How To Prove That Ghosts Don’t Exist

Your grandmother swears that she has seen ghosts. You don’t indulge in such unscientific nonsense.

To settle this familial debate, you set up a brilliant experiment: Identify the spookiest cemetery in town, bribe the caretaker and fix a CCTV camera overlooking the graves.

Back home, you feed the live video to a motion-detection program on your laptop and wait. Nights turn into weeks – new moon followed by full moon. You spot nothing except a few rodents and owls.

Finally, you inform your family with glee: “There are no ghosts. Here is the video proof.”

Your grandmother deadpans, “Maybe, they are not here. But our village home had them for years.” Grandma wins!

The Proof of Absence

Proving the absence of anything is much harder than showing its presence.

It is impossible to substantiate that apparitions don’t exist. You will have to demonstrate that they cannot be found in this universe, and they have not ‘lived’ anytime in the past.

The reverse is easy — procure one wraith from Grandma’s village.

The Absence of Proof

For centuries, the Western World believed that swans were always white. The Europeans had not seen black ones, which led them to assume that they did not exist.

So, when Willem de Vlamingh found black swans in the Swan River, Australia, in 1697, it startled the Westerners. They refused to accept his claim until he sent a few specimens to Batavia.

Since Grandma cannot adduce a spirit, you can call her bigoted and biased. But what if a team of scientists with impeccable credentials show credible proof that spectres exist?

Example from Nutritional Medicine

Consider this 2013 study by the German Cancer Research Center, which concluded that high blood level of vitamin D reduces cancer incidence and death rates (mortality).

Also, read this research paper from 2019 by Harvard scientists proving that vitamin D supplementation significantly reduced total cancer death rates.

Figuratively, these experts have given verifiable evidence of apparitions.

Now, evaluate this article published in 2018 by the National Cancer Institute with a headline ‘Vitamin D Supplements Don’t Reduce Cancer Incidence, Trial Shows’.

These pundits could not detect any wraiths.

How are you going to reconcile the diametrically opposite conclusions? And if you have cancer, are you going to refuse or pause your vitamin D supplementation?

The Way Forward

I submit that when two studies conflict, with one showing that a nutrient improved a medical problem and the other claiming no utility, apply your common sense:

• Why did one group find a benefit if there was none?
• What is special about the research that failed to detect an advantage that others could prove?

In a separate article, I will explain why such ‘negative’ results are often artefacts of statistical limitations of trials — they don’t prove ‘spirits don’t exist’; they declare that ‘they did not find ghosts’.

In other words, if you come across a media article claiming ‘Fish oil does not improve heart health’ or ‘Cinnamon does not help in blood sugar control’, don’t lose sleep over it. Both of these are extensively proven in multiple clinical trials by respected researchers.

Don’t ignore negative findings; change your belief slightly using something called ‘Bayesian Adjustment’. But that is another article altogether.

On this website: How to understand the evidence from clinical trials of nutrients

Disclaimer: Cancer, heart disease or diabetes are serious medical conditions. One must follow a doctor’s instructions and never treat such ailments only with nutrients. However, the other extreme — only medicines can treat a disease — is also untrue. Unfortunately, many experts choose studies showing ‘no benefit’ to refute nutritional interventions, without explaining why trials showing improvement should be ignored.

Summary

• Proving a positive relation is easier than establishing a negative or absent connection.
• If you have learned something over the years and new evidence claims that it is wrong, don’t change your belief immediately. Wait for more studies to corroborate that assertion.

To Read More

• National Institutes of Health website: Vitamin D — Fact Sheet for Health Professionals
• Journal of Applied Oral Science: Absence of evidence is not evidence of absence
• International Journal of Radiation Oncology: Understanding the Differences Between Bayesian and Frequentist Statistics

First Published on: 8th June 2025
Image Credit: pikisuperstar on Freepik