Outdoor Solar Lights

The reason is that…
(a) relative to their stars, planets are brighter in the infrared than in visible light.
(b) the longer the wavelength used, the better the angular resolution of a telescope with a fixed aperture size.
(c) because of the properties of their atmospheres, planets reflect more infrared light than visible light.

Stars give off most of their energy as visible light, whereas planets emit most of their energy in the infrared region of the spectrum. Therefore, relative to their stars, planets are brighter in the infrared than in visible light and so the correct answer is (a).

The reason is that…
(a) relative to their stars, planets are brighter in the infrared than in visible light.
(b) the longer the wavelength used, the better the angular resolution of a telescope with a fixed aperture size.
(c) because of the properties of their atmospheres, planets reflect more infrared light than visible light.

Stars give off most of their energy as visible light, whereas planets emit most of their energy in the infrared region of the spectrum. Therefore, relative to their stars, planets are brighter in the infrared than in visible light and so the correct answer is (a).

I am interested in the amount of visible light being emitted by the sun, as a possibility of a factor in global dimming. I have read (somewhere) that duing the Middle Ages the full moon was bright enough that hunting was done during full moon. (Moon reflects the light of the sun)

There is really no relationship linking all those things.

Global dimming has more to do with dust and clouds than anything else.

The solar constant is, well, constant. Not really, but the variability is quite small and not well measured in the past.

World temperature is too complex a thing to measure. I do not believe reports that the world temperature is higher now than ever before. You cannot just take a bunch of reported temperature readings and average them. It just isn’t that simple.

The full Moon is still bright enough to hunt by today. It hasn’t really changed in thousands of years. Heck, I can read by the light of the Full Moon!

You may be thinking about efforts to measure the solar constant by observing the brightness of the Moon. But that has nothing to do with temperature or plant growth.

I recently had two 14" Solatubes installed in my kitchen and have made myself sick…they are horrible. The light is bright and harsh. Is it difficult to remove them? I feel trapped in light!

Lynn ? Those are called Florescent Bulbs. They can be removed by twirling them until they drop into your hands.

Hey, I need an opinion of whether this will be possible or not. We have a bunch of individual solar sidewalk lights outside out house. a few of them smapped loose, but the electronics work perfectly still, so I figured I would try to do the following:

Each solar panel in the lights puts out around 4.3v on a good bright day, and then I have a few other ones that put out around 3.5v on a bright day.

So I realized… my laptop charger uses 18vDC to charge… So my electronics-stupid brain though "Well that means I can just hook a bunch of these together to get around 18 volts, hook up the 2 wire plug and there we go!"

Now I am assuming I am missing something, likely a shortage of amps, or something like that… but what would I have to do to hook these small panels together and make it work? (if possible)

Also, even more out of likelyhood, I have a 10vDC-15vDC to 120vAC 60Hz converter for my car lighter port, that gives me two regular AC outlets. What are the chances of me hooking that to my small solar panels?

how many of these tiny panels would I actually need to power my 18vDC laptop? or say, my 5vDC PSP?

Those small solar cells just put out a few milliamps of current. Laptops and inverters take a lot of power. You could theoretically charge your laptop battery, but it would take days (if not weeks). Your best bet would be to charge a cell phone, MP3 player, or a flashlight.

Okay. I have an odd one. Solar sneezing. What causes it?

By solar sneezing, I mean on those occassions that you look into the sun or a bright light and suddenly sneeze. Why does this reaction occur, and WHY does it only happen to some people, not everyone?

Solar Sneezes, or Photic Sneezes are something that happens in 17-25% of people. There are different theories behind the cause for this, from the sun creating tears that seep down and irritate your sinus and things like that, but the timing doesn’t work.

However there is one theory that seems to fit. The optic nerve is close enough to the trigeminal nerve (which is where your sneezes originate from) to overstimulate the trigeminal nerve and cause you to sneeze. The same things happens to some people when they breath in cold air quickly. Since your sinuses are all connected, so are most of the nerves.

