(Disclaimer: While the science discussed herein is sound this is not meant to be taken all that seriously and is in no way intended to harm, demean or belittle anyone of any weight or size. It is a post that appeals to my sometimes weird view of the world and my always weird sense of humour).
I sometimes wake up in the middle of the night and start pondering: Physics – the study of the mechanics behind how the world and everything else ‘works’ – is a common theme for these midnight musings.
Last night was one of those nights. The particular theme for the night was: Matter. That is: the stuff everything, including us, is made of that is not pure energy in some form or another. (Some might say that all matter – a thing that has mass and occupies some part of space – is pure energy in one or several very specific forms but i want to keep this simple as possible so let’s say there is matter and energy and they together make up everything we can see or know of in our world/universe).
The curious thing about matter is that it has an attraction to every other particle of matter IN THE UNIVERSE!!! The more matter that is clumped together in one place in time and space the greater the nett attraction will be to another lump of matter somewhere else. The further apart two bits of matter are the weaker the force strength between them (inverse square law applies). But the point i make again, and is important to note, is that every bit of matter in the universe is attracted to every other bit. (In this sense at the least, we are ALL connected!)
The most obvious example of this is between our body’s mass and that of the Earth’s. The mutual force is known as ‘Gravity’. Just as the earth pulls us back towards it’s centre of mass (Earth’s core), so too we pull the Earth towards OUR centre of mass, but owing to the considerably larger mass of the Earth compared to our own we basically give it all the credit for the force of gravity. It is quite true though, that it works proportionately both ways. The force the earth’s gravity pulls on our body’s mass can be easily measured and the result is what we call our weight!
I work in kilograms and weigh around 75kg, but for those who don’t you can approximate pounds to kilos by multiplying a kg by 2 to get pounds (It is more like 2.2 but most are not that good at multiplying by 11 or 22).
Now to the bit in the title of the post…
Here are two ways i can weigh less than i normally would. I can move away from the centre of the earth, or i can use a counter-acting force upon my body to the force of Earth’s gravity. (Anti-gravity if you will but is actually a different gravity (from a large mass) opposing that of earth.)
If i weigh myself at the base of a tall building and then rise up several floors and weigh myself again i will actually weigh LESS. Admittedly over a few floors the difference won’t be much, but it should be measurable if you have a good enough set of scales. 🙂 If i were to travel up a high mountain and weigh myself the difference may be measurable on just a normal set of scales, because i would be several thousand feet (a mile or two) further away from the centre of Earth’s mass than if i was at the foot (You’d also undoubtedly have lost a fair few calories and therefore mass making the ascent;-) ). As astronauts find when they orbit the Earth or travel to the moon you can be so far from Earth that you weigh practically nothing at all.
But what if you don’t have a convenient mountain, rocket ship or tall building handy? Worry not, you can weigh less (or even weigh more) depending upon WHEN you weigh yourself. This is because at certain times of day there are two objects of quite large size that you are also attracted to other than the Earth that are either massive enough or close enough to act as an opposing force to the direction of the force of Earth’s gravity and therefore your weight on Earth. (There are actually an enormous number of such objects in the universe but most of them are to far away or not massive enough or both to make any real difference).
The two objects are the closest, the Moon and the most massive (in our solar system) the Sun. Since the earth rotates past these once in every 24 hours (with about 45 minutes leeway for the moon) each will be in a position relative to your centre of mass and that of the earth so as to be attracting your body to it and directly away from the earth, making you weigh less! (Again it might not be detectable on your bathroom scale but it is the logical result of the two forces of gravity pulling on you from opposite sides of you). If you weigh yourself at midday when the Sun is pulling you in a vertical direction away from earth’s gravity your weight will be less; if you weigh yourself at midnight the effect is reversed (Sun and earth’s gravity pulling in same direction on you) and you weigh more. Similarly for whenever the moon is directly over you or behind the earth from you.
If you REALLY want to weigh less then weigh yourself when both the Sun and the Moon are pulling you together away from the earth’s surface. This is on a new moon at midday. The reverse (you weigh most as earth Sun and Moon are all pulling in the same direction) is at a new Moon at midnight.
If you want to weigh even less then use the entire Milky Way Galaxy’s centre of mass (located somewhere in the direction of the constellation Sagittarius) to pull you from the earth – when Sagittarius is at it’s highest point in the night sky, preferably with a new Moon at midnight! 🙂
I would have taken this one last step further and used the centre of mass of the known universe (the sum total of all matter there is pulling you towards it’s centre) except for the fact that we are pretty much right at the centre. Whichever direction in the sky you look, day or night, the furthest things we can see are fairly evenly scattered about us and are calculated to be some 46 billion light years away – a trick that is pretty impressive and weird at the same time as the light from them takes 13.5 billion years to reach us, virtually the estimated age of the universe and nothing is supposed to travel faster than light. The universe is not old enough for the most distant objects we can detect to be as far from us (in all directions) as they ‘are’. There is a ‘trick’ involved but i won’t go into that here).
While we’re on the subject, it’s probably also worth pointing out that since your weight is directly related to how far you are from the centre of the earth’s mass (Typically some 6370 kilometres (3920 miles) away) and the earth is not round but squashed flatter so that it is wider at the Equator than around the poles, you weigh less the closer you are to the equator at any given elevation above mean sea level!
So if you want to weigh less, move to a mountain on the equator and measure yourself at midnight on a New Moon when Sagittarius is high up in the sky.
Come to think of it it might just be easier (not to mention far more effective) to watch what you eat and reduce it if you can while making some regular attempts at raising your metabolism, like by exercising. But don’t overdo it – slow and steady is best. Take it off the same rate you put it on and all should be well.
P.S. For those who may be curious my greatest weight loss would be if i moved to the equator and was standing at an elevation of around 10,000 feet in which case i might weigh about 1/2000 th less than i do which is a loss of around 40 grams or about one ounce. 🙂