Would We Notice If Everything in the Universe Doubled in Size?

Imagine a scenario where the entire universe suddenly becomes twice as big. Would we notice such a significant change? In this exploration, we will delve into the implications of such an event, particularly focusing on gravitational effects, the square cube law, and its impact on life forms.

Gravitational Changes and Their Impact

Our understanding of how the universe functions, starting from the fundamental principle of gravitational forces, would be profoundly altered. The universal law of gravitation, F GMm/r2, describes the force between two objects. This force is directly proportional to the product of the masses of the objects and inversely proportional to the square of the distance between them. When the universe doubles in size, the radii of all celestial bodies also double, leading to a significant change in their gravitational fields.

Considering the Earth, its gravitational acceleration, g GM/r2, would decrease by a factor of 4. This means that the surface gravity would become much lower, greatly affecting everything on and within the planet. Every living thing would experience a substantial shift in its balance of forces, and even static objects would seem to float or hover under the new gravitational regime.

The Square Cube Law and Its Consequences

The square cube law is a fundamental principle in physics that dictates how the volume and surface area of an object change as the object grows. According to this law, if an object's size is doubled, its volume increases by a factor of 8 (23) while its surface area increases by a factor of 4 (22). This mismatch in surface area and volume leads to a series of significant problems for living organisms and objects in general.

Imagine an average adult male suddenly growing to be 3.4 meters tall and weighing 720 kilograms. At first glance, this might not seem life-threatening. However, the core issue lies in the area-to-volume ratio. Bones, for instance, which determine how much weight they can support, would only quadruple in thickness, while the weight they need to support increases by a factor of 8. This means that each unit area of bone now supports twice as much weight, leading to a risk of fracturing or collapse.

The same principle applies to other parts of the body. Breathing, for example, would become a significant challenge. Small insects rely on a network of tiny holes called spiracles to breathe. With the volume of these holes doubling, but the insect's body size increasing by a factor of 8, there would be less air available for respiration. This imbalance could lead to inadequate oxygen supply to cells, affecting their normal functioning and survival.

Consequences for Life Forms

The change in cellular processes would also be drastic. Cells, which are the basic units of life, would face challenges in maintaining homeostasis due to the square cube law. If every cell were to be twice the size, the internal processes would become wildly imbalanced. Alternatively, if additional cells were created to accommodate the new size, the transfer of nutrients and other compounds would face significant challenges due to the same surface-to-volume ratio issues.

The transformation would also affect organic molecules at the atomic level. DNA, proteins, and other macromolecules would experience stress due to the enlargement, potentially leading to mutations or other forms of molecular damage. Even cellular processes, such as mitosis and DNA replication, would need to adapt to maintain normal function, which is unlikely in such a sudden and extensive change.

All these factors would lead to a rapid adaptation process, or in some cases, the outright failure of life forms. Plants would struggle to absorb enough nutrients from soil, causing them to wilt and eventually die. Animals, from small to large, would face challenges in maintaining internal balance, leading to a cascade of physiological issues.

Conclusion

Clearly, if the universe suddenly doubled in size, the consequences would be far-reaching and immediate. Everything we know about physics, biology, and chemistry would be disrupted. The surface gravity of planets, the internal structures of organisms, and the molecular processes within life forms would all be affected. In a matter of moments, life as we know it would face an existential crisis, leading to either rapid adaptation or the end of many forms of life.

In conclusion, we would indeed notice if everything in the universe doubled in size. The changes would be so profound and pervasive that they would quickly render the existence of complex life forms unsustainable.