Anybody ever seen one in real life?

Can you see the moon’s earthshine? The zodiacal light?

When I say ‘sky’ I mean the darkest part of it, away from the corona and twilight.

Yes, I have seen two. The Moon seems darker than the sky, but I could see some features; the earthshine is quite remarkable. This could be an optical delusion.

To see the zodiacal light clearly, that takes a dark night and good eyes. But you can also see it before dawn or after sunset.

Perhaps this picture will help.

Does anybody have these? Any suggestions on the best way to soften the light?

Call the people who installed them. They have diffusers that will cut the amount of light down. We’ve had that problem before with a few customers. They really do put out alot of light, especially on a clear day.

Does anybody have these? Any suggestions on the best way to soften the light?

Call the people who installed them. They have diffusers that will cut the amount of light down. We’ve had that problem before with a few customers. They really do put out alot of light, especially on a clear day.

I was sitting on the porch the other night, and as always I was looking at the stars. I have seen faint green lights moving in straight lines from time to time, higher than any airplane could possibly be. I am pretty positive that these are satellites. Well as I was sitting on my porch around 8:30 pm, I noticed what I thought was a super bright star that I had not seen just a few seconds before when I was looking up. As I looked up at it, it appeared that the light shined directly over head for maybe two or three seconds, and then the light turned to a faint green and moved on off in a straight line heading south. Could it be possible to see the reflections off the solar panels off of the sattellites from the sun, if you just happen to be in the right place at the right time. It really was amazing what I saw. Serious non alien answers only please!

The magnitude scale used by astronomers ranks the brightness of stars from 1 to 6. The brightest stars are in first place and get ranked as magnitude 1 (mag 1, for short). The dimmest stars that can be seen without a telescope are mag 6. The planet Venus is often a standout as the morning or evening "star" when its reflected sunlight outshines any true star. Artificial satellites can also be very bright depending on how much sunlight they reflect. Going up in brightness on the scale the numbers are 0, -1, -2, -3, and so on. Venus can reach -4 at its brightest and the Iridium communication satellites can reflect brief flares of sunlight as bright as mag -8. The brightness of the International Space Station usually ranges from mag 2 (dim) to mag -1 (bright).

What is an Iridium flare?

Iridium communication satellites have polished panels that act like mirrors to reflect bright flares of sunlight. The satellites in the Iridium group have their orbits arranged to provide continuous coverage. Original plans called for a "constellation" or group of 77 satellites, which is also the atomic number of the chemical element Iridium. Currently, there are 66 active satellites in orbit and 6 more as backups. The orbits are polar and 780 km (485 miles) in altitude. Each satellite orbits once around the Earth in a little over 100 minutes.

Where should I look?

A clear, open view of the sky is important and so is a location that is free from the glare of streetlights. The light from a bright moon can also be troubling. Azimuth refers to the compass points around the horizon (north = 0 degrees, east = 90 degrees, south = 180 degrees, and west = 270 degrees). Altitude describes how high up the object will appear. Measuring in degrees, altitude is 0 degrees at the horizon and ninety degrees at the zenith (straight up). Near the horizon (from 0 to 20 degrees) the sky is often dusky and objects are hard to see.

Your hand can serve as a guide for estimating angles. Close one eye, stretch your arm straight out and your fist will span about 10 degrees. With your hand wide open, looking from the tip of your little finger to the tip of your thumb, you will see a span of about 20 degrees.

When should I look?

Timing is important since the satellite will be visible for only a few minutes. The bright flares of sunlight reflected from Iridium communication satellites last only for a few seconds – but they are spectacular! Check your watch for the correct time and get outside a couple of minutes before the scheduled appearance of the satellite. Since the timing depends on your location, this web site has links with preset latitude and longitude for several locations in Brevard County. Good predictions for Iridium flares are very dependent on accurate coordinates for your location.