A faint, yet persistent, anomaly flickered across his screens – a series of rapid X-ray flares emanating from a seemingly empty patch of sky in a distant galaxy. "Curious," Aris murmured, his fingers dancing across the holographic interface. Black holes, by their very nature, are invisible, trapping all light within their event horizons. Yet, their presence is often betrayed by the super-heated matter that spirals into them, forming luminous accretion disks that glow fiercely in X-rays and radio waves.