Actually people have increased the mass of the earth. Probably not by much but… Every time you plant a pumpkin seed you are helping create solid matter that comes partly from sunlight energy. The more of us grazing and farming there are, the heavier we are making the earth. Heat and light from the sun must make this planet heavier to some degree. Damn, one more thing to worry about with global warming.
Sure, but the mass was already here before that happened - it was just part of the atmosphere instead of the ground. Unless you’re talking about the weight of the energy itself (E=mc[sup]2[/sup]), but that’s a really, really tiny amount.
That does seem to be what he’s talking about. Read closely.
No, I’m talking about plant life harvesting energy that might have otherwise been dissipated out into space, namely light and heat from the sun. Obviously this is a small amount of mass relative to the weight of the earth, but surely a fairly significant contributer to the earth’s mass over it’s lifetime. Even the oxygen we breath and the ozone that protects us is a byproduct of the photosynthesis process and some of that tons of atmosphere wouldn’t be here without sunlight and cabbage.
There must be somebody who has devised a rough calculation for this…
I did read closely, and it wasn’t abundantly clear to me that was what he was talking about - the inclusion of the term ‘solid matter’, plus using photosynthesis as an example, made it seem ambiguous as to whether he was talking about the conversion of energy to mass, or was labouring under a misconception.
What, you can’t hear the gentle patter of sun capsules on your roof? It’s my favorite part of spring.
So, if I’m reading this correctly, the assertion is that humans have increased the mass of the Earth by increasing the amount of stored chemical potential energy on the Earth. If we had done so, this would be true (though still incredibly neglible). But humans have not, in fact, increased the amount of stored chemical potential energy on the Earth. Quite the contrary, in fact. Haven’t you heard anything in the past fifty years or so about the energy crisis?
All I know is that this extra 40 pounds I’m carrying around had to come from somewhere. I’m betting the earth itself is to blame.
I guess I am proposing that possibility Chronos. There are millions of acres of crops on the earth where plants are rapidly nurtured from seed to adult plant to harvest back to seed, in areas that would otherwise be covered with dried up prairie grass. Billions of trees have been planted for both decroative and commercial purposes. Global warming has increased the growing season and the area of the earth where plants will grow. There are patches of grass in spots that would otherwise have been covered with ice and snow. As waters heat up algae and other water plant growth ensues. As we over-fish the oceans seaweed that would be grazed back grows freely as we continue to dump fertilizers into the waters.
On the other side (humans slowing down the earth’s mass increase) you have humans altering the terrain in ways not friendly to plants. A field of oak trees replaced by a Walmart parking lot and a freeway exit. Rainforests being cleared and replaced with cocoa trees.
All I’m saying is that when Cecil says “Net change pound-wise, nada” he is probably wrong, and I can think of a few ways this could be roughly calculated if we really wanted to know.
Whether the carbon is in the form of a tree or CO2 in the atmosphere, it’s all part of the earth when it comes to measuring the mass of the planet. Moving it from one form to another doesn’t have any impact on the bottom line, and all the things you just mentioned are just that.
New matter has to come from outside the planet, or matter from the planet needs to be sent away. Unless you have a killer pumpkin gun you aren’t going to change anything by planting a seed.
What Filmsg is referring to is the conversion of electromagnetic radiation into the energy stored in chemical bonds between molecules, by ions, or electrons in an excited state. For a photon at the most energetic state of the visual range (~400nm) that’ll give us an energy per photon of about 510[sup]-19[[/sup] J, equivilent to the energy stored in a mass of 5.510[sup]-33[/sup] g. Given that the Earth has a flux of roughly 10[sup]17[/sup] photons per square centimeter per second[sup][/sup] that gives us 1.310[sup]36[/sup] photons/s, or about 7 g/s increase. That’s actually about 620 kg/day, or ~225 tonnes/year increase. That might seem like a lot to a Jenny Craig client, but compared to Earth’s mass of 6*10[sup]24[/sup] kg, it’s not even a credible rounding error, even over the course of millions of years.
Furthermore, most of the light incident on the Earth isn’t absorbed and kept but is instead reflected or reradiated–hence, the pretty blue pictures of Earth from orbit. The Earth has an albedo of ~0.37, so we’re only getting 60% of that to start with, plus most of the energy is reradiated to space in the form of infrared energy. I don’t know what the overall energy balance is (although I’m going to guess that error bounds are at least an order of magnitude either way) but it’s only a tiny fraction of the actual energy incident on the Earth’s surface. The amount of energy permanently bound up by photosynthesis is phenomenal to us, but it’s not even a beggar’s alms to what Sol throws off thoughtlessly every second. And of course, when we release it by burning or digesting it, it goes back to heat.
So, compared to the amount we accrue from dust and meteroites, the mass we “gain” from sunlight is truly negligable.
Stranger
[sup]*[/sup]The light isn’t, of course, all blue, but for the sake of erring toward the high end answer, and also not spending a lot of time figuring out what the actually power delivered is, I’m just going to assume that they’re all 400nm. You don’t like it? Do your own calcuations.