What is the acceleration of light?

Question

In a dark room, I flick on the light switch. Light, traveling at the speed of light, goes from the bulb to the wall. I do not beleive it is possible for something to go from 0 to speed of light instantly. Therefore, the speed of light changed over time - acceleration! How long(short) does it take to go from 0 to speed of light? And is this acceleration constant?

First, It has not been proven that photons are massless, only that at most, they have very small mass. Second, the speed of light through the glass was slower than the speed of light from the glass through the air, so there definately IS some acceleration taking place. On the side, why is there a limit on the speed of light? As the light speeds up after it passes throught the glass bulb, what cuases it to speed up as it travels through the air? Or does light have a natural tendency to travel at the speed of light? Or what is it about the glass that slows the light down? Glass is electrons and protons - air is electrons and protons. Perhaps this will help.

Thank you for the note about CTE - The amount of linear expansion that occurs in a material when there is a temperature change is termed as coefficient of thermal expansion. So, as the light is giving off heat, the bulb is heating up and expanding. Does the speed of light through a medium also depend on the temperature of the medium? In a crazy kind of way, as the heat increases the size of the bulb, it would require slightly more time to pass through, causing a slight over all decrease in speed, hmm??

Answer 1

Light travelles at a constant speed in a vacume Therefor no acceleration" But Light has to get to this speed so what is the inital acceleration of light

Answer 2

Light does not behave like a physical object in this regard. It is energy and so it instantly travels at the highest velocity possible within that medium. (Light does travel more slowly through water and air than through a vacuum.)

On a different topic, you could figure out how long it takes for the light to be generated once the switch is flipped and the electricity heats the filament (or excites the gas in a fluorescent bulb) to generate the photons of light.

Answer 3

The reason you don't believe that light can go from 0 to 300,000 km/s in an instant is because you are applying your intuition as a human being on rules of motion for MASSLESS elementary particles.

Given that photons (aka light as particles) have zero mass, they don't have inertia to overcome like you and I or anything material that we are accustomed to (i.e. driving a car). So yeah, light goes from 0 to speed of light instantly! There is no acceleration. The speed is constant. BTW, this is a property of the vacuum space, not a property of photons (in other words, all zero mass particles travel at this speed, C, the speed of light in vacuum).

Answer 4

I'm writing this because there is no good resource with accurate knowledge of energy.
Context: I am 26 years old, never get refreshing sleep, always wake up mentally and physically tired.
I slight sleep apnea, not even mild.

How to reduce fatigue (so you wake up in the morning and are mentally and physically exausted)
1. Drink 1 to 1.5 glasses of water. Context: You are in the middle of the desert, the king awards you unlimited food anything except fruit, and you cannot have water. You feast, just how long do you think your energy will last. Answer: You will feel tired the next day. Water is critical to prevent mental fatigue, and almost as important for physical fatigue. Start your morning with water! Consider using electrolytes and adding one teaspoon bit of sugar for further benefits. Take any vitamins after.
2. Eat something rich in carbs at least with a multivitamin + B12 (methylcobalamine) 1000mcg form. This should greatly assist physical fatigue especially if you followed the first step.
3. In about an hour you should be less physically fatigued than you woke up, probably still a little physically fatigued. Take a 6 min walk outside for a further boost.
4. Do you love frank's hot sauce? Hate brocolli? Perfect. Have raw brocoli with hot sauce, you'll be plenty distracted. For a nice tough add garlic powder, not garlic salt.
5. All juice concentrate contain glucose fructose (the heaviest syrop you can fill a bucket with, also the most unhealthy. If drinking 1-2 glasses of water to start the day sounds challenging, add zest. Squeeze some lime and or lemon, and if you are stressed add about half a shot glass on the 2nd second one to take the edge off
6. If you refuse to eat broccoli with hot sauce, and if you don't eat fruit too often or even if you do, you should get a "phytosterols" supplement as well as a blueberry 36:1 supplement, take these at breakfast and at dinner. The multivitamin, only take that in the morning.
7. Take vitamin C in the morning to boost the immune system for day.
8. Take Natural Factors Serenity if you have anxiety or feel you need a drink every day or are too edgy.
9. Take Ginkgo Biloba 50:1 in the morning or at launch to increase blood circulation to the brain.
10. Take Siberian Ginseng 500 mg, Taurine 300 mg in morning, to boast both mental and physical fatigue.
11. Take PS (phosphatidylserine) Soy Free at least in the morning, if not at supper as well. It's litterally food for the brain.
12. Tryptophan (1500 mg) or 5-htp (200 mg) or time release melatonin (1mg max) to naturally induce sleep. Will not work if you have significant amounts of anxiety. Take another serenity if this is the case along with which ever former works better for you.
13. Consider taking your vitamins with yogourt to boost energy and absorbtion.
14. Wear earplugs if noises evoke anxiety, eliminate all light sources, do not use your bed as a chair or station from which you operate your computer, the horizontal position should be reserved for sleep alone; have alternate forms of intimacy.
15. If temperature is not consistent, you cannot get a good nights sleep.

Answer 5

gentle alterations direction AND velocity while it is going with the aid of a lens. the two a sort of count huge sort as "acceleration," considering the fact that by making use of definition acceleration is the vector fee of replace of velocity. > "If an merchandise has an acceleration, then in accordance to F=ma, gentle has to have mass." I fail to work out your reasoning there. F=ma easily does not mean that something that improve up has to have mass.

Answer 6

Light travels at the speed of light in vacuum, which is a constant. Constant speed means no acceleration.

Answer 7

Intensity of light doesn't depend on speed of light..... Light always travel with constant speed. The change in intensity you see is mostly due to warming up of coil in bulb.

Answer 8

If light does not accecelerate that would mean that light is raw energy emerging from the sub-atomic universe which is always flowing and never had a begining because it always existed

Answer 9

i dont remember specifics, but light does accelerate and it will continue going until its source (i.e the light) can no longer provide power for it to expand. theres a lot of places online u can read up on this...

Answer 10

I don't think you quite understand. The light wasn't in existence before you flipped the switch. Then it was in existence, and moved at its velocity. It did not accelerate.