Yes I do. What happens to light reflected off your skin in a room? It hits the wall, gets reflected around until it is absorbed, which happens very quickly. (Again, think how quickly it is dark in the room after you turn out the light.) The energy from the visible light becomes heat. The heat equilibrates in the room - it all becomes the same temperature. There is no information left from either the light source or any object it reflected off of. The energy isn't lost, but the history of it is lost.Kumar said:
Mojo
Mostly harmless
It doesn't "wander," it travels very, very fast in straight lines until it hits something. If it hits something it will be reflected or absorbed. If it hits the retina of someone's eye, it will form an image and they will see whatever the light came from. If it doesn't hit anything at all it will keep going. End of story.Kumar said:
Sunlight near the sun is brighter (inverse square law). In addition, sunlight at the earth's surface has less of the short end of the spectrum because some of it is stopped by the atmosphere.
You know something, Kumar, my daughter learned about this level of very basic science when she was about 7 or 8 years old. By the time she reached high school, questions like you are asking now would no longer be necessary for her. Since you have now spent more time on this forum than she did in school learning this stuff, I can only conclude that you are either extremely stupid, deluded or a troll. Or any combination thereof.
India has some of the most remarkable brains on this planet. You're not one of them.
India has some of the most remarkable brains on this planet. You're not one of them.
Mojo
Mostly harmless
I see no point in answering this question, as you obviously haven't bothered to read the answers you've been given to this and similar questions in the past.Kumar said:
There isn't actually that much between us and the sun, and what there is is mostly transparent. That's how the light can get through it.
Mojo
Mostly harmless
Surely the laser light would be coherent, whereas light produced by other means would be Kumaresque.rppa said:
Ashles,
If things are unclear we have to try to clear it again & again as we clean a glass which is still unclear. Something positive or some logic can be there, if any concept persist but remain unclear as homeopathy etc. persist here. I think you are yet, unable to satisfy, even to 'otherwise skeptic' in Chritianity & skepticism' thread. ???
If things are unclear we have to try to clear it again & again as we clean a glass which is still unclear. Something positive or some logic can be there, if any concept persist but remain unclear as homeopathy etc. persist here. I think you are yet, unable to satisfy, even to 'otherwise skeptic' in Chritianity & skepticism' thread. ???
I am familiar with most of those words, but I am afraid the order you have put them in creates something of a problem.Kumar said:
What I said in the Christianity and Scepticism thread was that people can hold contradictory beliefs.
It doesn't make the beliefs true.
And things that aren't true can sometimes be a comfort to people.
It doesn't make them true. Or even a particularly good idea to believe.
I'm not sure if this answers your post. But I am sure it won't make any difference to what you think.
Absolutely not. You can not tell the difference between red light produced with a helium-neon laser, and the same wavelength of red light produced by any other means.
I should amplify that what I meant was COHERENT light produced by other means (thanks Mojo). Michelson, for instance, did not have access to lasers when he invented his interferometer. He had to produce coherent light by other means.
The more I learn about 19th century physics, the more I am amazed at the precision of what they were able to measure, considering the state of technology. Actually, 19th century bridges and tunnels impress the heck out of me too.
Can't scientific measuring instruments recognize this differance?
What difference? You can't tell the difference because THERE IS NO DIFFERENCE. See if this sounds like a familiar statement: Every photon of a given wavelength is identical to every other photon of the same wavelength.
As for spectra, the blackbody spectra from any object of the same temperature is the same. The only "entity of its source" it tells you is the temperature.
Some mention was there previously that star compositions is known by its emitted light or cosmic rays.
Yes, but you can't tell from that, that you are looking at a star. You could be looking at a candle with the same chemical content. In fact, the reason we know that a given set of lines from a star is associated with, for instance helium, is that when we cause a sample of helium in the lab to emit WE SEE EXACTLY THE SAME LINES. There is nothing there that says "star". It just says "helium".
That's atomic lines, which we only see in situations where something is very hot. Nearly all of the situations you ask about involve temperatures far too low to see atomic lines, and the only thing present will be the blackbody spectrum.
Blackbody spectrum. Identical. Same as a rock at the same temperature.
Should we not consider chracteristic emissions & object's colours reflections?
There is nothing characteristic about the thermal (blackbody) emissions. There is nothing to consider.
I should amplify that what I meant was COHERENT light produced by other means (thanks Mojo). Michelson, for instance, did not have access to lasers when he invented his interferometer. He had to produce coherent light by other means.
The more I learn about 19th century physics, the more I am amazed at the precision of what they were able to measure, considering the state of technology. Actually, 19th century bridges and tunnels impress the heck out of me too.
Can't scientific measuring instruments recognize this differance?
What difference? You can't tell the difference because THERE IS NO DIFFERENCE. See if this sounds like a familiar statement: Every photon of a given wavelength is identical to every other photon of the same wavelength.
As for spectra, the blackbody spectra from any object of the same temperature is the same. The only "entity of its source" it tells you is the temperature.
Some mention was there previously that star compositions is known by its emitted light or cosmic rays.
Yes, but you can't tell from that, that you are looking at a star. You could be looking at a candle with the same chemical content. In fact, the reason we know that a given set of lines from a star is associated with, for instance helium, is that when we cause a sample of helium in the lab to emit WE SEE EXACTLY THE SAME LINES. There is nothing there that says "star". It just says "helium".
That's atomic lines, which we only see in situations where something is very hot. Nearly all of the situations you ask about involve temperatures far too low to see atomic lines, and the only thing present will be the blackbody spectrum.
Blackbody spectrum. Identical. Same as a rock at the same temperature.
Should we not consider chracteristic emissions & object's colours reflections?
There is nothing characteristic about the thermal (blackbody) emissions. There is nothing to consider.
rppa,
I don't know whay you don't accept that any reflected light from anybody & being, can be specific to that body or being in colour wavelengths & dimentions. This is same as we see & recognize photo of a person--coloured or black & white. I can't say much about radiated heat or black body radiation-- if can be specific.
I don't know whay you don't accept that any reflected light from anybody & being, can be specific to that body or being in colour wavelengths & dimentions. This is same as we see & recognize photo of a person--coloured or black & white. I can't say much about radiated heat or black body radiation-- if can be specific.
Sure.Kumar said:
Find some evidence and then we can seperate the belief from the pile of all the other beliefs for which there is no evidence:
Fairies, ESP, homeopathy, alien abduction, Aztec alien landing sites, ghosts, Zeus, reptilian controllers, telekinesis, the loch ness monster, Harry Potter etc. etc. ad nauseam.
Or do you believe in every one of those until they are disproven?
You see Rppa?Kumar said:
You have explained it so that a five year old could understand. But still Kumar asks the same questions.
This means that:
A) He understands fully, but is trying to wind you up
B) He is a moron incapable of understanding anything
C) He has decided that everything is mystical and exciting and will ignore any facts that indicate that everything doesn't work by magic
Which of these possibilities makes you think that further explanation will help?