible light travels at a slightly different speed when it goes through the glass prism. Violet light slows down more than red light when it enters the prism. That is why you see violet light being refracted more than any other colour (that is, bending more toward the normal than any other colour). Red light is refracted the least" (bold for emphasis). Since blue is closer to violet than red, I said it was true.
It was just a quiz, but it means the difference from an 89% to a 95% :P. Was I right? Was I wrong? Thanks for your input! 174.93.65.84 ( talk) 20:27, 6 June 2013 (UTC)
Hi! I am also a grade 10 student from India. I know scattering of light is inversely proportional to the fourth power of wavelength; that is why blue light scatters more than any other visible light color. Is this the same reason (=inversely proportional to the fourth power of wavelength) why blue light refract more than any other visible light color? 106.209.202.129 ( talk) 05:47, 10 June 2013 (UTC)
Is there any Medical Diagnosis whatsoever referencing to a state in which one's body produces more lactic acid than normal, so that a person feel pain while doing aerobic exercise? Ben-Natan ( talk) 23:36, 6 June 2013 (UTC)